Oxytocin And Uterotonic Agent Use For Cesarean Delivery

The central objective of this study will be to evaluate a standardized, evidence-based regimen versus a conventional regimen for uterotonic drug dosing during cesarean delivery

The investigators primary hypothesis is that the proposed uterotonic drug regimen, when compared to conventional dosing regimen, during cesarean delivery will:

1. Reduce the overall amount of oxytocin and other uterotonic agents used to obtain satisfactory uterine tone.

Secondary outcomes to be evaluated will be:

1. Reduce the side effects associated with uterotonic drug use
2. Reduce the time to establishment and maintenance of adequate uterine tone

The current guidelines for the administration of oxytocin during cesarean delivery are diverse, empiric, and vague. A stepwise, standardized, checklist driven algorithm for the use of oxytocin and other uterotonic agents during cesarean delivery is needed to guide practitioners in a clear and concise manner. This algorithm should encompass laboring and non-laboring women, as well as prophylactic and therapeutic uses of oxytocin and other uterotonic agents.

More specifically, the investigators believe that the following points should be incorporated into a protocol: 1) oxytocin should be used in initial doses of less than 5 IU; 2) oxytocin should not be administered as a rapid IV bolus; 3) an initial rapid infusion of oxytocin should be followed by a maintenance infusion; 4) higher initial and infusion doses of oxytocin offer no clinical benefit and should be avoided; and 5) if it appears that oxytocin is not producing effective uterine contractions, other uterotonic drugs acting via different pathways should be considered in a standardized way.

• Uterine Atony
• Hypotension

• Drug: Oxytocin
  500 mL bag of oxytocin (30 IU/500 mL) to be connected to the IV, and controlled per obstetrician request.
  Other Names:

  • methylergonovine maleate (methergine) 0.2 mg IM
  • carboprost tromethamine (hemabate) 0.25 mg IM
  • misprostol 600 mcg buccally
• Drug: Oxytocin
  3 IU oxytocin and be given IV at time of baby delivery (Time 0). Up to two additional syringes can be given at 3 and 6 mins until uterine tone adequate (as per obstetrician on graded scale).
  Other Names:

  • methylergonovine maleate (methergine) 0.2 mg IM
  • carboprost tromethamine (hemabate) 0.25 mg IM
  • misprostol 600 mcg buccally

• Active Comparator: Standard Care Group

  "Standard Care Group" (reflects current clinical regimen at BWH) will receive a 500 mL bag of oxytocin (30 IU/500 mL) to be connected to the IV, and controlled per obstetrician request. The obstetrician and anesthesiologist will be asked to consider this infusion "oxytocin". If inadequate uterine tone exists in which the obstetrician desires alternative uterotonic agents, these will be provided on their request (e.g. methylergonovine maleate (methergine) 0.2 mg IM or carboprost tromethamine (hemabate) 0.25 mg IM. The time of the requests will be recorded.

  If uterine tone remains inadequate at 15 min, misoprostol 600 mcg will be given buccally.

  Intervention: Drug: Oxytocin
• Active Comparator: Protocol Group

  "Protocol Group" will receive 3 mL syringes marked "study solution-oxytocin" which contain 3 IU oxytocin and be given IV at time of baby delivery (Time 0). Up to two additional syringes can be given at 3 and 6 mins until uterine tone adequate (as per obstetrician on graded scale).

  If inadequate uterine tone is noted at 9 min, the 1 mL syringe marked marked "study solution-9 min", containing methylergonovine maleate (methergine) 0.2mg, will be given IM.

  If inadequate uterine tone is noted at 12 min, the 1 mL syringe marked marked "study solution-12 min", containing carboprost tromethamine (hemabate) 0.25 mg, will be given IM.

  If uterine tone remains inadequate at 15 min, misoprostol 600 mcg will be given buccally.

  Intervention: Drug: Oxytocin

Inclusion Criteria:

• American Society of Anesthesiologists (ASA) I or II health status
• Age between 18 and 50 yrs
• Singleton pregnancies in vertex position
• Elective (with or without prior labor) cesarean delivery with a planned lower uterine (pfannenstiel) incision

Exclusion Criteria:

• Conditions that predispose to uterine atony and postpartum hemorrhage