Clinical Focus

  • Anesthesia

Academic Appointments

Professional Education

  • Residency: Stanford University Anesthesiology Residency (2015) CA
  • Board Certification: American Board of Anesthesiology, Anesthesia (2016)
  • Internship: Santa Clara Valley Medical Center (2012) CA United States of America
  • Medical Education: Loma Linda University (2011) CA United States of America

Contact

  • Academic
    vyin@stanford.edu
    University - Academic staff Department: Anesthesia Position: Clinical Assistant Professor
  • Clinical (Primary)  Anesthesia Department 300 Pasteur Dr Rm H3580 MC 5640 Stanford, CA 94305 (650) 725-8544 (fax)

Additional Clinical Info

Additional Info

  • Mail Code: 5640

All Publications

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

    Abstract

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

    View details for DOI 10.1213/ANE.0000000000001658

    View details for PubMedID 28212181

    View details for PubMedCentralID PMC5319709