What is the management of Rhabdomyolysis?

Management of Rhabdomyolysis

Immediately initiate aggressive intravenous fluid resuscitation with isotonic saline targeting a urine output of 300 mL/hour to prevent acute kidney injury, which is the most critical intervention in rhabdomyolysis management. 1

Immediate Fluid Resuscitation

Aggressive IV fluid administration is the cornerstone of treatment and must be started without delay. 1 Early initiation is critical, as delayed treatment significantly increases the risk of acute kidney injury. 2, 1

• For severe rhabdomyolysis (CK >15,000 IU/L): Administer more than 6L of fluid per day 2, 1
• For moderate cases: Administer 3-6L per day 2, 1
• Target urine output: Maintain at least 300 mL/hour to facilitate myoglobin clearance and prevent renal tubular obstruction 1, 3
• Monitor closely for fluid overload, particularly in patients with cardiac or renal compromise 1

The large volume requirements reflect the need to rapidly clear myoglobin from the circulation before it causes tubular obstruction and acute tubular necrosis. 3, 4

Discontinue All Causative Agents Immediately

Stop all medications and supplements that may have contributed to rhabdomyolysis as soon as the diagnosis is suspected. 2, 1

• Statins and other prescription medications must be discontinued immediately 2, 1
• Dietary supplements to discontinue: red yeast rice (containing lovastatin), creatine monohydrate, wormwood oil, licorice, and Hydroxycut 2, 1
• In anesthesia settings: Avoid succinylcholine and inhaled anesthetics in at-risk populations 1

Electrolyte Monitoring and Correction

Check electrolyte panels every 6-12 hours in severe cases, with particular attention to potassium levels. 1

• Repeated bioassessment should include: plasma myoglobin, CK, and potassium measurements 2
• Correct significant hyperkalemia immediately, as it can precipitate cardiac arrhythmias and arrest 1
• Monitor and correct: hypocalcemia and hyperphosphatemia 1
• Assess for metabolic acidosis via arterial blood gas, which commonly occurs in severe cases 2, 1

Hyperkalemia is particularly dangerous as it can lead to life-threatening cardiac complications including pulseless electrical activity and cardiac arrest. 1

Compartment Syndrome Surveillance

Maintain high suspicion for compartment syndrome, which can both cause and complicate rhabdomyolysis. 2, 1

• Early signs to monitor: pain, tension, paresthesia, and paresis 2, 1
• Late signs indicating irreversible damage: pulselessness and pallor 2, 1
• Perform early fasciotomy when:
  • Compartment pressure exceeds 30 mmHg, OR
  • Differential pressure (diastolic blood pressure – compartment pressure) is <30 mmHg 2, 1

Missing compartment syndrome in traumatic or severe exertional cases can lead to irreversible muscle and nerve damage. 1

Pain Management Algorithm

Use acetaminophen as first-line analgesic at 500-1000 mg (maximum 4-6 grams daily) to avoid nephrotoxic effects. 2, 1

• Avoid all NSAIDs (ibuprofen, ketoprofen, diclofenac, naproxen, mefenamic acid) due to gastrointestinal and renal toxicity 2, 1
• For severe pain unresponsive to acetaminophen:
  • Use oral morphine 20-40 mg for opioid-naive patients 2, 1
  • Provide round-the-clock dosing with rescue doses (10-15% of total daily dose) for breakthrough pain 2
• In patients with established acute kidney injury (eGFR <30 mL/min):
  • Use fentanyl or buprenorphine as safest opioid choices 2, 1

Renal Replacement Therapy Indications

Consider renal replacement therapy for specific complications that cannot be managed medically. 1

• Indications for RRT:
  • Refractory hyperkalemia
  • Severe metabolic acidosis
  • Progressive acute kidney injury despite adequate hydration 1
• Initiate RRT if: CK remains persistently elevated despite 4 days of adequate hydration 1
• Consider discontinuation when: urine output recovers adequately (>100 mL/day) 1

Duration of IV Fluid Therapy

Continue intravenous fluids until CK levels decrease to less than 1,000 U/L. 3

This endpoint indicates that active muscle breakdown has ceased and the risk of ongoing myoglobin-induced renal injury has substantially decreased. 3, 4

Critical Pitfalls to Avoid

• Do not delay fluid resuscitation, as this is associated with higher risk of acute kidney injury and worse outcomes 1
• Do not use inadequate fluid volumes, which may fail to prevent renal complications 1
• Do not miss compartment syndrome, particularly in traumatic or severe exertional cases 1
• Do not use NSAIDs for pain management due to nephrotoxic effects in patients already at high risk for acute kidney injury 2, 1

Special Considerations for Statin-Induced Cases

For statin-associated rhabdomyolysis, consider nonstatin therapies for continued lipid management after discontinuation. 2

• Alternative lipid-lowering agents: ezetimibe, PCSK9 inhibitors, or bempedoic acid 2
• If statins are eventually needed: use hydrophilic statins (fluvastatin, pravastatin) as they have fewer metabolic interactions 2
• Genetic risk factors: SLCO1B1 gene mutations increase risk of statin-induced rhabdomyolysis 2