A comparative evaluation of cimetidine and sodium citrate to decrease gastric acidity: effectiveness at the time of induction of anaesthesia.

Patients coming for elective surgery were randomly assigned to one of three treatment groups: control, cimetidine 300 mg orally two hours pre-operatively, or sodium citrate 0.3 M solution 30 ml orally, given as the patient was leaving the ward for the operating room. Each group consisted of 15 patients. This study reconfirms the average 26 per cent risk of significant aspiration in patients, coming for elective surgery, who have not received an agent intended to decrease gastric acidity or to decrease volume of gastric content. Sodium citrate is effective most of the time (87 per cent) in decreasing gastric acidity but is associated with a large mean volume (40.8 ml) of aspirate. From the results of this study cimetidine appears to be the preferable agent to use because it is completely effective in decreasing gastric acidity but does not increase the mean volume (17.0 ml) of the aspirate. Cimetidine appears to be an excellent agent to use as a preventative measure against aspiration during the induction of anaesthesia. Sodium citrate is a reasonable alternative if there is a contraindication to the use of cimetidine. However, these agents should be regarded only as adjuncts in the prevention of aspiration of gastric contents at the time of induction of anaesthesia.