Bolus administration of oxytocin is superior to infusion in time to achieving adequate uterine tone.

Oxytocin is the most commonly used uterotonic agent worldwide to achieve adequate uterine tone and prevent postpartum hemorrhage. Over the past decade, the trend has been towards lowering the dose to reduce oxytocin-related adverse effects including nausea, hypotension, chest pain, EKG changes, and maternal death. However, the optimal strategy for oxytocin administration remains controversial. Prior literature found bolus doses less than 5 IU to be effective in achieving adequate uterine tone with a significant reduction in adverse side effects. There is limited high quality data comparing bolus versus infusion administration of oxytocin. The current standard of care at the institution is an infusion of oxytocin 18 IU/hour (0.3 IU/min) and has been proven to be effective in achieving adequate uterine tone. However, the time to uterine tone appears to be slightly longer (3-4 mins) with the infusion method. Given that the estimated uterine blood flow is between 500-700 mls/min, the uterus can lose a significant amount of blood per second if uterine tone is not achieved quickly. Thus, the purpose of this research study is to compare bolus and infusion administration of oxytocin on parturients undergoing elective cesarean section. The primary objective of this study is to test the hypothesis that administration by bolus (vs. standard of care infusion) results in more rapid achievement of adequate uterine tone. Secondary objectives include determining estimated blood loss, prevalence of hypotension, nausea, vomiting, and patient satisfaction.

Inclusion Criteria:

• Parturients between the ages of 18 to 45 with singleton pregnancies
• Undergoing elective cesarean section under spinal anesthesia
• American Society of Anesthesia (ASA) physical status class I or II
• Patients must be able to provide written informed consent

Exclusion Criteria:

• Parturients in labor or ruptured membranes
• Multiple gestation
• Risk factors predisposing to uterine atony (history of placenta previa, preeclampsia, diabetes mellitus macrosomia, hydramnios, bleeding diathesis, uterine fibroids)
• History of uterine atony or postpartum hemorrhage
• History of inherited or acquired coagulation disorders, thrombocytopenia (platelet count <100), or anemia (hemoglobin < 8)
• History of allergy to oxytocin
• Patients not alert and orientated to person, place, and date. Patient must have, in the investigator's opinion, the physical and mental capacity to answer survey questions

Pregnant women

Data will not be shared