ACID ASPIRATION PROPHYLAXIS IN ELECTIVE BILIARY SURGERY - A COMPARISON OF OMEPRAZOLE AND FAMOTIDINE USING MANUALLY AIDED GASTRIC ASPIRATION

We have compared the effects of single oral doses of omeprazole 40 mg, famotidine 40 mg or placebo on gastric secretion in 45 non-obese pati ents the night before elective biliary surgery. After stable anaesthes ia had been established, a Salem orogastric tube was introduced and ga stric contents were aspirated by a blinded observer. The volume and pH were noted. After the abdomen was opened aspiration was repeated but on this occasion with the surgeon's manual assistance. We found that t he initial aspirate volume underestimated total gastric volume by an a ver age (SD) of 7.1 (6.6) ml. Famotidine, but not omeprazole, produced a significant decrease in gastric volume and acidity. Patients were c onsidered to be at risk if pH < 2.5 and volume > 0.4 ml.kg(-1) Three p atients in the omeprazole group, three in the placebo group and none i n the famotidine group came into this category. We conclude that a sin gle oral dose of omeprazole 40 mg given the night before surgery does not afford adequate prophylaxis for acid aspiration syndrome.