Effect of glucagon on the diagnostic accuracy of double-contrast barium enema examinations.

The effect of glucagon-induced hypotonicity on the diagnostic accuracy of double-contrast barium enema examinations was determined in 133 consecutive patients in a double-blind crossover study. All patients underwent colonoscopy and served as their own controls by undergoing a double-contrast study after intravenous injection of 1 mg of glucagon and another after intravenous injection of 1 ml of saline placebo, in randomized order. The frequencies of good/excellent hypotonicity and quality of examinations after first doses of glucagon (55.3% and 80.8%) were not significantly different from the frequencies of good/excellent results after first doses of saline (51.3% and 86.5%). The sensitivity was 72.6% after glucagon and 64.5% after placebo; the specificity was 88.7% after glucagon and 77.9% after placebo; and the respective accuracies were 81.2% and 71.9%. These percentages should be used only to compare results with and without glucagon and, by study design, do not represent results of a complete double-contrast study. The variation among these percentages was not statistically significant, but diverticulitis was more accurately diagnosed after glucagon. It was concluded that glucagon does not significantly improve the sensitivity and specificity of the double-contrast barium enema examination and should be used only in selected instances.