Edward Riley

All Publications

• Programmed Intermittent Epidural Boluses (PIEB) for Maintenance of Labor Analgesia: An Incremental Step Before the Next Paradigm Shift? Turkish journal of anaesthesiology and reanimation Carvalho, B., Riley, E. T. 2017; 45 (2): 73-75

  View details for DOI 10.5152/TJAR.2017.09034

  View details for PubMedID 28439436

• Programmed Intermittent Epidural Boluses (PIEB) for Maintenance of Labor Analgesia: A Superior Technique to Continuous Epidural Infusion? Turkish journal of anaesthesiology and reanimation Riley, E. T., Carvalho, B. 2017; 45 (2): 65-66

  View details for DOI 10.5152/TJAR.2017.09031

  View details for PubMedID 28439433

• Risk Factors for Severe Postpartum Hemorrhage After Cesarean Delivery: Case-Control Studies. Anesthesia and analgesia Butwick, A. J., Ramachandran, B., Hegde, P., Riley, E. T., El-Sayed, Y. Y., Nelson, L. M. 2017

  Abstract

  Women who undergo intrapartum caesarean delivery (CD) are at increased risk of postpartum hemorrhage (PPH) compared with those undergoing prelabor CD. To determine whether the presence and strength of the associations between individual risk factors and severe PPH vary among women undergoing prelabor CD or intrapartum CD, stratified analyses are needed according to CD subtype.To identify risk factors for severe PPH within 2 distinct CD populations, prelabor CD and intrapartum CD, we performed 2 case-control studies. Women in each study cohort delivered at a tertiary obstetric center in the United States between 2002 and 2012. For each study, cases were women who had a blood loss ≥1500 mL or who received an intraoperative or postoperative transfusion up to 48 hours after delivery. Risk factors for severe PPH among women undergoing prelabor CD or intrapartum CD were examined in separate logistic regression models.For prelabor CD, we identified 269 cases and 550 controls. Clinical factors with the highest adjusted odds for severe PPH during prelabor CD were general anesthesia (adjusted odds ratio [aOR] = 22.3; 95% confidence interval [CI] = 4.9-99.9; reference group = spinal anesthesia), multiple pregnancies (aOR = 8.0; 95% CI = 4.2-15.0; reference group = singleton pregnancy), and placenta previa (aOR = 6.3; 95% CI = 3.4-11.8). For intrapartum CD, we identified 278 cases and 572 controls. Clinical factors with the highest adjusted odds for severe PPH during intrapartum CD were general anesthesia (aOR = 5.4; 95% CI = 1.7-17.1), multiple pregnancies (aOR = 3.2; 95% CI = 1.7-6.3), and a predelivery hemoglobin ≤ 9.9 g/dL (aOR = 3.0; 95% CI = 1.3-6.9; reference group = predelivery hemoglobin ≥ 11 g/dL).Women who undergo prelabor CD and intrapartum CD have several shared risk factors for severe PPH (general anesthesia and multiple pregnancies). However, the risk factor profiles for severe PPH differed between these CD cohorts. Recognizing these differences may be important when planning resources and interventions for high-risk patients undergoing either prelabor or intrapartum CD.

  View details for DOI 10.1213/ANE.0000000000001962

  View details for PubMedID 28277324

• Effect of a High-Rate Versus a Low-Rate Oxytocin Infusion for Maintaining Uterine Contractility During Elective Cesarean Delivery: A Prospective Randomized Clinical Trial. Anesthesia and analgesia Duffield, A., McKenzie, C., Carvalho, B., Ramachandran, B., Yin, V., El-Sayed, Y. Y., Riley, E. T., Butwick, A. J. 2017; 124 (3): 857-862

  Abstract

  Oxytocin is routinely used as prophylaxis against uterine atony. During elective cesarean delivery (CD), an oxytocin bolus is used to initiate adequate uterine tone, followed by an oxytocin infusion to maintain uterine contractility. However, it is unclear whether oxytocin maintenance infusion rate influences total estimated blood loss (EBL).We performed a prospective, randomized, double-blind trial in 51 women undergoing elective CD. Women were randomly assigned to receive an oxytocin maintenance infusion of 2.5 or 15 U/h. All women received an oxytocin 1 U bolus to initiate adequate uterine tone. The primary outcome was EBL. EBL values between groups were compared using a Mann-Whitney U test; P < .05 as statistically significant. The median EBL difference with 95% confidence intervals was also calculated. Secondary outcomes included adequacy of uterine tone, use of additional uterotonics, and oxytocin-related side effects, including hypotension.Of 51 women, 24 received a low-rate infusion and 27 received a high-rate infusion. Median (interquartile range) EBL values in the low-rate and high-rate groups were 634 (340-886) mL versus 512 (405-740) mL, respectively (P = .7). The median difference in EBL between groups was 22 mL; 95% confidence interval = -158 to 236 mL. The rate of postpartum hemorrhage did not differ between groups (low-rate group: 4/24 [16.7%] versus high-rate group: 4/26 [15.4%]). There were no between-group differences over time (first 20 minutes after commencing infusion) in the incidence of adequate uterine tone (P = .72) or hypotension (P = .32).Among women undergoing elective CD receiving an oxytocin maintenance infusion, EBL and uterine tone did not differ between women receiving 2.5 U/h oxytocin and those receiving 15 U/h oxytocin. Our findings suggest that efficacy can be obtained with a low oxytocin maintenance infusion rate; however, dose-finding studies are needed to determine the infusion rate that optimizes drug efficacy while minimizing side effects.

  View details for DOI 10.1213/ANE.0000000000001658

  View details for PubMedID 28212181

  View details for PubMedCentralID PMC5319709

• Implementation of Programmed Intermittent Epidural Bolus for the Maintenance of Labor Analgesia. Anesthesia and analgesia Carvalho, B., George, R. B., Cobb, B., McKenzie, C., Riley, E. T. 2016; 123 (4): 965-971

  Abstract

  Programmed intermittent epidural bolus (PIEB) is an exciting new technology that has the potential to improve the maintenance of epidural labor analgesia. PIEB compared with a continuous epidural infusion (CEI) has the potential advantage of greater spread within the epidural space and therefore better sensory blockade. Studies have demonstrated a local anesthetic-sparing effect, fewer instrumental vaginal deliveries, less motor blockade, and improvements in maternal satisfaction with PIEB compared with CEI. However, the optimal PIEB regimen and pump settings remain unknown, and there are a number of logistical issues and practical considerations that should be considered when implementing PIEB. The PIEB bolus size and interval, PIEB start time delay period, and patient-controlled epidural analgesia bolus size and lockout time can influence the efficacy of PIEB used for epidural labor analgesia. Educating all members of the health care team is critical to the success of the technique. This review summarizes the role of PIEB for the maintenance of labor analgesia, outlines implementation strategies, suggests optimal settings, and presents potential limitations of the technique.

  View details for DOI 10.1213/ANE.0000000000001407

  View details for PubMedID 27464978

• Reply to Dr Kumar. Regional anesthesia and pain medicine McKenzie, C. P., Carvalho, B., Riley, E. T. 2016; 41 (4): 547-?

  View details for DOI 10.1097/AAP.0000000000000433

  View details for PubMedID 27315183

• Programmed intermittent epidural boluses for maintenance of labor analgesia: an impact study INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA McKenzie, C. P., Cobb, B., Riley, E. T., Carvalho, B. 2016; 26: 32-38

  Abstract

  The aim of this impact study was to compare the analgesic efficacy and side effect profile of programmed intermittent epidural boluses (PIEB)+patient-controlled epidural analgesia (PCEA) to continuous epidural infusion (CEI)+PCEA for maintenance labor analgesia after the introduction of PIEB at our institution.We conducted a retrospective analysis after replacing the background CEI with PIEB for our labor PCEA. Pre-change pump settings were CEI 12mL/h with PCEA (12mL bolus, lockout 15min); PIEB settings were a 9mL bolus every 45min with PCEA (10mL bolus, lockout 10min). We compared medical records of all women receiving epidural or combined spinal-epidural labor analgesia for vaginal delivery for two months before PIEB implementation to a two-month period of PIEB utilization following a five-month introductory familiarization period. The primary outcome was the proportion of women requiring rescue clinician boluses.Fewer patients in the PIEB group required rescue clinician boluses compared to the CEI group (12% vs. 19%, P=0.012). Time to first rescue bolus request and total bolus dose were not different. Peak (median [IQR]) pain scores were 2[0-5] with CEI and 0[0-4] with PIEB. There was no difference in instrumental delivery rates.Using PIEB compared to CEI as the background maintenance epidural analgesia method in conjunction with PCEA reduced the number of women requiring clinician rescue boluses while providing comparable labor analgesia. The findings of this clinical care impact study confirm the results of randomized controlled studies and suggest PIEB may be a preferable technique to CEI for the maintenance of labor analgesia.

  View details for DOI 10.1016/j.ijoa.2015.11.005

  View details for Web of Science ID 000376707400007

  View details for PubMedID 26775896

• The Wiley Spinal Catheter-Over-Needle System for Continuous Spinal Anesthesia A Case Series of 5 Cesarean Deliveries Complicated by Paresthesias and Headaches REGIONAL ANESTHESIA AND PAIN MEDICINE McKenzie, C. P., Carvalho, B., Riley, E. T. 2016; 41 (3): 405-410

  Abstract

  Intrathecal catheter devices using a catheter-over-needle design and softer flexible material have been introduced to clinical practice with the aim of reducing some of the complications such as postdural puncture headaches and paresthesias seen with previous versions of intrathecal catheters. We present a case series of 5 cesarean deliveries using the Wiley Spinal intrathecal system (Epimed, Johnstown, New York), which was recently approved by the US Food and Drug Administration. The intrathecal catheter system consists of a flexible 23-gauge intrathecal cannula over a 27-gauge pencil-point spinal needle. The placement of the intrathecal catheter was successful in all 5 cases; however, paresthesias in 3 cases and postdural puncture headaches in 2 cases complicated the placement and use of the device. Although the unique catheter-over-needle design facilitates the use of smaller-gauge spinal needles for dural puncture and larger-gauge catheters for medication administration, this case series using the Wiley Spinal suggests that paresthesias and postdural puncture headaches may still limit its widespread utilization. Future studies are needed to determine the true incidence of complications and to determine the role of continuous spinal anesthesia in the obstetric population.

  View details for DOI 10.1097/AAP.0000000000000367

  View details for Web of Science ID 000378154200017

  View details for PubMedID 26909488

• Scheduled acetaminophen with as-needed opioids compared to as-needed acetaminophen plus opioids for post-cesarean pain management. International journal of obstetric anesthesia Valentine, A. R., Carvalho, B., Lazo, T. A., Riley, E. T. 2015; 24 (3): 210-216

  Abstract

  Combination opioid-acetaminophen drugs are commonly used for pain management after cesarean delivery. The aim of this study was to determine if scheduled acetaminophen decreases opioid use compared to as-needed combination acetaminophen-opioid administration.We performed a retrospective chart review of women who underwent cesarean delivery before and after a clinical practice change. All patients received spinal anesthesia containing intrathecal morphine 200μg and scheduled non-steroidal anti-inflammatory drugs for 48h postoperatively. The first group (As-Needed Group, n=120) received combination oral opioid-acetaminophen analgesics as needed for breakthrough pain. The second group (Scheduled Group, n=120) received oral acetaminophen 650mg every 6h for 48h postoperatively with oral oxycodone administered as needed for breakthrough pain. The primary outcome was opioid use, measured in intravenous morphine mg equivalents, in the first 48h postoperatively.The Scheduled Group used 9.1±2.1mg (95% CI 5.0-13.2) fewer intravenous morphine equivalents than the As-Needed Group (P <0.0001) over the study period. Fewer patients in the Scheduled Group exceeded acetaminophen 3g daily compared to the As-Needed Group (P=0.008). Pain scores were similar between study groups.After cesarean delivery, scheduled acetaminophen results in decreased opioid use and more consistent acetaminophen intake compared to acetaminophen administered as needed via combination acetaminophen-opioid analgesics, without compromising analgesia.

  View details for DOI 10.1016/j.ijoa.2015.03.006

  View details for PubMedID 25936786

• Elective ceasarean section at 38 weeks versus 39 weeks: neonatal and maternal outcomes in a randomised controlled trial reply BJOG-AN INTERNATIONAL JOURNAL OF OBSTETRICS AND GYNAECOLOGY Cho, Y., Carvalho, B., Butwick, A., Blumenfeld, Y., Riley, E. 2014; 121 (13): 1748-1749

  View details for DOI 10.1111/1471-0528.13080

  View details for Web of Science ID 000345508600045

• Elective ceasarean section at 38 weeks versus 39 weeks: neonatal and maternal outcomes in a randomised controlled trial. BJOG : an international journal of obstetrics and gynaecology Cho, Y., Carvalho, B., Butwick, A., Blumenfeld, Y., Riley, E. 2014; 121 (13): 1748-?

  View details for DOI 10.1111/1471-0528.13079

  View details for PubMedID 25413764

• Serious complications related to obstetric anesthesia: the serious complication repository project of the society for obstetric anesthesia and perinatology. Anesthesiology D'Angelo, R., Smiley, R. M., Riley, E. T., Segal, S. 2014; 120 (6): 1505-1512

  Abstract

  Because of the lack of large obstetric anesthesia databases, the incidences of serious complications related to obstetric anesthesia remain unknown. The Society for Obstetric Anesthesia and Perinatology developed the Serious Complication Repository Project to establish the incidence of serious complications related to obstetric anesthesia and to identify risk factors associated with each.Serious complications were defined by the Society for Obstetric Anesthesia and Perinatology Research Committee which also coordinated the study. Thirty institutions participated in the approximately 5-yr study period. Data were collected as part of institutional quality assurance and sent to the central project coordinator quarterly.Data were captured on more than 257,000 anesthetics, including 5,000 general anesthetics for cesarean delivery. There were 157 total serious complications reported, 85 of which were anesthesia related. High neuraxial block, respiratory arrest in labor and delivery, and unrecognized spinal catheter were the most frequent complications encountered. A serious complication occurs in approximately 1:3,000 (1:2,443 to 1:3,782) obstetric anesthetics.The Serious Complication Repository Project establishes the incidence of serious complications in obstetric anesthesia. Because serious complications related to obstetric anesthesia are rare, there were too few complications in each category to identify risk factors associated with each. However, because many of these complications can lead to catastrophic outcomes, it is recommended that the anesthesia provider remains vigilant and be prepared to rapidly diagnose and treat any complication.

  View details for DOI 10.1097/ALN.0000000000000253

  View details for PubMedID 24845921

• Preferred spoken language mediates differences in neuraxial labor analgesia utilization among racial and ethnic groups. International journal of obstetric anesthesia Caballero, J. A., Butwick, A. J., Carvalho, B., Riley, E. T. 2014; 23 (2): 161-167

  Abstract

  The aims of this study were to assess racial/ethnic disparities for neuraxial labor analgesia utilization and to determine if preferred spoken language mediates the association between race/ethnicity and neuraxial labor analgesia utilization.We performed a retrospective cohort study of 3129 obstetric patients who underwent vaginal delivery at a tertiary care obstetric center. Bivariate analyses and multivariate logistic regression models were used to assess the relationships between race/ethnicity, preferred spoken language and neuraxial labor analgesia.Hispanic ethnicity (adjusted OR 0.77, 95% CI 0.61-0.98) and multiparity (adjusted OR 0.59, 95% CI 0.51-0.69) were independently associated with a reduced likelihood of neuraxial labor analgesia utilization. When preferred spoken language was controlled for, the effect of Hispanic ethnicity was no longer significant (adjusted OR 0.84, 95% CI 0.66-1.08) and only non-English preferred spoken language (adjusted OR 0.82, 95% CI 0.67-0.99) and multiparity (adjusted OR 0.59, 95% CI 0.51-0.69) were associated with a reduced likelihood of neuraxial labor analgesia utilization.This study provides evidence that preferred spoken language mediates the relationship between Hispanic ethnicity and neuraxial labor analgesia utilization.

  View details for DOI 10.1016/j.ijoa.2013.09.001

  View details for PubMedID 24703871

• On-time scheduled cesarean delivery start time process-improvement initiative. Obstetrics and gynecology Blumenfeld, Y. J., Riley, E., Hilton, G., Lee, H. C., El-Sayed, Y. Y., Druzin, M. L. 2014; 123: 138S-9S

  Abstract

  Cesarean deliveries comprise approximately 30% of all births, many of which are scheduled. Given the labile nature of labor and delivery units, scheduled cesarean deliveries are often delayed. Our aim was to improve on-time scheduled cesarean delivery start times.A multidisciplinary team (obstetrician-gynecologist, nursing, anesthesia, and hospital administration) met to review scheduled cesarean delivery data, identify logistic barriers to on-time starts, and develop a plan to improve cesarean delivery start times. After identifying possible barriers to on-time starts, the following process was instituted: planned preoperative visit 1-2 days before scheduled cesarean delivery, mandatory submission of History & Physical and consent forms by the time of the preoperative visit, and initial preparation of the first scheduled patient for cesaren delivery by nighttime nursing before morning change of shift. The process launched on March 1, 2013. Data from scheduled cesarean deliveries 6 months before and 3 months after the initiative were reviewed and analyzed.Of 1,298 total cesarean deliveries, 423 were scheduled, defined as cesarean delivery scheduled at least 24 hours in advance (300 before and 123 after the initiative). Sixty-four of 300 scheduled cesarean deliveries (21.3%) were on time before compared with 67 of 123 (54.5%) after the initiative began (P<.001). Among delayed cases, there was no difference in the average delay time between those before and after the initiative (55.7 compared with 54.4 minutes P=.93); however, 50.7% of cases were either on time or delayed by 15 minutes or less before the initiative compared with 69.9% of cases after (P<.001).A multidisciplinary initiative significantly increased scheduled cesarean delivery on-time start times.

  View details for DOI 10.1097/01.AOG.0000447113.07157.f3

  View details for PubMedID 24770007

• Analgesic and sympatholytic effects of low-dose intrathecal clonidine compared with bupivacaine: a dose-response study in female volunteers. British journal of anaesthesia Ginosar, Y., Riley, E. T., Angst, M. S. 2013; 111 (2): 256-263

  Abstract

  BACKGROUND: /st>A wide range of doses has been suggested for intrathecal clonidine, but no dose-ranging study has examined analgesic effects below 100 µg. The primary aim of this volunteer study was to assess the dose vs analgesic effect relationship for doses of intrathecal clonidine below 100 µg. METHODS: /st>After IRB approval and signed informed consent, 11 healthy female volunteers participated in this randomized, double-blinded, cross-over study using a dose-ranging sparse-sampling technique. Participants received intrathecal clonidine (doses 0-100 µg; n=10) and intrathecal bupivacaine (doses 0-8.8 mg; n=9) on separate study days. At baseline, 30, and 60 min from drug administration, experimental heat pain tolerance was assessed at both a lumbar and a cranial dermatome. Heat and cold perception thresholds were assessed at the same time intervals. Heart rate (HR), arterial pressure, and forearm-finger and toe-leg cutaneous temperature gradients (Tfinger-arm and Ttoe-leg) were used as measures of sympatholysis. RESULTS: /st>Both intrathecal clonidine and bupivacaine caused significant, dose-dependent analgesic effects at the leg but not the head. Significant analgesia to experimental heat pain was detected above 25 µg clonidine and 3 mg bupivacaine. Administration of bupivacaine but not clonidine resulted in a significant dose-related decrease in HR and Ttoe-leg; neither drug caused dose-related sympatholytic effects in the doses used. CONCLUSIONS: /st>After 50 µg clonidine or 5 mg bupivacaine, the heat pain tolerance increased by ∼1°C, similar to the analgesic effect of 5 mg epidural morphine or 30 µg epidural fentanyl in previous studies using this experimental heat pain model. Our results provide additional data for rational dose selection of intrathecal clonidine.

  View details for DOI 10.1093/bja/aet027

  View details for PubMedID 23533254

• Analgesic and sympatholytic effects of low-dose intrathecal clonidine compared with bupivacaine: a doseresponse study in female volunteers BRITISH JOURNAL OF ANAESTHESIA Ginosar, Y., Riley, E. T., Angst, M. S. 2013; 111 (2): 256-?

  View details for DOI 10.1093/bja/aet027

  View details for Web of Science ID 000322337900001

  View details for PubMedID 23533254

• Peripartum outcomes and anaesthetic management of parturients with moderate to complex congenital heart disease or pulmonary hypertension ANAESTHESIA Maxwell, B. G., El-Sayed, Y. Y., Riley, E. T., Carvalho, B. 2013; 68 (1): 52-59

  Abstract

  We performed a retrospective cohort analysis of pregnancies among women with moderate to complex congenital heart disease or pulmonary hypertension over a 12-year period, resulting in a cohort of 107 cases in 65 women. Neuraxial analgesia or anaesthesia was provided in 84%, 89% and 95% of spontaneous vaginal, operative vaginal and caesarean deliveries, respectively. The caesarean delivery rate was 43% compared to our institution average of 27% over the same period (p = 0.02), and 38% had operative vaginal deliveries compared to a 10.5% institution rate (p < 0.01). Invasive monitoring was used in 28% of all deliveries. There were one maternal and two neonatal deaths. This study provides detailed anaesthetic and peripartum management of women with congenital heart disease, a patient population in whom evidence-based practice and data are largely lacking. We observed a predominance of neuraxial anaesthetic techniques, increased caesarean and operative delivery rates, and favourable maternal and neonatal outcomes. Multicentre studies and registries to compare anaesthetic and obstetric management strategies further and delineate risk factors for adverse outcomes are required.

  View details for DOI 10.1111/anae.12058

  View details for Web of Science ID 000312304000012

  View details for PubMedID 23121251

• Intrathecal morphine 100 and 200 mu g for post-cesarean delivery analgesia: a trade-off between analgesic efficacy and side effects INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Wong, J. Y., Carvalho, B., Riley, E. T. 2013; 22 (1): 36-41

  Abstract

  Intrathecal morphine is highly effective for post-cesarean analgesia; however, the optimal dose is yet to be established. The aim of this study was to compare analgesia and side effects after a change in institutional practice to give 200 μg rather than 100 μg.We conducted a retrospective chart review of 241 patients who had an elective cesarean delivery and received either 100 or 200 μg of intrathecal morphine. The primary outcome variables were mean and peak verbal pain scores (0-10) and analgesic use (milligram-morphine equivalents). Postoperative administration of antiemetics, antipruritics and episodes of nausea or vomiting were recorded. Data are reported as mean±SD or percentages with P<0.05 considered statistically significant.Women receiving intrathecal morphine 200 μg had lower pain scores and opioid use compared with morphine 100 μg. Mean verbal pain scores were 1.6±1.1 versus 2.0±1.1 (P=0.01) and peak verbal pain scores were 4.9±2.0 versus 5.6±1.8, respectively (P=0.008). The group receiving 200 μg used less opioids in the first 24 h after surgery (44±35 versus 54±35 milligram-morphine equivalents, respectively, P=0.04) and received less intravenous opioids (18% versus 30%, P=0.02). However, women receiving intrathecal morphine 200 μg had more nausea (mean number of episodes of nausea 1.9±1.3 versus 1.6±1.3, P=0.037) and used more antiemetics (52% versus 24%, P<0.0001).Intrathecal morphine 200 μg provided better analgesia but with more nausea compared with morphine 100 μg. Our results can be used to help guide intrathecal morphine dosing in cesarean delivery based on patient preference for analgesia versus side effects.

  View details for DOI 10.1016/j.ijoa.2012.09.006

  View details for Web of Science ID 000315829600007

  View details for PubMedID 23159009

• Subdural hematoma after an epidural blood patch INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Verduzco, L. A., Atlas, S. W., Riley, E. T. 2012; 21 (2): 189-192

  Abstract

  We report the case of a 37-year-old postpartum patient who developed a contained subacute spinal subdural hematoma causing mass effect on the cauda equina and severe spinal stenosis after undergoing an epidural blood patch for postdural puncture headache. Recovery occurred following administration of oral steroids.

  View details for DOI 10.1016/j.ijoa.2011.10.003

  View details for Web of Science ID 000303619600016

  View details for PubMedID 22317890

• Spinal anaesthesia for caesarean delivery in a parturient with babesiosis and Lyme disease ANAESTHESIA Sultan, P., Green, C., Riley, E., Carvalho, B. 2012; 67 (2): 180-183

  Abstract

  We present a case of a parturient with babesiosis and Lyme disease who was scheduled for elective caesarean section. The caesarean section was performed under spinal anaesthesia, and the patient had a coronary artery dissection 4 days postoperatively. Neuraxial anaesthesia and possible mechanisms for the coronary artery dissection in a patient with babesiosis and Lyme disease are discussed.

  View details for DOI 10.1111/j.1365-2044.2011.06941.x

  View details for Web of Science ID 000299158200012

  View details for PubMedID 22251109

• Intrathecal fentanyl added to bupivacaine and morphine for cesarean delivery may induce a subtle acute opioid tolerance INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Carvalho, B., Drover, D. R., Ginosar, Y., Cohen, S. E., Riley, E. T. 2012; 21 (1): 29-34

  Abstract

  Previous studies have demonstrated that the addition of intrathecal fentanyl to a spinal anesthetic for cesarean delivery improves intraoperative analgesia. However, intrathecal fentanyl may induce acute tolerance to opioids. The objective of this study was to investigate whether the addition of intrathecal fentanyl to spinal anesthesia with intrathecal morphine increases postoperative analgesic requirements and pain scores.In this randomized, double-blinded study, 40 women having elective cesarean delivery were enrolled. Patients received spinal anesthesia with hyperbaric bupivacaine 12 mg, morphine 200 μg, and fentanyl 0, 5, 10 or 25 μg. Each patient received intravenous patient-controlled analgesia morphine for 24h postoperatively. Outcome measures included postoperative morphine usage and pain scores, as well as intraoperative pain, nausea, hypotension and vasopressor use.Total morphine use over the 24-h post-spinal study period was similar among the study groups (P=0.129). Postoperative pain scores were higher in patients receiving fentanyl 5, 10 and 25 μg compared to fentanyl 0 μg control group (P=0.003).The study results suggest that intrathecal fentanyl may induce acute tolerance to intrathecal morphine. However, because there was no difference in postoperative analgesia requirement and the difference in pain scores was small, the clinical significance of this finding is uncertain.

  View details for DOI 10.1016/j.ijoa.2011.09.002

  View details for Web of Science ID 000301325800006

  View details for PubMedID 22100823

• Non-invasive measurement of hemoglobin during cesarean hysterectomy: a case series INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Butwick, A. J., Hilton, G., Riley, E. T., Carvalho, B. 2011; 20 (3): 240-245

  Abstract

  Obstetric patients diagnosed with abnormal placentation (placenta accreta, increta or percreta) are at increased risk of major postpartum hemorrhage and cesarean hysterectomy. Obstetric anesthesiologists are primarily involved in intraoperative transfusion management in these cases. Hemoglobin assessment is invaluable for assisting transfusion decision-making during the acute period of obstetric hemorrhage. However, laboratory and point-of-care tests of hemoglobin concentration are time-dependent and intermittent, and do not provide a real-time assessment of change during the acute phase of blood loss. A new non-invasive hemoglobin monitor has been introduced recently, which provides real-time measurement of hemoglobin values (SpHb) using multi-wavelength pulse co-oximetry. We present a review of five patients with suspected abnormal placentation who received SpHb monitoring during cesarean hysterectomy at our institution. We discuss the potential clinical utility of non-invasive hemoglobin monitoring for pregnant patients at high risk of obstetric hemorrhage, and the potential role of SpHb in guiding transfusion therapy.

  View details for DOI 10.1016/j.ijoa.2011.03.009

  View details for Web of Science ID 000293042800009

  View details for PubMedID 21640577

• The Association Between Thromboelastographic Parameters and Total Estimated Blood Loss in Patients Undergoing Elective Cesarean Delivery ANESTHESIA AND ANALGESIA Butwick, A., Ting, V., Ralls, L. A., Harter, S., Riley, E. 2011; 112 (5): 1041-1047

  Abstract

  In this study, we assessed the relationship between coagulation parameters using kaolin-activated thromboelastography (TEG®) and total estimated blood loss (EBL) in patients undergoing elective cesarean delivery (CD).TEG® parameters were recorded in 52 patients before and after elective CD. Laboratory markers of coagulation (prothrombin time, activated partial thromboplastin time, fibrinogen) were also assessed in a smaller subset (21 patients). Correlation and linear regression analysis was used to assess the relationship among TEG® parameters, relevant clinical variables, and total EBL. Secondary analysis included comparisons of TEG® and coagulation profiles pre-CD versus post-CD.EBL weakly correlated with percentage change in maximum amplitude (r=0.3; P=0.04) and post-CD maximum rate of thrombus generation (r=0.31; P=0.02). Post-CD values for split point, reaction time, time to maximum rate of thrombin generation, prothrombin time, and activated partial thromboplastin time were significantly increased compared with baseline values (P<0.05). Post-CD α angle, maximum amplitude, total thrombus generation, fibrinogen, and platelet counts were significantly decreased compared with baseline values (P<0.05).There is a weak association between clot strength (as assessed by kaolin-activated TEG®) and EBL in patients undergoing elective CD under neuraxial anesthesia, and a modest reduction in the degree of maternal hypercoagulability occurs in the early postpartum period after elective CD.

  View details for DOI 10.1213/ANE.0b013e318210fc64

  View details for Web of Science ID 000289785100009

  View details for PubMedID 21474664

• Kinked PerifixA (R) FX Springwound epidural catheters CANADIAN JOURNAL OF ANESTHESIA-JOURNAL CANADIEN D ANESTHESIE Hilton, G., Jette, C. G., Ouyang, Y., Riley, E. T. 2011; 58 (4): 413-414

  View details for DOI 10.1007/s12630-011-9462-1

  View details for Web of Science ID 000288663100014

  View details for PubMedID 21253920

• ED50 and ED95 of Intrathecal Bupivacaine in Morbidly Obese Patients Undergoing Cesarean Delivery ANESTHESIOLOGY Carvalho, B., Collins, J., Drover, D. R., Ralls, L. A., Riley, E. T. 2011; 114 (3): 529-535

  Abstract

  It has been suggested that morbidly obese parturients may require less local anesthetic for spinal anesthesia. The aim of this study was to determine the effective dose (ED(50)/ED(95)) of intrathecal bupivacaine for cesarean delivery in morbidly obese patients.Morbidly obese parturients (body mass index equal to or more than 40) undergoing elective cesarean delivery were enrolled in this double-blinded study. Forty-two patients were randomly assigned to receive intrathecal hyperbaric bupivacaine in doses of 5, 6, 7, 8, 9, 10, or 11 mg (n = 6 per group) coadministered with 200 μg morphine and 10 μg fentanyl. Success (induction) was defined as block height to pinprick equal to or more than T6 and success (operation) as success (induction) plus no requirement for epidural supplementation throughout surgery. The ED(50)/ED(95) values were determined using a logistic regression model.ED(50) and ED(95) (with 95% confidence intervals) for success (operation) were 9.8 (8.6-11.0) and 15.0 (10.0-20.0), respectively, and were similar to corresponding values of a nonobese population determined previously using similar methodology. We were unable to measure ED(50)/ED(95) values for success (induction) because so few blocks failed initially, even at the low-dose range. There were no differences with regard to secondary outcomes (i.e., hypotension, vasopressor use, nausea, and vomiting).Obese and nonobese patients undergoing cesarean delivery do not appear to respond differently to modest doses of intrathecal bupivacaine. This dose-response study suggests that doses of intrathecal bupivacaine less than 10 mg may not adequately ensure successful intraoperative anesthesia. Even when the initial block obtained with a low dose is satisfactory, it will not guarantee adequate anesthesia throughout surgery.

  View details for DOI 10.1097/ALN.0b013e318209a92d

  View details for Web of Science ID 000287660300012

  View details for PubMedID 21307769

• Retrospective analysis of anesthetic interventions for obese patients undergoing elective cesarean delivery JOURNAL OF CLINICAL ANESTHESIA Butwick, A., Carvalho, B., Danial, C., Riley, E. 2010; 22 (7): 519-526

  Abstract

  To examine the relationship between body mass index (BMI), perioperative times, and anesthetic interventions in patients undergoing elective cesarean delivery.Retrospective chart review.University-affiliated hospital.All patients were ranked according to BMI (kg/m(2)) at the time of delivery. The BMI groups were designated a priori: ≤ 29.9 kg/m(2) (Group C); 30-34.9 kg/m(2) (Group I); 35-39.9 kg/m(2) (Group II), and ≥ 40 kg/m(2) (Group III). One hundred patients (25 pts per group) underwent elective cesarean delivery. Data collected included anesthetic technique, perioperative times, anesthesia-related costs, and neonatal outcomes.A higher percentage of Group III patients (60%) received combined spinal-epidural (CSE) anesthesia than did Group C or Group I (18% and 16%, respectively; P < 0.05). The total intraoperative period was significantly longer in Group III (101 min) compared with Groups C, I, and II (81 min, 90 min, and 92 min, respectively; P < 0.05). Total intraoperative time increased significantly with BMI (R = 0.394 kg/m(2); P < 0.001). The highest anesthesia-related costs during the study were generated by patients with BMI ≥ 40 kg/m(2).Our single-center experience showed that choice of anesthetic technique (CSE vs. spinal anesthesia) varies according to obesity class. Longer intraoperative periods must be considered in deciding upon the mode of anesthesia for patients with BMI ≥ 40 kg/m(2) who undergo elective cesarean delivery.

  View details for DOI 10.1016/j.jclinane.2010.01.005

  View details for Web of Science ID 000284791000006

  View details for PubMedID 21056808

• Minimum effective bolus dose of oxytocin during elective Caesarean delivery BRITISH JOURNAL OF ANAESTHESIA Butwick, A. J., Coleman, L., Cohen, S. E., Riley, E. T., Carvalho, B. 2010; 104 (3): 338-343

  Abstract

  The aim of this study was to determine the lowest effective bolus dose of oxytocin to produce adequate uterine tone (UT) during elective Caesarean delivery (CD).Seventy-five pregnant patients undergoing elective CD under spinal anaesthesia were randomized to receive oxytocin (0.5, 1, 3, 5 units) or placebo. UT was assessed by a blinded obstetrician as either adequate or inadequate, and using a verbal numerical scale score (0-10; 0, no UT; 10, optimal UT) at 2, 3, 6, and 9 min after oxytocin administration. Minimum effective doses of oxytocin were analysed (ED(50) and ED(95)) using logistic regression. Oxytocin-related side-effects (including hypotension) were recorded.There were no significant differences in the prevalence of adequate UT among the study groups at 2 min (73%, 100%, 93%, 100%, and 93% for 0, 0.5, 1, 3, and 5 units oxytocin, respectively). The high prevalence of adequate UT after placebo and low-dose oxytocin precluded determination of the ED(50) and ED(95). UT scores were significantly lower in patients receiving 0 unit oxytocin at 2 and 3 min compared with 3 and 5 units oxytocin (P<0.05, respectively). The prevalence of hypotension was significantly higher after 5 units oxytocin vs 0 unit at 1 min (47% vs 7%; P=0.04).The routine use of 5 units oxytocin during elective CD can no longer be recommended, as adequate UT can occur with lower doses of oxytocin (0.5-3 units).

  View details for DOI 10.1093/bja/aeq004

  View details for Web of Science ID 000274485900011

  View details for PubMedID 20150347

• Analgesic requirements and postoperative recovery after scheduled compared to unplanned cesarean delivery: a retrospective chart review INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Carvalho, B., Coleman, L., Saxena, A., Fuller, A. J., Riley, E. T. 2010; 19 (1): 10-15

  Abstract

  Studies examining the effects of various analgesics and anesthetics on postoperative pain following cesarean delivery conventionally use the scheduled cesarean population. This study compares postoperative analgesic requirements and recovery profiles in women undergoing scheduled cesarean compared to unplanned cesarean delivery following labor. We postulated that unplanned cesarean deliveries may increase postoperative analgesic requirements.We conducted a retrospective chart review of 200 cesarean deliveries at Lucile Packard Children's Hospital, California. We examined the records of 100 patients who underwent scheduled cesarean delivery under spinal anesthesia (hyperbaric bupivacaine 12 mg with intrathecal fentanyl 10 microg and morphine 200 microg) and 100 patients that following a trail of labor required unplanned cesarean under epidural anesthesia (10-25 mL 2% lidocaine top-up with epidural morphine 4 mg after clamping of the umbilical cord). We recorded pain scores, analgesic consumption, time to first analgesic request, side effects, and length of hospital stay.We found no differences in postoperative pain scores and analgesic consumption between scheduled and unplanned cesarean deliveries for up to five days postoperatively. There were no differences in treatment of side effects such as nausea, vomiting, or pruritus (P>0.05).The results indicate that women experience similar pain and analgesic requirements after scheduled compared to unplanned cesarean delivery. This suggests that the non-scheduled cesarean population may be a suitable pain model to study pain management strategies; and that alterations in pain management are not necessary for the unplanned cesarean delivery population.

  View details for DOI 10.1016/j.ijoa.2009.02.012

  View details for Web of Science ID 000273845400004

  View details for PubMedID 19954964

• Retrospective analysis of transfusion outcomes in pregnant patients at a tertiary obstetric center INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Butwick, A. J., Aleshi, P., Fontaine, M., Riley, E. T., GOODNOUGH, L. T. 2009; 18 (4): 302-308

  Abstract

  The decision to use red blood cell transfusion and/or blood products (fresh frozen plasma, platelets, cryoprecipitate) to manage obstetric hemorrhage or treat postpartum anemia is often made empirically by physicians. We performed a retrospective study to review transfusion outcomes in pregnant and postpartum patients at a large obstetric center.A retrospective, observational study was performed of obstetric in-patients who received red blood cell transfusion and/or blood products over a one-year period. Data abstracted included transfusion data, pre-transfusion hemoglobin (Hb) and lowest recorded (nadir) Hb, and maternal and neonatal outcomes.During the study period, 74 patients received transfusion therapy (1.4%). Pre-transfusion and nadir Hb values were 7.6 g/dL and 7.0 g/dL respectively. Median [IQR] total red blood cells transfused were 2 units [2-3], with 41 (55%) patients receiving 1-2 units. Based on chart review, no specific indications for transfusion were identified in 25 patients (34%), and 13 patients (18%) had undetected postpartum anemia (Hb values <8.2 g/dL) at least 24h after delivery.More formal assessment and documentation of the etiologic factors associated with transfusion management in pregnant patients is advised. In addition, the identification and management of undetected postpartum anemia is underappreciated.

  View details for DOI 10.1016/j.ijoa.2009.02.005

  View details for Web of Science ID 000271135300002

  View details for PubMedID 19628384

• Hetastarch co-loading is as effective as pre-loading for the prevention of hypotension following spinal anesthesia for cesarean delivery INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Carvalho, B., Mercier, F. J., Riley, E. T., Brummel, C., Cohen, S. E. 2009; 18 (2): 150-155

  Abstract

  Pre-loading with hetastarch decreases the incidence and severity of hypotension after spinal anesthesia for cesarean delivery. However, pharmacokinetic studies with crystalloid predict that fluid loading should be more efficacious if rapidly administered immediately after induction of spinal anesthesia. The aim of this study was to compare pre- and co-loading of hetastarch for the prevention of hypotension following spinal anesthesia for cesarean delivery.Forty-six healthy term parturients scheduled for cesarean delivery were randomized to receive 500 mL of 6% hetastarch intravenously, either slowly before spinal anesthesia (pre-loading) or as quickly as possible immediately after spinal anesthesia (co-loading). Systolic blood pressure was maintained at or above 90% of baseline with intravenous vasopressor boluses (ephedrine 5mg/mL+phenylephrine 25 microg/mL). The primary outcome was the volume of vasopressor mix required. Secondary outcomes included blood pressure and heart rate changes, time to first vasopressor use, nausea or vomiting, and neonatal outcomes (umbilical artery and vein pH, Apgar scores).The pre-loading group used 3.5+/-2 mL (mean+/-SD) of vasopressor mixture compared with 3.2+/-3 mL in the co-loading group (P=0.6). There were no differences in any important maternal hemodynamic or neonatal outcome values between the two study groups.Hetastarch co-loading is as effective as pre-loading for the prevention of hypotension after spinal anesthesia for cesarean delivery. Surgery need not be delayed to allow a predetermined pre-load to be administered before induction of spinal anesthesia.

  View details for DOI 10.1016/j.ijoa.2008.12.006

  View details for Web of Science ID 000265542200009

  View details for PubMedID 19223168

• Successful pregnancy and cesarean delivery via noninvasive ventilation in mitochondrial myopathy JOURNAL OF PERINATOLOGY Yuan, N., El-Sayed, Y. Y., Ruoss, S. J., Riley, E., Enns, G. M., Robinson, T. E. 2009; 29 (2): 166-167

  Abstract

  We report a case study of a 22-year-old woman with mitochondrial thymidine kinase 2 deficiency and chronic respiratory failure due to severe neuromuscular weakness requiring noninvasive positive pressure ventilation (NIPPV) since 12 years of age. During pregnancy and cesarean delivery, she was successfully supported with NIPPV. A multidisciplinary team approach should be used in pregnant patients with these disorders with specific attention to management of pulmonary complications, selection of route of delivery, anesthesia, and analgesia.

  View details for DOI 10.1038/jp.2008.178

  View details for Web of Science ID 000263492700016

  View details for PubMedID 19177045

• Accidental intrathecal sufentanil overdose during combined spinal-epidural analgesia for labor INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Coleman, L., Carvalho, B., Lipman, S., Schmiesing, C., Riley, E. 2009; 18 (1): 78-80

  Abstract

  A laboring woman was accidentally given 45 microg of sufentanil intrathecally in the course of combined spinal-epidural analgesia. She experienced intense pruritus and transient swallowing difficulty without respiratory depression, but still had incomplete pain relief, with delivery and episiotomy repair requiring additional analgesia. This case highlights the importance of adding local anesthetic to intrathecal opioids to facilitate effective analgesia during the second stage of labor. The contributory systems issues and multiple factors that allowed this error to occur are examined.

  View details for DOI 10.1016/j.ijoa.2008.10.001

  View details for Web of Science ID 000262736700017

  View details for PubMedID 19111229

• A Randomized Trial of Maximum Cephalad Sensory Blockade with Single-Shot Spinal Compared with Combined Spinal-Epidural Techniques for Cesarean Delivery 39th Annual Meeting of the Society-for-Obstetric-Anesthesia-and-Perinatology Horstman, D. J., Riley, E. T., Carvalho, B. LIPPINCOTT WILLIAMS & WILKINS. 2009: 240–45

  Abstract

  Previous studies have shown more extensive cephalad sensory blockade in women receiving combined spinal-epidural (CSE) anesthesia compared with single-shot spinal (SSS) anesthesia for elective cesarean delivery. It has been postulated that introduction of the epidural needle during CSE disturbs the negative pressure in the epidural space, resulting in relatively greater cerebrospinal fluid (CSF) pressure and increased spread of intrathecal local anesthetic. We tested the hypothesis that CSE results in more extensive cephalad sensory blockade than SSS anesthesia and that loss-of-resistance during initiation of CSE anesthesia increases CSF pressure compared with SSS.Thirty parturients scheduled for elective cesarean delivery were enrolled in this randomized, double-blind study. Patients received either SSS or CSE anesthesia with equal doses of intrathecal anesthetic (hyperbaric bupivacaine 12 mg, fentanyl 10 microg and morphine 200 microg). Before the intrathecal injection, the CSF pressure was measured with a fiberoptic pressure sensor. Maximum cephalad sensory blockade to pinprick, cold and touch was measured. The total dose of phenylephrine required to maintain baseline arterial blood pressure was also recorded.There were no significant differences in the median (interquartile range) pinprick sensory block height [T4 (T4-2) vs T3 (T4-1)] or CSF pressures [6 (4-12) vs 9 (8-12) mm Hg] between the SSS and CSE groups. There were no significant correlations between CSF pressure and block height or total dose of phenylephrine.The SSS and CSE techniques inserted in the lateral decubitus position resulted in similar extent of sensory blockade and CSF pressure. These findings suggest that altering the intrathecal dose is not necessary and that any difference in intrathecal pressure associated with initial placement of an epidural needle in the epidural space during CSE anesthesia is clinically inconsequential.

  View details for DOI 10.1213/ane.0b013e31818e0fa6

  View details for Web of Science ID 000261963000037

  View details for PubMedID 19095857

• Randomized comparison of intravenous terbutaline vs nitroglycerin for acute intrapartum fetal resuscitation 27th Annual Meeting of the Society-of-Maternal-Fetal-Medicine Pullen, K. M., Riley, E. T., Waller, S. A., Taylor, L., Caughey, A. B., Druzin, M. L., El-Sayed, Y. Y. MOSBY-ELSEVIER. 2007

  Abstract

  The purpose of this study was to compare terbutaline and nitroglycerin for acute intrapartum fetal resuscitation.Women between 32-, 42 weeks' gestation were assigned randomly to 250 microg of terbutaline or 400 microg nitroglycerin intravenously for nonreassuring fetal heart rate tracings in labor. The rate of successful acute intrapartum fetal resuscitation and the maternal hemodynamic changes were compared. Assuming a 50% failure rate in the terbutaline arm, we calculated that a total of 110 patients would be required to detect a 50% reduction in failure in the nitroglycerin group (50% to 25%), with an alpha value of .05, a beta value of .20, and a power of 80%.One hundred ten women had nonreassuring fetal heart rate tracings in labor; 57 women received terbutaline, and 53 women received nitroglycerin. Successful acute resuscitation rates were similar (terbutaline 71.9% and nitroglycerin 64.2%; P = .38). Terbutaline resulted in lower median contraction frequency per 10 minutes (2.9 [25-75 percentile, 1.7- 3.3] vs 4 [25-75 percentile, 2.5- 5]; P < .002) and reduced tachysystole (1.8% vs 18.9%; P = .003). Maternal mean arterial pressures decreased with nitroglycerin (81-76 mm Hg; P = .02), but not terbutaline (82-81 mm Hg; P = .73).Although terbutaline provided more effective tocolysis with less impact on maternal blood pressure, no difference was noted between nitroglycerin and terbutaline in successful acute intrapartum fetal resuscitation.

  View details for DOI 10.1016/j.ajog.2007.06.063

  View details for Web of Science ID 000250097300031

  View details for PubMedID 17904983

• The Episure (TM) syringe: A novel loss of resistance syringe for locating the epidural space 37th Annual Meeting of the Society-of-Obstetric-Anesthesiology-and-Perinatology Riley, E. T., Carvalho, B. LIPPINCOTT WILLIAMS & WILKINS. 2007: 1164–66

  Abstract

  The Episure syringe is a unique spring-loaded loss-of-resistance (LOR) syringe with a coaxial compression spring within a Portex Pulsator LOR syringe. This syringe supplies a constant pressure while the operator is advancing the Tuohy needle.We evaluated the syringe using an artificial model of the ligamentum flavum, an anesthetized pig, and women who desired epidural analgesia for labor.The operator, using the spring-loaded syringe, was able to stop the forward movement of the needle, so that compared with a standard LOR syringe less of the needle protruded out the back of the laboratory model. Satisfactory labor analgesia in the human study and radiograph analyses in the porcine model confirmed epidural placement in all attempts.The spring-loaded syringe is a potentially useful LOR syringe that provides a reliable, objective end-point for identification of the epidural space.

  View details for DOI 10.1213/01.ane.0000281935.78144.82

  View details for Web of Science ID 000249678500043

  View details for PubMedID 17898406

• Fetal oxygen saturation after combined spinal-epidural Labor analgesia: a case series JOURNAL OF CLINICAL ANESTHESIA Carvalho, B., Fuller, A. I., Brummel, C., Durbin, M., Riley, E. T. 2007; 19 (6): 476-478

  Abstract

  Fetal oxygen saturation (FSpo(2)) is an emerging technology for intrapartum fetal monitoring. We monitored FSpo(2) before and after combined spinal-epidural analgesia in 8 laboring women requesting neuraxial analgesia. Fetal heart rate (FHR) and FSpo(2) (using the Nellcor N400/FS14 system [Nellcor, Pleasanton, CA]) were recorded at baseline and every minute for 45 minutes after analgesia. We observed no significant changes in FSpo(2) after analgesia (mean DeltaFSpo(2) 2 +/- 7 %, P = 0.46). Fetal oxygen saturation at baseline and after analgesia was 53% +/- 9% and 51% +/- 8%, respectively. We observed no significant FHR changes or any fetal bradycardia following combined spinal-epidural analgesia.

  View details for DOI 10.1016/j.jclinane.2007.01.009

  View details for Web of Science ID 000250817600017

  View details for PubMedID 17967682

• How we treat: management of life-threatening primary postpartum hemorrhage with a standardized massive transfusion protocol TRANSFUSION Burtelow, M., Riley, E., Druzin, M., Fontaine, M., Viele, M., Goodnough, L. T. 2007; 47 (9): 1564-1572

  Abstract

  Management of massive, life-threatening primary postpartum hemorrhage in the labor and delivery service is a challenge for the clinical team and hospital transfusion service. Because severe postpartum obstetrical hemorrhage is uncommon, its occurrence can result in emergent but variable and nonstandard requests for blood products. The implementation of a standardized massive transfusion protocol for the labor and delivery department at our institution after a maternal death caused by amniotic fluid embolism is described. This guideline was modeled on a existing protocol used by the trauma service mandating emergency release of 6 units of group O D- red cells (RBCs), 4 units of fresh frozen or liquid plasma, and 1 apheresis unit of platelets (PLTs). The 6:4:1 fixed ratio of uncrossmatched RBCs, plasma, and PLTs allows the transfusion service to quickly provide blood products during the acute phase of resuscitation and allows the clinical team to anticipate and prevent dilutional coagulopathy. The successful management of three cases of massive primary postpartum hemorrhage after the implementation of our new massive transfusion protocol in the maternal and fetal medicine service is described.

  View details for DOI 10.1111/j.1537-2995.2007.01404.x

  View details for Web of Science ID 000249330500002

  View details for PubMedID 17725718

• Single-dose, extended-release epidural morphine (DepoDur (TM)) compared to conventional epidural morphine for post-cesarean pain ANESTHESIA AND ANALGESIA Carvalho, B., Roland, L. M., Chu, L. F., Campitelli, V. A., Riley, E. T. 2007; 105 (1): 176-183

  Abstract

  A single-dose of neuraxial morphine sulfate provides good post-Cesarean analgesia; however, its efficacy is limited to the first postoperative day. In a recent phase III study, extended-release epidural morphine (EREM) formulation provided more effective, prolonged analgesia after Cesarean delivery, compared to conventional epidural morphine. However, the study protocol did not allow for the use of nonsteroidal antiinflammatory drugs, used various postoperative analgesics, and monitoring and treatment of respiratory depression were not standardized. Our aims in this study were to compare postoperative analgesic consumption, pain scores and side effects of EREM with conventional morphine for the management of post-Cesarean pain in a setting more reflective of current obstetric practice.Seventy healthy parturients undergoing elective Cesarean delivery were enrolled in this randomized, double-blind study. Using a combined spinal epidural technique, patients received an intrathecal injection of bupivacaine 12 mg and fentanyl 10 mcg. After closure of the fascia, a single-dose of either conventional morphine 4 mg or EREM 10 mg was administered epidurally. Postoperatively, all patients received ibuprofen 600 mg orally every 6 h. Oral oxycodone and IV morphine were available for breakthrough pain. All patients received pulse oximetry and respiratory monitoring for 48 h post-Cesarean delivery.Single-dose EREM significantly improved pain scores at rest and during activity. The median (interquartile range) of supplemental opioid medication usage for 48 h post-Cesarean (in milligram-morphine equivalents) decreased from 17 (22) to 10 (17) mg with EREM compared to conventional epidural morphine (P = 0.037). Both drugs were well tolerated with no significant difference in adverse event profiles.EREM provides superior and prolonged post-Cesarean analgesia compared to conventional epidural morphine with no significant increases in adverse events.

  View details for DOI 10.1213/01.ane.0000265533.13477.26

  View details for Web of Science ID 000247444800032

  View details for PubMedID 17578973

• Successful spinal blockade in a parturient with myotonia congenita INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Butwick, A. J. 2007; 16 (3): 292-293

  View details for DOI 10.1016/j.ijoa.2007.01.003

  View details for Web of Science ID 000248160500022

  View details for PubMedID 17451935

• Obstetric anesthesia controversies: vasopressor choice for postspinal hypotension during cesarean delivery. International anesthesiology clinics Macarthur, A., Riley, E. T. 2007; 45 (1): 115-132

  View details for PubMedID 17215703

• Experimental heat pain for detecting pregnancy-induced analgesia in humans ANESTHESIA AND ANALGESIA Carvalho, B., Angst, M. S., Fuller, A. J., Lin, E., Mathusamy, A. D., Riley, E. T. 2006; 103 (5): 1283-1287

  Abstract

  Animal studies suggest that increased circulating estrogen and progesterone, and activation of the endorphin system cause prenancy-induced antinociceptive effects. Human studies have provided inconsistent results and have often lacked a nonpregnant control group. In this study, we compared sensitivity to experimental heat and cold pain in pregnant and nonpregnant women. Nineteen healthy nonpregnant female volunteers and 20 pregnant women at term were enrolled. Pain threshold and tolerance were examined using experimental heat-induced pain and cold pressor pain models. Subjects were evaluated pre- and 1-2 days post-delivery (pregnant), or on consecutive days (nonpregnant). Heat pain tolerance was significantly increased in the pregnant women during pre and postdelivery when compared with nonpregnant controls (50.0 +/- 1.0 vs 49.0 +/- 1.2 and 50.1 +/- 0.7 vs 49.2 +/- 1.2 degrees C; mean +/- sd). However, pain induced by the cold pressor test was endured for a similar amount of time by both study groups. Pregnancy-induced analgesic effects at term can be detected in a model of experimental heat pain. These effects persist during the first 24-48 h after delivery. Experimental heat pain is a suitable modality for further characterizing the phenomenon of pregnancy-induced analgesia in humans.

  View details for DOI 10.1213/01.ane.0000239224.48719.28

  View details for Web of Science ID 000241570600038

  View details for PubMedID 17056970

• Valdecoxib for postoperative pain management after cesarean delivery: A randomized, double-blind, placebo-controlled study 37th Annual Meeting of the Society-for-Obstetric-Anesthesia-and-Perinatology Carvalho, B., Chu, L., Fuller, A., Cohen, S. E., Riley, E. T. LIPPINCOTT WILLIAMS & WILKINS. 2006: 664–70

  Abstract

  Although nonsteroidal antiinflammatory drugs (NSAIDs) improve postoperative pain relief after cesarean delivery, they carry potential side effects (e.g., bleeding). Perioperative cyclooxygenase (COX)-2 inhibitors show similar analgesic efficacy to nonsteroidal antiinflammatory drugs in many surgical models but have not been studied after cesarean delivery. We designed this randomized double-blind study to determine the analgesic efficacy and opioid-sparing effects of valdecoxib after cesarean delivery. Healthy patients undergoing elective cesarean delivery under spinal anesthesia were randomized to receive oral valdecoxib 20 mg or placebo every 12 h for 72 h postoperatively. As a result of cyclooxygenase-2 inhibitors safety concerns that became apparent during this study, the study was terminated early after evaluating 48 patients. We found no differences in total analgesic consumption between the valdecoxib and placebo groups (121 +/- 70 versus 143 +/- 77 morphine mg-equivalents, respectively; P = 0.26). Pain at rest and during activity were similar between the groups despite adequate post hoc power to have detected a clinically significant difference. There were also no differences in IV morphine requirements, time to first analgesic request, patient satisfaction, side effects, breast-feeding success, or functional activity. Postoperative pain was generally well controlled. Adding valdecoxib after cesarean delivery under spinal anesthesia with intrathecal morphine is not supported at this time.

  View details for DOI 10.1213/01.ane.0000229702.42426.a6

  View details for Web of Science ID 000240049800025

  View details for PubMedID 16931678

• Single-dose extended-release epidural morphine for pain after hip arthroplasty. Journal of opioid management Martin, G., Hartmannsgruber, M., Riley, E., Manvelian, G. 2006; 2 (4): 209-218

  Abstract

  This randomized, double-blind study compared the safety and efficacy of a new single-dose extended-release epidural morphine (EREM) formulation for postoperative pain following hip arthroplasty. Patients were administered a single dose of EREM (10, 20, or 30 mg, n = 93) or a single epidural dose of placebo (n = 27) before surgery and general anesthesia. Following surgery, patients had access to fentanyl with the use of intravenous patient-controlled analgesia. Postoperative fentanyl use, time to first postoperative fentanyl use, pain intensity at rest and with activity, patient ratings of pain control, and adverse events were recorded. Compared with placebo-treated patients, single-dose EREM patients used less total supplemental fentanyl (p < or = 0.049), had a longer time to first fentanyl use (p < 0.001), and were less likely to use any supplemental fentanyl (p < or = 0.042). EREM-treated patients reported lower pain intensity for up to 48 hours postdose compared with placebo-treated patients. Single-dose EREM was effective for postoperative pain relief for up to 48 hours following hip arthroplasty, with a safety and tolerability profile consistent with that of other epidurally administered opioids.

  View details for PubMedID 17319482

• Epidural anesthesia for elective cesarean delivery with intraoperative arterial occlusion balloon catheter placement 36th Annual Meeting of the Society-for-Obstetric-Anesthesia-and-Perinatology Fuller, A. J., Carvalho, B., Brummel, C., Riley, E. T. LIPPINCOTT WILLIAMS & WILKINS. 2006: 585–87

  Abstract

  Obstetric hemorrhage is a leading cause of maternal mortality. We describe the anesthetic management of elective cesarean delivery in patients at high risk for hemorrhage. The utility and limitations of intraarterial balloon catheter placement and epidural anesthesia are described.

  View details for DOI 10.1213/01.ane.0000189551.61937.ea

  View details for Web of Science ID 000234912900049

  View details for PubMedID 16428566

• Recombinant factor VIIa for life-threatening post-partum haemorrhage BRITISH JOURNAL OF ANAESTHESIA Butwick, A. J., Riley, E. T. 2005; 95 (4): 558-558

  View details for Web of Science ID 000231921400023

• The ED50 and ED95 of intrathecal isobaric bupivacaine with opioids for cesarean delivery ANESTHESIOLOGY Carvalho, B., Durbin, M., Drover, D. R., Cohen, S. E., Ginosar, Y., Riley, E. T. 2005; 103 (3): 606-612

  Abstract

  The ideal intrathecal isobaric bupivacaine dose for cesarean delivery anesthesia is uncertain. While small doses (5-9 mg) of bupivacaine may reduce side effects such as hypotension, they potentially increase spinal anesthetic failures. This study determined the ED50 and ED95 of intrathecal isobaric bupivacaine (with adjuvant opioids) for cesarean delivery.After institutional review board approval and written informed consent were obtained, 48 parturients undergoing elective cesarean delivery under combined spinal-epidural anesthesia were enrolled in this double-blind, randomized, dose-ranging study. Patients received a 5-, 6-, 7-, 8-, 9-, 10-, 11-, or 12-mg intrathecal isobaric bupivacaine dose with 10 microg fentanyl and 200 microg morphine. Overall anesthetic success was recorded when no intraoperative epidural supplement was required during the cesarean delivery. ED50 and ED95 values for overall anesthetic success were determined using a logistic regression model.ED50 and ED95 values for overall anesthetic success were 7.25 and 13.0 mg, respectively. No advantages for low doses could be demonstrated with regard to hypotension, nausea, vomiting, pruritus, or maternal satisfaction, although this study was underpowered to detect significant differences in secondary outcome variables.The ED50 and ED95 values (7.25 and 13.0 mg, respectively) for intrathecal isobaric bupivacaine in this circumstance are similar to values the authors determined recently for hyperbaric bupivacaine using similar methodology. These ED50 and ED95 values are significantly higher than those advocated in previous reports in which success was claimed using lower intrathecal bupivacaine doses. The current study used stricter criteria to define "successful" anesthesia and support the use of larger bupivacaine doses to ensure adequate patient comfort.

  View details for Web of Science ID 000231574300023

  View details for PubMedID 16129987

• "Ultra-light" patient-controlled epidural analgesia during labor: effects of varying regimens on analgesia and physician workload INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Carvalho, B., Cohen, S. E., Giarrusso, K., Durbin, M., Riley, E. T., Lipman, S. 2005; 14 (3): 223-229

  Abstract

  Patient-controlled epidural analgesia (PCEA) offers many advantages over continuous epidural infusions for maintenance of labor analgesia. Some of these benefits may depend on the PCEA settings. This study evaluated several regimens for "ultra-light" (0.125%) PCEA with basal continuous infusion (CI) in labor with goals of minimizing physician interventions while providing good analgesia.Two hundred and twenty ASA I-II women receiving epidural analgesia during active labor (cervical dilation <5 cm) were randomly assigned in a double-blind manner to four treatment groups (n=30 in each). Analgesia was maintained with a PCEA/CI pump using bupivacaine 0.0625% + sufentanil 0.35 microg/mL. PCEA settings were: group A: CI 10 mL/h, PCEA bolus 6 mL, 8-min lockout; group B: CI 10 mL/h, PCEA bolus 12 mL, 16-min lockout; group C: CI 15 mL/h, PCEA bolus 6 mL, 8-min lockout; group D: CI 15 mL/h, PCEA bolus 12 mL, 16-min lockout.In groups A, B, C and D, 76, 77, 75 and 85% of parturients respectively, required no physician rescue boluses. Pain scores were low and maternal satisfaction was high in all groups, with minimal differences among them. Spontaneous vaginal delivery occurred in 78% of patients overall, instrumental (forceps or vacuum) delivery in 10% and cesarean section in 12%.These ultra-light PCEA regimens provided excellent analgesia with minimal physician workload and a high spontaneous delivery rate. Use of moderate to high-volume, ultra-light PCEA/CI techniques should facilitate provision of labor analgesia in busy obstetric units.

  View details for DOI 10.1016/j.ijoa.2005.02.003

  View details for Web of Science ID 000230915700008

  View details for PubMedID 15935646

• A survey of labor patient-controlled epidural anesthesia practice in Californian hospitals 37th Annual Meeting of the Society-for-Obstetric-Anesthesia-and-Perinatology Carvalho, B., Wang, P., Riley, E. T., Cohen, S. E. LIPPINCOTT WILLIAMS & WILKINS. 2005: A29–A29

  View details for Web of Science ID 000228673000082

• Valdecoxib for postoperative pain management after cesarean section: A randomized, double-blinded, placebo controlled study 37th Annual Meeting of the Society-for-Obstetric-Anesthesia-and-Perinatology Fuller, A. J., Brummel, C., Saxena, A., Chu, L., Riley, E. T., Cohen, S. E., Carvalho, B. LIPPINCOTT WILLIAMS & WILKINS. 2005: A15–A15

  View details for Web of Science ID 000228673000053

• Single-dose, sustained-release epidural morphine in the management of postoperative pain after elective Cesarean delivery: Results of a multicenter randomized controlled study ANESTHESIA AND ANALGESIA Carvalho, B., Riley, E., Cohen, S. E., Gambling, D., PALMER, C., Huffnagle, H. J., Polley, L., Muir, H., Segal, S., Lihou, C., Manvelian, G. 2005; 100 (4): 1150-1158

  Abstract

  In this multicenter, randomized, controlled study, we compared the analgesic efficacy and safety profile of a new single-dose extended-release epidural morphine (EREM) formulation (DepoDur) with that of epidural morphine sulfate for the management of postoperative pain for up to 48 h after elective cesarean delivery. ASA physical status I or II parturients (n = 75) were anesthetized with a combined spinal/epidural technique. Parturients received intrathecal bupivacaine 12-15 mg and fentanyl 10 mug for spinal anesthesia and a single epidural injection of either 5 mg of standard (conventional preservative-free) morphine or 5, 10, or 15 mg of extended-release morphine after cord clamping for postoperative pain control. Single-dose EREM 10 and 15 mg groups significantly decreased total supplemental opioid medication use and improved functional ability scores for 48 h after surgery compared with those receiving 5 mg of standard morphine. Visual analog scale pain scores at rest and with activity at 24 to 48 h after dosing were significantly better in the 10- and 15-mg single-dose EREM groups versus the standard morphine group. There were no significant differences between the two 5 mg (single-dose EREM and standard morphine) groups. Single-dose EREM was well tolerated, and most adverse events were mild to moderate in severity. Single-dose EREM is a potentially beneficial epidural analgesic for the management of post-cesarean delivery pain and has particular advantages over standard morphine for the period from 24 to 48 h after surgery.

  View details for DOI 10.1213/01.ANE.0000149544.58230.FF

  View details for Web of Science ID 000227792400040

  View details for PubMedID 15781537

• Randomized comparison of intravenous nitroglycerin and subcutaneous terbutaline for external cephalic version under tocolysis AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY El-Sayed, Y. Y., Pullen, K., Riley, E. T., Lyell, D., Druzin, M. L., Cohen, S. E., Chitkara, U. 2004; 191 (6): 2051-2055

  Abstract

  The purpose of this study was to compare the efficacy and safety of intravenous nitroglycerin with that of subcutaneous terbutaline as a tocolytic agent for external cephalic version at term.We performed a prospective randomized trial. Patients between 37 and 42 weeks of gestation were assigned randomly to receive either 200 microg of intravenous nitroglycerin therapy or 0.25 mg of subcutaneous terbutaline therapy for tocolysis during external cephalic version. The rate of successful external cephalic version and side effects were compared between groups.Of 59 randomly assigned patients, 30 patients received intravenous nitroglycerin, and 29 patients received subcutaneous terbutaline. The overall success rate of external cephalic version in the study was 39%. The rate of successful external cephalic version was significantly higher in the terbutaline group (55% vs 23%; P = .01). The incidence of palpitations was significantly higher in patients who received terbutaline therapy (17.2% vs 0%; P = .02), as was the mean maternal heart rate at multiple time periods.Compared with intravenous nitroglycerin, subcutaneous terbutaline was associated with a significantly higher rate of successful external cephalic version at term.

  View details for DOI 10.1016/j.ajog.2004.04.040

  View details for Web of Science ID 000225925800030

  View details for PubMedID 15592291

• Preloading vs. postloading of colloid for the prevention of hypotension after spinal anesthesia for cesarean section 36th Annual Meeting of the Society-for-Obstetric-Anesthesia-and-Perinatology Brummel, C., Mercier, F., Fuller, A., Mathusamy, A., Lipman, S., Cohen, S. E., Riley, E. T. LIPPINCOTT WILLIAMS & WILKINS. 2004: B33–B33

  View details for Web of Science ID 000221070400108

• Pain tolerance in pregnancy 36th Annual Meeting of the Society-for-Obstetric-Anesthesia-and-Perinatology Fuller, A. J., Lin, E., Mathusamy, A., Carvalho, B., Angst, M., Golianu, B. Y., Riley, E. T. LIPPINCOTT WILLIAMS & WILKINS. 2004: B9–B9

  View details for Web of Science ID 000221070400061

• ED50 and ED95 of intrathecal hyperbaric bupivacaine coadministered with opioids for cesarean delivery Annual Meeting of the American-Society-of-Anesthesiologists Ginosar, Y., Mirikatani, E., Drover, D. R., Cohen, S. E., Riley, E. T. LIPPINCOTT WILLIAMS & WILKINS. 2004: 676–82

  Abstract

  Successful cesarean delivery anesthesia has been reported with use of small doses (5-9 mg) of intrathecal bupivacaine coadministered with opioids. This double-blind, randomized, dose-ranging study determined the ED50 and ED95 of intrathecal bupivacaine (with adjuvant opioids) for cesarean delivery anesthesia.Forty-two parturients undergoing elective cesarean delivery with use of combined spinal-epidural anesthesia received intrathecal hyperbaric bupivacaine in doses of 6, 7, 8, 9, 10, 11, or 12 mg in equal volumes with an added 10 microg intrathecal fentanyl and 200 microg intrathecal morphine. Sensory levels (pinprick) were evaluated every 2 min until a T6 level was achieved. The dose was a success(induction) if a bilateral T6 block occurred in 10 min; otherwise, it was a failure(induction). In addition to being a success(induction), the dose was a success(operation) if no intraoperative epidural supplement was required; otherwise, it was a failure(operation). ED50 and ED95 for both success(induction) and success(operation) were determined with use of a logistic regression model.ED50 for success(induction) and success(operation) were 6.7 and 7.6 mg, respectively, whereas the ED95 for success(induction) and success(operation) were 11.0 and 11.2 mg. Speed of onset correlated inversely with dose. Although no clear advantage for low doses could be demonstrated (hypotension, nausea, vomiting, pruritus, or maternal satisfaction), this study was underpowered to detect significance in these variables.The ED95 of intrathecal bupivacaine under the conditions of this study is considerably in excess of the low doses proposed for cesarean delivery in some recent publications. When doses of intrathecal bupivacaine less than the ED95, particularly near the ED50, are used, the doses should be administered as part of a catheter-based technique.

  View details for Web of Science ID 000189251700030

  View details for PubMedID 15108985

• Neonatal chest wall rigidity following the use of remifentanil for cesarean delivery in a patient with autoimmune hepatitis and thrombocytopenia INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Carvalho, B., Mirikitani, E. J., Lyell, D., Evans, D. A., Druzin, A., Riley, E. T. 2004; 13 (1): 53-56

  Abstract

  Remifentanil is a useful adjunct in general anesthesia for high-risk obstetric patients. It provides effective blunting of the rapid hemodynamic changes that may be associated with airway manipulation and surgical stimulation. There have been no previous reports of opioid-related rigidity in the neonate delivered by a parturient receiving intraoperative remifentanil. We present a case of short-lived neonatal rigidity and respiratory depression following remifentanil administration during cesarean section to a parturient with autoimmune hepatitis complicated by cirrhosis, esophageal varices and thrombocytopenia.

  View details for DOI 10.1016/j.ijoa.2003.09.001

  View details for Web of Science ID 000188228500013

  View details for PubMedID 15321443

• The site of action of epidural fentanyl infusions in the presence of local anesthetics: A minimum local analgesic concentration infusion study in nulliparous labor Annual Meeting of the Society-of-Obstetric-Anesthesiology-and-Perinatology Ginosar, Y., Columb, M. O., Cohen, S. E., Mirikatani, E., Tingle, M. S., Ratner, E. F., Angst, M. S., Riley, E. T. LIPPINCOTT WILLIAMS & WILKINS. 2003: 1439–45

  Abstract

  We have previously demonstrated that continuous epidural infusions of fentanyl without local anesthetics elicit analgesia by a systemic mechanism. In this study, we examined the hypothesis that, in the presence of epidural bupivacaine, continuous infusions of epidural fentanyl elicit analgesia by a spinal mechanism. Forty-eight nulliparous women in active labor participated in this prospective, randomized, double-blinded study. Women received lumbar epidural analgesia with 20-30 mL bupivacaine 0.125% until pain free. Subjects were then randomized to either IV or epidural (EPI) fentanyl infusion groups. Each infusion delivered fentanyl 30 microg/h. All women received an epidural infusion of bupivacaine at a rate of 20 mL/h, the concentration of which was determined by the response of the previous woman in the same group to the analgesic regimen used. Unlike previous studies that assessed the minimum local analgesic concentration (MLAC) for bolus administration at the initiation of analgesia, this study assessed MLAC(infusion) for the maintenance of analgesia throughout the first stage of labor. MLAC(infusion) was determined using the up-down sequential analysis described by Dixon and Massey. The MLAC(infusion) of epidural bupivacaine was 0.063% (95% confidence interval, 0.058-0.068) and 0.019% (95% confidence interval, 0.000-0.038) in the IV and EPI groups respectively. A continuous infusion of fentanyl was more than three times as potent when administered by the epidural than by the IV route. This marked increase in potency for the epidural route is highly suggestive for a predominantly spinal mechanism of action for infused epidural fentanyl under the conditions of this study.This study determined the median effective concentration for epidural infusions of bupivacaine during labor analgesia. Coadministered epidural fentanyl infusions were more than three times more potent than IV fentanyl infusions, suggesting a predominantly spinal mechanism of opioid action under these study conditions.

  View details for DOI 10.1213/01.ANE.0000081792.84877.A2

  View details for Web of Science ID 000186143600038

  View details for PubMedID 14570662

• The site of action of epidural fentanyl in humans: The difference between infusion and bolus administration Annual Meeting of the Society-of-Obstetric-Anesthesiology-and-Perinatology Ginosar, Y., Riley, E. T., Angst, M. S. LIPPINCOTT WILLIAMS & WILKINS. 2003: 1428–38

  Abstract

  Most published studies suggesting that epidural fentanyl acts predominantly at spinal sites administered the drug as a bolus injection, whereas most studies suggesting that it acts predominantly at supraspinal sites administered the drug as an infusion. In this study we tested the hypothesis that the mode of administration (bolus versus infusion) of epidural fentanyl determines its site of action. Ten healthy volunteers were enrolled in this randomized, double-blinded, cross-over study. On separate study days fentanyl was administered into the epidural space as a bolus (0.03 mg followed by 0.1 mg 210 min later) and as an infusion (0.03 mg/h followed by 0.1 mg/hr 210 min later for 200 min). Using a thermal and electrical experimental pain model, the heat ( degrees C) and electrical current (mA) causing maximum tolerable pain were assessed repetitively over a period of 420 min. The analgesic efficacy measures were obtained at a lumbar and a cranial dermatome. Plasma fentanyl concentrations were determined throughout the study. Epidural bolus administration of fentanyl resulted in segmental analgesia (leg > head), whereas the epidural infusion of fentanyl produced nonsegmental analgesia (leg = head). There was a significant linear relationship between the analgesic effect and the plasma concentration of fentanyl for the epidural infusion but not for the epidural bolus administration of fentanyl. These findings support our hypothesis and might explain the apparent conflict in the literature regarding the site of action of epidural fentanyl.In an experimental pain study in volunteers, epidural fentanyl caused segmental analgesia when administered as a bolus and nonsegmental systemic analgesia when administered as a continuous infusion. This finding may help resolve the long-standing controversy surrounding the site of action of epidural fentanyl.

  View details for DOI 10.1213/01.ANE.0000081793.60059.10

  View details for Web of Science ID 000186143600037

  View details for PubMedID 14570661

• "Ultra-light" PCEA techniques in labor: Minimizing physician workload while optimizing outcome 35th Annual Meeting of the Society-for-Obstetric-Anesthesia-and-Perinatology Carvalho, B., Giarrusso, K., Durbin, M., Lipman, S., Rohlf, S., Riley, E. T., Cohen, S. E. LIPPINCOTT WILLIAMS & WILKINS. 2003: 2–2

  View details for Web of Science ID 000181969900005

• A study to assess the efficacy and safety of spinal levobupivacaine with and without fentanyl for labor analgesia 35th Annual Meeting of the Society-for-Obstetric-Anesthesia-and-Perinatology Birnbach, D. J., Riley, E. T., Cohen, S. E., Mirikitani, E., D'Angelo, R., Sharma, S. K., Arkoosh, V. A., Stein, D. J., Browne, I. M., Kerimoglu, B., Palmer, C. M. LIPPINCOTT WILLIAMS & WILKINS. 2003: 9–9

  View details for Web of Science ID 000181969900018

• A comparison of the 24-gauge Sprotte (R) and Gertie Marx (R) spinal needles for combined spinal-epidural analgesia during labor ANESTHESIOLOGY Riley, E. T., Hamilton, C. L., Ratner, E. F., Cohen, S. E. 2002; 97 (3): 574-577

  Abstract

  Prior experience with the combined spinal-epidural technique (CSE) for labor analgesia demonstrated a high (up to 14%) failure rate because of failure to obtain cerebrospinal fluid (CSF) or lack of response to appropriate doses of intrathecal sufentanil. The current study was designed to test whether a longer needle with a shorter side port (Gertie Marx needle; 127 mm long) would eliminate failures to obtain CSF compared with the needle we had used previously (Sprotte needle; 120 mm long).Seventy-three parturients were randomly assigned to have a CSE performed with one of these two needles. After identifying the epidural space with an 18-gauge Touhy needle at the L2-L3 or L3-L4 interspace, the spinal needle was introduced through the Touhy needle until penetration of the dura was felt or until the needle was maximally inserted. If no CSF was obtained, the alternate needle was tried. After obtaining CSF, 10 microg sufentanil diluted in 1.8 ml saline was injected. Verbal pain scores (0-10) were obtained every 5 min for 30 min.Failure to obtain CSF occurred six times in the Sprotte group compared with none in the Gertie Marx group (P < 0.05). In all six failures in the Sprotte group, the Gertie Marx needle subsequently proved successful in obtaining CSF. There were no differences in pain scores between the groups.The extra length of the 127-mm Gertie Marx needle resulted in a higher success rate for obtaining CSF when used in the CSE technique. Side port design was not a factor influencing success in this clinical setting.

  View details for Web of Science ID 000177766100008

  View details for PubMedID 12218522

• Epidural catheter function during labor predicts anesthetic efficacy for subsequent cesarean delivery INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Riley, E. T., Papasin, J. 2002; 11 (2): 81-84

  Abstract

  One of the benefits of labor epidural analgesia is that the catheter can be used to initiate a surgical block should the need for cesarean delivery arise. However, sometimes it is not possible to obtain adequate surgical anesthesia via a previously placed labor epidural catheter and it is unknown what factors are associated with this failure. We retrospectively investigated the incidence of failure to convert a labor epidural to a successful surgical block in our institution over a period of one year and determined the factors associated with this failure. There were 246 cases in which a patient had an epidural catheter placed for labor and then had a cesarean delivery. Of these 246 cases, 220 developed surgical anesthesia using the catheter. In six cases the anesthesiologist did not attempt to use the epidural catheter for the cesarean delivery. In 20 cases (classified as failed blocks), the catheter was injected, but another method of anesthesia was then used. Factors associated with failure of the epidural block were an increased requirement for supplemental local anesthetic boluses during labor in order to provide adequate analgesia and that the attending anesthesiologist for the cesarean delivery was not a specialist in obstetric anesthesia. Most epidural catheters placed for labor can be used to induce a surgical block. When significantly more local anesthetic than usual is required to maintain analgesia during labor, however, the epidural catheter may not be functioning properly and consideration should be given to replacing it.

  View details for DOI 10.1054/ijoe.2001.0927

  View details for Web of Science ID 000175931500002

  View details for PubMedID 15321557

• Phenylephrine added to prophylactic ephedrine infusion during spinal anesthesia for elective cesarean section Annual Meeting of the American-Society-of-Anesthesiologists Mercier, F. J., Riley, E. T., Frederickson, W. L., Roger-Christoph, S., Benhamou, D., Cohen, S. E. LIPPINCOTT WILLIAMS & WILKINS. 2001: 668–74

  Abstract

  Because ephedrine infusion (2 mg/min) does not adequately prevent spinal hypotension during cesarean delivery, the authors investigated whether adding phenylephrine would improve its efficacy.Thirty-nine parturients with American Society of Anesthesiologists physical status I-II who were scheduled for cesarean delivery received a crystalloid preload of 15 ml/kg. Spinal anesthesia was performed using 11 mg hyperbaric bupivacaine, 2.5 microg sufentanil, and 0.1 mg morphine. Maternal heart rate and systolic blood pressure were measured at frequent intervals. A vasopressor infusion was started immediately after spinal injection of either 2 mg/min ephedrine plus 10 microg/min phenylephrine or 2 mg/min ephedrine alone. Treatments were assigned randomly in a double-blind fashion. The infusion rate was adjusted according to systolic blood pressure using a predefined algorithm. Hypotension, defined as systolic blood pressure less than 100 mmHg and less than 80% of baseline, was treated with 6 mg ephedrine bolus doses.Hypotension occurred less frequently in the ephedrine-phenylephrine group than in the ephedrine-alone group: 37% versus 75% (P = 0.02). Ephedrine (36+/-16 mg, mean +/- SD) plus 178+/-81 microg phenylephrine was infused in former group, whereas 54+/-18 mg ephedrine was infused in the latter. Median supplemental ephedrine requirements and nausea scores (0-3) were less in the ephedrine-phenylephrine group (0 vs. 12 mg, P = 0.02; and 0 vs. 1.5, P = 0.01, respectively). Umbilical artery pH values were significantly higher in the ephedrine-phenylephrine group than in the group that received ephedrine alone (7.24 vs. 7.19). Apgar scores were similarly good in both groups.Phenylephrine added to an infusion of ephedrine halved the incidence of hypotension and increased umbilical cord pH.

  View details for Web of Science ID 000170872900016

  View details for PubMedID 11575540

• Cost-effectiveness of a trial of labor after previous cesarean OBSTETRICS AND GYNECOLOGY Chung, A., Macario, A., El-Sayed, Y. Y., Riley, E. T., Duncan, B., Druzin, M. L. 2001; 97 (6): 932-941

  Abstract

  To determine the cost-effective method of delivery, from society's perspective, in patients who have had a previous cesarean.We completed an incremental cost-effectiveness analysis of a trial of labor relative to cesarean using a computerized model for a hypothetical 30-year old parturient. The model incorporated data from peer-reviewed studies, actual hospital costs, and utilities to quantify health-related quality of life. A threshold of $50,000 per quality-adjusted life-years was used to define cost-effective.The model was most sensitive to the probability of successful vaginal delivery. If the probability of successful vaginal birth after cesarean (VBAC) was less than 0.65, elective repeat cesarean was both less costly and more effective than a trial of labor. Between 0.65 and 0.74, elective repeat cesarean was cost-effective (the cost-effectiveness ratio was less than $50,000 per quality-adjusted life-years), because, although it cost more than VBAC, it was offset by improved outcomes. Between 0.74 and 0.76, trial of labor was cost-effective. If the probability of successful vaginal delivery exceeded 0.76, trial of labor became less costly and more effective. Costs associated with a moderately morbid neonatal outcome, as well as the probabilities of infant morbidity occurring, heavily impacted our results.The cost-effectiveness of VBAC depends on the likelihood of successful trial of labor. Our modeling suggests that a trial of labor is cost-effective if the probability of successful vaginal delivery is greater than 0.74. Improved algorithms are needed to more precisely estimate the likelihood that a patient with a previous cesarean will have a successful vaginal delivery.

  View details for Web of Science ID 000169206300013

  View details for PubMedID 11384699

• Is a trial of labor in a patient who has had a previous cesarean delivery cost-effective? Chung, A. J., Macario, A., El-Sayed, Y. Y., Riley, E. T., Druzin, M. L. LIPPINCOTT WILLIAMS & WILKINS. 2000: U212–U212

  View details for Web of Science ID 000089136800986

• Is a trial of labor in a patient who has had a previous cesarean delivery cost-effective? Chung, A., Macario, A., El-Sayed, Y., Riley, E. T., Duncan, B., Sheinberg, D. LIPPINCOTT WILLIAMS & WILKINS. 2000: U11–U11

  View details for Web of Science ID 000086274300035

• Analgesia for labor pain: A cost model Annual Meeting of the American-Society-of-Anesthesiologists Macario, A., Scibetta, W. C., Navarro, J., Riley, E. LIPPINCOTT WILLIAMS & WILKINS. 2000: 841–50

  Abstract

  Epidural analgesia and intravenous analgesia with opioids are two techniques for the relief of labor pain. The goal of this study was to develop a cost-identification model to quantify the costs (from society's perspective) of epidural analgesia compared with intravenous analgesia for labor pain. Because there is no valid method to assign a dollar value to differing levels of analgesia, the cost of each technique can be compared with the analgesic benefit (patient pain scores) of each technique.The authors created a cost model for epidural and intravenous analgesia by reviewing the literature to determine the rates of associated clinical outcomes (benefit of each technique to produce analgesia) and complications (e.g., postdural puncture headache). The authors then analyzed data from their institution's cost-accounting system to determine the hospital cost for parturients admitted for delivery, estimated the cost of each complication, and performed a sensitivity analysis to evaluate the cost impact of changing key variables. A secondary analysis was performed assuming that the cost of nursing was fixed (did not change depending on the number of nursing interventions).If the cesarean section rate equals 20% for both intravenous and epidural analgesia, the additional expected cost per patient to society of epidural analgesia of labor pain ranges from $259 (assuming nursing costs in the labor and delivery suite do not vary with the number of nursing interventions) to $338 (assuming nursing costs do increase as the number of interventions increases) relative to the expected cost of intravenous analgesia for labor pain. This cost difference results from increased professional costs and complication costs associated with epidural analgesia.Epidural analgesia is more costly than intravenous analgesia. How the cost of the anesthesiologist and nursing care is calculated affects how much more costly epidural analgesia is relative to intravenous analgesia. Published studies have determined that epidural analgesia provides relief of labor pain superior to intravenous analgesia, quantified in one study as 40 mm better on a 100-mm scale during the first stage of labor and 29 mm better during the second stage of labor. Patients, physicians, and society need to weigh the value of improved pain relief from epidural analgesia versus the increased cost of epidural analgesia.

  View details for Web of Science ID 000085628800026

  View details for PubMedID 10719963

• Walking with labor epidural analgesia - The impact of bupivacaine concentration and a lidocaine-epinephrine test dose Annual Meeting of the Society-for-Obstetric-Anesthesia-and-Perinatology Cohen, S. E., Yeh, J. Y., Riley, E. T., Vogel, T. M. LIPPINCOTT WILLIAMS & WILKINS. 2000: 387–92

  Abstract

  Regional analgesia techniques for labor that permit ambulation are popular among parturients. This study evaluated the influence of bupivacaine bolus concentration and a 3-ml 1.5% lidocaine-epinephrine test dose, on analgesic effectiveness and the ability to walk after block placement.Using a randomized double-blind study design, epidural analgesia was initiated in 60 parturients undergoing labor as follows: Group TD/B.0625 received a 3-ml lidocaine-epinephrine test dose + 12 ml bupivacaine, 0.0625%; group TD/B.125 received a 3-ml test dose + 12 ml bupivacaine, 0.125%; group B.0625 received 15 ml bupivacaine, 0.0625% (no test dose); and group B.125 received 15 ml bupivacaine, 0.125% (no test dose). Initial boluses in all groups contained 10 microg sufentanil. Bupivacaine, 0.0625%, with 0.33 microg/ml sufentanil was infused throughout labor at 13.5-15 ml/h. Analgesia balance, proprioception, motor block, and patient ability to stand and walk were evaluated at various intervals.A bolus of 0.125% bupivacaine containing sufentanil, without a previous test dose, proved to be optimal with respect to analgesia and early ambulation. When a test dose was given before bupivacaine, 0.125%, fewer women walked within 1 h of block placement. Bupivacaine, 0.0625%, with sufentanil, with or without a test dose, provided inadequate analgesia, necessitating additional bupivacaine, which impaired the ability to walk. A high percentage of women in all groups (73-93%) walked at some stage during labor.Omitting a lidocaine-epinephrine test dose and using 0.125% bupivacaine for the initial bolus should permit ambulation in the early postblock period for most parturients who elect this option.

  View details for Web of Science ID 000085078600015

  View details for PubMedID 10691224

• Lumbar epidural morphine in humans and supraspinal analgesia to experimental heat pain ANESTHESIOLOGY Angst, M. S., Ramaswamy, B., Riley, E. T., Stanski, D. R. 2000; 92 (2): 312-324

  Abstract

  Epidural administration of morphine is a common analgesic technique to manage pain. Morphine spreads from the epidural space to the cerebrospinal fluid and then rostrally, causing side effects mediated by the brain stem. However, data on the rostral spread of morphine-mediated analgesia are sparse. This study examined the rostral spread of analgesic effects on heat and electrical pain after epidural administration of morphine.In a randomized, double-blinded, placebo-controlled, crossover study, 5 mg morphine or saline placebo were injected into the lumbar epidural space in nine healthy volunteers. Correct needle placement was confirmed with fluoroscopy. Analgesia to experimental nociceptive heat and electrical stimuli was measured at lumbar (L4), thoracic (T10), cervical (C2), and trigeminal (V2) levels before and 2, 5, 10, and 24 h after epidural injection. Plasma samples for assaying morphine concentrations were drawn before and after each analgesic evaluation.Epidural morphine significantly attenuated experimental heat pain at all dermatomes tested compared with saline placebo. Analgesic effects were significant at L4 after 2, 5, and 10 h, at T10 after 5, 10, and 24 h, and at V2 after 10 h. Electrical pain was attenuated at the lumbar and thoracic but not at the cervical dermatome. Analgesic effects were significant at L4 after 2, 5, and 10 h and at T10 after 5 and 10 h. Morphine plasma concentrations were below the detection limit (1 ng/ml) in eight of the nine subjects 10 h after epidural injection.Lumbar epidural injection of morphine attenuated cutaneous heat pain up to the trigeminal dermatome during a 24-h observation period. In a clinical context, this implies that some types of pain may be attenuated up to the supraspinal level after lumbar epidural administration of morphine.

  View details for Web of Science ID 000085078600007

  View details for PubMedID 10691216

• Complications of labor epidural analgesia: How much risk are patients willing to accept? Vogel, T. M., Riley, E. T., Johnson, K., Cohen, S. E. LIPPINCOTT WILLIAMS & WILKINS. 1999: U437–U437

  View details for Web of Science ID 000082480601069

• Complications of labor epidural analgesia: How much risk are patients willing to accept? Vogel, T. M., Riley, E. T., Johnson, K., Cohen, S. E. LIPPINCOTT WILLIAMS & WILKINS. 1999

  View details for Web of Science ID 000079459400094

• Randomized comparison of intravenous nitroglycerin and magnesium sulfate for treatment of preterm labor OBSTETRICS AND GYNECOLOGY El-Sayed, Y. Y., Riley, E. T., Holbrook, R. H., Cohen, S. E., Chitkara, U., Druzin, M. L. 1999; 93 (1): 79-83

  Abstract

  To compare the safety and efficacy of high-dose intravenous (IV) nitroglycerin with those of IV magnesium sulfate for acute tocolysis of preterm labor.Thirty-one women with preterm labor before 35 weeks' gestation were assigned randomly to IV magnesium sulfate or IV nitroglycerin for tocolysis. Preterm labor was defined as the occurrence of at least two contractions in 10 minutes, with cervical change or ruptured membranes. Acute tocolysis was defined as tocolysis for up to 48 hours. Magnesium sulfate was administered as a 4-g bolus, then at a rate of 2-4 g/h. Nitroglycerin was administered as a 100-microg bolus, then at a rate of 1- to 10-microg/kg/min. The primary outcome measure was achievement of at least 12 hours of successful tocolysis.Thirty patients were available for analysis. There were no significant differences in gestational age, cervical dilation, or incidence of ruptured membranes between groups at the initiation of tocolysis. Successful tocolysis was achieved in six of 16 patients receiving nitroglycerin, compared with 11 of 14 receiving magnesium sulfate (37.5 versus 78.6%, P = .033). Tocolytic failures (nitroglycerin versus magnesium sulfate) were due to persistent contractions with cervical change or rupture of previously intact membranes (five of 16 versus two of 14), persistent hypotension (four of 16 versus none of 14), and other severe side effects (one of 16 versus one of 14). Maternal hemodynamic alterations were more pronounced in patients who received nitroglycerin, and 25% of patients assigned to nitroglycerin treatment had hypotension requiring discontinuation of therapy.Tocolytic failures were more common with nitroglycerin than with magnesium sulfate. The hemodynamic alterations noted in patients receiving nitroglycerin, including a 25% incidence of persistent hypotension, might limit the usefulness of IV nitroglycerin for the acute tocolysis of preterm labor.

  View details for Web of Science ID 000077885200017

  View details for PubMedID 9916961

• Obstetric postanesthesia care unit stays - Reevaluation of discharge criteria after regional anesthesia Annual Meeting of the American-Society-of-Anesthesiologists Cohen, S. E., Hamilton, C. L., Riley, E. T., Walker, D. S., Macario, A., Halpern, J. W. LIPPINCOTT WILLIAMS & WILKINS. 1998: 1559–65

  Abstract

  Obstetric patients may have long postanesthesia care unit (OB-PACU) stays after surgery because of residual regional block or other conditions. This study evaluated whether modified discharge criteria might allow for earlier discharge without compromising patient safety.Data were prospectively collected for 6 months for all patients (N=358) who underwent cesarean section or tubal ligation and recovered in the OB-PACU. Regional anesthesia was used in 94% of patients. The duration of anesthesia and PACU stays, the presence and treatment of events in the PACU, and the regression of neural blockade were recorded. Discharge from the OB-PACU required a 60-min minimum stay, stable vital signs, adequate analgesia, and ability to flex the knees. After completion of prospective data collection, events that kept patients in the PACU after 60 min were reevaluated as to whether patients needed to stay in the PACU for medical reasons. "Needed to stay" events included bleeding, cardiorespiratory problems, sedation, dizziness, and pain. "Safe to leave" conditions included pruritus, nausea, and residual neural blockade. The cumulative duration of OB-PACU stays not clearly justifiable for medical reasons was calculated.Residual block and spinal opioid side effects accounted for the majority of "unnecessary" stays. Annually, 429 h of PACU time could have been saved using the revised criteria. Complications did not develop subsequently in any patient deemed "safe to leave."In many obstetric patients, the duration of PACU stays could safely be shortened by continuing observation in a lower-acuity setting. This may result in greater flexibility and more efficient use of nursing personnel.

  View details for Web of Science ID 000077376100035

  View details for PubMedID 9856733

• Complications of labor epidural analgesia: Do the perceptions of patients and anesthesiologists differ? Vogel, T. M., Riley, E. T., Cohen, S. E., Johnson, K. LIPPINCOTT WILLIAMS & WILKINS. 1998: U865–U865

  View details for Web of Science ID 000075810901013

• Intrathecal sufentanil produces sensory changes without hypotension in male volunteers 46th Annual Meeting of the American-Society-of-Anesthesiologists Riley, E. T., Hamilton, C. L., Cohen, S. E. LIPPINCOTT WILLIAMS & WILKINS. 1998: 73–78

  Abstract

  Intrathecally administered sufentanil is frequently associated with hypotension and sensory changes in women undergoing labor. In this study, the authors examined whether intrathecally administered sufentanil has similar effects in pain-free individuals with low concentrations of progesterone (i.e., male volunteers).Ten male volunteers were randomly assigned to receive an intrathecal injection of either 10 microg sufentanil or saline in a double-blind fashion. Blood pressure, heart rate, oxyhemoglobin saturation, and temperatures from the body core and skin of the calf and ipsilateral great toe were recorded. Cold and pin prick sensation, motor block, and visual analogue scores for sedation, pruritus, and nausea also were assessed. Current perception thresholds using the Neurometer current perception threshold instrument (Neurotron, Inc., Baltimore, MD) were determined for three frequencies (2,000, 250, and 5 Hz, corresponding to stimulation of Abeta, Adelta, and C fibers, respectively) on the upper and lower extremities.Pruritus and sensory changes to pin prick and cold occurred in the sufentanil group but not the saline group. Neither group had a significant change in blood pressure, heart rate, oxyhemoglobin saturation, sedation, or core temperature. There was a clinically insignificant difference in the calf minus toe temperature index between the saline and sufentanil groups. There was a small increase in the current perception thresholds at 250 Hz in the sufentanil group.Intrathecally administered sufentanil did not affect blood pressure in male volunteers. The other effects of sufentanil, however, were similar to those observed in women undergoing labor. This suggests that the hypotension occurring in these women after intrathecally administered sufentanil is secondary to relief of pain, rather than to a sympathectomy.

  View details for Web of Science ID 000074710800012

  View details for PubMedID 9667296

• "Walking epidurals": Impact of bupivacaine bolus concentration and a lidocaine-epinephrine test dose Yeh, J. Y., Riley, E. T., Vogel, T. M., Cohen, S. E. LIPPINCOTT WILLIAMS & WILKINS. 1998: U8–U8

  View details for Web of Science ID 000073081300007

• Intrathecal sufentanil for labor analgesia does not cause a sympathectomy 46th Annual Meeting of the American-Society-of-Anesthesiologists Riley, E. T., Walker, D., Hamilton, C. L., Cohen, S. E. LIPPINCOTT WILLIAMS & WILKINS. 1997: 874–78

  Abstract

  Intrathecal sufentanil (ITS) is frequently used to provide analgesia during labor. Decreases in blood pressure and sensory changes in this circumstance suggest that ITS may have a local anesthetic effect and thus cause a sympathectomy. To determine whether ITS given to laboring women causes a sympathectomy, the authors evaluated central and lower extremity temperature changes after ITS administration. These findings were compared with those in a control group of women having spinal anesthesia with bupivacaine for elective cesarean section in whom an extensive sympathectomy was expected.Twenty parturients classified as American Society of Anesthesiologists' physical status 1 or 2 had temperatures measured centrally, at the calf, and at the great toe at frequent intervals after receiving 10 microg ITS for labor analgesia (sufentanil group, n = 10), or hyperbaric bupivacaine 12 mg in their spinal anesthetic for cesarean section (bupivacaine group, n = 10). Calf-to-toe temperature indices (C-T) were calculated by subtracting toe temperature from calf temperature. A decrease in this index means that the toe had warmed compared with the calf and is an indication of vasodilation and a sympathectomy.There was no significant change in the C-T indices or central temperature in the sufentanil group, but the C-T indices and central temperature decreased significantly in the bupivacaine group.The decreases in the C-T index and central temperature in the bupivacaine group indicate the presence of a sympathectomy. The lack of change in the C-T indices and central temperature in the sufentanil group indicates that no significant vasodilation occurred. Therefore, the decrease in blood pressure seen after ITS administration for labor analgesia is unlikely to be the result of a sympathectomy.

  View details for Web of Science ID A1997YD11700022

  View details for PubMedID 9357890

• Changes in the position of epidural catheters associated with patient movement ANESTHESIOLOGY Hamilton, C. L., Riley, E. T., Cohen, S. E. 1997; 86 (4): 778-784

  Abstract

  Epidural catheter movement has been noted with change of patient position and can result in inadequate anesthesia. This study was designed to measure movement and to develop a technique that minimizes catheter displacement.In 255 parturients requesting epidural anesthesia for labor or cesarean section, a multiorificed lumbar epidural catheter was inserted with the patient in the sitting flexed position. The distance to the epidural space, length of catheter inserted, and amount of catheter position change as the patient moved from the sitting flexed to sitting upright and then to the lateral decubitus position were measured before the catheter was secured to the skin. Adequacy of analgesia, the need for catheter manipulation, and whether the patient was considered obese were noted. Data were grouped according to body mass index (BMI): < 25, 25-30, and > 30 kg/m2.The groups did not differ with respect to the length of catheter initially inserted or changes in catheter position between initial taping and removal. The distance to the epidural space differed significantly among the groups, increasing with greater BMI. Catheters frequently appeared to be drawn inward with position change from the sitting flexed to lateral decubitus position, with the greatest change seen in patients with BMI > 30. Only nine catheters were associated with inadequate analgesia, four of which were replaced. No analgesic failures occurred in the BMI > 30 group. In patients judged by the anesthesiologist to be obese or to have an obese back, BMI was greater, and distance to the epidural space and the magnitude of catheter movement with position change were greater than in those who were not obese.Epidural catheters moved a clinically significant amount with reference to the skin in all BMI groups as patients changed position. If catheters had been secured to the skin before position change, many would have been pulled partially out of the epidural space. To minimize the risk of catheter displacement, particularly in obese patients, we recommend that multiorificed catheters be inserted at least 4 cm into the epidural space and that patients assume the sitting upright or lateral position before securing the catheter to the skin.

  View details for Web of Science ID A1997WT00800009

  View details for PubMedID 9105221

• Intrathecal sufentanil for labor analgesia: Do sensory changes predict better analgesia and greater hypotension? American-Society-of-Anesthesiologists Annual Meeting Riley, E. T., Ratner, E. F., Cohen, S. E. LIPPINCOTT WILLIAMS & WILKINS. 1997: 346–51

  Abstract

  Sensory changes and hypotension occur after intrathecal sufentanil (ITS) is given during labor. The goal of this study was to determine whether sensory changes are predictive of hemodynamic changes or duration of pain relief. We also examined whether sensory and hemodynamic changes relate to the concentration of ITS administered. Forty-five ASA physical status I and II women in active labor were randomly assigned to receive 10 micrograms ITS diluted in either 1, 2, or 3 mL of normal saline (15 in each group). An observer blinded to treatment recorded verbal pain scores, blood pressure, and sensory changes to light touch, pinprick, and cold at frequent intervals. Excellent analgesia was obtained in 42 of 45 patients. There were no differences among the groups with respect to the number of patients with sensory changes, the duration of analgesia or sensory changes, the quality of analgesia, or the severity of hypotension. The groups were therefore combined for further analyses. Among this combined group, the duration of analgesia was 99 +/- 7 min (mean +/- SE). Cold, pinprick, and light touch sensation were decreased in 66%, 50%, and 33% of patients, respectively. Motor block was absent in all patients. The duration and quality of analgesia were similar in subjects with and without sensory changes. Systolic blood pressure decreased 23 +/- 2 mm Hg (P < 0.05) during the first 30 min after ITS, and six patients were given ephedrine. The magnitude of blood pressure change was not affected by the diluent volume or the presence of sensory changes. Because sensory changes were not predictive of the duration or quality of analgesia or the degree of hemodynamic change, we conclude that analgesia with ITS is predominantly mediated via spinal cord opioid receptors rather than by a local anesthetic-type conduction blockade.

  View details for Web of Science ID A1997WF15900019

  View details for PubMedID 9024026

• Intravenous nitroglycerin: a potent uterine relaxant for emergency obstetric procedures. Review of literature and report of three cases. International journal of obstetric anesthesia Riley, E. T., Flanagan, B., Cohen, S. E., Chitkarat, U. 1996; 5 (4): 264-268

  View details for PubMedID 15321327

• The OOPS procedure (operation on placental support): In utero airway management of the fetus with prenatally diagnosed tracheal obstruction 27th Annual Meeting of the Canadian-Association-of-Paediatric-Surgeons Skarsgard, E. D., Chitkara, U., Krane, E. J., Riley, E. T., Halamek, L. P., Dedo, H. H. W B SAUNDERS CO. 1996: 826–28

  Abstract

  Tracheal obstruction of the newborn caused by cervical masses such as teratomas and cystic hygromas can result in a profound hypoxic insult and even death, owing to an inability to establish an adequate airway after birth. Prenatal sonographic diagnosis of these congenital anomalies permits (1) anticipation of an airway problem at the time of delivery and (2) formulation of an algorithm for airway management while oxygen delivery to the baby is maintained through the placental circulation. This is the report of a fetus in whom a large anterior cervical cystic hygroma was detected by prenatal ultrasonography. A multidisciplinary management team was assembled, and an algorithm for airway management was developed. Elective cesarean delivery of the fetal head and thorax, under conditions of uterine tocolysis, permitted a controlled evaluation of the airway and endotracheal intubation while oxygen supply to the infant was maintained through the placenta. The baby remained intubated, and 2 days later underwent subtotal excision of the cervical cystic hygroma. Pharmacological maintenance of the feto-placental circulation after hysterotomy is an invaluable adjunct to airway management of the neonate with prenatally diagnosed tracheal obstruction.

  View details for Web of Science ID A1996UQ51500024

  View details for PubMedID 8783114

• Ketorolac and spinal morphine for postcesarean analgesia. International journal of obstetric anesthesia Cohen, S. E., Desai, J. B., Ratner, E. F., Riley, E. T., Halpern, J. 1996; 5 (1): 14-18

  Abstract

  This study was designed to compare spinal morphine (SM), ketorolac (K), and a combination of the two drugs with respect to analgesic efficacy and side effects in postcesarean patients. Forty-eight parturients having bupivacaine spinal anesthesia for cesarean delivery randomly received in a double-blind manner either: SM: 0.1 mg or SM: 0.2 mg (but no K); SM: 0.1 mg plus K 60 mg intravenously (i.v.) one hour after spinal injection, and 30 mg i.v. every 6 h for three doses or i.v. K dosed as previously described (but no SM). Analgesia and side effects were evaluated during the first 20 h. Forty-eight women were studied. There were no significant differences in analgesia among the groups, although patients receiving SM: 0.1 mg tended to have less satisfactory intraoperative analgesia. Pruritus was common in all patients receiving SM whereas patients who received K had the lowest overall scores for severity of side effects. No serious complications occurred and all groups expressed similarly high satisfaction at the 24 h visit. We conclude that there is no advantage to combining SM and K, and that K provides satisfactory postcesarean analgesia with few side effects.

  View details for PubMedID 15321377

• PREVENTION OF HYPOTENSION AFTER SPINAL-ANESTHESIA FOR CESAREAN-SECTION - 6 PERCENT HETASTARCH VERSUS LACTATED RINGERS SOLUTION ANESTHESIA AND ANALGESIA Riley, E. T., Cohen, S. E., Rubenstein, A. J., Flanagan, B. 1995; 81 (4): 838-842

  Abstract

  This study was designed to determine whether preoperative administration of 6% hetastarch decreases the incidence and severity of hypotension after spinal anesthesia for cesarean section. Forty nonlaboring ASA class I and II women having nonurgent cesarean sections were randomized to receive either 500 mL of 6% hetastarch plus 1 L lactated Ringer's solution (LR) (n = 20), or 2 L of LR (n = 20) prior to induction of spinal anesthesia. Hypotension occurred in 45% of patients who received hetastarch vs 85% of those who received only LR (P < 0.05), and minimum systolic blood pressure was lower in the LR group than in the hetastarch group (85 +/- 12 vs 93 +/- 12 mm Hg [mean +/- SD]; P < 0.05). In addition, the LR group had a higher maximum heart rate (115 +/- 17 vs 104 +/- 16 bpm), a shorter mean time to hypotension (7 +/- 4 vs 10 +/- 7 min), and required more 5-mg doses of ephedrine for treatment of hypotension (0 vs 2 [median]; P < 0.05) than the hetastarch group. Neonatal outcome, as determined by Apgar scores and cord blood gas analyses, was good and similar in both groups. We conclude that 6% hetastarch plus LR is more effective than LR alone and that its routine use before spinal anesthesia for cesarean section should be considered.

  View details for Web of Science ID A1995RX47700031

  View details for PubMedID 7574020

• SPINAL VERSUS EPIDURAL-ANESTHESIA FOR CESAREAN-SECTION - A COMPARISON OF TIME EFFICIENCY, COSTS, CHARGES, AND COMPLICATIONS ANESTHESIA AND ANALGESIA Riley, E. T., Cohen, S. E., Macario, A., Desai, J. B., Ratner, E. F. 1995; 80 (4): 709-712

  Abstract

  Spinal anesthesia recently has gained popularity for elective cesarean section. Our anesthesia service changed from epidural to spinal anesthesia for elective cesarean section in 1991. To evaluate the significance of this change in terms of time management, costs, charges, and complication rates, we retrospectively reviewed the charts of patients who had received epidural (n = 47) or spinal (n = 47) anesthesia for nonemergent cesarean section. Patients who received epidural anesthesia had significantly longer total operating room (OR) times than those who received spinal anesthesia (101 +/- 20 vs 83 +/- 16 min, [mean +/- SD] P < 0.001); this was caused by longer times spent in the OR until surgical incision (46 +/- 11 vs 29 +/- 6 min, P < 0.001). Length of time spent in the postanesthesia recovery unit was similar in both groups. Supplemental intraoperative intravenous (i.v.) analgesics and anxiolytics were required more often in the epidural group (38%) than in the spinal group (17%) (P < 0.05). Complications were noted in six patients with epidural anesthesia and none with spinal anesthesia (P < 0.05). Average per-patient charges were more for the epidural group than for the spinal group. Although direct cost differences between the groups were negligible, there were more substantial indirect costs differences. We conclude that spinal block may provide better and more cost effective anesthesia for uncomplicated, elective cesarean sections.

  View details for Web of Science ID A1995QP46200010

  View details for PubMedID 7893022

• IS NITROUS-OXIDE SAFE FOR BONE-MARROW HARVEST ANESTHESIA AND ANALGESIA Lederhaas, G., BROCKUTNE, J. G., Negrin, R. S., Riley, E., Brodsky, J. B. 1995; 80 (4): 770-772

  Abstract

  Patients with non-Hodgkins lymphoma undergoing autologous bone marrow harvest were studied in a prospective, randomized fashion. All patients received a general anesthetic consisting of intravenous thiopental, fentanyl, and vecuronium and were ventilated with oxygen and isoflurane. Group I (19) patients also were ventilated with nitrous oxide (70%) whereas patients in Group II (19) did not receive nitrous oxide. Bone marrow samples were obtained at the beginning and end of the harvest. Viability of bone marrow mononuclear cells was assessed with a colony-forming unit-granulocyte macrophage (CFU-GM) assay, CFU-GM growth is a marker for myeloid progenitor cells and is dependent on intact deoxyribonucleic acid synthesis. Rate of neutrophil engraftment after autologous bone marrow transplantation was also studied. Both groups of patients were statistically similar in age, weight, anesthetic duration, CFU-GM counts at both sample draws, and the time for successful engraftment. There appears to be no difference in bone marrow viability as assayed by both CFU-GM colony growth and engraftment in human bone marrow exposed to a general anesthetic with nitrous oxide.

  View details for Web of Science ID A1995QP46200021

  View details for PubMedID 7893033

• OBSTETRIC MANAGEMENT OF PATIENTS WITH TRANSPLANTS INTERNATIONAL ANESTHESIOLOGY CLINICS Riley, E. T. 1995; 33 (2): 125-140

  View details for Web of Science ID A1995RE01300008

  View details for PubMedID 7657378

• KETOROLAC, NASAL POLYPOSIS, AND BRONCHIAL-ASTHMA - A CAUSE FOR CONCERN ANESTHESIA AND ANALGESIA Haddow, G. R., Riley, E., Isaacs, R., MCSHARRY, R. 1993; 76 (2): 420-422

  View details for Web of Science ID A1993KY03700037

  View details for PubMedID 8424525