After developing a research interest in obstetric anesthesia during anesthesia residency in the United Kingdom, I completed a clinical research fellowship in obstetric anesthesia at Stanford University School of Medicine in 2005. This training provided a key platform in launching my research career as a clinician investigator in obstetric anesthesia. After completing my fellowship at Stanford, I developed a strong clinical research interest in developing preventive strategies for postpartum hemorrhage. With collaborators within the Divisions of Obstetric Anesthesia and Maternal-Fetal Medicine, I have been principal investigator on a number of clinical studies which have investigated strategies for optimizing anesthetic outcomes for women undergoing cesarean delivery. I have also developed research interests investigating point-of-care devices for assessing the maternal hematologic and hemostatic profiles during the peripartum period.

In 2011, I completed a M.S. in Clinical Epidemiology at Stanford University which has allowed me to advance my career as an outcomes-based researcher in obstetrics. By integrating my background in clinical epidemiology and clinical obstetric anesthesia research, my overarching goal is to develop clinical prediction rules which will assist providers in identifying patients at risk of obstetric morbidity related to postpartum hemorrhage.

I have previously won the Gertie Marx award (best paper by a junior investigator) at the Annual Meeting of the Society for Obstetric Anesthesia and Perinatology (SOAP) and the award for best paper at the Obstetric Anesthetists' Association (OAA) Annual Meeting. I have given the prestigious Gerard W. Ostheimer “What’s New in Obstetrics?” lecture at the 2012 SOAP Conference, and have presented at other national and international obstetric anesthesia meetings. I serve on the associate editorial board of the International Journal of Obstetric Anesthesia, and I am an ad-hoc reviewer for over 8 anesthesia and obstetric journals. I am currently a recipient of federal funding (K23) from the National Institute of Health.

Clinical Focus

  • Anesthesia
  • Obstetric Anesthesia
  • Outcomes Research
  • Outcomes, Pregnancy

Academic Appointments

Honors & Awards

  • Gertie Marx Award (1st prize), Society of Obstetric Anesthesia and Perinatology (SOAP) (2006)
  • Outstanding Interdepartmental Faculty Professor, Department of Obstetrics and Gynecology, Stanford University School of Medicine (2011)
  • Gerard W. Ostheimer Lecture: 'What's New in Obstetrics -2011?', Annual Meeting of the Society of Obstetric Anesthesia and Perinatology (2012)
  • Mentored Patient-Oriented Research Career Development Award (K23), NICHD, NIH (2013)

Boards, Advisory Committees, Professional Organizations

  • Member of the Associate Editorial Board, International Journal of Obstetric Anesthesia (2013 - Present)
  • Member of the Associate Editorial Board, BMC Pregnancy and Childbirth (2014 - Present)
  • Member of the Education Committee, Society for Obstetric Anesthesia and Perinatology (2012 - Present)
  • Member, Child Health Research Institute, Stanford University School of Medicine (2012 - Present)

Professional Education

  • Residency:South Thames West - St George's School of Anaesthesia (2004) UK
  • Fellowship:Stanford University School of Medicine (2006) CA
  • Residency:The Royal Sussex County Hospital (1999) United Kingdom
  • Internship:Hemel Hempstead Hospital (1997) UK
  • Medical Education:St George's Hospital Medical School (1997) England
  • M.S., Department of Health Research and Policy, Stanford University, Epidemiology (2011)
  • FRCA, Fellow of the Royal College of Anaesthetists, UK, Anesthesiology (2003)
  • Residency:Eastbourne District General Hospital (2001) United Kingdom
  • Internship:Worthing District General Hospital (1999) UK
  • Internship:The Royal Surrey County Hospital (1998) United Kingdom

Research & Scholarship

Current Research and Scholarly Interests

I am a clinician investigator with primary research interests in optimizing strategies to better prevent and treat postpartum hemorrhage, a condition which is a leading cause of maternal morbidity and mortality. Integrating a background in clinical epidemiology and clinical research, the overarching goal of my current research is to develop and validate clinical prediction rules which will ultimately aid health-care providers in identifying patients at risk of obstetric morbidity secondary to postpartum hemorrhage. I have also led investigations investigating the clinical utility of point-of-care devices for the assessment of the maternal hematologic and hemostatic profiles. These devices offer the potential to provide real-time and continuous data to assist physicians who manage patients with life-threatening obstetric hemorrhage. For prior and ongoing work, I have received institutional and industry funding for clinical trials in obstetrics, and I am currently a recipient of federal funding (K23) from the National Institute of Health.

Clinical Trials

  • Thromboelastography in Non-elective Cesarean Delivery Not Recruiting

    The purpose of the study is to assess the coagulation changes that occur in laboring patients undergoing non-elective (intrapartum)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. For more information, please contact Alexander J Butwick, MBBS, FRCA, (650) 736 - 8513.

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  • Oxytocin Infusions and Blood Loss in Patients Undergoing Elective Cesarean Delivery. Recruiting

    Although prior dose-finding studies have investigated the optimal bolus dose of oxytocin to initiate adequate uterine tone, it is unclear what oxytocin infusion regimen is required to maintain adequate uterine tone after delivery. The study investigators aim to compare two different infusion rates of oxytocin to assess the optimal infusion regimen for reducing blood loss in women undergoing elective Cesarean delivery.

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  • Thromboelastography to Assess Age-Related Coagulation Differences in Patients Undergoing Cesarean Delivery Not Recruiting

    The purpose of the study is to assess potential age-related differences on coagulation profile of patients undergoing Cesarean Section, using thromboelastography (TEG). The investigators will compare coagulation data collected from the study to assess potential differences in coagulation parameters for the following age groups: (i) women less than 35 yrs (ii) women 35 yrs or older.

    Stanford is currently not accepting patients for this trial. For more information, please contact Alexander J Butwick, MBBS, FRCA, 650-736-8513.

    View full details


2015-16 Courses


All Publications

  • Morbidity associated with cesarean delivery in the United States: is placenta accreta an increasingly important contributor? AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY Creanga, A. A., Bateman, B. T., Butwick, A. J., Raleigh, L., Maeda, A., Kuklina, E., Callaghan, W. M. 2015; 213 (3)


    To examine cesarean morbidity and its predictors in the United States.We used 2000-2011 Nationwide Inpatient Sample data to identify cesarean deliveries and records with 12 potential cesarean complications, including placenta accreta. We estimated cesarean morbidity rates and rate changes during 2000-2011, and fitted Poisson regression models to assess the relative incidence of morbidity among repeat versus primary cesareans and explore its predictors.During 2000-2011, 76 in 1,000 cesareans (97 in 1,000 primary and 48 in 1,000 repeat cesareans) were accompanied by ≥1 of 12 complications. The unadjusted composite cesarean morbidity rate increased by 3.6% only among women with a primary cesarean (p<0.001), while the unadjusted rate of placenta accreta increased by 30.8% only among women with a repeat cesarean (p=0.025). The adjusted rate of overall composite cesarean morbidity decreased by 1% annually during 2000-2011 (p<0.001). Compared to women with a primary cesarean, those who underwent a repeat cesarean were half as likely (incidence rate ratio=0.50; 95%CI 0.49-0.50) to develop a complication, but 2.13 (95%CI 1.98-2.29) times more likely to have a placenta accreta diagnosis. Both cesarean morbidity and placenta accreta were positively associated with: age >30 years; non-Hispanic black race-ethnicity; presence of a chronic medical condition; and delivery in urban, teaching, or larger hospitals.Overall, cesarean morbidity declined modestly during 2000-2011, but placenta accreta became an increasingly important contributor to repeat cesarean morbidity. Clinicians should maintain a high index of suspicion for abnormal placentation and make adequate preparations for patients who need cesarean deliveries.

    View details for DOI 10.1016/j.ajog.2015.05.002

    View details for Web of Science ID 000360551700027

    View details for PubMedID 25957019

  • Mode of anaesthesia for preterm Caesarean delivery: secondary analysis from the Maternal-Fetal Medicine Units Network Caesarean Registry BRITISH JOURNAL OF ANAESTHESIA Butwick, A. J., E-Sayed, Y. Y., Blumenfeld, Y. J., Osmundson, S. S., Weiniger, C. F. 2015; 115 (2): 267-274


    Preterm delivery is often performed by Caesarean section. We investigated modes of anaesthesia and risk factors for general anaesthesia among women undergoing preterm Caesarean delivery.Women undergoing Caesarean delivery between 24(+0) and 36(+6) weeks' gestation were identified from a multicentre US registry. The mode of anaesthesia was classified as neuraxial anaesthesia (spinal, epidural, or combined spinal and epidural) or general anaesthesia. Logistic regression was used to identify patient characteristic, obstetric, and peripartum risk factors associated with general anaesthesia.Within the study cohort, 11 539 women had preterm Caesarean delivery; 9510 (82.4%) underwent neuraxial anaesthesia and 2029 (17.6%) general anaesthesia. In our multivariate model, African-American race [adjusted odds ratio (aOR)=1.9; 95% confidence interval (CI)=1.7-2.2], Hispanic ethnicity (aOR=1.5; 95% CI=1.2-1.8), other race (aOR=1.4; 95% CI=1.1-1.9), and haemolysis, elevated liver enzymes and low platelets (HELLP) syndrome or eclampsia (aOR=2.8; 95% CI=2.2-3.5) were independently associated with receiving general anaesthesia for preterm Caesarean delivery. Women with an emergency Caesarean delivery indication had the highest odds for general anaesthesia (aOR=3.5; 95% CI=3.1-3.9). For every 1 week decrease in gestational age at delivery, the adjusted odds of general anaesthesia increased by 13%.In our study cohort, nearly one in five women received general anaesthesia for preterm Caesarean delivery. Although potential confounding by unmeasured factors cannot be excluded, our findings suggest that early gestational age at delivery, emergent Caesarean delivery indications, hypertensive disease, and non-Caucasian race or ethnicity are associated with general anaesthesia for preterm Caesarean delivery.

    View details for DOI 10.1093/bja/aev108

    View details for Web of Science ID 000358808100017

  • Risk Factors for Prolonged Postpartum Length of Stay Following Cesarean Delivery AMERICAN JOURNAL OF PERINATOLOGY Blumenfeld, Y. J., El-Sayed, Y. Y., Lyell, D. J., Nelson, L. M., Butwick, A. J. 2015; 32 (9): 825-832


    Objective This study aims to identify risk factors for prolonged postpartum length of stays (LOS) after cesarean delivery (CD). Study Design Patients undergoing CD were sourced from a multicenter registry of 19 academic centers between 1999 and 2002 (n = 57,067). Prolonged postpartum LOS was defined as a hospitalization duration ≥ 90th centile. Maternal, antepartum, perioperative, and neonatal variables were compared between women with and without prolonged postpartum LOS. Results The 90th centile for postpartum LOS was 4 days, with 14,954 women experiencing prolonged postpartum LOS. Women with perioperative complications had the highest independent risk for a prolonged postpartum LOS: ileus (adjusted odds ratio [aOR] = 12.28; 95% confidence interval CI = 8.98-16.8); endometritis (aOR = 10.45; 95% CI = 9.51-11.5), and wound complications (aOR = 5.49; 95% CI = 4.54-6.63). Several antepartum, perioperative, and neonatal variables were associated with a prolonged postpartum LOS. Conclusion Perioperative complications had the highest risk for prolonged LOS after CD. Strategies to reduce perioperative complications are needed to decrease the health care burden of prolonged post-CD LOS.

    View details for DOI 10.1055/s-0034-1543953

    View details for Web of Science ID 000358571000004

  • Transfusion and coagulation management in major obstetric hemorrhage CURRENT OPINION IN ANESTHESIOLOGY Butwick, A. J., Goodnough, L. T. 2015; 28 (3): 275-284


    Major obstetric hemorrhage is a leading cause of maternal morbidity and mortality. We will review transfusion strategies and the value of monitoring the maternal coagulation profile during severe obstetric hemorrhage.Epidemiologic studies indicate that rates of severe postpartum hemorrhage (PPH) in well resourced countries are increasing. Despite these increases, rates of transfusion in obstetrics are low (0.9-2.3%), and investigators have questioned whether a predelivery 'type and screen' is cost-effective for all obstetric patients. Instead, blood ordering protocols specific to obstetric patients can reduce unnecessary antibody testing. When severe PPH occurs, a massive transfusion protocol has attracted interest as a key therapeutic resource by ensuring sustained availability of blood products to the labor and delivery unit. During early postpartum bleeding, recent studies have shown that hypofibrinogenemia is an important predictor for the later development of severe PPH. Point-of-care technologies, such as thromboelastography and rotational thromboelastometry, can identify decreased fibrin clot quality during PPH, which correlate with low fibrinogen levels.A massive transfusion protocol provides a key resource in the management of severe PPH. However, future studies are needed to assess whether formula-driven vs. goal-directed transfusion therapy improves maternal outcomes in women with severe PPH.

    View details for DOI 10.1097/ACO.0000000000000180

    View details for Web of Science ID 000353844000008

  • Second-line uterotonics and the risk of hemorrhage-related morbidity. American journal of obstetrics and gynecology Butwick, A. J., Carvalho, B., Blumenfeld, Y. J., El-Sayed, Y. Y., Nelson, L. M., Bateman, B. T. 2015; 212 (5): 642 e1-7


    Uterine atony is a leading cause of postpartum hemorrhage (PPH). Although most cases of PPH respond to first line therapy with uterine massage and oxytocin administration, second line uterotonics including methylergonovine and carboprost are integral for the management of refractory uterine atony. Despite their ubiquitous use, it is uncertain whether the risk of hemorrhage-related morbidity differs in women exposed to methylergonovine or carboprost at Cesarean delivery (CD).We performed a secondary analysis using the Maternal-Fetal Medicine Units Network Cesarean Registry. We identified women who underwent CD and received either methylergonovine or carboprost for refractory uterine atony. The primary outcome was hemorrhage-related morbidity defined as intraoperative or postoperative red blood cells (RBC) transfusion or the need for additional surgical interventions including uterine artery ligation, hypogastric artery ligation, or peripartum hysterectomy for atony. We compared the risk of hemorrhage-related morbidity in those exposed to methylergonovine vs. carboprost. Propensity-score matching was used to account for potential confounders.The study cohort comprised 1,335 women; 870 (65.2%) women received methylergonovine and 465 (34.8%) women received carboprost. After accounting for potential confounders, the risk of hemorrhage-related morbidity was higher in the carboprost group than the methylergonovine group (RR = 1.7; 95% CI = 1.2 - 2.6).In this propensity-score matched analysis, methylergonovine was associated with reduced risk of hemorrhage-related morbidity during CD compared to carboprost. Based on these results, methylergonovine may be a more effective second line uterotonic.

    View details for DOI 10.1016/j.ajog.2015.01.008

    View details for PubMedID 25582104

  • Antenatal Corticosteroids for Preterm Premature Rupture of Membranes: Single or Repeat Course? AMERICAN JOURNAL OF PERINATOLOGY Brookfield, K. F., El-Sayed, Y. Y., Chao, L., Berger, V., Naqvi, M., Butwick, A. J. 2015; 32 (6): 537-543
  • The impact of advanced maternal age on peripartum thromboelastographic coagulation profiles: a prospective observational exploratory study CANADIAN JOURNAL OF ANESTHESIA-JOURNAL CANADIEN D ANESTHESIE Butwick, A., Gutierrez, M. C., Hilton, G. 2015; 62 (5): 504-512


    Advanced maternal age (AMA) is a known risk factor for pregnancy-related venous thromboembolism. However, it is unclear if underlying differences exist in the maternal coagulation profiles of AMA vs non-AMA women. The aim of this prospective observational study was to compare peripartum thromboelastography parameters of AMA and non-AMA women undergoing elective Cesarean delivery (CD).We compared the peripartum thromboelastographic profiles of healthy AMA women (age > 35 yr) and non-AMA women (age ≤ 35 yr) undergoing elective CD under neuraxial anesthesia. Blood samples were drawn prior to CD and at 24 hr and 72 hr post-CD. At each time point, we assessed thromboelastographic and other standard laboratory coagulation indices. We used a linear mixed-effects regression model (SAS(®) PROC MIXED) to assess between-group differences for individual thromboelastographic and laboratory coagulation parameters.The median [interquartile range] ages of women were 38 [37-41] yr and 29 [25-34] yr in the AMA and non-AMA groups, respectively (P < 0.001). We observed no statistically significant effect of study group on any thromboelastographic or laboratory coagulation parameters. No statistically significant correlations were found between any thromboelastographic parameter and maternal age. Peripartum thromboelastography and coagulation profiles of healthy AMA and healthy non-AMA women up to 72 hr post-CD were also similar.These data suggest that maternal thromboelastographic profiles of healthy AMA and non-AMA women undergoing elective CD are similar. The study was registered at (identifier: NCT01416454).

    View details for DOI 10.1007/s12630-014-0300-0

    View details for Web of Science ID 000352615100009

    View details for PubMedID 25549988

  • Second-line uterotonics and the risk of hemorrhage-related morbidity AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY Butwick, A. J., Carvalho, B., Blumenfeld, Y. J., El-Sayed, Y. Y., Nelson, L. M., Bateman, B. T. 2015; 212 (5)
  • In response. Anesthesia and analgesia Ducloy-Bouthors, A., Vallet, B., Susen, S., Wong, C. A., Butwick, A., Lockhart, E. 2015; 120 (4): 956-957

    View details for DOI 10.1213/ANE.0000000000000621

    View details for PubMedID 25790218

  • 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

  • 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
  • Patterns of Second-Line Uterotonic Use in a Large Sample of Hospitalizations for Childbirth in the United States: 2007-2011 ANESTHESIA AND ANALGESIA Bateman, B. T., Tsen, L. C., Liu, J., Butwick, A. J., Huybrechts, K. F. 2014; 119 (6): 1344-1349
  • Medical Advances in the Treatment of Postpartum Hemorrhage ANESTHESIA AND ANALGESIA Ducloy-Bouthors, A., Susen, S., Wong, C. A., Butwick, A., Vallet, B., Lockhart, E. 2014; 119 (5): 1140-1147


    Postpartum hemorrhage (PPH) is a leading cause of maternal mortality worldwide. Recent advances in the management of severe bleeding for trauma patients may provide insight into PPH management, but must be applied with caution considering the significant differences between trauma and obstetric patients. In this review, we summarized evidence for current management strategies for patients with major obstetric hemorrhage, including (1) rapid laboratory assessment of coagulopathy, (2) early transfusion of plasma and high plasma-to-red blood cell transfusion ratios in massive PPH, and (3) use of tranexamic acid and fibrinogen concentrates in the setting of PPH complicated by coagulopathy.

    View details for DOI 10.1213/ANE.0000000000000450

    View details for Web of Science ID 000343633500022

    View details for PubMedID 25329026

  • Risk factors for obstetric morbidity in patients with uterine atony undergoing Caesarean delivery BRITISH JOURNAL OF ANAESTHESIA Butwick, A. J., Carvalho, B., El-Sayed, Y. Y. 2014; 113 (4): 661-668

    View details for DOI 10.1093/bja/aeu150

    View details for Web of Science ID 000343087400019

  • Anticoagulant prescribing practices and anesthetic interventions among anticoagulated pregnant patients: a retrospective study. International journal of obstetric anesthesia Butwick, A., Hass, C., Wong, J., Lyell, D., El-Sayed, Y. 2014; 23 (3): 238-245


    The peripartum management of anticoagulated patients poses important challenges for obstetric anesthesiologists, especially when deciding to perform neuraxial block. However, there is limited evidence evaluating anticoagulant prescribing practices and neuraxial block utilization in this setting. Our objective was to examine peripartum anticoagulant prescribing and anesthetic practices in a cohort of anticoagulated patients receiving subcutaneous enoxaparin, and subcutaneous or intravenous unfractionated heparin.We performed a retrospective study of anticoagulant prescribing patterns and anesthetic interventions among patients receiving enoxaparin and/or unfractionated heparin who delivered at a USA obstetric center over a seven-year period.We identified 101 patients who received enoxaparin and/or unfractionated heparin before delivery. Thirty-nine (38.6%) patients received enoxaparin only, 41 (40.6%) patients received enoxaparin bridged to subcutaneous unfractionated heparin, 11 (10.9%) patients received enoxaparin and were converted to intravenous unfractionated heparin and 10 (9.9%) patients received only subcutaneous unfractionated heparin. The overall rate of neuraxial block utilization was 80.2%. The median [IQR] time-period between the last dose of enoxaparin and neuraxial block was significantly shorter for patients who received only enoxaparin vs. enoxaparin with subcutaneous unfractionated heparin (54h [12-192h] (n=26) vs. 216h [39-504h] (n=23), P=0.04). Among patients who received only subcutaneous unfractionated heparin, the time period between unfractionated heparin and neuraxial block was 24h [19-51h].In this study, the neuraxial block rate was high among patients receiving enoxaparin and/or subcutaneous unfractionated heparin with patients undergoing relatively long periods off anticoagulation. Careful multidisciplinary planning is recommended for the peripartum management of anticoagulated pregnant patients.

    View details for DOI 10.1016/j.ijoa.2014.03.007

    View details for PubMedID 24910353

  • Perioperative and transfusion outcomes in women undergoing cesarean hysterectomy for abnormal placentation TRANSFUSION Brookfield, K. F., Goodnough, L. T., Lyell, D. J., Butwick, A. J. 2014; 54 (6): 1530-1536


    Women with placenta increta (PI) and placenta percreta (PP) are at high risk of obstetric hemorrhage; however, the severity of hemorrhage and perioperative morbidity may differ according to the degree of placental invasion. We sought to compare blood component usage and perioperative morbidity between women with PI versus PP undergoing cesarean hysterectomy (CH).We identified 77 women who underwent CH for PI or PP from the NICHD MFMU Network Cesarean Registry, which sourced data from 19 centers from 1999 to 2002. We examined demographic, obstetric, and surgical data and rates of transfusion and perioperative morbidity. We performed statistical tests for between-group analyses; p values less than 0.05 were significant.Rates of intraoperative or postoperative red blood cell (RBC) transfusion were similar between groups (PI 84% vs. PP 88%; p = 0.7). We observed no between-group differences in rates of fresh-frozen plasma (FFP) transfusion (intraoperative FFP-PI 30% vs. PP 41%; p = 0.3; postoperative FFP-PI 28% vs. PP 18%; p = 0.4) or platelet (PLT) transfusion (intraoperative PLTs-PI 14% vs. PP 29%; p = 0.2; postoperative PLTs-PI 9% vs. PP 9%; p = 1.0). Among the morbidities, a higher proportion of PP women underwent cystotomy (PI 14% vs. PP 38%; p = 0.02) and postoperative mechanical ventilation (PI 14% vs. PP 35%; p = 0.03).Rates of intraoperative RBC, FFP, and PLT transfusion are similar for PI and PP women, and perioperative outcomes are worse for PP women. We suggest the same mobilization transfusion medicine support for both groups, including blood ordering (type and cross-match for CH) and availability of emergency blood protocols including fibrinogen-containing preparations.

    View details for DOI 10.1111/trf.12483

    View details for Web of Science ID 000337591200015

    View details for PubMedID 24188691

  • 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


    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 Web of Science ID 000336703300011

    View details for PubMedID 24703871

  • Preventing spinal hypotension during Caesarean delivery: what is the latest? British journal of anaesthesia Butwick, A. J., Columb, M. O., Carvalho, B. 2014

    View details for DOI 10.1093/bja/aeu267

    View details for PubMedID 25080429

  • Obstetric Anesthesia Clinics (Commentary Article) Society of Obstetric Anesthesia and Perinatology - Summer Newsletter Butwick, A., Tiouririne, M. 2014
  • Platelet Counts and Coagulation Tests Prior to Neuraxial Anesthesia in Patients With Preeclampsia A Retrospective Analysis CLINICAL AND APPLIED THROMBOSIS-HEMOSTASIS Sultan, P., Butwick, A. 2013; 19 (5): 529-534


    This retrospective, descriptive study aimed to assess hematologic testing practices in 100 patients with preeclampsia undergoing neuraxial blockade (NB). Prior to NB, platelet (PLT) count was performed in 61 (98%) of 62 women in labor and in 37 (97%) of 38 women undergoing cesarean delivery (CD). No patients had a pre-NB PLT count <70 × 10(9)/L. Pre-NB tests for prothrombin time (PT) and activated partial thromboplastin time (APTT) were less common and varied among laboring patients (15 [24%] of 62) and patients prior to CD (18 [47%] of 38). Prior to NB, PT and APTT values were within normal limits in all patients. The time intervals between laboratory testing and NB ranged from <2 to >12 hours. The lack of consistency in pre-NB coagulation testing and the variable time intervals between laboratory tests and NB may be due to a lack of consensus among anesthesiologists for determining "safe" hemostatic conditions for NB placement in patients with preeclampsia.

    View details for DOI 10.1177/1076029612441860

    View details for Web of Science ID 000324472400010

    View details for PubMedID 22531481

  • Anesthetic management of a parturient with VACTERL association undergoing Cesarean delivery. Canadian journal of anaesthesia = Journal canadien d'anesthésie Hilton, G., Mihm, F., Butwick, A. 2013; 60 (6): 570-576


    PURPOSE: We present the anesthetic management of a parturient with VACTERL association undergoing combined regional and general anesthesia for Cesarean delivery. Defined as a syndrome, VACTERL association comprises at least three of the following abnormalities: vertebral, anal atresia, cardiac, tracheoesophageal, renal, and limb. CLINICAL FEATURES: The patient's anatomic abnormalities and comorbidities comprised severe cervicothoracic scoliosis, kyphoscoliosis, congenitally fused ribs, and severe restrictive lung disease. She had a Mallampati class 3 airway, a right laterally flexed neck, and reduced mandibular protrusion. We performed a lumbar spine ultrasound for epidural placement which was used to provide peri- and postoperative analgesia. Due to the anticipated difficult tracheal intubation, the patient underwent an awake fibreoptic intubation and subsequently received general anesthesia. The patient's trachea was extubated on the first postoperative day, and she received adequate post-Cesarean epidural analgesia. CONCLUSION: This case highlights the challenges that anesthesiologists face when managing parturients at extremely high risk for perioperative anesthetic morbidity due to the presence of severe pre-existing disease, anticipated difficult airway, and major spinal abnormalities complicating neuraxial anesthesia. We used a combined general and epidural anesthetic approach to control ventilation, provide effective postoperative analgesia, and reduce the risk of anesthetic-related perioperative morbidity. An individualized approach should be considered for the anesthetic management of high-risk pregnant patients with complex and multiple medical and surgical morbidities undergoing labour and delivery.

    View details for DOI 10.1007/s12630-013-9919-5

    View details for PubMedID 23519725

  • Methodological queries about point-of-care haemoglobin data ANAESTHESIA Butwick, A. 2013; 68 (5): 540-541

    View details for DOI 10.1111/anae.12187

    View details for Web of Science ID 000317520200027

    View details for PubMedID 23573859

  • Postpartum hemorrhage and low fibrinogen levels: the past, present and future. International journal of obstetric anesthesia Butwick, A. J. 2013; 22 (2): 87-91

    View details for DOI 10.1016/j.ijoa.2013.01.002

    View details for PubMedID 23473552

  • General anesthesia at cesarean delivery portends worse maternal and neonatal outcomes Brookfield, K., Osmundson, S., Naqvi, M., Butwick, A., Lyelll, D. MOSBY-ELSEVIER. 2013: S283-S283
  • What's New in Obstetric Anesthesia in 2011? Reducing Maternal Adverse Outcomes and Improving Obstetric Anesthesia Quality of Care ANESTHESIA AND ANALGESIA Butwick, A. 2012; 115 (5): 1137-1145


    This article accompanied the "What's New in Obstetric Anesthesia?" lecture presented at the Society for Obstetric Anesthesia and Perinatology Annual Meeting in May 2012. The invited lecturer reviewed the obstetric, obstetric anesthesiology, perinatology, and key medical literature published in 2011. This review identifies key topics and themes from the 2011 literature relevant to the science and clinical practice of obstetric anesthesiology and the interdisciplinary care of obstetric patients. Specific topics include health care policy issues that affect pregnant women, updated information on maternal mortality and morbidity, and clinical and outcomes-based research related to anesthetic practices for women undergoing cesarean delivery.

    View details for DOI 10.1213/ANE.0b013e31826af982

    View details for Web of Science ID 000310762100020

    View details for PubMedID 22984153

  • 2012 Gerard W. Ostheimer Lecture - What's new in obstetric anesthesia? INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Butwick, A. J. 2012; 21 (4): 348-356


    The aim of the 2012 "What's new in obstetric anesthesia?" review is to highlight important scientific and medical advances in the fields of obstetric anesthesiology, obstetrics and perinatology from literature published in 2011. This review will consider advances in the prevention and treatment of important obstetric and obstetric anesthesia-related morbidities, research relevant to the course of labor and electronic fetal monitoring, and advances in neuraxial analgesia and anesthesia for obstetric patients.

    View details for DOI 10.1016/j.ijoa.2012.08.005

    View details for Web of Science ID 000310409000009

    View details for PubMedID 22959260

  • Postpartum hemorrhage treated with a massive transfusion protocol at a tertiary obstetric center: a retrospective study INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Gutierrez, M. C., GOODNOUGH, L. T., Druzin, M., Butwick, A. J. 2012; 21 (3): 230-235


    A massive transfusion protocol may offer major advantages for management of postpartum hemorrhage. The etiology of postpartum hemorrhage, transfusion outcomes and laboratory indices in obstetric cases requiring the massive transfusion protocol were retrospectively evaluated in a tertiary obstetric center.We reviewed medical records of obstetric patients requiring the massive transfusion protocol over a 31-month period. Demographic, obstetric, transfusion, laboratory data and adverse maternal outcomes were abstracted.Massive transfusion protocol activation occurred in 31 patients (0.26% of deliveries): 19 patients (61%) had cesarean delivery, 10 patients (32%) had vaginal delivery, and 2 patients (7%) had dilation and evacuation. Twenty-six patients (84%) were transfused with blood products from the massive transfusion protocol. The protocol was activated within 2h of delivery for 17 patients (58%). Median [IQR] total estimated blood loss value was 2842 [800-8000]mL. Median [IQR] number of units of red blood cells, plasma and platelets from the massive transfusion protocol were: 3 [1.75-7], 3 [1.5-5.5], and 1 [0-2.5] units, respectively. Mean (SD) post-resuscitation hematologic indices were: hemoglobin 10.3 (2.4)g/dL, platelet count 126 (44)×10(9)/L, and fibrinogen 325 (125)mg/dL. The incidence of intensive care admission and peripartum hysterectomy was 61% and 19%, respectively.Our massive transfusion protocol provides early access to red blood cells, plasma and platelets for patients experiencing unanticipated or severe postpartum hemorrhage. Favorable hematologic indices were observed post resuscitation. Future outcomes-based studies are needed to compare massive transfusion protocol and non-protocol based transfusion strategies for the management of hemorrhage.

    View details for DOI 10.1016/j.ijoa.2012.03.005

    View details for Web of Science ID 000307685000005

    View details for PubMedID 22647592

  • Continuous spinal anesthesia for Cesarean hysterectomy and massive hemorrhage in a parturient with placenta increta CANADIAN JOURNAL OF ANESTHESIA-JOURNAL CANADIEN D ANESTHESIE Sultan, P., Hilton, G., Butwick, A., Carvalho, B. 2012; 59 (5): 473-477


    We present anesthetic management using a continuous spinal anesthesia (CSA) technique in a patient with placenta increta who underwent elective Cesarean hysterectomy with massive postpartum hemorrhage.A 34-yr-old parturient (G3P2) was scheduled for Cesarean delivery and possible hysterectomy at 35(+3) weeks due to suspected placenta accreta. Her body mass index was 21 kg·m(-2) and she had a reassuring airway. Inadvertent dural puncture occurred during combined spinal-epidural (CSE) placement, and a decision was made to thread the epidural catheter and utilize a CSA technique. Following delivery of a healthy infant, morbid adherence of the placenta to the myometrium was confirmed, and a supracervical hysterectomy was performed. Eight litres of blood loss occurred postpartum requiring resuscitation with crystalloid 3,800 mL, colloid 1,500 mL, red blood cells 16 units, fresh frozen plasma 16 units, platelets 4 units, and cryoprecipitate 1 unit. The patient developed pulmonary edema requiring conversion to general anesthesia. The patient's cardiovascular status was stable throughout surgery, and her lungs were mechanically ventilated for 18 hr postoperatively in the intensive care unit. The intrathecal catheter was removed 24 hr after placement. She developed no adverse neurological sequelae and reported no postdural puncture headache. The pathology report confirmed placenta increta.A CSA technique may be a viable option in the event of inadvertent dural puncture during planned CSE or epidural placement in patients with a reassuring airway undergoing Cesarean delivery. Although a catheter-based neuraxial technique is appropriate for Cesarean hysterectomy for abnormal placentation, conversion to general anesthesia may be required in the event of massive perioperative hemorrhage and fluid resuscitation.

    View details for DOI 10.1007/s12630-012-9681-0

    View details for Web of Science ID 000302574200007

    View details for PubMedID 22395824

  • Managing Patients with Abnormal Placentation: What Are the Best Anesthetic and Transfusion Strategies? ANESTHESIOLOGY Butwick, A. J. 2012; 116 (5): 1156-1157

    View details for DOI 10.1097/ALN.0b013e31824e60d1

    View details for Web of Science ID 000303199600029

    View details for PubMedID 22531257

  • Non-invasive haemoglobin measurement in patients undergoing elective Caesarean section BRITISH JOURNAL OF ANAESTHESIA Butwick, A., Hilton, G., Carvalho, B. 2012; 108 (2): 271-277


    The ability to measure haemoglobin (Hb) real-time and non-invasively offers important clinical value in the assessment of acute changes in maternal Hb during the peripartum period. This study evaluates the Masimo Rainbow SET(®) Radical-7 Pulse CO-Oximeter in a pregnant population undergoing Caesarean section (CS).Fifty patients undergoing elective CS were enrolled in this prospective, controlled study and followed for 48 h after surgery. Non-invasive Masimo Hb (SpHb) values were compared with laboratory Hb values from venous blood samples drawn at baseline, immediately post-CS, and 24 h post-CS using the Bland-Altman plots. Longitudinal analysis of SpHb changes over time was performed using mixed-effects regression modelling.For the comparison between SpHb and laboratory Hb, SpHb displayed a significant positive bias at baseline {1.22 g dl(-1) [95% confidence interval (CI): 0.89-1.54]} and at 24 h post-CS [1.36 g dl(-1) (95% CI: 1.04-1.68)]. The bias immediately post-CS was 0.14 g dl(-1) (95% CI: -0.18 to 0.46). The limits of agreement at baseline, immediately post-CS, and at 24 h post-CS were: -0.9 and 3.33, -2.35 and 2.56, and -0.55 and 3.27 g dl(-1), respectively. The mean decrease in SpHb from baseline to 48 h post-CS was ?1 g dl(-1).The variability in bias and limits of agreements of the Rainbow SET(®) Radical-7 Pulse CO-Oximeter SpHb may limit its clinical utility for assessing Hb concentration in patients undergoing elective CS. Modifications are needed in the calibration of the device to improve accuracy and precision in an obstetric setting. The study was registered at (NCT01108471) before participant enrolment: URL=

    View details for DOI 10.1093/bja/aer373

    View details for Web of Science ID 000299414800015

    View details for PubMedID 22116296

  • How we treat: transfusion medicine support of obstetric services TRANSFUSION Goodnough, L. T., Daniels, K., Wong, A. E., Viele, M., Fontaine, M. F., Butwick, A. J. 2011; 51 (12): 2540-2548


    Obstetric services depend on the transfusion service (TS) to provide diagnostic testing and blood component therapy for clinical care pathways.We describe three quality improvement (QI) initiatives implemented to improve TS support of obstetric services.We implemented a pathway for patients requiring an ABO/Rh order for every admission to obstetric services, along with reconciliation of the daily hospital birth manifest and TS umbilical cord log to identify every woman eligible for RhIG. After assessment over 6 months, 21 (1%) of 2041 women lacked an admission ABO/Rh; all subsequently had ABO/Rh determinations. Umbilical cords were missing for eight (0.4%) mothers; four were D- and received RhIG. We developed algorithms for diagnostic blood ordering for patients deemed at "low,"moderate," or "high" risk of blood transfusion. A 27% reduction in total diagnostic test volumes and 24% reduction in charges was documented after compared to before implementation. We analyzed the impact of our massive transfusion protocol (MTP) on blood inventory management for 31 (0.25%) women undergoing 12,945 deliveries, representing 11% of 286 MTPs for all clinical services over a 32-month interval. O- uncrossmatched red blood cells (RBCs) represented 103 (24%) of 421 RBC units issued. Wastage rates of RBCs, plasma, and platelets ordered and issued in the MTPs were 0.7, 16, and 3%, respectively.QI initiatives for RhIG prophylaxis, diagnostic blood test ordering, and MTP improve TS support of obstetric services.

    View details for DOI 10.1111/j.1537-2995.2011.03152.x

    View details for Web of Science ID 000298340300006

    View details for PubMedID 21542850

  • Epidural Catheter Removal in Patients on Warfarin Thromboprophylaxis A More Cautious Interpretation of Results Required? REGIONAL ANESTHESIA AND PAIN MEDICINE Carvalho, B., Mariano, E. R., Butwick, A. J. 2011; 36 (6): 632-632

    View details for DOI 10.1097/AAP.0b013e31822e0c7e

    View details for Web of Science ID 000296532100021

    View details for PubMedID 22024706

  • An In Vitro Investigation of the Coagulation Effects of Exogenous Oxytocin Using Thromboelastography in Healthy Parturients ANESTHESIA AND ANALGESIA Butwick, A., Harter, S. 2011; 113 (2): 323-326


    We investigated the coagulation effects in vitro of exogenous oxytocin in whole blood of healthy term parturients.Thromboelastography (TEG®) was performed on kaolin-activated citrated blood samples from 25 healthy, term, nonlaboring parturients. We compared the in vitro effects on the maternal thromboelastographic profile of 3 different exogenous oxytocin concentrations (22.5, 30.1, and 32.9 ?U/mL) and a control (0 ?U/mL). These exogenous oxytocin concentrations were chosen to approximate maternal plasma oxytocin concentrations during elective cesarean delivery, vaginal delivery, and nonelective cesarean delivery, respectively.Increasing the oxytocin concentration was significantly associated with hypercoagulable effects as observed with TEG® (decreasing reaction time, clot formation time, and Tmax; increasing ? angle and maximum rate of thrombus generation). Compared with control samples, the median percentage change (interquartile range) in TEG® values for samples with the highest exogenous oxytocin concentration (32.9 ?U/mL) was largest for reaction time: -40.3% (-45.8%, -22.2%); and Tmax: -39.2% (-42.9%, -28.5%).The results of this in vitro investigation suggest that exogenous oxytocin is associated with modest hypercoagulable effects in the maternal blood of healthy term parturients.

    View details for DOI 10.1213/ANE.0b013e3182222a82

    View details for Web of Science ID 000293064500019

    View details for PubMedID 21642611

  • The Proseal laryngeal mask airway and elective caesarean section ANAESTHESIA AND INTENSIVE CARE Dyer, R. A., James, M. F., Butwick, A. J., Carvalho, B. 2011; 39 (4): 760-761

    View details for Web of Science ID 000293264000036

    View details for PubMedID 21823396

  • 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

  • Oxytocin for labour and caesarean delivery: implications for the anaesthesiologist CURRENT OPINION IN ANESTHESIOLOGY Dyer, R. A., Butwick, A. J., Carvalho, B. 2011; 24 (3): 255-261


    The implications of the obstetric use of oxytocin for obstetric anaesthesia practice are summarised. The review focuses on recent research on the uterotonic effects of oxytocin for prophylaxis and management of uterine atony during caesarean delivery.Oxytocin remains the first-line agent in the prevention and management of uterine atony. In-vitro and in-vivo studies show that prior exposure to oxytocin induces uterine muscle oxytocin receptor desensitization. This may influence oxytocin dosing for adequate uterine tone following delivery. Oxytocin has important cardiovascular side-effects (hypotension, tachycardia and myocardial ischaemia). Recent studies suggest that the effective dose of oxytocin for prophylaxis against uterine atony during caesarean delivery is significantly lower than the 5-10 IU historically used by anaesthesiologists. Slow administration of small bolus doses of oxytocin minimises maternal haemodynamic disturbance. Continuous oxytocin infusions are recommended for maintaining uterine tone after bolus administration, although ideal infusion rates are still to be established. The efficacy of the long-acting oxytocin analogue carbetocin requires further investigation. Recommendations are presented for oxytocin dosing during caesarean delivery.Oxytocin remains the first-line uterotonic after vaginal and caesarean delivery. Recent research elucidates the therapeutic range of oxytocin during caesarean delivery, as well as receptor desensitization. Evidenced-based protocols for the prevention and treatment of uterine atony during caesarean delivery are recommended.

    View details for DOI 10.1097/ACO.0b013e328345331c

    View details for Web of Science ID 000289974800004

    View details for PubMedID 21415725

  • The effectiveness of preemptive sphenopalatine ganglion block on postoperative pain and functional outcomes after functional endoscopic sinus surgery Cho, D., Drover, D. R., Nekhendzy, V., Butwick, A. J., Collins, J., Hwang, P. H. WILEY-BLACKWELL. 2011: 212-218


    The sphenopalatine ganglion block (SPGB) with local anesthetic is used to treat facial pain and headache of various etiologies; it has been widely used during functional endoscopic sinus surgery (FESS). The purpose of this study was to investigate whether preemptive SPGB may positively impact postoperative pain and functional outcomes after FESS.A prospective, double-blind, randomized, placebo-controlled study was performed. A total of 60 patients (18-70 years), undergoing general anesthesia for bilateral FESS, were randomly assigned to receive SPGB with either 2 mL 0.25% bupivacaine with epinephrine 1:100,000 (BP, treatment group) or normal saline (NS, control group). SPGB was performed preemptively 10 minutes before the start of surgery. Preoperative and postoperative (day 0, day 7, and day 30) visual analog pain scale, Sino-Nasal Outcome Test (SNOT-20), computed tomography (CT) and endoscopic scores were compared between the 2 groups.A total of 29 patients were enrolled in BP, and 27 were enrolled in NS. Three patients withdrew from the study, and 1 was withdrawn by the investigator due to severe hypertension after induction of anesthesia. There were no differences in patient demographic characteristics between the study groups. On day 7, the mean visual analog pain scales were 1.12 ± 0.3 in NS and 0.48 ± 0.23 in BP (p = 0.053). There were no statistical differences in other outcome measures (SNOT-20, CT and endoscopic scores) between the 2 groups.A limited trend toward reduced postoperative pain after FESS was noted with bupivacaine compared to saline, but statistical significance was not achieved. Preemptive SPGB may offer sinonasal symptomatic benefits for patients undergoing FESS, but larger studies are warranted.

    View details for DOI 10.1002/alr.20040

    View details for Web of Science ID 000308912700014

    View details for PubMedID 22287376

  • 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

  • The postoperative anaesthetic review. Journal of perioperative practice Sultan, P., Jigajinni, S., McGlennan, A., Butwick, A. 2011; 21 (4): 135-139


    An anaesthetic preoperative assessment for all patients is the standard of care in UK hospitals. The Royal College of Anaesthetists (RCoA) 2009 guidelines state that a postoperative visit, within 24 hours following surgery, is recommended for patients only in certain circumstances. This article critiques these guidelines and explores factors which must be taken into consideration when deciding whether or not anaesthetists should routinely visit their patients after they leave the recovery area. We discuss the physiological rationale for performing a postoperative anaesthetic visit; the identification of post-operative morbidity including provision of adequate post-operative analgesia; patient benefits; limitations of performing postoperative review, and the implications that expanding anaesthetists' responsibilities as perioperative physicians has had upon anaesthetic training and service provision. Finally, this article offers an alternative model for deciding when to perform a post-anaesthetic visit.

    View details for PubMedID 21560554

  • Anticoagulant and antithrombotic drugs in pregnancy: what are the anesthetic implications for labor and cesarean delivery? JOURNAL OF PERINATOLOGY Butwick, A. J., Carvalho, B. 2011; 31 (2): 73-84


    Neuraxial anesthetic techniques are commonly used during the peripartum period to provide effective pain relief for labor and anesthesia during cesarean delivery. Major neurologic complications are rare after neuraxial anesthesia; however, spinal hematoma is associated with catastrophic neurologic outcomes (including lower-limb paralysis). Anticoagulant and antithrombotic drugs can increase the risk of spinal hematoma after neuraxial anesthesia, and better understanding of the pharmacokinetics and pharmacodynamics of anticoagulants has led to greater appreciation for withholding anticoagulation before and after neuraxial anesthesia. A number of national anesthetic societies have produced guidelines for performing neuraxial anesthesia in patients receiving anticoagulation. However, there is limited information about anesthetic implications of anticoagulation during the peripartum period. This article will review the risks of spinal hematoma after neuraxial anesthesia in pregnant patients; current guidelines for neuraxial anesthesia for anticoagulated patients; and relevant pharmacological data of specific anticoagulant and antithrombotic drugs in pregnancy.

    View details for DOI 10.1038/jp.2010.64

    View details for Web of Science ID 000286808100001

    View details for PubMedID 20559281

  • 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

  • ST depression at caesarean section and the relation to oxytocin dose. A randomised controlled trial BJOG-AN INTERNATIONAL JOURNAL OF OBSTETRICS AND GYNAECOLOGY Butwick, A., Dyer, R. 2010; 117 (9): 1165-1165
  • Minimum effective bolus dose of oxytocin during elective Caesarean delivery BRITISH JOURNAL OF ANAESTHESIA Butwick, A. J., Carvalho, B. 2010; 105 (1): 92-93
  • Minimum effective bolus dose of oxytocin during elective Caesarean delivery - Conflict of interest BRITISH JOURNAL OF ANAESTHESIA Butwick, A. J., Carvalho, B. 2010; 104 (6): 783-785
  • Neuraxial anesthesia in obstetric patients receiving anticoagulant and antithrombotic drugs INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Butwick, A. J., Carvalho, B. 2010; 19 (2): 193-201

    View details for DOI 10.1016/j.ijoa.2009.06.008

    View details for Web of Science ID 000277553700012

    View details for PubMedID 20202816

  • 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

  • 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

  • Obstetric hemorrhage during an exit procedure for severe fetal airway obstruction CANADIAN JOURNAL OF ANAESTHESIA-JOURNAL CANADIEN D ANESTHESIE Butwick, A., Aleshi, P., Yamout, I. 2009; 56 (6): 437-442


    To report a case of massive obstetric hemorrhage occurring during Cesarean delivery for an ex utero intrapartum treatment (EXIT) procedure. Methods to optimize the anesthetic, obstetric, and perinatal management are discussed.A healthy parturient underwent an urgent EXIT procedure at 32 weeks gestation for a giant fetal neck mass. During the intraoperative period, severe intraoperative hemorrhage occurred from the site of the uterine incision. No evidence of placental bleeding, premature placental separation, or inadequate uterine relaxation was observed during the perioperative period. Placement of a uterine stapling device was unsuccessful in achieving adequate surgical hemostasis. Initial attempts with laryngoscopy and rigid bronchoscopy to secure the fetal airway on placental support were unsuccessful, and early termination of placental support was deemed necessary due to the severity of maternal blood loss. After full delivery of the neonate and termination of placental support, neonatal ventilation with bag-mask ventilation was achieved and successful endotracheal intubation occurred during repeat bronchoscopy.The risk of obstetric hemorrhage due to uterine relaxation and inadequate surgical hemostasis in patients undergoing EXIT procedures is poorly reported. To reduce adverse maternal and neonatal outcomes, the premature termination of placental support during EXIT procedures may be required in the setting of severe obstetric hemorrhage.

    View details for DOI 10.1007/s12630-009-9092-z

    View details for Web of Science ID 000265940000007

    View details for PubMedID 19396506

  • A survey of perioperative and postoperative anesthetic practices for cesarean delivery. Anesthesiology research and practice Aiono-Le Tagaloa, L., Butwick, A. J., Carvalho, B. 2009; 2009: 510642-?


    The aim of this survey was to review cesarean delivery anesthetic practices. An online survey was sent to members of the Society of Obstetric Anesthesia and Perinatology (SOAP). The mode of anesthesia, preferred neuraxial local anesthetic and opioid agents, postoperative analgesic regimens, and monitoring modalities were assessed. 384 responses from 1,081 online survey requests were received (response rate = 36%). Spinal anesthesia is most commonly used for elective cesarean delivery (85% respondents), with 90% of these respondents preferring hyperbaric bupivacaine 0.75%. 79% used intrathecal fentanyl and 77% used morphine (median [range] dose 200?mcg [50-400]). 91% use respiratory rate, 61% use sedation scores, and 30% use pulse oximetry to monitor for postoperative respiratory depression after administration of neuraxial opioids. Postoperative analgesic regimens include: nonsteroidal anti-inflammatory agents, acetaminophen, oxycodone, and hydrocodone by 81%, 45%, 25%, and 27% respondents respectively. The majority of respondents use spinal anesthesia and neuraxial opioids for cesarean delivery anesthesia. There is marked variability in practices for monitoring respiratory depression postdelivery and for providing postoperative analgesia. These results may not be indicative of overall practice in the United States due to the select group of anesthesiologists surveyed and the low response rate.

    View details for DOI 10.1155/2009/510642

    View details for PubMedID 21217809

  • Vaginal twin delivery: a survey and review of location, anesthesia coverage and interventions INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Carvalho, B., Saxena, A., Butwick, A., Macario, A. 2008; 17 (3): 212-216


    Twin pregnancies are associated with increased perinatal morbidity and mortality. No consensus exists whether vaginal twin delivery should take place in the labor room or operating room, or whether anesthesiologists should be present. We surveyed members of the California Society of Anesthesiologists (CSA) to review management of vaginal twin delivery, and examined anesthetic intervention retrospectively at our institution.230 CSA members were asked to complete an online survey on location of vaginal twin delivery in their institution and whether they were required to be present throughout. We then retrospectively reviewed charts of vaginal twin deliveries at our institution over a 36-month period to analyze frequency and type of anesthetic intervention.The online survey response rate was 58%; 64% of responders reported that vaginal twin deliveries were performed in the operating room and 55% that an anesthesiologist was present. There was a strong association between anesthesiologist's presence and delivery in the operating room (OR 7; 95% CI 3-20). We reviewed 81 charts of women who underwent vaginal twin delivery. The median (range) time that the anesthesiologist was present for each delivery was 60 (20-380) min. Of women undergoing vaginal twin delivery, 27% required anesthetic intervention during the second stage of labor with 6% having emergency cesarean delivery.There is a lack of consensus regarding the appropriate location for vaginal twin delivery and the role of anesthesiologists. A significant percentage of women undergoing vaginal twin delivery in our institution received anesthetic intervention in the immediate delivery period.

    View details for DOI 10.1016/j.ijoa.2007.04.004

    View details for Web of Science ID 000257844200003

    View details for PubMedID 17881218

  • Intraoperative forced air-warming during cesarean delivery under spinal anesthesia does not prevent maternal hypothermia ANESTHESIA AND ANALGESIA Butwick, A. J., Lipman, S. S., Carvalho, B. 2007; 105 (5): 1413-1419


    Prewarming and intraoperative warming with forced air-warming systems prevent perioperative hypothermia and shivering in patients undergoing elective cesarean delivery with epidural anesthesia. We tested the hypothesis that intraoperative lower body forced air-warming prevents hypothermia in patients undergoing elective cesarean delivery with spinal anesthesia.Thirty healthy patients undergoing cesarean delivery with spinal anesthesia were randomly assigned to forced air-warming or control groups (identical cover applied with forced air-warming unit switched off). A blinded investigator assessed oral temperature, shivering, and thermal comfort scores at 15-min intervals until discharge from the postanesthetic care unit. Umbilical cord blood gases and Apgar scores were also measured after delivery.The maximum core temperature changes were similar in the two groups (-1.3 degrees C +/- 0.4 degrees C vs -1.3 degrees C +/- 0.3 degrees C for the forced air-warming group and control group, respectively; P = 0.8). Core hypothermia (< or =35.5 degrees C) occurred in 8 of 15 patients receiving forced air-warming and in 10 of 15 unwarmed patients (P = 0.5). The incidence and severity of shivering did not significantly differ between groups. Umbilical cord blood gases and Apgar scores were similar in both groups (P = NS).We conclude that intraoperative lower body forced air-warming does not prevent intraoperative hypothermia or shivering in women undergoing elective cesarean delivery with spinal anesthesia.

    View details for DOI 10.1213/01.ane.0000286167.96410.27

    View details for Web of Science ID 000250317500039

    View details for PubMedID 17959975

  • Can we improve maternal outcome for high-risk obstetric patients? INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Carvalho, B. 2007; 16 (4): 311-313

    View details for DOI 10.1016/j.ijoa.2007.04.005

    View details for Web of Science ID 000250284800003

    View details for PubMedID 17698338

  • 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

  • Neuraxial anesthesia for cesarean delivery in a parturient with type 1 von Willebrand disease and scoliosis JOURNAL OF CLINICAL ANESTHESIA Butwick, A. J., Carvalho, B. 2007; 19 (3): 230-233


    We present the case of a parturient with von Willebrand disease and scoliosis who required cesarean delivery. Neuraxial anesthesia was used for the patient. The indications for neuraxial anesthesia with regard to type 1 von Willebrand disease are reviewed.

    View details for DOI 10.1016/j.jclinane.2006.08.013

    View details for Web of Science ID 000247128200014

    View details for PubMedID 17531735

  • The effect of colloid and crystalloid preloading on thromboelastography prior to Cesarean delivery CANADIAN JOURNAL OF ANAESTHESIA-JOURNAL CANADIEN D ANESTHESIE Butwick, A., Carvalho, B. 2007; 54 (3): 190-195


    Fluid preloading with colloids reduces hypotension after spinal anesthesia for Cesarean delivery more effectively than crystalloids. However, the effects of fluid preloading regimens on coagulation in pregnant patients remain unresolved. The aim of this study was to compare the effects on coagulation of fluid preloading with 6% hydroxyethyl starch (HES) and lactated Ringer's (LR) solution using thromboelastography (TEG) with kaolin-activated whole blood in healthy pregnant patients prior to spinal anesthesia for Cesarean delivery.After obtaining Ethics committee approval, 30 parturients were prospectively randomized prior to spinal anesthesia for elective Cesarean delivery to receive fluid preloading with either 1500 mL LR or 500 mL 6% HES over 30 min. Thromboelastography was performed immediately prior to and after fluid preloading. Standard TEG parameters were analyzed in terms of r time (min), k time (min), alpha angle (degrees) and maximum amplitude (mm).Group HES had statistically significant longer reaction times (r) and clot formation times (k) after fluid loading compared to baseline values (P < 0.05 respectively), although these post-fluid loading TEG parameters remained within a normal reference range. No significant differences in TEG values were seen after preloading within the LR group.Fluid preloading with 500 mL 6% HES in healthy parturients produced mild coagulation effects, as measured with TEG, prior to spinal anesthesia for Cesarean delivery. No significant effects on coagulation with TEG were observed following preloading with 1500 mL LR.

    View details for Web of Science ID 000245113600005

    View details for PubMedID 17331930

  • Remifentanil patient-controlled analgesia in labor ANESTHESIA AND ANALGESIA Butwick, A., Carvalho, B. 2006; 102 (1): 333-333

    View details for Web of Science ID 000234275700071

    View details for PubMedID 16368862

  • Maternal and neonatal side-effects of remifentanil patient-controlled analgesia in labour BRITISH JOURNAL OF ANAESTHESIA Volikas, I., Butwick, A., Wilkinson, C., Pleming, A., Nicholson, G. 2005; 95 (4): 504-509


    Remifentanil has been suggested as an ideal opioid for patient-controlled analgesia (PCA) in labour, but the safety profile has not been established. The aims of this preliminary prospective observational study were to investigate the maternal side-effects and early neonatal effects, and to assess the placental transfer of remifentanil PCA during labour.Women with no known obstetric complications or contraindication to remifentanil were recruited (n=50). Remifentanil was administered at a bolus dose of 0.5 microg kg(-1) and a lockout period of 2 min. A visual analogue scale was used to assess pain, nausea and itching. Maternal observations were recorded hourly and fetal heart rate trace was assessed every 2 h. Umbilical cord gases, 1 and 5 min Apgar scores and neurological evaluation of the neonate were recorded. Maternal venous blood and umbilical artery and vein cord blood samples were collected for analysis of remifentanil concentration.Fifty women enrolled in the study (24 multiparous, 26 primiparous). There was no evidence of cardiovascular instability or respiratory depression. Pain scores decreased significantly, but there was no significant change in nausea after initiating the PCA. A statistically significant increase in itching was found to be clinically mild and 22 women were slightly drowsy (95% confidence interval [CI], 30-58.7%) but alert to voice. Ten fetal heart rate traces demonstrated changes in the first 20 min, but did not require intervention (95% CI, 10-33.7%). The median 1 and 5 min Apgar scores were 9. The mean umbilical cord gases and neurological examination were within normal limits. Maternal vein and umbilical vein cord samples demonstrated placental transfer of remifentanil, and small amounts were detected in umbilical artery samples.At the bolus dose used remifentanil PCA has an acceptable level of maternal side-effects and minimal effect on the neonate. Remifentanil crosses the placenta and appears to be either rapidly metabolized or redistributed in the neonate.

    View details for DOI 10.1093/bja/aei219

    View details for Web of Science ID 000231921400013

    View details for PubMedID 16113038

  • Management of pregnancy in a patient with beta thalassaemia major INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Butwick, A., Findley, I., Wonke, B. 2005; 14 (4): 351-354


    beta thalassaemia is one of the world's most wide-spread monogenetic disorders. Advances in the management of beta thalassaemia major by extensive blood transfusions and chelation therapy have improved survival of patients into adult life. Due to the prolonged life expectancy and improvements in quality of life, pregnancy has now become an important issue for patients and clinicians. We report a case of a pregnant patient with beta thalassaemia major who underwent a successful caesarean section under spinal anaesthesia. The multidisciplinary approach to management of beta thalassaemia major and pregnancy is discussed.

    View details for DOI 10.1016/j.ijoa.2005.02.002

    View details for Web of Science ID 000232874100019

    View details for PubMedID 16140004

  • 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

  • Ventilator-assisted nasotracheal intubation ANAESTHESIA Butwick, A., Garewal, D. 2004; 59 (2): 197-197

    View details for Web of Science ID 000188226600028

    View details for PubMedID 14725535

  • A pilot study of the effect of the Queen's Square external bladder stimulator on urinary retention after knee replacement surgery ANAESTHESIA Butwick, A., Carter, P., Dolin, S. J. 2003; 58 (6): 587-591


    Postoperative urinary retention remains an important problem after major orthopaedic surgery and can increase morbidity. External vibration applied to the suprapubic region has improved bladder emptying and urinary symptoms in patients with neurogenic bladders. Forty-three patients undergoing elective major knee surgery were randomly assigned to receive either a Queen's Square bladder stimulator or placebo device for 24 h postoperatively. No statistically significant differences in rates of urinary retention could be demonstrated in the bladder stimulator group compared to the placebo group (41% and 33%, respectively). There were no differences between the two groups when analysed for prostatic symptoms, type and effectiveness of analgesia and fluid balance. We conclude that, while the Queen's Square external bladder stimulator may be effective in treating chronic urinary retention associated with a neurogenic bladder, it does not appear to be effective in preventing postoperative urinary retention.

    View details for Web of Science ID 000183025400017

    View details for PubMedID 12846628

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