Warning Signs - Page 2
Although most trail runners will never subject their bodies to the rigors of a 100-mile race, these examples illustrate that rhabdomyolysis can afflict all athletes. The condition, although uncommon, has a scary death rate—up to eight percent of cases are fatal, typically due to kidney failure and/or internal bleeding problems (Cervellin G et al 2010). In addition, rhabdomyolysis is the reported cause of eight to 15 percent of cases of sudden-onset renal failure.
The ultramarathoners in California and Scotland mentioned earlier all survived; however, three were treated for kidney failure. The following review includes the most current information about the warning signs of rhabdomyolysis, as well as prevention measures and treatment plans.
What the Heck Is Rhabdomyolysis (even if you can’t pronounce it)?
Exertional rhabdomyolysis is caused by direct muscle injury and subsequent massive muscle breakdown, resulting in a release of muscle proteins that can overwhelm the kidneys. Injury to cell membranes occurs from exposure to extreme heat, and/or crushing, pounding or tearing trauma. One of the proteins released from damaged muscle cells is myoglobin—imagine a big chunky molecule. Myoglobin can leak out of damaged cells and in essence “clog up” the intricate tubules in the kidneys, causing renal failure.
Heat and dehydration combined with extreme exercise are the most common combination that promotes such massive muscle breakdown. “Running the ‘extra mile’ has become the norm with both newly minted and well-trained athletes,” says A. Joseph Bilik, M.D., FACS, of Sarasota, Florida. “The combination of dehydration and extreme effort puts both these groups at increasing risk for glycogen deprivation and ultimately rhabdomyolysis. This process liberates intracellular electrolytes (sodium, potassium and calcium) as well as muscle-damage byproducts, which can result in renal failure.”
Electrolytes such as potassium and magnesium require homeostasis for proper cell function throughout the body, including the kidneys. Damaged cells allow intracellular electrolytes to leak into the bloodstream, which may affect heart and kidney function (having flashbacks to high-school biology?). Importantly, increased potassium in the blood stream can seriously affect heart function and may lead to heart-rate disturbances.
Athletes at Risk
Pushing a very hard run that is significantly faster than usual training miles, intense whole-body weight lifting or strenuous whole-body plyometric programs may put athletes at risk for rhabdomyolysis. It can also occur when trail runners suddenly increase training intensity after an episode of de-conditioning, like recovering from illness or a training break. The WS100 athletes hospitalized for rhabdomyolysis were in general relatively younger, faster runners with recent injuries. However many reports demonstrate “rhabdo” does not discriminate; both men and women of all ages are susceptible, and fitness levels vary from the elite athlete to the weekend warrior.
Clinical reports have shown a relationship between some common medications and exertional rhabdomyolysis. Athletes taking statin drugs that lower cholesterol, antihistamines/anti-nausea medications, psychiatric prescriptions and others may be more susceptible. At least two cases have been reported where trekkers taking phenothiazine (a drug found in some prescription antihistamines and psychiatric meds) developed rhabdomyolysis, resulting in one death (Koizumi T et al 1996).