One chilly January morning, an ambulance was dispatched to a private residence in an upscale neighborhood. On arrival, the crew found an 82-year-old female lying on her right side on the floor. Initial assessment revealed the patient was conscious and alert to her surroundings. She responded appropriately to questions: She was able to tell providers that she was in her bedroom inside her home and that she fell "yesterday, while it was still light outside."
After the crew ruled out the need for spinal precautions, a physical exam was performed. The patient was lying on her right upper arm, and her right forearm was swollen and taught like the skin of a drum. The skin color was noted to be a mottled, pale-blue color. Her right fingers were cold to the touch, and, despite not appearing to be injured, palpation of the right hand elicited significant pain. The patient reported a sensation of "pins and needles," extending from the right forearm into the right fingers, which she was unable to move.
The crew recognized these signs and symptoms as consistent with compartment syndrome, and, although unusual in this setting, possible acute rhabdomyolysis.„
Frequency & Causes
Rhabdomyolysis is the breakdown of muscle tissue, with secondary leakage of potentially toxic cellular contents into systemic circulation. Of particular interest to field personnel are acute cases resulting from three primary causes: crush injuries, compartment syndrome and excited delirium.
When muscle tissue is injured, calcium and sodium ions rush into the cell, and potassium, myoglobin, phosphorous and uric acid rush out. Small amounts of these ions generally cause no harm, but in large quantities, they quickly overwhelm the body_s buffer systems and upset the delicate chemical balance, resulting in life-threatening conditions, such as metabolic acidosis (phosphate and sulfate ions are released into systemic circulation from injured muscle cells), hyperkalemia (potassium ions released into circulation), hypovolemia (fluid moves across the osmotic gradient into injured tissue) and hyperuricemia (free circulation of muscle breakdown components poison the kidneys). These conditions can produce fatal cardiac rhythm disturbances and acute renal failure (acute tubular necrosis from hyperuricemia).
Recognition & Assessment
Mechanism & history:A high index of suspicion for rhabdomyolysis should be maintained in cases of crush injury where large muscle masses are involved (pelvis and lower extremities), or, as in the opening scenario, suspected compartment„ syndrome, where prolonged pressure on a muscle and circulatory compromise have caused muscle damage secondary to swelling of the muscle within the fascia "compartment."„
With respect to compartment syndrome, the history may include compression from an unconscious or semi-conscious patient lying on an extremity for a prolonged period of time, a snake or spider bite, a recent fracture, or a cast that causes circumferential compression. The patient and their caregivers should be asked whether they_ve noticed a reddish or "tea colored" urine lately.
Physical examination:„ When conducting the physical exam, look for the "six Ps": pain in the extremity (both at baseline and on palpation), pressure (the extremity feels taught or tense to palpation), parasthesia (numbness or a sensation of "pins and needles"), paralysis, pallor, and perfusion compromise distal to the injury. In compartment syndrome, swelling is often present with or without evidence of injury; circumferential swelling from a variety of causes (e.g., acute envenomation, burns) presents an especially high possibility that compartment syndrome may result.„
Excited delirium is another state worthy of discussion. The extreme motor activity of the patient, particularly if exacerbated by the application of restraints, presents the potential for rhabdomyolysis and its associated complications. (For an in-depth discussion of excited delirium, read "In a Delirium" at jems.com/jems.)„
Treatment is directed at restoring systemic homeostasis and preventing or reversing the attendant complications of rhabdomyolysis: hypovolemia, hyperkalemia, acute renal failure, dysrhythmias and cardiac arrest. The following treatment regimen addresses these concerns.„
>Proper airway positioning/C-spine management, if indicated;
>Albuterol, nebulized and inhaled, to increase plasma insulin concentration (which optimizes the function of the sodium potassium pump, and thereby helps to decrease serum potassium levels);
>Crystalloid fluid bolus/NaHCo3: 1Ï2 L (pediatric: 30 ml/kg) with 1 mEq/kg NaHCo3 added to first liter to treat hypovolemia, optimize renal output, control hyperkalemia and reverse acidosis;
>Pain control as appropriate; and
>Thorough IV line flushing.
If, and only if, ECG changes (indicative of potential serious cardiac rhythm disturbances consistent with hyperkalemia) are present,„ calcium chloride should be administered slowly IVP over 60 seconds. Consult your local guidelines for specific dosages and administration protocols.
Clinical treatment includes establishing a definitive diagnosis through evaluation of serum creatine kinase and myoglobin levels, as well as diuresis and ongoing therapy to improve renal perfusion and raise the alkalinity of the urine. In cases of severe compartment syndrome and crush injury, surgery (such as fasciotomy) may be indicated, with appropriate follow up and ongoing treatment subsequent to hospital discharge.
After placing the patient on high-flow oxygen, obtaining an ECG and establishing an IV line, the crew contacted the base hospital and requested a consultation for a patient who presented with the potential for acute compartment syndrome of the right upper extremity. A 500 cc fluid challenge was ordered to be followed by 50 mEq sodium bicarbonate and careful release of pressure on the limb and subsequent careful handling of the limb.„
The crew followed these steps, and 15 minutes later, signs of perfusion had returned to the right arm and hand. The patient was transported, evaluated at the emergency room, kept several hours for observation and released without further complications.„JEMS
Mark Rockis a graduate of the University of Oregon and did post-graduate work at Portland_s Neurological Sciences Institute. A recent appointee to the JEMS EMT and Paramedic Advisory Committee (EPAC), Rock practices as a paramedic in Ventura, Calif. Contact him at„firstname.lastname@example.org.„
>>„Seiler JG 3rd, Casey PJ, Binford SH: "Compartment Syndromes of the upper extremity."„Journal of the Southern Orthopedic Association. 9(4):233Ï247, 2000.
>>„Heppenstall RB, Scott R, Sapega A, et al: "A comparative study of the tolerance of skeletal muscle to ischemia."„Journal of Bone & Joint Surgery. 68(6):820Ï828, 1986.
>>„Better OS, Stein JH: "Early management of shock & prophylaxis of acute renal failure in traumatic rhabdomyolysis."„New England Journal of Medicine. 322(12):825Ï829, 1990.„