Objective: To compare the effects of vasopressin versus norepinephrine infusion on the outcome of kidney injury in septic shock.
Design and setting: Post-hoc analysis of the multi-center double-blind randomized controlled trial of vasopressin versus norepinephrine in adult patients who had septic shock (VASST).
Patients and intervention: 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.
Measurement and results: 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.
Conclusions: Vasopressin may reduce progression to renal failure and mortality in patients at risk of kidney injury who have septic shock.