Brendan Carvalho, MD

Division Chief, Obstetric Anesthesia | Professor

Anesthesia

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Stanford Hospital
Department of Anesthesia
300 Pasteur Drive, Rm H3589
Stanford, CA 94305

Locations

Stanford Hospital
Department of Anesthesia

300 Pasteur Drive, Rm H3589

Stanford, CA 94305

Maps, Directions & Parking

Phone : (650) 723-4000

Work and Education

Professional Education

University of Witwatersrand, Johannesburg, South Africa, 12/31/1994

Residency

St Thomas Hospital, London, England, 07/31/1999

Southwest School of Anesthesia, England, 07/31/2001

Internship

Groote Schuur Hospital, Cape Town, South Africa, 12/31/1995

Board Certifications

Anesthesia, American Board of Anesthesiology, 2014

Languages

Afrikaans

English

Publications

Establishing optimal methodology for studying chatbots in clinical decision making: A new frontier. Journal of clinical anesthesia Ismaiel, N., Carvalho, B., Sultan, P. 2024; 101: 111707

View details for DOI 10.1016/j.jclinane.2024.111707

View details for PubMedID 39693685

Quality of recovery after cesarean delivery in patients with Class III Obesity: a prospective observational cohort study. International journal of obstetric anesthesia Zimmo, K., Ching-Johnson, J., Jones, P. M., Singh, S. I., Dobrowlanski, A., Symons, Y. T., de Vrijer, B., Sultan, P., Carvalho, B., Sebbag, I. 2024; 61: 104312

View details for DOI 10.1016/j.ijoa.2024.104312

View details for PubMedID 39700745

Comparative efficacy of intravenous treatments for perioperative shivering in patients undergoing caesarean delivery under neuraxial anaesthesia: A systematic review and Bayesian network meta-analysis of randomised-controlled trials. Journal of clinical anesthesia Ferrea, G., Monks, D. T., Singh, P. M., Fedoruk, K., Singh, N. P., Blake, L., Carvalho, B., Sultan, P. 2024; 100: 111680

Abstract

Shivering affects 52 % of patients undergoing caesarean delivery under neuraxial anaesthesia. Despite extensive research focused on its prevention, there is still no consensus regarding optimal pharmacological treatment. This systematic review and network meta-analysis aims to compare available intravenous treatments of perioperative shivering in patients undergoing caesarean delivery under neuraxial anaesthesia.We searched seven databases (PubMed MEDLINE, Scopus, Web of Science, Embase, LILACS, Cochrane CRCT and clinicaltrials.gov) for randomised controlled trials comparing intravenous treatments of perioperative shivering during caesarean delivery and performed a Bayesian model network meta-analysis. We assessed study quality using the Cochrane risk of bias assessment tool. The primary outcome evaluated in this meta-analysis was shivering control (cessation or significant reduction in intensity), and secondary outcomes included time to shivering control, shivering recurrence, and incidence of maternal nausea.Twenty randomised controlled trials, with a total of 1983 patients, were included in this analysis. Network estimates of odds ratios (OR [95 % Credible Interval]) of effective treatment of shivering compared with saline were: dexmedetomidine (38.1 [14.2 to 111.5]), tramadol (33.6 [15.1 to 81.8]), nalbuphine (26.2 [10.8 to 80.2]), meperidine (20.9 [6.2 to 73.1]), ondansetron (6.6 [2.2 to 23.2]), and clonidine (3.2 [0.6 to 14.9]). The rank order of interventions by surface area under the cumulative ranking curve scores (in parenthesis) for shivering control was dexmedetomidine (0.87) > tramadol (0.85) > nalbuphine (0.74) > meperidine (0.66) > ondansetron (0.41) > clonidine (0.3) > amitriptyline (0.03). Dexmedetomidine was also the top-ranked intervention for time to shivering control, shivering recurrence and maternal nausea. We judged the certainty in the evidence to be moderate for dexmedetomidine and nalbuphine, and low for all other interventions.This network meta-analysis identified four effective intravenous treatments for shivering in patients undergoing caesarean delivery under neuraxial anaesthesia: dexmedetomidine, tramadol, nalbuphine and meperidine. Dexmedetomidine was the top-ranked intervention for all outcomes.

View details for DOI 10.1016/j.jclinane.2024.111680

View details for PubMedID 39608094

Consensus Statement on Pain Management for Pregnant Patients with Opioid-Use Disorder from the Society for Obstetric Anesthesia and Perinatology, Society for Maternal-Fetal Medicine, and American Society of Regional Anesthesia and Pain Medicine. Anesthesia and analgesia Lim, G., Carvalho, B., George, R. B., Bateman, B. T., Brummett, C. M., Ip, V. H., Landau, R., Osmundson, S. S., Raymond, B., Richebe, P., Soens, M., Terplan, M. 2024

Abstract

Pain management in pregnant and postpartum people with an opioid-use disorder (OUD) requires a balance between risks associated with opioid tolerance, including withdrawal or return to opioid use, considerations around social needs of the maternal-infant dyad, and the provision of adequate pain relief for the birth episode that is often characterized as the worst pain a person will experience in their lifetime. This multidisciplinary consensus statement between the Society for Obstetric Anesthesia and Perinatology (SOAP), Society for Maternal-Fetal Medicine (SMFM), and American Society of Regional Anesthesia and Pain Medicine (ASRA) provides a framework for pain management in obstetric patients with OUD. The purpose of this consensus statement is to provide practical and evidence-based recommendations and is targeted to health care providers in obstetrics and anesthesiology. The statement is focused on prenatal optimization of pain management, labor analgesia, and postvaginal delivery pain management, and postcesarean delivery pain management. Topics include a discussion of nonpharmacologic and pharmacologic options for pain management, medication management for OUD (eg, buprenorphine, methadone), considerations regarding urine drug testing, and other social aspects of care for maternal-infant dyads, as well as a review of current practices. The authors provide evidence-based recommendations to optimize pain management while reducing risks and complications associated with OUD in the peripartum period. Ultimately, this multidisciplinary consensus statement provides practical and concise clinical guidance to optimize pain management for people with OUD in the context of pregnancy to improve maternal and perinatal outcomes.

View details for DOI 10.1213/ANE.0000000000007237

View details for PubMedID 39504271

A Survey of Obstetric Anaesthesia Services and Practices in the United Kingdom. Cureus O'Carroll, J., Zucco, L., Warwick, E., Arbane, G., Moonesinghe, R., El-Boghdadly, K., Guo, N., Carvalho, B., Sultan, P. 2024; 16 (10): e70851

Abstract

Background Variability in obstetric anaesthetia practice and care delivered within the UK is under-explored. The ObsQoR study explored structures, processes, and outcomes of obstetric anaesthesia in 107 hospitals within the UK's National Health Service, and the results of the hospital-level survey are reported here. Methods Hospitals were surveyed to assess obstetric anaesthesia provision, practice, and care delivery. Questions explored staffing, service provision and training, facilities present, clinical practices, outcome measurement, and key indicators of quality in obstetric anaesthesia. Results We received responses from 106 participating hospitals, representing 69% of all UK obstetric units. One hundred (94%) hospitals had a dedicated consultant obstetric anaesthetist within working hours, with 27 (25%) of hospitals' duty anaesthetists having additional clinical responsibilities outside the care of obstetric patients outside of working hours. Around 102 hospitals (98%) offer multidisciplinary team training, of which 95 (93%) use a simulation-based method. Dedicated high-risk antenatal clinics were present in 50 (47%) hospitals. The majority of hospitals provide written patient information in multiple languages for discussing obstetric anaesthesia options (77, 82%). Seventy-three hospitals (69%) use point-of-care testing to estimate haemoglobin concentration. Labour epidural analgesia is most commonly delivered via patient-controlled epidural analgesia in 80 (76%) hospitals, and the incidence of post-dural puncture headaches was recorded by 80 (76%) hospitals. Conclusions These results demonstrate variation in the provision of staffing, facilities, clinical practices, and outcome measurements across the UK. To deliver safe and equitable care across the UK, there needs to be standardisation of anaesthetic peripartum care based on national recommendations and the benchmarking and measurement of appropriate markers of quality.

View details for DOI 10.7759/cureus.70851

View details for PubMedID 39493055

View details for PubMedCentralID PMC11531797

The evaluation of the performance of ChatGPT in the management of labor analgesia. Journal of clinical anesthesia Ismaiel, N., Nguyen, T. P., Guo, N., Carvalho, B., Sultan, P. 2024; 98: 111582

Abstract

ChatGPT4 is a leading large language model (LLM) chatbot released by OpenAI in 2023. ChatGPT4 can respond to free-text queries, answer questions and make suggestions regarding virtually any topic. ChatGPT4 has successfully answered anesthesia and even obstetric anesthesia knowledge-based questions with reasonable accuracy. However, ChatGPT4 has yet to be challenged in obstetric anesthesia clinical decision-making.In this study, we evaluated the performance of ChatGPT4 in the management of clinical labor analgesia scenarios compared to expert obstetric anesthesiologists.Eight clinical questions with progressively increasing medical complexity were posed to ChatGPT4.The ChatGPT4 responses were rated by seven expert obstetric anesthesiologists based on safety, accuracy and completeness of each response using a five-point Likert rating scale.ChatGPT4 was deemed safe in 73% of responses to the presented obstetric anesthesia clinical scenarios (27% of responses were deemed unsafe). None of the ChatGPT4 responses were unanimously deemed to be safe by all seven expert obstetric anesthesiologists. Moreover, ChatGPT4 responses were overall partly accurate (score 4 out of 5) and somewhat incomplete (score 3.5 out of 5).In summary, approximately one quarter of all responses by ChatGPT4 were deemed unsafe by expert obstetric anesthesiologists. These findings may suggest the need for more fine-tuning and training of LLMs such as ChatGPT4 specifically for clinical decision making in obstetric anesthesia or other specialized medical fields. These LLMs may come to play an important future role in assisting obstetric anesthesiologists in clinical decision making and enhancing overall patient care.

View details for DOI 10.1016/j.jclinane.2024.111582

View details for PubMedID 39167880

Comparison of artificial intelligence large language model chatbots in answering frequently asked questions in anaesthesia. BJA open Nguyen, T. P., Carvalho, B., Sukhdeo, H., Joudi, K., Guo, N., Chen, M., Wolpaw, J. T., Kiefer, J. J., Byrne, M., Jamroz, T., Mootz, A. A., Reale, S. C., Zou, J., Sultan, P. 2024; 10: 100280

Abstract

Patients are increasingly using artificial intelligence (AI) chatbots to seek answers to medical queries.Ten frequently asked questions in anaesthesia were posed to three AI chatbots: ChatGPT4 (OpenAI), Bard (Google), and Bing Chat (Microsoft). Each chatbot's answers were evaluated in a randomised, blinded order by five residency programme directors from 15 medical institutions in the USA. Three medical content quality categories (accuracy, comprehensiveness, safety) and three communication quality categories (understandability, empathy/respect, and ethics) were scored between 1 and 5 (1 representing worst, 5 representing best).ChatGPT4 and Bard outperformed Bing Chat (median [inter-quartile range] scores: 4 [3-4], 4 [3-4], and 3 [2-4], respectively; P<0.001 with all metrics combined). All AI chatbots performed poorly in accuracy (score of ≥4 by 58%, 48%, and 36% of experts for ChatGPT4, Bard, and Bing Chat, respectively), comprehensiveness (score ≥4 by 42%, 30%, and 12% of experts for ChatGPT4, Bard, and Bing Chat, respectively), and safety (score ≥4 by 50%, 40%, and 28% of experts for ChatGPT4, Bard, and Bing Chat, respectively). Notably, answers from ChatGPT4, Bard, and Bing Chat differed statistically in comprehensiveness (ChatGPT4, 3 [2-4] vs Bing Chat, 2 [2-3], P<0.001; and Bard 3 [2-4] vs Bing Chat, 2 [2-3], P=0.002). All large language model chatbots performed well with no statistical difference for understandability (P=0.24), empathy (P=0.032), and ethics (P=0.465).In answering anaesthesia patient frequently asked questions, the chatbots perform well on communication metrics but are suboptimal for medical content metrics. Overall, ChatGPT4 and Bard were comparable to each other, both outperforming Bing Chat.

View details for DOI 10.1016/j.bjao.2024.100280

View details for PubMedID 38764485

View details for PubMedCentralID PMC11099318

In Response. Anesthesia and analgesia Mootz, A. A., Carvalho, B., Sultan, P., Nguyen, T. P., Reale, S. C. 2024; 138 (6): e37-e38

View details for DOI 10.1213/ANE.0000000000006979

View details for PubMedID 38771606

Associations between anxiety, sleep, and blood pressure parameters in pregnancy: a prospective pilot cohort study. BMC pregnancy and childbirth Miller, H. E., Simpson, S. L., Hurtado, J., Boncompagni, A., Chueh, J., Shu, C. H., Barwick, F., Leonard, S. A., Carvalho, B., Sultan, P., Aghaeepour, N., Druzin, M., Panelli, D. M. 2024; 24 (1): 366

Abstract

The potential effect modification of sleep on the relationship between anxiety and elevated blood pressure (BP) in pregnancy is understudied. We evaluated the relationship between anxiety, insomnia, and short sleep duration, as well as any interaction effects between these variables, on BP during pregnancy.This was a prospective pilot cohort of pregnant people between 23 to 36 weeks' gestation at a single institution between 2021 and 2022. Standardized questionnaires were used to measure clinical insomnia and anxiety. Objective sleep duration was measured using a wrist-worn actigraphy device. Primary outcomes were systolic (SBP), diastolic (DBP), and mean (MAP) non-invasive BP measurements. Separate sequential multivariable linear regression models fit with generalized estimating equations (GEE) were used to separately assess associations between anxiety (independent variable) and each BP parameter (dependent variables), after adjusting for potential confounders (Model 1). Additional analyses were conducted adding insomnia and the interaction between anxiety and insomnia as independent variables (Model 2), and adding short sleep duration and the interaction between anxiety and short sleep duration as independent variables (Model 3), to evaluate any moderating effects on BP parameters.Among the 60 participants who completed the study, 15 (25%) screened positive for anxiety, 11 (18%) had subjective insomnia, and 34 (59%) had objective short sleep duration. In Model 1, increased anxiety was not associated with increases in any BP parameters. When subjective insomnia was included in Model 2, increased DBP and MAP was significantly associated with anxiety (DBP: β 6.1, p = 0.01, MAP: β 6.2 p < 0.01). When short sleep was included in Model 3, all BP parameters were significantly associated with anxiety (SBP: β 9.6, p = 0.01, DBP: β 8.1, p < 0.001, and MAP: β 8.8, p < 0.001). No moderating effects were detected between insomnia and anxiety (p interactions: SBP 0.80, DBP 0.60, MAP 0.32) or between short sleep duration and anxiety (p interactions: SBP 0.12, DBP 0.24, MAP 0.13) on BP.When including either subjective insomnia or objective short sleep duration, pregnant people with anxiety had 5.1-9.6 mmHg higher SBP, 6.1-8.1 mmHg higher DBP, and 6.2-8.8 mmHg higher MAP than people without anxiety.

View details for DOI 10.1186/s12884-024-06540-w

View details for PubMedID 38750438

View details for PubMedCentralID 2941423

Strategies for optimising early detection and obstetric first response management of postpartum haemorrhage at caesarean birth: a modified Delphi-based international expert consensus. BMJ open Pingray, V., Williams, C. R., Al-Beity, F. M., Abalos, E., Arulkumaran, S., Blumenfeld, A., Carvalho, B., Deneux-Tharaux, C., Downe, S., Dumont, A., Escobar, M. F., Evans, C., Fawcus, S., Galadanci, H. S., Hoang, D. T., Hofmeyr, G. J., Homer, C., Lewis, A. G., Liabsuetrakul, T., Lumbiganon, P., Main, E. K., Maua, J., Muriithi, F. G., Nabhan, A. F., Nunes, I., Ortega, V., Phan, T. N., Qureshi, Z. P., Sosa, C., Varallo, J., Weeks, A. D., Widmer, M., Oladapo, O. T., Gallos, I., Coomarasamy, A., Miller, S., Althabe, F. 2024; 14 (5): e079713

Abstract

There are no globally agreed on strategies on early detection and first response management of postpartum haemorrhage (PPH) during and after caesarean birth. Our study aimed to develop an international expert's consensus on evidence-based approaches for early detection and obstetric first response management of PPH intraoperatively and postoperatively in caesarean birth.Systematic review and three-stage modified Delphi expert consensus.International.Panel of 22 global experts in PPH with diverse backgrounds, and gender, professional and geographic balance.Agreement or disagreement on strategies for early detection and first response management of PPH at caesarean birth.Experts agreed that the same PPH definition should apply to both vaginal and caesarean birth. For the intraoperative phase, the experts agreed that early detection should be accomplished via quantitative blood loss measurement, complemented by monitoring the woman's haemodynamic status; and that first response should be triggered once the woman loses at least 500 mL of blood with continued bleeding or when she exhibits clinical signs of haemodynamic instability, whichever occurs first. For the first response, experts agreed on immediate administration of uterotonics and tranexamic acid, examination to determine aetiology and rapid initiation of cause-specific responses. In the postoperative phase, the experts agreed that caesarean birth-related PPH should be detected primarily via frequently monitoring the woman's haemodynamic status and clinical signs and symptoms of internal bleeding, supplemented by cumulative blood loss assessment performed quantitatively or by visual estimation. Postoperative first response was determined to require an individualised approach.These agreed on proposed approaches could help improve the detection of PPH in the intraoperative and postoperative phases of caesarean birth and the first response management of intraoperative PPH. Determining how best to implement these strategies is a critical next step.

View details for DOI 10.1136/bmjopen-2023-079713

View details for PubMedID 38719306