Rhabdomyolysis

Rhabdomyolysis is a syndrome involving the breakdown of skeletal muscle causing myoglobin and other intracellular proteins and electrolytes to leak into the circulation. The development of rhabdomyolysis is associated with a wide variety of diseases, injuries, medications and toxins. While the exact mechanisms responsible for all the causes are not fully understood, it is clear that muscle damage can occur from direct injury or by metabolic inequalities between energy consumption and energy production. Rhabdomyolysis is diagnosed by elevations in serum creatine phosphokinase (CPK), and while there is no established serum level cut-off, many clinicians use five times the upper limit of normal (similar to 1000 U/l). Rhabdomyolysis can be complicated by acute renal failure (occurring in 4%-33% of patients), compartment syndrome, cardiac dysrhythmias via electrolyte abnormalities, and disseminated intravascular coagulopathy. The mainstay of treatment is hospitalisation with aggressive intravenous fluid (IVF) resuscitation with the correction or prevention of electrolyte abnormalities. There are additional adjunctive therapies to IVF, such as alkalinisation of the urine with sodium bicarbonate, diuretic therapy or combinations of both; however the lack of large randomised control studies concerning the benefits of these treatments makes it difficult to make strong recommendations for or against their use in the treatment of rhabdomyolysis. Regardless of these controversies, the overall prognosis for rhabdomyolysis is favourable when treated with early and aggressive IVF resuscitation, and full recovery of renal function is common. Irrespective of the cause of rhabdomyolysis the mortality rate may still be as high as 8%. This is a comprehensive review of the pathophysiology, diagnosis, complications and treatment options for rhabdomyolysis.