Rhabdomyolysis (Rhabdo for short) secondary to a combination over exertion and dehydration is gaining attention in exercise circles due to documented cases recently with the increasingly popular high-intensity workout regimens. The threat of Rhabdo is not only confined to the the gym. It ought to be planned for and considered in the tactical environment as well. It is not a concern in the Care Under Fire stage of care, but, as Schwartz, et. al. note in Tactical Emergency Medicine, it ought to be addressed during tactical en route care. In addition to being caused by exertion and dehydration, Rhabdo and the subsequent renal failure my be secondary to a crush injury in the tactical environment. However, this brief essay assumes that crush injuries will tip-off care providers to included Rhabdo in their differential diagnosis. Rhabdo due to exertion may not, however, be as apparent.
Essentially, Rhabdomyolysis is the release of myoglobin into the blood stream, which damages the kidneys in two ways: 1) physically blocking the nerphrons with myoglobin; 2) chemotoxic toxification. While this can only be definitively determined by a lab test at a higher echelon of care, it is beneficial to keep this in mind. For instance, in a disaster situation or MCI, an operator may exert himself and present with acute muscle pain and local edema. It has been shown that the level or exertion required for the Rhabdo is dependent on individual fitness. In fact, as little as 50 sit-ups a day for 5 consecutive days led to a case. Studies of NYC Firemen have shown that there is an inverse relation between risk or Rhabado and fitness level. Therefore, risk is difficult to determine as a group and needs to be considered with patient history in mind.
In addition to exertion, non-exercise risk factors can combine to increase the chance of occurrence. For instance, metabolic myopathies and Malignant Hyperthermia, both of which can be inherited, may increase risk when combined with nominal exertion. Furthermore, viral illness such as Epstien-Barr, herpes simplex, and parainfluenze may increase risks. Finally, the US Army has shown a 200-fold increase in risk in those with sickle cell traits.
While medics in the tactical environment may not have the capabilities to diagnose Rhbado, they can manage it if the patient’s exam leads one to believe it is an issue. However, only 50% of patients present with the classic signs of myalgias, tenderness or swelling of muscles, dark urine. Therefore, if a medic suspects Rhabdo, s/he needs to treat the acute risk of damage to renal tubes. To do so, it is suggested that one needs to use a saline infusion producing an ideal urine output of 200 ml/h. Of course, drugs and buffering with alkalization is optimal, but that is beyond the scope of most medics, and it is probably not needed for support during transport to higher medical care.
The best treatment is, as always, prevention in the tactical environment where resources are precious and limited. Risk ought to be mitigated by ensuring members of your team are in good shape. If they posses any of the listed non-exertional risks, they need to be instructed to use caution when performing tasks and operations.
For more detailed information, see this paper: Rhabdo_Military_Pers.