Approach to the evaluation and diagnosis of rhabdomyolysis

AKI: acute kidney injury; BUN: blood urea nitrogen; CBC: complete blood count; CK: creatine kinase; COVID-19: coronavirus disease 2019; Cr: creatinine; HIV: human immunodeficiency virus; RBC: red blood cell.

* No absolute cut-off value for CK elevation is defined, but serum CK is usually >5000 units/L with nonexertional rhabdomyolysis and >10,000 units/L with exertional rhabdomyolysis. The serum CK begins to rise within 2 to 12 hours following the onset of muscle injury and reaches its maximum within 24 to 72 hours. The degree of CK elevation should be considered in the clinical context of the history and examination findings, including premorbid CK values when available. As an example, an asymptomatic CK elevation of >2000 units/L can occur as a transient physiologic response to vigorous exercise.

¶ Refer to UpToDate content on the differential diagnosis of rhabdomyolysis.