Risk Factors and Outcomes of Post-traumatic Acute Kidney Injury requiring Renal Replacement Therapy: A Case–Control Study

Background: Acute kidney injury (AKI) following severe trauma is common. However, the requirement of renal replacement therapy (RRT) in these patients is rare and is associated with high morbidity and mortality. The primary objective of this study was to the identify odds of risk factors, in particular, hypotension at presentation, for the requirement of RRT in patients with AKI following trauma. Methods: We performed a case–control study involving patients who were admitted to the intensive care unit (ICU) at a level I trauma center for at least 24 hours. The primary outcome measure was a study of the odds of risk factors associated with the requirement of RRT in such patients. Univariate comparisons and multiple logistic regression analyses were done to identify other risk factors. Results: The presence of crush injury, sepsis, and elevated serum creatinine (sCr) on arrival were identified to be independent risk factors for RRT requirement. Hypotension and exposure to radiocontrast or nephrotoxic antimicrobials were not found to be associated with the need for RRT. Acute kidney injury requiring RRT was associated with significantly increased ICU length of stay (15 days vs 5 days; p < 0.001) and higher mortality (83% vs 35%; p < 0.001). Conclusion: The presence of crush injury, sepsis, and elevated sCr on presentation were identified to be independent risk factors while hypotension association was insignificant for AKI requiring RRT in our investigation.