Impact of Erythromycin and Metoclopramide on Gastric Emptying of Solids in Term Pregnant Women Scheduled for Elective Cesarean Delivery: A Randomized Controlled Trial.

Background: We hypothesized that the preoperative administration of oral erythromycin and metoclopramide would reduce the risk of high gastric volume and contents, evaluated by bedside gastric ultrasonography in non-laboring pregnant subjects preparing for elective cesarean delivery.

Methods: This randomized double-blinded study included 150 parturients undergoing elective cesarean delivery. They received flavored water with oral erythromycin 400 mg (group E), oral metoclopramide 10 mg (group M), or placebo (group C) after standard meal ingestion, followed by ultrasonography measurement of gastric volume before and hourly after drug administration. The primary outcome was the mean gastric volume after six hours of fasting. Secondary outcomes included measuring gastric contents hourly until a safe level and assessing aspiration risk.

Results: Significant differences in mean (±SD) gastric volume (mL/kg) were observed after six hours among groups C, E, and M, with values of 1.05 ± 0.49, 0.71 ± 0.46, and 0.75 ± 0.48, respectively (p <  0.001). Six hours after ingesting a standard meal, low-risk gastric contents were observed in 42 parturients (84%) in Group E, 41 parturients (82%) in Group M, and 31 parturients (62%) in Group C (p =  0.017). At both the fifth- and sixth-hours post-ingestion, parturients in Groups E and M demonstrated a significantly higher gastric emptying fraction compared to Group C. Additionally, parturients in Groups E and M exhibited the shortest half-time gastric emptying and gastric emptying time.

Conclusions: Premedication with oral erythromycin or metoclopramide before elective cesarean delivery accelerated gastric emptying and may reduce aspiration risk after a standard meal.