The effects of injectable metoclopramine and ranitidine on the hydrogen ion concentration and volume of gastric aspirates in patients undergoing emergency.andelective caesaria

Abstract

This study was carried on 160 adult patients who were undergoing emergency or elective caesarian section. They were divided into 4 equal

groups of 40 patients each. All patients were classified as ASA 1 and ASA II

Group 1 did not receive any sedation. Group 11 received I.M. metoclopramide 10mg half an hour before surgery, group III were given I.M. ranitidine

50mg half an hour preoperatively and group IV received both I.M. ranitidine 50mg and I.M. metaclopramide 10mg half an hour before operation. All 160 patients were given I.V. Atropine 0.6mg during preoxygenation prior to induction.

After intubation and stabilization of the patients under standard procedures a nasogastric tu~e size 14 or 16 was passed orally into the stomach and all the gastric contents were removed. The volumes were noted and the pH determined both at induction and at reversal.

Results of the study showed that patients in group 1 (control) had a high mean gastric volume

37.5+ 3.89mls S.E.M. and a low mean pH

+ 3.19-012

S.E.M. with 55% of the patient having gastric

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aspirate volumes above 25mls and 57.5% of the patients having pH below 2.5.

A critical value of pH below 2.5 and a gastric volume of above 25mls has been determined to be the high risk factors in acid gastric aspiration syndrome. Patients receiving metoclopramide in group 11 did not show a significant change in pH values as compared ~o the control group but

definitely had reduced gastric aspirate volumes of + lO.23-1.59mls S.E.M. as compared to 37.5mIs in

group 1.

Ranitidine raised the pH above 2.5 in 97.5% of the patients in group III and also significantly

reduced the gastric volumes to +

s S.E.M.

9.08-1.20ml

The combination of ranitidine and metoclopramide did not show any particular superiority over ranitidine alone and the results between group III and IV were comparatively the same.

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Therefore injectable ranitidine with or without metoclopramide is effective in raising the pH above 2.5 in 97.5% of the patients and reducing gastric volumes below 25mls in 87.5% of the patients. None of the patients who received Ranitidine had a combination of pH below 2.5 and a gastric aspirate volume above 25mls in group III and IV.