Mechanism and pharmacology of shock due to rattlesnake venom in sheep

Abstract

Acute hypotension produced by the intravenous injection of 20 μg/kg of rattlesnake (Crotalus atrox) venom in sheep was spontaneously restored within frac12—2 hr (crotalin collapse). Slow continuous intravenous infusion of larger doses of crotalin produced a fall in cardiac output and systemic arterial pressure, hemoconcentration, and hypoventilation. This condition could only be reversed by therapeutic intervention and was termed “crotalin shock.” Administration of antivenin in crotalin shock proved to be ineffective. Intravenous dextran infusion restored cardiac output and accentuated respiratory depression. Administration of steroids in conventional therapeutic doses resulted in a rise in systemic arterial pressure and alveolar ventilation with little change in blood flow. Simultaneous administration of dextran and corticosteroids gave better results than either material used alone. Continuous intravenous infusion of isoproterenol improved alveolar ventilation and restored spontaneous breathing in some cases of crotalin-induced respiratory arrest. dextran; ventilation; steroids; antivenin; isoproterenol; respiratory failure; hemoconcentration Submitted on September 29, 1964