Page 86 - Journal of Special Operations Medicine - Fall 2016

dietary supplement. This is a common situation in the physical activity may be performed by the Soldier. Once
53
military and other situations where training or testing the evaluation is completed and satisfactory, the indi-
may involve large groups of individuals. 11,29,54,55 There vidual can gradually return to activity using the criteria
may be other individuals with similar symptoms who for the lower-risk individual. 48
have not sought immediate medical care.
Primary Prevention
Return to Activity Primary prevention comprises actions taken to pre-
The great majority of warfighters who sustain an ER vent the development of ER and is the ultimate goal of
episode recover and return to duty without consequence public health efforts to minimize the incidence of this
or increased risk for future recurrence. Return to phys- problem. Several studies have shown that the exercise-
57
56
ical activity in a warfighter, however, does require de- induced rise in serum CK and myoglobin levels can be
termining who may be at risk for recurrence, because reduced by a period of preconditioning before more
the risk not only involves the individual but may have intense physical training. 58,59 This adaptation may be
operational impact on the unit. Table 1 provides guide- mediated by a training-induced increase in the size and
lines that medical providers can use to make this deter- number of mitochondria in the myocytes that can pro-
60
mination. For the patient at low risk, or if physiological vide additional adenosine triphosphate (ATP) to assist
ER is involved, a three-phase program for returning in stabilizing cellular walls during exercise. Risk for ER
the Soldier to duty is described in Table 2. If an indi- in normal healthy individuals can be reduced by empha-
vidual appear to be at higher risk, based on the Table sizing graded, individual preconditioning before begin-
1 guidelines, further evaluation is recommended. These ning a more strenuous exercise regimen and/or group
evaluations include a complete history and physical ex- exercise. In group activity, exercises of specific muscle
amination, along with a consultation with a regional groups (common in calisthenics-type exercises) should
or national ER expert to rule out myopathic disorders. be introduced gradually, starting with only a few rep-
Other diagnostic tests may be called for (e.g., muscle etitions and emphasizing the correct form. Sudden in-
biopsies, electromyographic studies, caffeine–halothane creases in exercise volume should be avoided. The US
muscle contracture tests, and/or progressive exercise Army Field Manual 7-22 provides progression sched-
challenge test). While the evaluation is ongoing, light ules for a very wide variety of exercises.

Table 1 Criteria to Assist in Determination of Patients Who Might Be at High or Lower Risk for Recurrence of
Exertional Rhabdomyolysis a
Suspicion of High Risk: At least one of the following Lower Risk: None of the high-risk conditions should exist
conditions must be present: and at least one of the following conditions must be present:
Delayed recovery (more than 1 week) when activities have Rapid clinical recovery and CK normalization after exercise
been restricted restrictions
Personal or family history of recurrent muscle cramps or No family history of rhabdomyolysis or previous reporting
severe muscle pain that interferes with activities of daily of debilitating exercise-induced muscle pain, cramps, or heat
living or sports and/or exercise performance injury
Personal or family history of malignant hyperthermia, No personal history of rhabdomyolysis or previous reporting
or family history of unexplained complications or death of debilitating exercise-induced muscle pain, cramps, or heat
following general anesthesia injury
Personal or family history of ER Existence of other group or unit-related cases of ER during
the same exercise sessions
Personal or family history of sickle cell disease or trait Suspected or documented concomitant viral illness or
infectious disease
Muscle injury after low to moderate work or activity Sufficiently fit or well-trained individual with a history of
very intense training/exercise bout
ER complicated by acute renal injury of any degree Taking a drug or dietary supplement that could contribute to
the development of ER
Persistent elevation of CK (greater than 5 times the upper
limit of the normal laboratory range) despite rest for at least
2 weeks
Personal history of significant heat injury (heat stroke)
Serum CK peak ≥100,000U/L
CK, creatine kinase; ER, exertional rhabdomyolysis.
a Adapted from O’Connor et al. 48

68 Journal of Special Operations Medicine Volume 15, Edition 3/Fall 2016