Relationship of creatine kinase elevation and acute kidney injury in pediatric trauma patients.

BACKGROUND: Rhabdomyolysis following trauma has been associated with renal impairment. Nevertheless, the literature is scant in risk assessment of acute kidney injury (AKI) and survival in children experiencing posttraumatic rhabdomyolysis.
METHODS: After institutional review board approval was obtained, the registry of an urban trauma center was reviewed for pediatric (age < 18 years) trauma admissions with available creatine kinase (CK) values. Variables extracted included demographics and trauma severity indices along with serum creatine, CK, and Blood Urea Nitrogen (BUN) values. AKI was defined per pediatric RIFLE (Risk, Injury, Failure, Loss, End stage) definition. Regression models were deployed to determine the independent risk factors for AKI and CK levels.
RESULTS: Overall, 521 patients constituted the study sample. AKI occurred in 70 patients (13.4%), with correlation to CK values in excess of 3,000 IU/L (41.4% vs. 4.9%, adjusted p < 0.001). Independent risk factors for AKI proved to be CK level of 3,000 or greater (adjusted odds ratio [AOR], 11.02; 95% confidence interval [CI], 4.56-26.64; p < 0.001), Injury Severity Score (ISS) of 15 or less (AOR, 0.25; 95% CI, 0.10-0.61), Glasgow Coma Scale (GCS) score of 8 or less (AOR, 15.00; 95% CI, 4.98-44.94), abdominal Abbreviated Injury Scale (AIS) score of 3 or less (AOR, 3.14; 95% CI, 1.04-5.36), imaging studies with contrast of 3 or less (AOR, 3.81; 95% CI, 1.37-10.57), blunt mechanism of injury (AOR, 2.76; 95% CI, 1.17-6.49), administration of nephrotoxic agents (AOR, 4.81; 95% CI, 1.23-18.79), and requirement for fluids administration in the emergency department (AOR, 2.36; 95% CI, 1.04-5.36). Mortality in the study sample with CK values of 3,000 or greater versus less than 3,000 IU/L did not reach statistical significance (25.0% vs. 9.3%, adjusted p = 0.787).
CONCLUSION: AKI in pediatric posttraumatic rhabdomyolysis occurs in 13% of trauma patients. CK values of 3,000 IU/L or greater pose a significant adjusted risk for AKI. Aggressive monitoring of CK values in pediatric trauma patients is warranted. LEVEL OF EVIDENCE: Prognostic study, level III.