Pre-operative neutralization of gastric acidity.

The incidence of Mendelson's syndrome in the four major Auckland hospitals is reviewed. The frequency of this condition was reduced following the pre-operative administration of magnesium trisilicate mixture in two hospitals. A trial was conducted in a third hospital and this showed that a 52 per cent incidence of highly acid gastric juice (pH less than 2.5) in patients prepared for elective surgery was reduced by administration of magnesium trisilicate mixture at the time of premedication. When the magnesium trisilicate mixture was given within the 30 minutes prior to induction of anaesthesia, the number of patients with highly acid gastric content fell to one per cent.