What are the diagnosis and treatment options for rhabdomyolysis?

Rhabdomyolysis Diagnosis and Treatment

Aggressive fluid resuscitation with isotonic saline (0.9% NaCl) targeting a urine output of >300 mL/hour is the cornerstone of rhabdomyolysis management and should be initiated immediately upon diagnosis to prevent acute kidney injury. 1

Diagnosis

Diagnostic Criteria

• Serum creatine kinase (CK) elevation ≥10 times the upper limit of normal is the primary diagnostic marker 1, 2
• Peak CK levels typically occur 24-72 hours after muscle injury 1
• Serial CK monitoring every 6-12 hours is recommended during the acute phase 1

Clinical Presentation

• Classic triad (present in <10% of cases) 2:
  • Myalgia
  • Muscle weakness
  • Pigmenturia (tea/cola-colored urine)
• Other presentations may include:
  • Non-specific symptoms
  • Pain, tension, paresthesia, and paresis in affected limbs (if compartment syndrome present) 1

Essential Laboratory Tests 1

• Serum CK (primary diagnostic marker)
• Plasma myoglobin (rises earlier than CK but has shorter half-life of 2-3 hours)
• Urinalysis (positive for blood on dipstick but negative for RBCs on microscopy)
• Serum electrolytes (watch for hyperkalemia, hypocalcemia, hyperphosphatemia)
• Renal function tests (BUN, creatinine)
• Coagulation studies if disseminated intravascular coagulation suspected

Treatment Algorithm

1. Immediate Management

• Fluid Resuscitation

  • Begin aggressive hydration with isotonic saline (0.9% NaCl) 1, 3
  • Target urine output >300 mL/hour 1, 3
  • Avoid potassium-containing fluids like Lactated Ringer's 1
  • Do not delay fluid resuscitation while waiting for laboratory results 1

• Electrolyte Management

  • Monitor and urgently correct hyperkalemia if present 1
  • Address symptomatic hypocalcemia 1
  • Monitor for hyperphosphatemia 4

2. Compartment Syndrome Management

• Monitor for signs of compartment syndrome (pain, tension, paresthesia, paresis) 1
• Measure compartment pressure if suspected (threshold >30 mmHg or differential pressure <30 mmHg) 1
• Obtain urgent surgical consultation for fasciotomy if compartment syndrome confirmed 1, 5
• Remove tight dressings and avoid limb elevation if compartment syndrome suspected 5

3. Renal Protection

• Discontinue all nephrotoxic medications (NSAIDs, ACE inhibitors/ARBs, certain antibiotics) 1
• Discontinue causative agents (e.g., statins) immediately 1
• Obtain nephrology consultation for all cases with acute kidney injury 1
• Consider renal replacement therapy for:
  • Severe hyperkalemia unresponsive to medical management
  • Refractory acidosis
  • Volume overload
  • Uremic symptoms 1

Special Considerations

Compartment Syndrome

• Fasciotomy is indicated in 5:
  • Hypotensive patients with intracompartment pressures ≥20 mmHg
  • Uncooperative/unconscious patients with pressures ≥30 mmHg
  • Normotensive patients with positive clinical findings and pressures ≥30 mmHg
• Benefits of fasciotomy decrease significantly if delayed beyond 8 hours 5

Renal Replacement Therapy

• Intermittent hemodialysis is preferred for most patients with crush-induced AKI 5
  • Provides rapid potassium clearance
  • Allows treatment of multiple patients per machine daily
  • Options for minimal anticoagulation in bleeding-prone patients
• Continuous renal replacement therapy may be used if available but requires high nursing care 5
• Peritoneal dialysis may be preferable in small children 5

Follow-up

• Recognize early symptoms of recurrence 1
• Follow up with primary care and/or nephrology within 1-2 weeks 1
• Consider genetic counseling for patients with recurrent episodes or positive family history 1

Common Pitfalls to Avoid

• Delaying fluid resuscitation while waiting for laboratory confirmation 1
• Using potassium-containing fluids for resuscitation 1
• Failing to recognize compartment syndrome early 5
• Continuing nephrotoxic medications 1
• Missing underlying genetic disorders in cases of recurrent rhabdomyolysis 1, 2

Rhabdomyolysis is a potentially life-threatening condition with approximately 10% mortality rate, which increases significantly in patients who develop acute renal failure 2. Early recognition and aggressive management are essential to prevent complications and improve outcomes.