Acute kidney injury in pediatric non-traumatic rhabdomyolysis

Our study aimed to determine the prevalence of acute kidney injury (AKI) in pediatric non-traumatic rhabdomyolysis, and to identify factors associated with its development. Clinical information and laboratory tests of children with rhabdomyolysis who were admitted between 2009 and 2018 were reviewed retrospectively. Rhabdomyolysis was defined by a peak serum creatine kinase (CK) level > 1000 IU/L within the first 72 h of admission. The primary outcome was the occurrence of AKI within the first 7 days of admission, which was determined by the KDIGO criteria. A total of 54 patients with a median age of 7.8 years old were included. Ten (18.5%) patients developed AKI. AKI was relatively rare in children with viral myositis (2.6%), whereas all patients with rhabdomyolysis related to seizure or irritability/dystonia developed AKI. Patients with AKI had higher white cell count (10.6 vs. 4.5 × 109/L) and lower serum bicarbonate (19.4 vs. 25.5 mmol/L) on admission, with higher peak serum CK (23,086.0 vs. 3959.5 IU/L). The AKI group was more likely to present with positive urine results (myoglobinuria, dipstick heme or protein ≥ 2+). Peak serum CK had a good discriminatory power for stage 2–3 AKI (AUC 0.930, p = 0.005), with an optimal cut-off of 15,000 IU/L identified from the ROC analysis. The overall prevalence of AKI in pediatric non-traumatic rhabdomyolysis was 18.5%. Positive urine tests (myoglobinuria, dipstick heme or protein ≥ 2+), high white cell count, lower serum bicarbonate on admission, and high peak serum CK were associated with development of AKI.