Idiosyncracies of the Hollander test in the obese patient

The Hollander test of gastric secretion in response to acute hypoglycemia is a time-honored method of evaluating vagal integrity. In the course of performing gastric bypass procedures in 19 morbidity obese patients who were twice their weight for height, Hollander tests were included in the preoperative evaluation. Infusion of a standard dose of 20 units of regular insulin failed to produce a hypoglycemia of 35 mg/dl in 13 patients (68%). There was a positive response to hypoglycemia of even a moderate degree in gastric secretory volume, pH, and total acid output at 75 minutes postinsulin injection in all patients. They lagged well behind the peak of relative hypoglycemia which occurred at 30 minutes postinsulin injection. If the Hollander test is to be used in the evaluation of gastric secretion in obese patients weighing more than 100 kg, it is recommended that the insulin dosage be adjusted to body weight at 0.2 units (RI) per kilogram body weight. In addition, collections of gastric and serum specimens must be continued for a full 2 hours postinsulin injection in order to insure recognition of vagal response.