Objectives: Extracorporeal lung support is currently used in the treatment of patients with severe respiratory failure until organ recovery and as a bridge to further therapeutic modalities. The aim of our study was to evaluate the impact of acute kidney injury on outcome in patients with acute respiratory distress syndrome under venovenous extracorporeal membrane oxygenation support and to analyze the association between prognosis and the time of occurrence of acute kidney injury and renal replacement therapy initiation.
Design: Retrospective observational study.
Setting: A large European extracorporeal membrane oxygenation center, University Medical Center Regensburg, Germany.
Patients: A total of 262 consecutive adult patients with acute respiratory distress syndrome have been treated with extracorporeal membrane oxygenation between January 2007 and May 2012.
Interventions: None.
Measurement and main results: Patient median age was 49 years (range, 18-78 yr); 183 (69.8%) were male. The leading cause of lung failure was pneumonia. The median Sequential Organ Failure Assessment score was 12.0 (8.8-15.0), and the median lung injury score was 3.3 (3.3-3.7). The median extracorporeal membrane oxygenation support duration was 9 days (6-15 d). One hundred eighty-three patients (69.8%) were successfully weaned and 156 patients (59.9%) survived to hospital discharge. One hundred thirty-one patients (50.0%) were treated with renal replacement therapy during extracorporeal membrane oxygenation support. The survival rate was significantly lower in patients requiring renal replacement therapy compared with those without renal replacement therapy (47.3% vs 71.8%; p < 0.001) overall. The Kaplan-Meier survival curves differed significantly for patients without renal replacement therapy versus patients with renal replacement therapy prior to extracorporeal membrane oxygenation support (p = 0.003). Furthermore, the multivariate logistic regression analysis suggests that the necessity of renal replacement therapy prior to extracorporeal membrane oxygenation insertion was an independent risk factor for mortality (95% CI, 0.77-0.88; p < 0.001). However, the necessity of renal replacement therapy during extracorporeal membrane oxygenation support was not an independent risk factor for mortality in these patients (p = 0.37).
Conclusions: Acute kidney injury is a major complication in acute respiratory distress syndrome probably mirroring severe systemic disease. In our cohort, development of acute kidney injury requiring renal replacement therapy prior to extracorporeal membrane oxygenation insertion was negatively associated with survival, whereas acute kidney injury that developed during extracorporeal membrane oxygenation support was not.