A randomized controlled study to compare the dose requirement of oxytocin for management of uterine atony in patients receiving prophylactic phenylephrine during caesarean delivery

Background & Aims: Most common side effect of subarachnoid block during caesarean delivery is postspinal hypotension which can lead to increased maternal and neonatal morbidity and mortality. Phenylephrine has been shown to be effective in preventing commonly encountered hypotension associated with spinal anesthesia (60% to 70%) in obstetric patients and has become the vasopressor of choice. The following study was conducted to compare the dose requirement of intravenous oxytocin between patients receiving an infusion of prophylactic intravenous phenylephrine to those receiving a saline control infusion under spinal anesthesia in patients undergoing caesarean delivery. Material & Methods: It was a double-blinded, randomized controlled study having 48 subjects in test and control arm each. Results: The mean oxytocin dose administered was higher in the phenylephrine group than in the control group (6.1 ± 2.7 (IU) vs. 5.2 ± 2.3 IU, respectively). The proportion of patients who required a secondary uterotonic agent was higher in the phenylephrine intervention group (22% vs. 8%, respectively). Conclusion: Obstetricians and anesthesiologists must pay close attention to uterine tone for patients receiving a phenylephrine infusion for the prevention of postspinal hypotension and the increased dose requirement of oxytocin. Future multicentric studies are required to further establish the effects of continuous infusion as found in our study.