Clinical Focus

  • Anesthesia
  • Anesthesia, Obstetrics

Academic Appointments

  • Professor - Med Center Line, Anesthesiology, Perioperative and Pain Medicine
  • Professor - Med Center Line (By courtesy), Obstetrics & Gynecology

Professional Education

  • Internship:Emanuel Hospital and Health Ctr (1990) OR
  • Residency:Stanford University School of Medicine (1993) CA
  • Residency:Stanford University School of Medicine (1992) CA
  • Medical Education:University of Washington School of Medicine (1989) WA
  • Board Certification: Anesthesia, American Board of Anesthesiology (1994)

Research & Scholarship

Clinical Trials

  • Thromboelastography to Assess Hemostatic Changes in Patients Undergoing Elective Cesarean Delivery. Not Recruiting

    The purpose of the study is to assess the coagulation changes that occur in patients undergoing elective Cesarean delivery using thromboelastography (TEG). We will compare coagulation data to assess potential coagulation changes associated with hemoglobin changes before and after surgery, and related to estimated blood loss.

    Stanford is currently not accepting patients for this trial.

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  • In-vitro Study to Assess the Coagulation Effects of Exogenous Oxytocin Using Thromboelastography. Not Recruiting

    Oxytocin is normally administered following delivery in pregnant patients to reduce postpartum bleeding by increasing uterine tone. It is unclear whether the use of intravenous oxytocin alters coagulation in pregnant patients. The purpose of the in-vitro study is to assess the coagulation changes of oxytocin in blood samples from pregnant patients using thromboelastrography (TEG). TEG is a point-of-care device which measures the viscoelastic properties of clot formation, and can provide rapid and detailed information about coagulation changes. We aim to collect blood samples from pregnant patients to assess the in-vitro effects of synthetic oxytocin on coagulation using TEG.

    Stanford is currently not accepting patients for this trial.

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  • Temperature Study in Cesarean Section Recruiting

    During surgery body temperature can decrease which can adversely affect how people recover from surgery. This is a common problem. We aim to reduce the incidence of this drop in body temperature during surgery by testing the effectiveness of two active body warming devices. One method is to warm the intravenous fluids that the patients will receive, as they are being infused. The other method is to use a forced-air warmer. This is a device that is similar to a blanket that the patient has laid over their upper body during the surgery which has warm air blown into it. The control group will not have any active warming methods. Study group 1 will have the intravenous fluid warmer in the pre- and intraoperative period. Study group 2 will have a forced-air warmer in the intra-operative period as well as the fluid warmer in the pre- and intraoperative period. We will also observe the neonates' vital signs following delivery.

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2015-16 Courses


All Publications

  • 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


    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

  • 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


    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


    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 ?g, and fentanyl 0, 5, 10 or 25 ?g. 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 ?g compared to fentanyl 0 ?g 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


    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


    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 ? 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


    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 ?g morphine and 10 ?g 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


    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


    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


    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


    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


    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


    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


    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 ANESTHESIA AND ANALGESIA Horstman, D. J., Riley, E. T., Carvalho, B. 2009; 108 (1): 240-245


    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 AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY Pullen, K. M., Riley, E. T., Waller, S. A., Taylor, L., Caughey, A. B., Druzin, M. L., El-Sayed, Y. Y. 2007; 197 (4)


    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 ANESTHESIA AND ANALGESIA Riley, E. T., Carvalho, B. 2007; 105 (4): 1164-1166


    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


    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


    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


    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


    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 ANESTHESIA AND ANALGESIA Carvalho, B., Chu, L., Fuller, A., Cohen, S. E., Riley, E. T. 2006; 103 (3): 664-670


    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

  • Epidural anesthesia for elective cesarean delivery with intraoperative arterial occlusion balloon catheter placement ANESTHESIA AND ANALGESIA Fuller, A. J., Carvalho, B., Brummel, C., Riley, E. T. 2006; 102 (2): 585-587


    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 000231921400024

    View details for PubMedID 16155040

  • 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


    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


    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

  • 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


    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


    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

  • ED50 and ED95 of intrathecal hyperbaric bupivacaine coadministered with opioids for cesarean delivery ANESTHESIOLOGY Ginosar, Y., Mirikatani, E., Drover, D. R., Cohen, S. E., Riley, E. T. 2004; 100 (3): 676-682


    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


    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 in humans: The difference between infusion and bolus administration ANESTHESIA AND ANALGESIA Ginosar, Y., Riley, E. T., Angst, M. S. 2003; 97 (5): 1428-1438


    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

  • 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


    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


    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

  • 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


    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

  • Analgesia for labor pain: A cost model Macario, A., Scibetta, W. C., Navarro, J., Riley, E. LIPPINCOTT WILLIAMS & WILKINS. 2000: 841-850


    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 Cohen, S. E., Yeh, J. Y., Riley, E. T., Vogel, T. M. LIPPINCOTT WILLIAMS & WILKINS. 2000: 387-392


    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


    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

  • 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


    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 ANESTHESIOLOGY Cohen, S. E., Hamilton, C. L., Riley, E. T., Walker, D. S., Macario, A., Halpern, J. W. 1998; 89 (6): 1559-1565


    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

  • Intrathecal sufentanil produces sensory changes without hypotension in male volunteers ANESTHESIOLOGY Riley, E. T., Hamilton, C. L., Cohen, S. E. 1998; 89 (1): 73-78


    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

  • Intrathecal sufentanil for labor analgesia does not cause a sympathectomy Riley, E. T., Walker, D., Hamilton, C. L., Cohen, S. E. LIPPINCOTT WILLIAMS & WILKINS. 1997: 874-878


    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


    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? Riley, E. T., Ratner, E. F., Cohen, S. E. LIPPINCOTT WILLIAMS & WILKINS. 1997: 346-351


    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 Skarsgard, E. D., Chitkara, U., Krane, E. J., Riley, E. T., Halamek, L. P., Dedo, H. H. W B SAUNDERS CO. 1996: 826-828


    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


    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



    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 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


    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


    View details for Web of Science ID A1995RE01300008

    View details for PubMedID 7657378


    View details for Web of Science ID A1993KY03700037

    View details for PubMedID 8424525

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