Causes of Rhabdomyolysis Different in Children Than in Adults?

William T. Basco, Jr, MD, FAAP


January 17, 2007

Acute Pediatric Rhabdomyolysis: Causes and Rates of Renal Failure

Mannix R, Tan ML, Wright R, Baskin M
Pediatrics. 2006 Nov;118(5):2119-2125

The authors begin by reviewing what is known about rhabdomyolysis in adults, including the fact that 17%-35% of adults with rhabdomyolysis will experience renal failure. The authors point out the existing pediatric data is very scarce, with only 2 reports, each having fewer than 20 patients, suggesting that pediatric rates of acute renal failure (ARF) during rhabdomyolysis were even higher than in adults.

The authors of this study identified 191 children treated in their hospital from 1993-2003 who had creatinine kinase (CK) levels above 1000 IU/L, the study definition of "rhabdomyolysis," without evidence of myocardial infarction. The authors then completed chart review to describe causes of ARF in patients with rhabdomyolysis and predictors of outcomes. Viral myositis was the cause in the largest proportion of rhabdomyolysis cases, at 38.2%. Trauma was the cause in 25.7%. A host of other conditions, including connective tissue disease, metabolic derangements (eg, diabetic keotacidosis), seizures, sepsis, drug reactions, and hypoxia, each contributed 2%-5% of cases. Of the remainder, 7.3% had an unknown cause. Only 0.5% of cases were due to muscular dystrophy. Muscle pain and fever were the most common symptoms at 45% and 40%, respectively. Weakness was present in 38%. Five percent (n = 9) of the children developed ARF. Of the subjects with a urine dipstick result showing hemoglobin of at least 2+, 20% developed ARF; none of the subjects with urine hemoglobin < 2+ developed ARF. Only 3 of the 9 patients with ARF had ARF only due to rhabdomyolysis, and all 3 of these subjects survived. The other 6 experienced ARF as part of multiorgan system failure (66% mortality).

Overall, 13 of the 191 patients died (6.8%), but over 2/3 of those who died were in cardiac arrest upon arrival to the emergency department. Although the authors were not able to ascertain follow-up on all subjects, none that were followed developed any degree of renal insufficiency. The authors conclude that the causes of rhabdomyolysis are different in children than in adults, with viral myositis being the most common cause in children under 9 years. In addition, the rate of ARF accompanying rhabdomyolysis is much lower (at 5%) than previous pediatric or adult literature might suggest.

It's difficult to comprehend that the largest published series of pediatric rhabdomyolysis cases reports on only 191 children! However, this is a large enough number to provide a relatively tight estimate of the ARF rate in these patients (the 95% CI was 2%-8%). So, this study provides a lot of data to help with assessing prognosis (the degree of hematuria) and with explaining causes, but it will take more prospective data to help determine best treatment options.



Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: