Mannitol is an independent risk factor of acute kidney injury after cerebral trauma: a case-control study

We retrospectively studied a random cohort of patients with cerebral trauma to investigate the risk factors of acute kidney injury (AKI) following cerebral trauma. AKI was determined using the RIFLE (risk, injury, failure, loss, or end-stage kidney) staging criteria. About 171 patients were chosen in the study, with 53 patients in AKI group and 118 patients without AKI in non-AKI group. By logistic regression analysis, univariate analysis revealed that age, hypertension, emergent surgery, systemic inflammatory response syndrome (SIRS), Glasgow coma score (GCS), sequential organ failure assessment (SOFA) score, the respiration, coagulation, and cardiovascular components of the SOFA score, mechanical ventilation time, red blood cell transfusion, plasma transfusion, and the accumulative doses of furosemide, torsemide, and mannitol were significantly related to AKI after cerebral trauma. Logistic multivariate regression analysis showed that SOFA score [odds ratio (OR) = 1.516, 95% confidence interval (CI) 1.222-1.881, p < 0.001], the accumulative doses of torsemide (OR = 0.016, 95% CI 1.002-1.031, p = 0.016), and the accumulative doses of mannitol (OR = 2.687, 95% CI 1.062-6.800, p = 0.037) were independent risk factors of AKI. This model had a good discrimination for AKI with an area under the receiver operating characteristic (ROC) curve of 0.901 (p < 0.001). The accumulative doses of mannitol as a risk factor of AKI were identified by propensity score match (PSM) method. We concluded that AKI was a common complication in patients with cerebral trauma. SOFA score and the accumulative doses of torsemide and mannitol were independent risk factors of AKI following cerebral trauma.