Hemodynamic response to naloxone during live Escherichia coli sepsis in splenectomized dogs.

This study was designed to investigate the concept that endogenous opioids are involved in the pathogenesis of septic shock. Infusion of live Escherichia coli (1.0-1.6 X 10(10) organisms/kg) in splenectomized dogs induced profound hypotension (p less than 0.001), peripheral vasodilatation (p less than 0.001), and metabolic acidosis (p less than 0.05) with maintenance of cardiac index as compared to control splenectomized dogs. Treatment with naloxone (3 mg/kg bolus and 2 mg/kg/hr infusion for 2.5 hours), a specific opiate antagonist, during septic shock attenuated the hypotension (p less than 0.002) and systemic acidosis (p less than 0.02) without altering cardiac index or total peripheral resistance. These experimental results indicate that naloxone may be of therapeutic value in the management of the early vasodilatory stage of septicemia.