Acute pediatric rhabdomyolysis: Causes and rates of renal failure

OBJECTIVES. The goals were to (1) compare the causes, clinical presentation, and prevalence of acute renal failure in pediatric rhabdomyolysis with the published data for adults; (2) determine predictors of acute renal failure in pediatric patients with rhabdomyolysis; and (3) explore the relationship of acute renal failure with treatment modalities such as fluid and bicarbonate administration. METHODS. We performed a retrospective chart review to identify patients with creatinine kinase levels of > 1000 IU/L who were treated in the emergency department of a tertiary pediatric hospital between 1993 and 2003, and we constructed regression models. RESULTS. Two hundred ten patients were studied. One hundred ninety-one patients met study eligibility (128 male and 63 female), with a median age of 11 years. The most common documented symptoms were muscle pain (45%), fever (40%), and symptoms of viral infection (39%). The most common causes of pediatric rhabdomyolysis were viral myositis (38%), trauma (26%), and connective tissue disease (5%). Six of 37 patients with creatinine kinase levels of >= 6000 IU/L had previously undiagnosed dermatomyositis or hereditary metabolic disease, compared with 10 of 154 patients with creatinine kinase levels of 1000 to 5999 IU/L. Nine of 191 patients developed acute renal failure. None of 99 patients with initial urinary heme dipstick results of < 2+ developed acute renal failure, compared with 9 of 44 patients with urinary heme dipstick results of >= 2+. Higher initial creatinine kinase levels and higher fluid administration rates were associated with higher maximal creatinine levels. CONCLUSIONS. The cause of acute pediatric rhabdomyolysis is different from that of adult rhabdomyolysis. The risk of acute renal failure in children is much less than the risk reported for adults.