Fasting volume and acidity of stomach contents associated with gastrointestinal symptoms.

Acid aspiration in an important cause of anaesthetic mortality. 430 patients referred for gastric analysis were reviewed. According to observations made at endoscopy, patients were divided into 4 groups--no abnormality, oesophagitis/gastritis, gastric ulcers and duodenal ulcers. The volume of gastric juice varied from 0 to 400 ml, and the pH from 0-8 to 8. The percentage of patients with overnight fasting gastric volume over 25 ml and a pH of less than 2-5 was disturbingly high in all groups: controls 38-5%, oesophagitis/gastritis 51-2%, gastric ulcers 40-0%, duodenal ulcers 73-3%. This last figure is significantly greater than the group with no detectable abnormality. These results indicated that the stomach of a fasting patient often contains sufficient volume of acid gastric juice to place the subject at risk from acid aspiration during anaesthesia. Antacid therapy in all these patients seems imperative and consideration should also be given to preoperative gastric aspiration before induction of general anaesthesia.