Gastric pH monitoring as a prognostic indicator for the prophylaxis of stress ulceration in the critically III.

Previous studies have documented the efficacy of prophylaxis in the prevention of stress ulceration and bleeding in critically ill patients. In an effort to determine whether all critically ill patients require prophylaxis, 144 patients admitted to an intensive care unit were monitored by continuous indwelling nasogastric or gastrostomy tubes. Any patient with a measured gastric pH of less than 4 was treated with prophylactic cimetidine or antacids to maintain a pH of 4 or greater. One hundred twenty-three (85 percent) met this criterion. The gastric pH of 21 patients (15 percent) never fell below 4 during continuous monitoring for 26+/- 4.2 hours. There was a significantly lower incidence of hypotension and respiratory failure in this group ( pl < 0.05). Mortality was higher in the patients who required prophylaxis (15 percent) than in those who did not (0 percent). No bleeding was encountered in any patient in either group. These data suggest that patients who do not require prophylaxis may be determined by continuous monitoring of intragastric pH. If, within 24 hours, intragastric pH does not fall below 4, minimal indications for prophylaxis exist. Intragastric pH monitoring is a simple, effective tool in the care and management of critically ill or traumatized patients.