What is the management of Rhabdomyolysis?

Management of Rhabdomyolysis

Aggressive fluid resuscitation is the cornerstone of rhabdomyolysis management, with a target urine output of >300 mL/hour to prevent acute kidney injury. 1, 2

Diagnosis and Initial Assessment

Definition and Diagnostic Criteria

• Rhabdomyolysis is defined as muscle breakdown with serum creatine kinase (CK) elevation at least 10 times the upper limit of normal 1, 3
• Peak CK levels typically occur 24-72 hours after muscle injury 1
• Diagnostic findings include:
  • Elevated serum CK (primary diagnostic marker)
  • Plasma myoglobin (rises earlier than CK but has shorter half-life of 2-3 hours)
  • Tea/cola-colored urine (myoglobinuria)
  • Positive dipstick for blood but negative for RBCs on microscopy 1

Essential Laboratory Tests

• Serum CK (monitor every 6-12 hours in acute phase)
• Electrolytes (particularly potassium, calcium, phosphorus, magnesium)
• Renal function tests (BUN, creatinine)
• Urinalysis
• Arterial blood gas (to assess for metabolic acidosis)
• Coagulation studies if disseminated intravascular coagulation is suspected 1

Immediate Management

Fluid Resuscitation

1. Begin immediate aggressive IV fluid resuscitation without delay, even before laboratory confirmation 1, 2
2. Initial fluid of choice: isotonic saline (0.9% NaCl) 2
3. Target urine output: >300 mL/hour 1, 4
4. Avoid potassium-containing fluids (e.g., Lactated Ringer's) as they may worsen hyperkalemia 1
5. Monitor fluid status closely to prevent volume overload, especially in patients with cardiac or renal compromise

Electrolyte Management

• Monitor and correct hyperkalemia urgently if present (life-threatening complication)
• Address hypocalcemia if symptomatic
• Monitor and correct hyperphosphatemia
• Assess for metabolic acidosis and correct if severe 1, 5

Ongoing Management

Monitoring

• Serial CK measurements every 6-12 hours until trending down 1
• Frequent electrolyte monitoring, particularly potassium
• Continuous assessment of renal function
• Urine output monitoring
• Vital signs and volume status 1, 5

Complications Management

1. Acute Kidney Injury

   • Nephrology consultation for all cases with AKI 1
   • Consider renal replacement therapy for:
     • Refractory hyperkalemia
     • Severe acidosis
     • Volume overload unresponsive to diuretics
     • Uremic symptoms 5

2. Compartment Syndrome

   • Monitor for signs: pain, tension, paresthesia, paresis
   • Measure compartment pressure if suspected (threshold >30 mmHg)
   • Urgent fasciotomy if confirmed 1

3. Disseminated Intravascular Coagulation

   • Monitor coagulation parameters
   • Treat according to hematology recommendations 5

Special Considerations

• Rhabdomyolysis from statins: Discontinue statin immediately; evaluate for statin-associated autoimmune myopathy if symptoms persist after discontinuation 6, 1
• Malignant hyperthermia-related rhabdomyolysis: Consider caffeine-halothane contracture test and RYR1 genetic testing 1
• Recurrent rhabdomyolysis: Evaluate for underlying genetic disorders, particularly if associated with exercise intolerance or positive family history 1, 3

Prevention of Recurrence

Identifying and Addressing Underlying Causes

• Discontinue nephrotoxic medications 6
• Avoid combining nephrotoxins (e.g., "triple whammy" of NSAIDs, diuretics, and ACE inhibitors/ARBs) 6
• Caution with medications that can cause rhabdomyolysis:
  • Statins (especially when combined with CYP3A4 inhibitors like certain macrolide antibiotics) 6
  • Red yeast rice supplements (contain lovastatin) 6
  • Wormwood oil, licorice, creatine monohydrate 6

Patient Education

• Avoid NSAIDs without medical consultation
• Use ACE inhibitors, decongestants, antivirals, antibiotics, and herbal products with caution 6
• Maintain adequate hydration, especially during exercise
• Recognize early symptoms of recurrence

Discharge Criteria and Follow-up

• Decreasing CK levels
• Normalized or improving renal function
• Resolved electrolyte abnormalities
• Adequate urine output
• Follow-up with primary care and/or nephrology within 1-2 weeks
• Serial monitoring of renal function and CK until normalized

Rhabdomyolysis is a potentially life-threatening condition that requires prompt recognition and aggressive management. The most critical intervention is early, vigorous fluid resuscitation to prevent acute kidney injury. Close monitoring of electrolytes, particularly potassium, is essential to prevent cardiac complications. With appropriate management, most patients recover completely, though some may develop chronic kidney disease requiring long-term follow-up.