Arginine vasopressin in the treatment of 50 patients with postcardiotomy vasodilatory shock

Background. The barroreflex-mediated secretion of arginine vasopressin has been found to be defective in a variety of vasodilatory shock states, such as postcardiotomy shock, and administration of the hormone markedly improves vasomotor tone and blood pressure. The high incidence of vasodilatory shock in patients undergoing left ventricular assist device (LVAD) implantation makes this population an ideal model in which to assess the risks and benefits of vasopressin. Methods. The medical records of the 102 patients receiving LVADs at Columbia-Presbyterian Medical Center from January 1995 to August 1998 were reviewed. Fifty patients were eligible for study based on a history of arginine vasopressin administration in the operating room or intensive care unit within 24 hours of implantation. Results. Despite LVAD implantation and the administration of vasopressors, patients were hypotensive with a mean arterial pressure less than 60 mm Hg. The administration of vasopressin (0.09 ± 0.05 U/min) increased mean arterial pressure (58 ± 13 to 75 ± 14 mm Hg; p< 0.001) while reducing norepinephrine administration (11.7 ± 13 to 7.9 ± 6.0 mcg/min; p = 0.023). There was no significant change in LVAD flow. The incidence of compromised regional perfusion was not different between LVAD patients who received vasopressin as compared to hemodynamically stable LVAD patients who did not receive vasopressin. Conclusions. We have demonstrated vasopressin at low doses to be a safe and an effective vasopressor in 50 patients with postcardiotomy vasodilatory shock.