INTRAVENOUS RANITIDINE REDUCES THE RISK OF ACID ASPIRATION OF GASTRICCONTENTS AT EMERGENCY CESAREAN-SECTION

This study documented gastric pH and volume and the number of patients at risk of acid aspiration of gastric contents in a group of mothers undergoing emergency cesarean section under general anesthesia. Patien ts were randomized in a double-blind fashion to receive ranitidine, 50 mg intravenously, or placebo at the time of decision to proceed to ce sarean section. In addition, all patients received 30 mL of 0.3 M sodi um citrate on entry into the operating room. Aspiration of gastric con tents was undertaken immediately after endotracheal intubation (PI) an d before tracheal extubation. Patients with both pH < 3.5 and volume > 25 mL were deemed to be at risk of acid aspiration should regurgitati on occur. Postintubation, 12 patients (4%) were at risk in the citrate -alone group and 7 patients (2.3%) were at risk in the ranitidine/citr ate group (not significant). Preextubation, 17 patients (5.6%) were at risk in the citrate-alone group and 1 patient (0.3%) was at risk in t he ranitidine/citrate group (P < 0.05). PI pH in patients receiving ra nitidine/citrate (mean 5.2, SD 0.8) was significantly higher than in p atients receiving citrate alone (mean 4.9, SD 1.1). None of the patien ts who received ranitidine more than 30 min before the PI sample were at risk compared to 6 (3.2%) in the citrate alone group (P = 0.05). We conclude that 50 mg of intravenous ranitidine given at the time of de cision to proceed to cesarean section reduces the risk of acid aspirat ion provided that at least 30 min have elapsed from injection to induc tion of anesthesia.