Reversal of refractory hypotension in septic shock by inhibitor of nitric oxide synthase.

Septic shock is a life-threatening condition that results from exposure to bacterial endotoxin. It is mediated by the release of cytokines. Some of these cytokines cause the release of vasoactive substances. We report the case of a 62-year-old male patient who received redo operation for replacement of the degenerative porcine aortic and mitral prostheses. High cardiac output shock developed on the seventh postoperative day with severe metabolic acidosis and oliguria. Systemic vascular resistance and mean arterial pressure elevated within 5 min and stabilized 60 min after the start of a single dose of intravenous administration of NG-monomethyl-L-arginine (50 mg), a potent and selective inhibitor of nitric oxide synthesis. These findings indicate that nitric oxide overproduction is an important contributor to refractory hypotension in high cardiac output septic shock. Our findings suggested the utilization of nitric oxide synthase inhibitor in the treatment of septic shock in humans.