Article AKI in Low-Risk versus High-Risk Patients in Intensive

Background and objectives AKI in critically ill patients is usually part of multiorgan failure. However, nonrenal organ failure may not always precede AKI and patients without evidence of these organ failures may not be at low risk forAKI. This study examined the risk and outcomes associatedwithAKI in critically ill patientswith and without cardiovascular or respiratory organ failures at presentation to the intensive care unit (ICU). Design, setting, participants, & measurementsA large, academic medical center database, with records from July 2000 through October 2008, was used and the authors identified a low-risk cohort as patients without cardiovascular and respiratory organ failures defined as not receiving vasopressor support or mechanical ventilation within the first 24 hours of ICU admission. AKI was defined using Kidney Disease Improving Global Outcomes criteria. The primary end points were moderate to severe AKI (stages 2–3) and risk-adjusted hospital mortality. Results Of 40,152 critically ill patients, 44.9 % received neither vasopressors nor mechanical ventilation on ICU day 1. Stages 2–3 AKI occurred less frequently in the low-risk patients versus high-risk patients within 24 hours (14.3 % versus 29.1%) andwithin 1week (25.7 % versus 51.7%) of ICU admission. Patients developing AKI in both risk groups had higher risk of death before hospital discharge. However, the adjusted odds of hospital mortality were greater (odds ratio, 2.99; 95 % confidence interval, 2.62 to 3.41) when AKI occurred in low-risk patients comparedwith thosewith respiratory or cardiovascular failures (odds ratio, 1.19; 95 % confidence interval, 1.09 to 1.3); interaction P,0.001. Conclusions Patients admitted to ICUwithout respiratory or cardiovascular failure have a substantial likelihood of developing AKI. Although survival for low-risk patients is better than for high-risk patients, the relative increase in mortality associated with AKI is actually greater for low-risk patients. Strategies aimed at preventing AKI should not exclude ICU patients without cardiovascular or respiratory organ failures