What is the appropriate management of rhabdomyolysis?

Management of Rhabdomyolysis

Initiate aggressive intravenous fluid resuscitation with isotonic saline immediately upon diagnosis, targeting a urine output of 300 mL/hour, as this is the cornerstone of treatment and delayed resuscitation significantly increases acute kidney injury risk and mortality. 1, 2

Immediate Fluid Resuscitation Protocol

Fluid administration must begin as early as possible—even before patient extrication in trauma scenarios—as delayed initiation is the single most important modifiable risk factor for acute kidney injury. 1, 3

• Administer isotonic saline (0.9% NaCl) as the primary resuscitation fluid, avoiding potassium-containing solutions like Lactated Ringer's or Hartmann's solution since potassium levels can increase markedly after reperfusion even with intact renal function 3
• For severe rhabdomyolysis (CK >30,000 U/L), infuse >6L per day; for moderate cases (CK 5,000-30,000 U/L), use 3-6L per day 1, 3
• Target urine output of ≥300 mL/hour (approximately 3-5 mL/kg/hour for a 70 kg patient), which is 6-10 times higher than standard oliguria thresholds 3, 4
• Insert a bladder catheter immediately to monitor hourly urine output and urine pH 3, 2
• Avoid starch-based fluids due to their association with increased rates of AKI 3

Critical Electrolyte Monitoring and Management

Check electrolyte panels every 6-12 hours in severe cases, focusing on potassium, calcium, and phosphorus, as hyperkalemia can precipitate sudden cardiac arrest. 1

• Correct significant hyperkalemia immediately using standard protocols (insulin/glucose, calcium gluconate, sodium bicarbonate for severe cases), as this is a life-threatening complication 1, 2, 5
• Monitor and correct hypocalcemia and hyperphosphatemia, which commonly occur but avoid aggressive calcium replacement early as it may worsen tissue calcification 1, 5
• Assess for metabolic acidosis via arterial blood gas, particularly in severe cases 1
• Measure CK, creatinine, potassium, calcium, and phosphorus every 6-12 hours until CK is declining and <5,000 U/L 1, 4

Medications to Immediately Discontinue

Stop all causative agents immediately, including statins, NSAIDs, and any potentially nephrotoxic medications. 1

• Discontinue statins and all prescription medications that may contribute to rhabdomyolysis 1
• Stop dietary supplements including red yeast rice, creatine monohydrate, wormwood oil, licorice, and Hydroxycut 1
• Avoid NSAIDs entirely due to nephrotoxic effects 6, 1
• In anesthesia settings, succinylcholine and inhaled anesthetics (halothane, isoflurane, sevoflurane) are absolutely contraindicated in patients with muscular dystrophy or at-risk populations 6, 1

Controversial Therapies: What NOT to Use Routinely

Do not use urinary alkalinization with sodium bicarbonate routinely, as current evidence does not demonstrate benefit over aggressive fluid resuscitation alone. 3

• Bicarbonate is reserved only for severe metabolic acidosis (pH <7.1) or life-threatening hyperkalemia, not for routine urine alkalinization 3, 2
• Large doses of bicarbonate can worsen hypocalcemia by decreasing free calcium levels 3
• Do not routinely use mannitol, as studies suggest little additional benefit compared to crystalloid resuscitation alone and it is potentially nephrotoxic 3
• Mannitol may only benefit patients with markedly elevated CK (>30,000 U/L) and adequate urine output, but this benefit remains undefined 3, 4
• Diuretics should only be considered after adequate volume expansion for management of volume overload, not as primary treatment 3

Compartment Syndrome Surveillance

Maintain high suspicion for compartment syndrome, which both causes and complicates rhabdomyolysis, particularly in trauma and severe exertional cases. 1, 2

• Monitor for early signs including pain out of proportion to examination, muscle tension, paresthesia, and paresis 1
• Perform early fasciotomy when compartment pressure exceeds 30 mmHg or when differential pressure (diastolic BP minus compartment pressure) is <30 mmHg 1, 4
• Late signs including pulselessness and pallor indicate irreversible damage 1

Renal Replacement Therapy Indications

Consider initiating RRT for refractory hyperkalemia, severe metabolic acidosis (pH <7.1), or progressive AKI despite adequate fluid resuscitation. 1

• If CK remains persistently elevated despite 4 days of adequate hydration, initiate RRT 1, 2
• Intermittent hemodialysis is the preferred modality as it provides rapid clearance of potassium 3
• Consider discontinuing RRT when urine output recovers adequately (>100 mL/day) 1

Pain Management Strategy

Use acetaminophen as first-line analgesic, avoiding nephrotoxic NSAIDs entirely. 1

• Reserve opioids for severe muscle pain unresponsive to acetaminophen 1
• Use oral morphine for opioid-naive patients with moderate to severe pain 1
• Fentanyl or buprenorphine are the safest opioid choices in patients with acute kidney injury 1

Critical Pitfalls to Avoid

The most common and dangerous errors in rhabdomyolysis management are delayed fluid resuscitation, inadequate fluid volume, and missing compartment syndrome. 1

• Delayed fluid resuscitation (>6 hours from onset) is associated with significantly higher risk of AKI and worse outcomes 1, 7
• Inadequate fluid volume (targeting standard urine output of 0.5 mL/kg/hour instead of 3-5 mL/kg/hour) fails to prevent renal complications 1, 3
• Failure to monitor and correct hyperkalemia can result in pulseless electrical activity and cardiac arrest 1, 5
• Missing compartment syndrome, particularly in traumatic or severe exertional cases, leads to irreversible muscle and nerve damage 1, 4

Duration of Treatment

Continue intravenous fluids until CK levels decline to <1,000 U/L and urine output remains adequate without aggressive hydration. 4, 7