What Is Rhabdomyolysis?
Rhabdomyolysis is a condition that may occur when muscle tissue is damaged due to an injury in which muscle in the body is damaged (rhabdomyo=skeletal muscle + lysis= rapid breakdown). There are three types of muscle in the body, including:
- skeletal muscles that move the body;
- cardiac muscle located in the heart; and
- smooth muscle that lines blood vessels, gastrointestinal tract, bronchi in the lung, and thebladder and uterus. This type of muscle is not under conscious control.
Rhabdomyolysis occurs when there is damage to the skeletal muscle.
The injured muscle cell leaks myoglobin (a protein) into the blood stream. Myoglobin can be directly toxic to kidney cells, and it can impair and clog the filtration system of the kidney. Both mechanisms can lead to kidney failure (the major complication of rhabdomyolysis).
Significant muscle injury can cause fluid and electrolyte shifts from the bloodstream into the damaged muscle cells, and in the other direction (from the damaged muscle cells into the bloodstream). As a result, dehydration may occur. Elevated levels of potassium in the bloodstream (hyperkalemia) may be associated with heart rhythm disturbances and sudden cardiac death due to ventricular tachycardia and ventricular fibrillation.
Complications of rhabdomyolysis also include disseminated intravascular coagulation, a condition that occurs when small blood clots begin forming in the body's blood vessels. These clots consume all the clotting factors and platelets in the body, and bleeding begins to occur spontaneously.
When muscles are damaged, especially due to a crush injury, swelling within the muscle can occur, causing compartment syndrome. If this occurs in an area where the muscle is bound by fascia (a tough fibrous tissue membrane), the pressure inside the muscle compartment can increase to the point at which blood supply to the muscle is compromised and muscle cells begin to die.
Rhabdomyolysis was first appreciated as a significant complication from crush and blast injuries sustained in a volcano eruption in Italy, in 1908. Victims of the blast injuries during the first and second World Wars help further understand the relationship between massive muscle damage and kidney failure.