We discussed a case about a young man with substance use disorder, who presented with acute encephalopathy and diffuse muscle aches. He was diagnosed with rhabdomyolysis with CK up to 12,000. His acute encephalopathy was due to acute methamphetamine intoxication.

Etiologies of rhabdomyolysis

• Traumatic (injury, immobilization, burns)
• Non-traumatic (Exertional such as exercise / shivering / seizures vs non-exertional such as medications / toxins / infections / electrolyte abnormalities)

Diagnosis of rhabdomyolysis

• CK ≥ 5x upper limit normal
• Red/brown urine, +/- myalgias, fevers, leukocytosis, hyperkalemia, hyperphosphatemia, hypocalcemia, AKI, elevated AST / ALT, myoglobinuria (UA w/ + Hgb but no RBC)

Treatment of rhabdomyolysis

• Treat underlying cause
• IV hydration
  • Goal: CK < 5000 and/or UOP 200-300 cc/hr
• Can consider sodium bicarbonate in severe rhabdomyolysis if ALL the following are true:
  • NO hypocalcemia (precipitates calcium carbonate -> worsening hypocalcemia)
  • Arterial pH < 7.50
  • Serum bicarb < 30

Complications of rhabdomyolysis

• Cardiac arrhythmia / arrest (related to hyperkalemia)
• Acute renal failure
• Compartment syndrome
• DIC (rare)