Late-onset rhabdomyolysis in burn patients in the intensive care unit

Rhabdomyolysis (RML), defined as creatine phosphokinase (CPK) >1000U/L, is relatively common immediately after a significant burn. Late-onset RML, occurring a week or more after a burn, is less well understood and recognised. All patients admitted to the Intensive Care Unit (ICU) following an acute burn between May 2006 and December 2009 were retrospectively identified. Patients with CPK>1000U/L a week or more after their burn had a detailed notes review. Seventy-six patients were admitted during 43 months. Late-onset RML was demonstrated in 7/76 (9%) patients. They had a similar pattern of normal or mildly raised CPK on admission that resolved over the following days, but suddenly increased sharply to over 1000U/L, a week or more after their burn, usually around day ten. A severe late-onset RML occurred in 5/76 (7%) patients, with a CPK rise of over 5000U/L, and all required haemodialysis. Potential triggering factors for late-onset RML include sepsis, nephrotoxic drugs and hypophosphataemia. It is important to consider measuring CPK in all patients with the above complications, even after it has previously been observed to be normal, in order to initiate early treatment.