To compare the effects of vasopressin versus norepinephrine infusion on the outcome of kidney injury in septic shock. Post-hoc analysis of the multi-center double-blind randomized controlled trial of vasopressin versus norepinephrine in adult patients who had septic shock (VASST). Seven hundred seventy-eight patients were randomized to receive a blinded infusion of either low-dose vasopressin (0.01-0.03 U/min) or norepinephrine infusion (5-15 microg/min) in addition to open-label vasopressors and were included in the outcome analysis. All vasopressors were titrated and weaned to maintain a target blood pressure. RIFLE criteria for acute kidney injury were used to compare the effects of vasopressin versus norepinephrine. In view of multiple simultaneous comparisons, a p value of 0.01 was considered statistically significant. Kidney injury was present in 464 patients (59.6%) at study entry. In patients in the RIFLE "Risk" category (n = 106), vasopressin as compared with norepinephrine was associated with a trend to a lower rate of progression to renal "Failure" or "Loss" categories (20.8 vs. 39.6%, respectively, p = 0.03), and a lower rate of use of renal replacement therapy (17.0 vs. 37.7%, p = 0.02). Mortality rates in the "Risk" category patients treated with vasopressin compared to norepinephrine were 30.8 versus 54.7%, p = 0.01, but this did not reach significance in a multiple logistic regression analysis (OR = 0.33, 99% CI 0.10-1.09, p = 0.02). The interaction of treatment group and RIFLE category was significant in predicting mortality. Vasopressin may reduce progression to renal failure and mortality in patients at risk of kidney injury who have septic shock.
