Aspiration of acid into the lungs is a known complication of general anesthesia. Routine practice often involves the use of pharmacological agents to limit gastric volume and increase gastric pH.

A meta-analysis was conducted that included randomized trials that comparing the effect of any PPI with any H2 receptor antagonist on gastric volume and acidity of gastric fluid.

Researchers searched electronic databases for trials that compared ranitidine with proton pump inhibitors. Nine trials were identified, of which seven were found to be suitable for the meta-analysis.

Pooled outcomes indicated that premedication with ranitidine was more effective than PPIs in reducing the volume of gastric secretions, by an average of 0.22 ml/kg. Additionally, ranitidine was more effective for enhancing gastric pH, by an average of 0.85 pH units.

Ranitidine treatment is associated with better outcomes in terms of gastric fluid volume and pH, compared to PPIs.

Source: Clark K, Lam LT, Gibson S, Currow D. The effect of ranitidine versus proton pump inhibitors on gastric secretions: a meta-analysis of randomised control trials. Anaesthesia 2009;64:652–657.