[Utility of premedication with different regimens of omeprazole and ranitidine in the prevention of acid broncho-aspiration syndrome].

OBJECTIVE

To study the usefulness of several omeprazole regimens on gastric fluid volume and pH in patients undergoing elective surgery.

MATERIAL AND METHODS

We analyzed 105 patients undergoing to elective surgery who received prophylactic treatment for the acid aspiration syndrome. They were randomly allocated into 7 homogeneous groups according to the therapeutic regime. Placebo (group 1), oral omeprazole (20 mg) the night prior to surgery (group 2), oral ranitidine (150 mg) the night before (group 6), two doses (the previous night and before surgery) in the remaining three groups: 20 mg of omeprazole (group 4), 40 mg of omeprazole (group 5) or 150 mg of ranitidine (group 7). In all patients we measured pH and volume of the gastric content after induction of anesthesia and one hour thereafter.

RESULTS

There were no statistically significant differences in mean pH values and gastric volume content among groups 1.2,3, and 6 (2.1 (pH) and 27 ml (gastric volume) in group 1, 2.1 and 23 ml in group 2, 2.6 and 19 ml in group 3, and 2.2 and 32 ml in group 6). With repeated doses of 40 mg omeprazol (group 5), mean pH values were comparable to those found with the two doses of ranitidine (4.1 +/- 1.8 vs 4.1 +/- 3.6) although gastric volumes were significantly less (12 +/- 2.6 ml vs 20 +/- 4.8 ml). These two groups showed significantly greater mean pH values and less gastric volumes than the remaining patients.

CONCLUSIONS

The incidence of patients with gastric content deemed at risk for acid aspiration (pH less than 2.5 and gastric volume greater than 25 ml) was less after premedication with two oral doses of omeprazole (40 mg) than either two doses of ranitidine (150 mg) or smaller doses of both drugs.