Effect of routine preoperative fasting on residual gastric volume and acid in patients undergoing myomectomy

Abstract

Background: Preoperative fasting of patients aims to reduce the residual gastric volume (RGV). The magnitude of this reduction is yet to be ascertained in the Nigerian population.

Aim: To compare the RGV and pH of patients fasted for 6–12 h with those allowed oral intake of fluid up to 2 h preoperatively.

Subjects and Methods: This randomized study involved 90 American Society of Anesthesiologists physical status I–II patients booked for abdominal myomectomy under general anesthesia. The patients were randomized into three groups. Preoperative fasting from midnight (Group F, n = 30) was fasted from midnight to the operation time. Carbohydrate‑rich drink group (Group C, n = 30) received 800 mL of oral carbohydrate solution in the evening before surgery (22:00 h). An additional 400 mL was given 2 h before anesthesia. Placebo drink group (Group P, n = 30) received water in the same protocol as Group C. The Student’s t‑test was used to analyze RGV and pH postoperative satisfaction and postoperative nausea and vomiting (PONV) were compared on a visual analog scale.

Results: The RGV and pH were similar for all groups (P = 0.45 and 0.90, respectively). Antiemetic consumption and PONV scores were lower in Group C compared with Groups F and P (P = 0.01). Patients’ in Group C had higher satisfaction (P < 0.001).

Conclusion: Preoperative carbohydrate or water intake up to 2 h before surgery is safe with better satisfaction when compared to overnight fasting.

Keywords: Fasting, myomectomy, pH, residual gastric volume