What is the management approach for a patient with suspected rhabdomyolysis (muscle breakdown) and severe leg pain?

From the Guidelines

The patient with suspected rhabdomyolysis and severe leg pain requires prompt intervention with aggressive intravenous fluid resuscitation and monitoring for compartment syndrome, as suggested by the most recent guidelines 1. The management approach for this patient should prioritize preventing complications like acute kidney injury and addressing the underlying cause of rhabdomyolysis.

• Initial management includes aggressive intravenous fluid resuscitation with normal saline at 1-2 L/hour initially, then adjusted to maintain urine output of 200-300 mL/hour.
• Serum creatine kinase (CK) levels should be measured immediately, with levels typically exceeding 5,000 U/L in rhabdomyolysis.
• Pain management with acetaminophen or opioids may be necessary, but NSAIDs should be avoided due to potential kidney stress, as recommended by the American College of Cardiology/American Heart Association 1.
• Urinary alkalinization with sodium bicarbonate may be considered if the patient's pH is below 6.5, though this remains controversial.
• Electrolyte abnormalities, particularly hyperkalemia, hypocalcemia, and hyperphosphatemia, must be monitored and corrected.
• Continuous cardiac monitoring is essential if electrolyte disturbances are present.
• The underlying cause of rhabdomyolysis should be identified and addressed, whether it's trauma, exertion, medications, or other factors, considering the potential risks of myopathy associated with certain medications, such as statins 1.
• Patients with severe cases, significant kidney injury, or refractory electrolyte abnormalities may require nephrology consultation and possibly dialysis.
• Compartment syndrome, a potential complication causing increased pressure within muscle compartments, requires surgical consultation for possible fasciotomy if suspected, with clinical signs including pain, tension, paraesthesia, paresis, and increased compartmental pressure monitoring 1.

From the Research

Patient Management Approach

The patient's condition, with severe leg pain and a history of rhabdomyolysis (CK >60,000), requires careful management to prevent further complications.

• The patient's severe leg pain could be indicative of compartment syndrome, a known complication of rhabdomyolysis 2, 3.
• Rhabdomyolysis is a serious condition that can lead to acute renal failure, with mortality rates approximately 10% and significantly higher in patients with acute renal failure 4.
• The management approach should focus on preserving renal function, resolving compartment syndrome, restoring metabolic derangements, and volume replacement 4, 5, 6.
• Aggressive intravenous volume expansion is indicated to prevent myoglobinuric renal failure 6.
• Serum potassium levels and electrocardiograms should be monitored to identify life- and limb-threatening complications of hyperkalemia 6.

Diagnostic Considerations

• The diagnosis of rhabdomyolysis is based on elevated serum creatine kinase activity, with a reasonable definition being at least 10 times the upper limit of normal 4.
• The clinical presentation can vary widely, with classical features including myalgia, weakness, and pigmenturia, although this classic triad is seen in less than 10% of patients 4.
• Compartment syndrome should be considered in patients with severe leg pain, and diagnosis can be supported with direct intra-compartmental pressure measurements and maintaining a high index of suspicion in acute presentations of exertional limb pain 2.

Treatment Options

• Emergent fluid resuscitation, fasciotomies, and debridement of necrotic muscle may be necessary in cases of compartment syndrome 2, 3.
• Urine alkalinization with sodium bicarbonate infusion may be considered, although optimal crystalloid selection is still debated 6.
• Patients with recurrent rhabdomyolysis or a history of exercise intolerance may require further investigations to identify underlying genetic disorders 4.