Rhabdomyolysis can be described as a syndrome involving the breakdown of striated muscle, which causes myoglobin and other intracellular proteins and electrolytes to leak into the circulation. The development of rhabdomyolysis is associated with a wide variety of disorders, including injuries, exercise, medication, infection and certain toxins.
It represents a disease with potentially severe sequelae if it is not identified and treated expediently. Rhabdomyolysis accounts for approximately 8-15% of cases of acute renal failure and it is associated with a mortality rate of 5%. Clinical presentation can vary from asymptomatic illness to fulminant and life-threatening condition with multiorgan system failure.
Historical aspects of rhabdomyolysis
The first historical description of rhabdomyolysis is found in the Old Testament among Israelites after abundant consumption of quail during their exodus from Egypt. It is a result of intoxication by hemlock herbs, consumed by quails during their spring migration across the Mediterranean Sea. Indirect evidence corroborates that mentioned biblical episode occurred during springtime.
In 1812, a physician in Napoleon's army described limb gangrene from rhabdomyolysis in carbon monoxide victims. German military medical literature referred to rhabdomyolysis as crush syndrome during World War I, and more detailed descriptions of the diseases ensued after the World War II and the Blitz of London in 1941.
The exact role of myoglobin in the development of rhabdomyolysis was first described in experimental studies in the early 1940s. In 1959, Korein and his colleagues classified rhabdomyolysis into exertional and non-exertional groups. Non-traumatic, non-exertional causes of rhabdomyolysis were recognized in the early 1970s and identified as a potential cause of acute renal failure.
Due to a lack of formal clinical definitions, the incidence of rhabdomyolysis (and myopathic events in general) has been challenging to evaluate in clinical research. Still, it is estimated that more than 25 thousand cases are reported annually in the USA alone, where it accounts for 7% of all cases of acute kidney injury.
Rhabdomyolysis and crush syndrome are commonly found as a result of natural disasters, particularly in areas often involved by earthquakes. It is known that crush syndrome develops in 30-50% of cases of traumatic rhabdomyolysis. Various organizations (one example is International Society of Nephrology) have implemented specific measures to support local agencies in providing life-saving treatments for patients with rhabdomyolysis.
The condition is more common in adults, and the incidence is higher in males. It can also occur in infants and children with inherited myopathies and various enzyme deficiencies of carbohydrate or lipid metabolism. Older patients with diabetes mellitus that are concurrently treated with statins and fibrates have an increased risk of developing rhabdomyolysis.
Management of the condition
In every case of suspected rhabdomyolysis, the most important treatment goal is to avoid acute kidney injury. Therefore the management of the condition includes swift and aggressive fluid replacement with saline, correction of electrolyte abnormalities, elimination of the causative agents, as well as treatment and prevention of any complications that may ensue.
Additional adjunctive therapies may include alkalinisation of the urine with sodium bicarbonate, diuretic therapy or combinations of both. However, the lack of large randomized control studies regarding the benefits of such treatments hampers the introduction of strong recommendations for or against their use in the treatment of rhabdomyolysis.
In conclusion, the overall prognosis for rhabdomyolysis is favorable when treated with early and aggressive IV fluid replacement, usually with full recovery of renal function. Still, the mortality rate may still be as high as 8%, irrespective of the cause of rhabdomyolysis. Therefore all clinicians should be aware of the most common causes, diagnosis and treatment options for this condition.