Mean arterial pressure and mean perfusion pressure deficit in septic acute kidney injury

Background: Changes in mean perfusion pressure (MPP) from premorbid resting values may contribute to the progression of septic acute kidney injury (AKI). Objectives: In patients with septic shock, we aimed to investigate the association of changes from premorbid values with AKI severity and progression. Methods: We obtained premorbid resting mean arterial pressure (MAP), central venous pressure (CVP), and MPP, and then recorded data from intensive care unit admission 2 hourly for the first 24 hours to calculate hemodynamic deficits. We recorded 4-hourly creatinine measurements for 96 hours. The association of hemodynamic variables with progression of AKI by Kidney Disease: Improving Global Outcomes >= 2 stages was explored by multivariate logistic regression. Results: Of 107 patients, 55 (51.4%) had severe AKI. Median MAP deficit was similar for patients with or without severe AKI. Median MPP deficit was 29% in patients with severe AKI and 24% in those without (P = .04), a difference determined by greater CVP levels. Central venous pressure was independently associated with worsening AKI (odds ratio, 1.26 [95% confidence interval, 1.01-1.58]; P = .04). Conclusions: Mean arterial pressure and MPP deficits were substantial in septic shock patients, with patients with severe AKI having a greater MPP deficit. However, only CVP was independently associated with AKI progression. These findings suggest a possible role for venous congestion in septic AKI. (C) 2015 Elsevier Inc. All rights reserved.