Elevated mean arterial pressure is associated with a lower risk of mortality in acute kidney injury patients receiving continuous renal replacement therapy

OBJECTIVE: maintenance of an appropriate mean arterial pressure (MAP) is important for critically ill patients. However, the association between MAP and prognosis in acute kidney injury (AKI) patients receiving continuous renal replacement therapy (CRRT) is thus far unclear. MATERIALS AND METHODS: a total of 1,144 AKI patients who had received CRRT between January 2009 and September 2016 were enrolled and their MAP was measured at CRRT initiation. Patients were categorized into four groups (Quartile 1: MAP < 67.3 mmHg; Quartile 2: 67.3 ≤ MAP < 76.7 mmHg; Quartile 3: 76.7 ≤ MAP < 86.3 mmHg; Quartile 4: MAP ≥ 86.3 mmHg), and 28- and 90-day mortality rates were compared. RESULTS: our results demonstrate that 204 (72.1%), 187 (63.4%), 174 (62.6%), and 145 (50.3%) deaths occurred in quartiles 1, 2, 3, and 4 within 28 days, respectively (p < 0.001). This trend also exists in 90-day mortality (Quartile 1: 81.3%; Quartile 2: 72.5%; Quartile 3: 72.3%; Quartile 4: 61.1%, p < 0.001). The Kaplan-Meier results indicate that higher MAP is associated with a reduction in 28- and 90-day mortality (both p < 0.001). After adjusting for potential confounders using Cox proportional hazard regression analysis, higher MAP was still associated with a decline in 28 - and 90-day mortality (both p < 0.001). CONCLUSION: MAP is a valuable parameter for predicting mortality in AKI patients who are receiving CRRT.