Page 108 - Journal of Special Operations Medicine - Summer 2015

he put himself through. Careful inquiry about his hydra- a urine sample for dipstick testing. The result is strongly
tion status and urinary output is also essential. positive for the detection of blood.

A detailed examination should help determine if this Rhabdomyolysis
is typical muscle fatigue or if there may be something
more sinister at play. Examination reveals an oral tem- Rhabdomyolysis results from injury of skeletal muscle.
perature of 36.8°C (98.2°F); he is alert with a heart rate This damage causes the muscle cells to “leak” their in-
of 90/min, respiration rate of 16/min, blood pressure of tracellular contents into the surrounding plasma. The
115/65mmHg, and an oxygen saturation level of 98% cause of the inciting muscle damage can be variable and

on room air. Looking at the patient’s lower limbs, you may depend on a combination of multiple factors. Typi-
do not see any obvious ecchymosis, edema, deformity, cal causes and risk factors may include :
2
or skin color changes. Palpation of muscle groups and
surrounding joints does not reveal any deformity, al- • Direct trauma from sources such as motor vehicle ac-
though direct palpation of the gastrocnemius bilater- cidents, blast injuries, crush injuries, or other form of
ally does cause a pain response. Lower-limb dermatome physical trauma
testing shows normal sensation with depressed lower- • Exertion from extreme physical exercise and exercise
limb deep tendon reflexes but normal peripheral pulses. until muscle failure
Strength testing against resistance shows weakness to • Seizures, especially if there is prolonged tonic-clonic
plantar flexion. Looking at the patient overall, he ap- movement, or instances of multiple seizures
pears mildly pale with dry lips. You ask about his hydra- • Interruption of blood supply from thrombosis forma-
tion status and he states “I should probably drink more. tion, embolism migration, mechanical restriction due
I just went to the bathroom and my urine was pretty to prolonged positioning that restricts blood flow,
dark.” You try to clarify this statement and the closest and medical intervention such as tourniquets
color approximation to the color is that of a cola drink • Dehydration and electrolyte imbalance, especially if
(Figure 1). resulting in a potassium-depleted state
• Dysregulation of body temperature, including hyper-
Figure 1 Darkened urine indicative of rhabdomyolysis. thermia and hypothermia
• Drugs, including prescription medications classically
consisting of statins, and neuromuscular blocking
agents, or drugs of abuse such as alcohol, cocaine,
and amphetamines
• Toxins, such as those from various insects and snakes,
and from some plant-derived toxins like those found
in hemlock

Infection from microbiological sources, and autoim-
mune-regulated muscle damage, as in polymyositis and
dermatomyositis conditions.

In a military or law enforcement population, the most
What Now?
likely source of rhabdomyolysis will be exertional. This
This patient presented with postworkout soreness, but can be through self-motivated exercise or through re-
also has notable muscle weakness and concerning urine. cruit training programs. In the Special Operations com-
Your differential diagnosis is expanded beyond benign munity, this should be carefully considered if providing
muscle fatigue. Consideration must be given to the pos- medical care for personnel undergoing tough selection
sibility of traumatic injuries, rhabdomyolysis, compart- programs. Looking for compounding factors such as
ment syndromes, electrolyte disturbance, or other causes dehydration, proceeding illness, or medication use is
of inflammatory myositis. As you are considering the important in determining risk and treatment. The mor-
likelihood of each diagnosis, the patient asks if he can tality rate for rhabdomyolysis in the civilian setting is
just have some more nonsteroidal anti- inflammatory estimated to be 8%. 2
drugs (NSAIDs) and wait it out. Realizing that this pre-
sentation is significantly different than that of the initial Pathophysiology
muscle soreness, and now may involve kidney issues,
you explain that NSAIDs, at this point, are not appro- Despite the lengthy list of potential causes of rhabdo-
priate, as they can decrease renal perfusion. You decide myolysis, all result in a similar final pathway with re-
1
to better qualify the description of the urine and obtain spect to the effect on myocytes and the release of their

98 Journal of Special Operations Medicine Volume 15, Edition 2/Summer 2015