Gastric fluid volume and acidity 2 h after intake of clear fluids in patients undergoing upper GI, lower GI, and non-GI surgery

Abstract

Summary Background In recent years, liberal preoperative fasting has been widely practiced. However, the safety of applying liberal preoperative fasting to patients suffering from gastrointestinal diseases is unclear. We therefore compared the gastric volume and pH of patients who underwent upper and lower gastrointestinal surgery and non-gastrointestinal surgery. Methods Patients scheduled for surgery at 08:45 on a given day were forbidden solid foods from 21:00 hours the day before surgery and allowed to drink only clear fluids (e.g. water, green tea, sports drinks, and clear juices) freely until 07:00 hours on the day of the surgery. After induction of anesthesia, gastric juice was obtained by inserting a 14 French gastric tube into the stomach to ascertain gastric volume and pH. In the present study, the patients were divided into three groups according to type of surgery: non-gastrointestinal (Group N), upper gastrointestinal (Group U), and lower gastrointestinal (Group L) surgery. The gastric volume and pH of the three groups were then compared. Results Gastric fluid volume of the patients in Groups N, U, and L was 8 (0, 20) ml, 4 (0, 12) ml and 13 (0, 20) ml, respectively. Patients in Group L had significantly greater gastric volume compared with those in Groups N ( p = 0.0156) and U ( p = 0.0003). The gastric pH in Groups N, U, and L was 1.6 (1.3, 3.7), 3 (1.6, 5.65) and 1.9 (1.4, 5.6), respectively. Gastric pH was significantly higher in Group U than in Group N ( p = 0.0061). Conclusion Although gastric volume and pH differed among patients who underwent upper, lower, and non-gastrointestinal surgery after liberal preoperative fasting, the values remained within the safety parameters (UMI10802).