The effects of vasopressin on hemodynamics and renal function in severe septic shock: a case series

Objective: To review all cases of septic shock treated with vasopressin to determine the effects on hemodynamic and renal function and to document any adverse effects. Setting: A 14-bed mixed medical-surgical ICU of St. Paul's Hospital, a 450-bed tertiary referral hospital affiliated with the University of British Columbia. Patients: All ICU patients who received vasopressin for treatment of severe septic shock between August 5, 1997, and March 21, 1999. Results: We identified 50 patients: age 60 (+/- 14); APACHE II score 27 (+/- 7). Baseline data (T0) was compared to data at T4, T24 and T48 (4, 24 and 48 h) on infusion. Mean arterial pressure (MAP) increased by 18 % from T0 to T4 and remained stable at T24 (p = 0.006) and T48 (p = 0.008). Systolic pulmonary artery pressure (PAP) was unchanged at 45 13 mmHg. Mean cardiac index (CI) decreased by 11 % at T4 (p = 0.03). Urine output increased 79 % at T4 (p = 0.005) and further increases were not significant at T24 and T48. Mean pressor dosage decreased by 33 % at T4 (p = 0.001), by 53 % at T24 (p = 0.002) and by 48 % at T48 (p = 0.01). Hospital mortality was 85 %. There were six cardiac arrests; all but one occurred at a vasopressin dose of 0.05 U/min or more. Conclusions: In this group of patients with severe septic shock, vasopressin infusion increased MAP and urine output and decreased catecholamine requirements. Doses higher than 0.04 U/min were not associated with increased effectiveness and may have been associated with higher adverse effects.