Effects of Continuous Vasopressin Infusion in Patients with

Despite improvements in the treatment of septic shock,the incidence of mortality remains 28–50%.1,2 Current hemodynamic support includes treatment with fluids, in-otropic agents such as dobutamine and milrinone, and cate-cholamine vasopressors such as norepinephrine, epineph-rine, dopamine, and phenylephrine.3,4 These agents improve blood pressure but may cause adverse effects related to re-duced blood flow to vital organs in patients already suscepti-ble to organ failure due to sepsis.5,6 In addition, α-adrenergic receptor down-regulation often necessitates higher dosage regimens of catecholamine vasopressors. Septic shock is associated with inappropriately normal or low vasopressin serum concentrations,7,8 which may contribute to the development of cardiovascular failure. Vasopressin increases systemic vascular resistance (SVR) and blood pressure by binding to V1 receptors on the vas-cular smooth muscle cells to cause vasoconstriction.9 This process occurs independently of adrenergic stimulation, which suggests that vasopressin may act synergistically with catecholamine vasopressors. In addition, vasopressin may increase glomerular filtration and urine output.10 Small, prospective cohort trials, retrospective case series, and ran-domized clinical trials involving patients with septic shoc