LAUSR

BACKGROUND Acute kidney injury (AKI) is common in severely injured trauma patients and is associated with poor outcomes. A positive fluid balance is associated with AKI and poor long-term renal outcomes among general intensive care unit (ICU) and cardiac surgery patients. Currently, the optimal endpoint of resuscitation of severely injured trauma patients is unknown, which may result in excess fluid administration. We hypothesized that positive fluid balance is common after severe trauma and is associated with increased AKI development. DESIGN A cohort study of adult (≥16 years) trauma patients requiring ICU admission from January 2017 to June of 2017 was conducted. Patients were excluded for early death, rhabdomyolysis, or prior history of end-stage renal disease or congestive heart failure. AKI within 7 days of admission was defined according to Kidney Disease Improving Global Outcomes creatinine-based criteria. Univariate and multivariable analyses were performed. RESULTS Of 364 patients, 74% were male. The median age was 41 years (IQR 27-59) and the median injury severity score (ISS) was 18 (IQR 10-29). Positive fluid balance (>2L) was observed in 49% of patients. AKI was diagnosed in 105 (29%) patients. After adjustment, there was an increased risk of AKI with a positive fluid balance >2L (RR 1.98 (95% CI 1.24-3.17)). Additionally, the risk of AKI incrementally increased by 1.22 with each liter fluid positive above a zero balance (95% CI 1.11-1.34). CONCLUSIONS Positive fluid balance in excess of 2L at 48-hours occurs in half of severely injured trauma patients and fluid positivity is independently and incrementally associated with AKI development. Fluid responsiveness should be investigated as an end point of post-traumatic resuscitation to prevent unnecessary fluid administration and subsequent AKI.