Professor Jed Wolfson
Anatomy and Physiology 1
October 27, 2011
Rhabdomyolysis: Disease of Muscular Breakdown
Rhabdomyolysis is the breakdown of damaged muscle tissues resulting in the release of muscle fiber contents into the bloodstream (Patel M.D.). This disease occurs when there is damage to the skeletal muscle. The breakdown products of damaged muscle cells, such as myoglobin, are harmful to the kidneys and frequently result in kidney damage or even kidney failure. The severity of the symptoms depends on the degree of muscle damage and the degree of the kidney damage, if any. The primary muscle damage can be caused by physical damage, medications, drug abuse and some infections. Some patients may have a higher risk of rhabdomyolsis because of a hereditary muscle condition that is already present. There are many causes of rhabdomyolysis. One of the most common causes of this disease is a crush accident, such as an auto accident. Long lasting muscle compression is also another cause of rhabdomyolysis. Long lasting muscle compression derives from “lying unconscious on a hard surface during an illness or while under the influence of drugs or alcohol “(Chang M.D.). An untrained athlete can also get this disease from severe muscle strain where the muscle becomes damaged. Significant muscle injury can cause fluid and electrolyte shifts from the bloodstream into the damaged muscle cells, and in the opposite direction (eMedicineHealth). Other causes of rhabdomyolysis are electrical shock, very high body temperature (hyperthermia) or heat stroke, diseases of the muscular system such as “congenital muscle enzyme deficiency or Duchenne's muscular dystrophy” (Chang M.D.).
Signs and symptoms of this disease may be hard to pinpoint because the course of the disease varies depending on the cause and each patient may experience different symptoms. Complications of this disease may also be present in the early stages as well as in the later stages. The symptoms of rhabdomyolysis come from the medical history of the patient. The patient may experience painful swollen bruised or tender areas of the body. Muscle weakness may also be experienced by the patient, such as difficulty moving the arms or the legs. Nausea, vomiting and a general sense of illness can be experienced by the patient. The rise in body temperature (hyperthermia) may cause confusion, dehydration, and even a lack of consciousness if not treated. The signs of rhabdomyolysis come from the physical findings of an examination done by a doctor or a healthcare provider. Less severe forms of rhabdomyolysis may not cause any symptoms or signs, and the diagnosis can only be found in abnormal blood tests. The urine, as seen in the photo to the right, may be dark, often described as "tea-colored", due to the presence of myoglobin in the urine. Damage to the kidneys can occur due to decreased or absent urine production, usually 12 to 24 hours after the initial muscle damage (Patel M.D.). A second recognized complication is disseminated intravascular coagulation (DIC), a severe disruption in blood clotting that may lead to uncontrollable bleeding (Warren M.D.).
Muscle biopsies can be useful if an episode of rhabdomyolysis is thought to be the result of an underlying muscle disorder. A biopsy sample taken during an episode is often uninformative, as it will show only evidence of cell death or may appear normal (eMedicineHealth). Taking the sample can be delayed for several weeks or even months. The histopathological appearance on the biopsy indicates the nature of the underlying disorder (eMedicineHealth). Biopsy sites may be identified by medical imaging, such as using magnetic resonance imaging (MRI), as the muscles may not be equally affected by this disease.
Early laboratory findings include increased levels of myoglobin, potassium, urea, and phosphorus found in blood levels. An “anion gap metabolic acidosis” could progress because...