[Pharmacologic prevention of Mendelson syndrome. A controlled clinical trial].

This controlled study considers the effect of ranitidine, both alone and in association with metoclopramide, on the acidity and volume of the gastric content of 75 patients requiring caesarean section. Ranitidine, when used alone (50 mg intravenously 30-60 minutes before the operation) significantly reduced (p less than 0.01) the acidity (pH greater than 2.5) and the volume (less than 25 ml) of the gastric content of the patient thus treated. Ranitidine in association with metoclopramide may also reduce the pH and the volume, but did not show any significant statistical differences when compared with the use of ranitidine alone.