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 > or = 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 > or = 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.