Evaluation and revision of a vasopressin/nitroglycerin protocol for use in variceal bleeding

BACKGROUND: Continuous infusion of IV vasopressin have been widely used to lower portal pressure and reduce bleeding from esophageal varices. Recently, the combination of vasopressin and nitroglycerin has been noted to be superior to vasopressin alone. This is due to the ability of nitroglycerin to reduce the detrimental effects of vasopressin while preserving its beneficial effects. In September 1989 the authors initiated a protocol in the medical intensive care unit of a large university teaching center that directed caregivers in the simultaneous use of vasopressin and nitroglycerin for use in variceal bleeding. OBJECTIVE: To determine whether the protocol was being used correctly and whether the addition of nitroglycerin produced the desired cardiovascular effects. METHOD: Nineteen patients (25 separate episodes) assigned to the vasopressin/nitroglycerin protocol were monitored retrospectively over a 20-month period for a total of 1068 hours of vasopressin/nitroglycerin infusion. Twenty-four patients received nitroglycerin at 10 to 50 micrograms per minute, 13 at 50 to 100 micrograms per minute and 6 at 100 to 400 micrograms per minute. RESULTS: Nitroglycerin dosage was not advanced appropriately in 78% of episodes despite evidence of bradycardia, hypertension and peripheral vasoconstriction. CONCLUSIONS: Revision of the protocol, giving additional guidance to clinicians on assessment and nitroglycerin advancement, was necessary and was accomplished.