Cardiopulmonary effects of low-dose arginine vasopressin in ovine acute lung injury.

Westphal M, Rehberg S, Maybauer MO, Maybauer DM, Enkhbaatar P, Westphal-Varghese BB, Schmalstieg FC, Morita N, Cox RA, Traber LD, Hawkins H, Whorton E, Traber DL

Abstract

To elucidate the effects of low-dose arginine vasopressin on cardiopulmonary functions and nitrosative stress using an established model of acute lung injury.Prospective, randomized, controlled laboratory experiment.Investigational intensive care unit.Eighteen chronically instrumented sheep.Sheep were randomly assigned to a sham group without injury or treatment, an injury group without treatment (40% total body surface area third-degree burn and 48 breaths of cold cotton smoke), or an injured group treated with arginine vasopressin (0.02 IU·min?¹) from 1 hr after injury until the end of the 24-hr study period (each n = 6). All sheep were mechanically ventilated and fluid resuscitated using an established protocol.There were no differences among groups at baseline. The injury was characterized by a severe deterioration of cardiopulmonary function (left ventricular stroke work indexes and Pao2/Fio2 ratio; p < .01 each vs. sham). Compared with controls, arginine vasopressin infusion improved myocardial function, as suggested by higher stroke volume indexes and left ventricular stroke work indexes (18-24 hrs and 6-24 hrs, respectively; p < .01 each), pulmonary edema (bloodless wet-to-dry-weight ratio; p = .018), bronchial obstruction (p = .01), and pulmonary shunt fraction (12-24 hrs; p < .001) and myocardial 3-nitrotyrosine content with stroke volume indexes (r = -.701; p = .004).Low-dose arginine vasopressin reduced nitrosative stress and improved cardiopulmonary functions in sheep with acute lung injury secondary to combined burn and smoke inhalation injury.