What laboratory result may indicate rhabdomyolysis in a patient who has experienced significant trauma?

Elevated serum creatine kinase (CK) is a key laboratory result that may indicate rhabdomyolysis, particularly following significant trauma. Rhabdomyolysis is a condition that involves the breakdown of muscle tissue, leading to the release of intracellular components into the bloodstream. One of the most prominent markers released during this process is creatine kinase, an enzyme found in high concentrations in skeletal muscle.

In cases of trauma, such as crush injuries or severe muscle damage, the damaged muscle fibers release large amounts of CK into the circulation. Consequently, a significantly elevated serum CK level serves as an important diagnostic indicator of rhabdomyolysis. Detecting this elevation is crucial as it helps guide further management and treatment strategies, including monitoring for potential complications such as acute kidney injury due to the nephrotoxic effects of myoglobin released from damaged muscle.

While increased serum creatinine can also suggest renal impairment that may occur secondary to rhabdomyolysis, the most direct and early indicator of muscle damage is the elevated serum creatine kinase. Other laboratory results such as low serum sodium and hyperkalemia may occur in the context of rhabdomyolysis but are not specific indicators for the diagnosis of this condition.