Epidemiology

Etiology

• Traumatic
  • Crush injury
  • Direct injury
• Nontraumatic
  • Seizures
  • Overexertion (e.g., strenuous exercise)
  • Intoxication (e.g., cocaine, heroin, amphetamines, MDMA, alcohol, carbon monoxide, phencyclidine)
  • Skeletal muscle ischemia
  • Infection
  • Adverse drug reactions (e.g., neuroleptics, statins)

Pathophysiology

• Rhabdomyolysis → release of the following substances:
  • Creatine phosphokinase (CPK) and serum myoglobin → pigment nephropathy → acute tubular necrosis → acute kidney injury (intrinsic)
  • Potassium → cardiac arrhythmia
  • Lactic acid → metabolic acidosis
• Hypovolemia → ↓ renal perfusion → acute kidney injury (prerenal)
  • Hypovolemia is predominantly due to third spacing of extracellular fluid into damaged muscle tissue.
• Reperfusion syndrome → compartment syndrome

Clinical features

Diagnostics

• Positive urine dipstick for blood without RBCs on microscopy

Treatment