24-hour intragastric pH: continuous monitoring or nasogastric aspiration?

Hourly gastric aspiration has commonly been used to assess the efficacy of antisecretory compounds. We have compared continuous ambulatory 24-hour pH monitoring using a radiotelemetry capsule with standard nasogastric aspiration. Eight studies were performed on four male duodenal ulcer patients in remission receiving either placebo or an antisecretory agent. A significant correlation was found between capsule and aspirate pH measurements (r = 0.88, p less than 0.01). Radiotelemetry capsule measurements clearly showed the onset of action of an antisecretory drug, and the buffering effect of food. Radiotelemetric pH monitoring is shown to be as good as gastric sampling in the measurement of 24-hour intragastric acidity, allows continuous measurement of pH during normal activity and can accurately assess the effect of drugs on gastric acidity.