What is the acute management of crush syndrome (traumatic rhabdomyolysis)?

Acute Management of Crush Syndrome (Traumatic Rhabdomyolysis)

Start aggressive intravenous fluid resuscitation with 0.9% normal saline at 1000 mL/hour immediately upon locating the victim—even while still trapped—to prevent acute kidney injury and life-threatening hyperkalemia. 1

Pre-Hospital/Field Management (Critical Window)

Immediate Fluid Resuscitation Before Extrication

• Establish IV access in any accessible limb; if no vein is available, insert an intra-osseous needle in a lower limb. 1
• Infuse 0.9% normal saline at 1000 mL/hour initially while the victim remains trapped. 1
• If extrication duration exceeds 2 hours, reduce the infusion rate by at least 50% (to ≥500 mL/hour) to prevent fluid overload. 2, 1
• This pre-extrication fluid therapy is the single most critical intervention—delays beyond 6 hours dramatically increase mortality and renal failure risk. 1, 3

Monitoring During Extrication

• Maintain continuous cardiac monitoring because hyperkalemia from muscle breakdown can cause fatal arrhythmias immediately upon reperfusion. 4
• Recognize that life-threatening hyperkalemia may occur even before the victim is freed from entrapment. 5

Hospital Management

Continued Aggressive Fluid Resuscitation

• Administer 3–6 liters of 0.9% normal saline in the first 24 hours, targeting a urine output of 200–300 mL/hour until myoglobinuria (tea-colored urine) resolves. 4, 1
• Insert a bladder catheter to monitor hourly urine output unless urethral injury is suspected. 1
• Adjust fluid volumes based on clinical response, volume status, signs of fluid overload, patient age, body mass, and environmental temperature. 1

Laboratory Monitoring

• Measure serial serum creatinine, BUN, creatine kinase (CK), potassium, calcium, phosphate, and acid-base status. 2, 4
• Renal failure is highly associated with massive muscle damage (CK >25,000 U/L) and insufficient initial fluid resuscitation (<10,000 mL in first 2 days). 3
• Monitor urine output and color hourly; myoglobinuria indicates ongoing renal risk. 4

Compartment Syndrome Assessment and Management

Clinical Diagnosis

• Assess for the "6 Ps": pain (especially out of proportion to injury), paresthesia, paresis, pain with passive stretch, pink color, and pulselessness. 1, 5
• Measure compartment pressures if available: ≥30 mmHg or differential pressure (diastolic BP minus compartment pressure) <30 mmHg confirms diagnosis. 4

Immediate Surgical Intervention

• Perform immediate fasciotomy for diagnosed compartment syndrome; delays beyond 6–8 hours significantly increase risk of irreversible muscle/nerve damage, limb loss, and death. 4
• Remove tight-fitting dressings immediately. 1
• Never elevate the affected limb above heart level—this reduces perfusion pressure and worsens compartment ischemia. 4, 5
• Perform radical removal of all necrotic muscle during fasciotomy. 6

Management of Life-Threatening Complications

Hyperkalemia Management

• Initiate standard hyperkalemia protocols immediately if potassium is elevated (calcium gluconate for cardiac protection, insulin/glucose, beta-agonists, sodium bicarbonate). 2
• Recognize that hypercatabolic state often requires one or more dialysis treatments per day to control potassium. 2

Renal Replacement Therapy

• Initiate dialysis for life-threatening acidosis, hyperkalemia, or fluid overload—do not wait for absolute indications. 1
• Earlier dialysis initiation may improve survival in trauma-associated AKI. 2, 1
• Intermittent hemodialysis is the preferred modality, providing rapid potassium clearance and ability to treat multiple patients per day. 2

Controversial Interventions to Avoid

Mannitol

• Do not administer mannitol before adequate volume resuscitation is achieved, as it can worsen renal injury in hypovolemic patients. 1
• Studies show little extra benefit regarding kidney function compared with crystalloid resuscitation alone. 2

Urine Alkalinization

• Do not perform routine urine alkalinization with bicarbonate—current evidence does not support benefit over aggressive fluid resuscitation alone. 2, 1
• Large doses of bicarbonate may decrease free calcium and worsen the hypocalcemia associated with crush injury. 2

Hyperbaric Oxygen

• Hyperbaric oxygen has no proven benefit in reversing muscle necrosis once compartment syndrome is established and should not replace emergent fasciotomy. 4

Critical Pitfalls to Avoid

• Never triage crush victims away from active treatment due to lack of dialysis availability—intensive fluid management can restore renal function and avoid dialysis need entirely. 1, 5
• Failure to recognize crush injury early and missing the critical 6-hour window for fluid resuscitation leads to poor outcomes. 1
• Patients arriving >40 hours after injury without adequate initial resuscitation have nearly 100% rate of renal failure versus 25% in those treated within 40 hours. 3
• Avoid starch-based fluids, which are associated with increased rates of AKI and bleeding. 2

Prognosis

• Overall mortality in crush-injury patients is approximately 20%, with AKI being the second most common cause of death after direct trauma. 4
• Even with optimal early management, a 2-hour entrapment duration confers high likelihood of poor functional outcome. 4