Rhabdomyolysis is a condition of rapid muscle breakdown. It can be caused by trauma, infections and medicines. The major complication of rhabdomyolysis is acute renal failure, in which the breakdown products of muscle cells, specifically a protein called myoglobin, clog up the kidneys' tubules. Rhabdomyolysis is treated with aggressive intravenous hydration.
History
Most patients with rhabdomyolysis have a history of trauma, especially crush injury, to their bodies. Other traumas can include a viral illness with fever, or past use of antipsychotic medicine or drugs such as cocaine and Ecstasy.
Features
Patients with rhabdomyolysis exhibit pain in their muscles, achiness and weakness. The affected muscles sometimes swell, which can lead to compartment syndrome, a condition in which the swelling damages other tissues within the muscle. The disease can also lead to permanent damage to the affected muscle or limb. Patients can also have cola-colored urine, which occurs as a result of the passage of the excess myoglobin into the urine, turning it a dark color.
Effects
Muscle breakdown leads to the presence of creatine kinase in the blood. This enzyme is present in large quantities inside muscle cells, and when these break down, the creatine kinase goes into the blood stream, where it can be measured. A creatine kinase level that is five times its normal levels is consistent with a diagnosis of rhabdomyolysis.
Considerations
Other lab findings include the presence of myoglobin in the urine. The urine can also falsely detect the level of blood, confusing the myoglobin with the similarly structured hemoglobin, the primary protein in the blood's red blood cells. Also, patients with rhabdomyolysis can have electrolyte disturbances, such as increases in their serum calcium and potassium levels. High serum potassium can predispose the patient to the development of cardiac arrhythmias.
Warning
Most patients with rhabdomyolysis develop muscle pain, but occasionally patients will present with other manifestations, such as cardiac arrhythmias, renal failure or compartment syndrome. Blood tests to assess the creatine kinase level can help establish the diagnosis in these circumstances.
