OBJECTIVE: To assess measurement of gastric electrical potential difference, pH of gastric mucosa, and endoscopic findings in patients in intensive care units who are at risk of developing stress ulcers.

DESIGN: Open comparison with age- and sex-matched control subjects.

SETTING: Herlev Hospital, Denmark.

SUBJECTS: Sixteen consecutive patients with no history of gastrointestinal haemorrhage, coagulopathy, or ulcer disease who had been admitted to the intensive care unit, and 16 age- and sex-matched outpatients with normal endoscopic findings.

INTERVENTIONS: Upper gastrointestinal endoscopy, during which any lesions that were found were scored according to severity, the gastric potential difference, and the pH of gastric juice were measured.

OUTCOME MEASURES: Correlation between the incidence of stress ulceration found at endoscopy, gastric potential difference, and gastric pH.

RESULTS: Gastric potential difference was significantly reduced and gastric pH significantly increased in the patients in the intensive care unit (p less than 0.05 in both cases), all of whom had stress ulcers in more than one gastric segment. Nine of the patients had gastric pH readings of greater than 4.

CONCLUSION: Gastric electrical potential difference may be useful measurement for the assessment of stress ulceration in patients in intensive care units.