PREVENTION OF MATERNAL HYPOTENSION FOLLOWING SPINAL ANESTHESIA IN EMERGENCY C- SECTIONS; PROPHYLACTIC PHENYLEPHRINE INFUSION VERSUS COLLOID COLOAD – A RANDOMIZED CONTROL TRIAL.

Abstract

Background: Spinal anesthesia is the preferred anesthetic technique for cesarean sections, but maternal hypotension remains a common complication, with incidence rates reaching up to 100% in the absence of preventive measures. Crystalloids, colloids, and vasopressors have all been employed to address this issue, with varying degrees of effectiveness. While vasopressors—particularly phenylephrine—demonstrate superior efficacy, their prophylactic use remains inconsistent across clinical settings due to a lack of consensus on optimal dosing strategies.

Objective: To compare the effectiveness of prophylactic phenylephrine infusion versus colloid infusion in preventing post-spinal maternal hypotension during emergency cesarean sections.

Methods: A prospective, randomized controlled trial was conducted at the emergency operation theater of Benazir Bhutto Hospital. Sixty ASA I–II patients undergoing cesarean section under spinal anesthesia were enrolled and randomized into two groups. Group A (n=30) received colloid infusion with 10 mL/kg of gelofusine over the first 10–15 minutes post-anesthesia. Group B (n=30) received a prophylactic phenylephrine infusion at 1.2–1.5 mcg/kg/min, titrated to maintain hemodynamic stability. Hypotension was defined as a >20% decrease in baseline mean arterial blood pressure (MABP), and bradycardia as heart rate <60 bpm.

Results: Hypotensive episodes occurred in 46.7% of patients in Group A (14/30), compared to only 3.33% in Group B (1/30), with a statistically significant difference (P = 0.0001; 95% CI = 20.35 to 62.6; Chi-Square = 14.776). All hypotensive episodes occurred within the first 10 minutes after spinal anesthesia. Bradycardia was observed in one patient in each group (3.33%).

Conclusion: Prophylactic phenylephrine infusion is significantly more effective than colloid infusion in preventing maternal hypotension following spinal anesthesia, with fewer rescue interventions required and better hemodynamic stability.