What type of rhabdomyolysis is a patient (Pt) found down for an unknown time at risk for developing?

Crush-Induced Rhabdomyolysis in Patients Found Down for Unknown Time

A patient found down for an unknown time is at risk for developing crush-induced rhabdomyolysis, which can lead to acute kidney injury, electrolyte abnormalities, and compartment syndrome if not promptly identified and treated.

Clinical Presentation and Diagnosis

Patients found down for an unknown period typically develop rhabdomyolysis due to prolonged pressure on muscle tissue causing muscle breakdown. This presents with:

• Muscle pain, tenderness, or weakness in compressed areas
• Swelling of affected limbs
• Dark, tea-colored urine (myoglobinuria)
• Laboratory findings:
  • Elevated creatine kinase (CK) levels (at least 10 times the upper limit of normal)
  • Elevated BUN with potential normal GFR initially
  • Electrolyte abnormalities (hyperkalemia, hypocalcemia)
  • Myoglobinuria on urinalysis

Immediate Management

1. Aggressive fluid resuscitation:

   • Isotonic saline at 200-300 mL/hour to maintain urine output >200-300 mL/hour 1
   • Continue until CK levels decrease to <1,000 U/L

2. Electrolyte monitoring and correction:

   • Monitor potassium, calcium, phosphate levels every 12-24 hours
   • Do not add potassium to IV fluids until adequate renal function is confirmed 1
   • Treat hyperkalemia aggressively if present

3. Renal function monitoring:

   • Check creatinine, BUN, and urine output frequently
   • If unexplained severe muscle symptoms develop, promptly evaluate CK, creatinine, and perform urinalysis for myoglobinuria 2

Complications to Monitor

1. Acute Kidney Injury:

   • Most significant complication of rhabdomyolysis
   • Inadequate fluid resuscitation is the most common preventable cause 1

2. Compartment Syndrome:

   • Perform frequent neurovascular checks
   • Measure compartment pressures if suspected
   • Consider surgical consultation for decompressive fasciotomy if compartment pressure >30 mmHg 1

3. Electrolyte Abnormalities:

   • Hyperkalemia (can cause cardiac arrhythmias)
   • Hypocalcemia
   • Hyperphosphatemia
   • Metabolic acidosis

When to Escalate Care

Consider early referral to nephrology or higher level of care for:

• CK levels >5,000 U/L with renal complications 1
• Development of acute kidney injury
• Oliguria despite adequate hydration
• Severe electrolyte imbalances unresponsive to treatment
• Need for potential renal replacement therapy

Special Considerations

• Elderly patients require more careful fluid titration to avoid volume overload 1
• CK levels may not peak until 24-72 hours after muscle injury 1
• Patients with pre-existing renal disease are at higher risk for complications

Prognosis

Prognosis is highly variable and depends on:

• Duration of immobility
• Extent of muscle damage
• Promptness of treatment
• Development of complications
• Pre-existing conditions

Early recognition and aggressive fluid resuscitation significantly improve outcomes and prevent progression to acute kidney injury, which is the most serious complication of crush-induced rhabdomyolysis.