Effect of glycopyrrolate on vasopressor requirements for non-elective cesarean section under spinal anesthesia: a randomized, double-blind, placebo-controlled trial

BACKGROUND: The study aimed to investigate whether prophylactic use of glycopyrrolate decreases the vasopressor requirements to prevent hypotension following spinal anesthesia during non-elective cesarean section. METHOD: In this double-blind randomized clinical trial, 258 patients undergoing non-elective cesarean section were randomly assigned (1:1) to receive intravenous 0.2 mg glycopyrrolate or normal saline (placebo) before spinal anesthesia. The primary outcome was phenylephrine equivalent needed intraoperatively. Secondary outcomes included incidences of maternal hypotension, reactive hypertension, bradycardia, need for atropine, tachycardia, intraoperative nausea/vomiting, shivering, pruritus, dry mouth, dizziness; neonatal APGAR score at 1 min and 5 min, neonatal resuscitation needed, NICU admission and neonatal death. RESULTS: Three patients withdrew from the study due to failed spinal anesthesia. 128 patients in the glycopyrrolate group and 127 patients in the placebo group were analyzed. The mean phenylephrine equivalent needed was 1108.96 μg in the glycopyrrolate group and 1103.64 μg in the placebo group (mean difference, 5.32 μg [95% CI − 67.97 to 78.62]; P = 0.88). Hypotension occurred in 38 patients (30%) in the glycopyrrolate group as compared with 49 patients (39%) in the placebo group (P = 0.13). Tachycardia was reported in 70% of the participants in the glycopyrrolate group and 57% of those in the placebo group (P = 0.04). No statistically significant difference was noted in hypotensive episodes > 1, reactive hypertension, bradycardia, need for atropine, nausea, vomiting, shivering, and dry mouth between the two groups. Neonatal outcomes were similar in the two groups. CONCLUSION: Prophylactic use of glycopyrrolate does not decrease the requirements of vasopressor to prevent hypotension in non-elective cesarean section under spinal anesthesia. TRIAL REGISTRATION: Registration number: NCT04401345. Date of registration: 26/05/2020. Website: https://clinicaltrials.gov