What is the immediate management for pediatric patients with rhabdomyolysis?

Immediate Management of Pediatric Rhabdomyolysis

Aggressive early fluid resuscitation with crystalloids is the cornerstone of management for pediatric rhabdomyolysis to prevent acute kidney injury. 1

Initial Assessment and Diagnosis

• Key diagnostic criteria:

  • Elevated serum creatine kinase (CK) >10 times upper limit of normal
  • Presence of myoglobinuria (dark/tea-colored urine)
  • Clinical symptoms may include muscle pain, weakness, and swelling

• Laboratory evaluation:

  • Immediate measurement of:
    • Creatine phosphokinase (CPK)
    • Plasma myoglobin
    • Electrolytes (especially potassium)
    • BUN and creatinine
    • Urinalysis for myoglobin

Fluid Management Protocol

• Initial resuscitation:

  • Administer up to 40-60 mL/kg of balanced/buffered crystalloid solutions in boluses (10-20 mL/kg per bolus) over the first hour 1
  • Titrate to clinical markers of cardiac output (heart rate, blood pressure, capillary refill, urine output)
  • Discontinue if signs of fluid overload develop (pulmonary edema, hepatomegaly)

• Maintenance fluid therapy:

  • Continue IV fluids at 3-6 L/day for moderate rhabdomyolysis (CPK <15,000 IU/L)
  • Increase to >6 L/day for severe rhabdomyolysis (CPK >15,000 IU/L) 1
  • Target urine output of 2 mL/kg/hour

• Fluid type:

  • Use balanced/buffered crystalloids rather than 0.9% saline 1
  • Avoid starches and gelatins 1

Monitoring Protocol

• Frequent reassessment:

  • Vital signs every 1-2 hours
  • Hourly urine output via bladder catheterization
  • Monitor urine pH (maintain at 6.5) 1
  • Serial measurements of CPK, myoglobin, electrolytes, and renal function
  • Daily weights and fluid balance

• Electrolyte management:

  • Hyperkalemia: Eliminate IV/oral potassium sources

    • For K+ >7.0-7.5 mEq/L or ECG changes:
      • Rapid-acting insulin (0.1 U/kg IV) with 25% dextrose (2 mL/kg)
      • Sodium bicarbonate (1-2 mEq/kg IV push)
      • Calcium gluconate (100-200 mg/kg/dose) for life-threatening arrhythmias 1

  • Hyperphosphatemia:

    • Eliminate phosphate from IV solutions
    • Consider phosphate binders (aluminum hydroxide 50-150 mg/kg/day divided q6h) for 1-2 days only 1

Compartment Syndrome Assessment

• Monitor for compartment syndrome signs:

  • Pain (spontaneous or with passive stretch)
  • Tension in affected muscle compartments
  • Paresthesia
  • Paresis
  • Repeat assessment every 30-60 minutes during first 24 hours 1

• If compartment syndrome suspected:

  • Measure compartment pressure (>30 mmHg or differential pressure <30 mmHg is diagnostic)
  • Early fasciotomy for established compartment syndrome 1

Indications for Renal Replacement Therapy

• Consider hemodialysis for:
  • Persistent hyperkalemia (>6.0 mEq/L) unresponsive to medical management
  • Severe metabolic acidosis (pH <7.1)
  • Volume overload unresponsive to diuretics
  • Uremic symptoms
  • Rapidly rising BUN/creatinine levels 2

Disposition Criteria

• Admission criteria:

  • CPK >5,000 IU/L
  • Presence of electrolyte abnormalities
  • Impaired renal function
  • Inability to maintain adequate oral hydration
  • Underlying medical conditions that increase risk of AKI

• ICU admission criteria:

  • Severe electrolyte abnormalities (especially hyperkalemia)
  • Evidence of acute kidney injury
  • Need for continuous cardiac monitoring
  • Compartment syndrome requiring surgical intervention
  • Hemodynamic instability

• Discharge criteria:

  • Decreasing CPK levels
  • Normal or improving renal function
  • Resolution of electrolyte abnormalities
  • Adequate oral intake
  • No evidence of compartment syndrome

Common Pitfalls and Caveats

1. Delayed recognition: Early aggressive fluid resuscitation is critical - patients who develop acute kidney injury typically had delayed initiation of volume resuscitation 1

2. Inadequate monitoring: Failure to monitor urine output and electrolytes frequently can lead to missed complications

3. Blood sample handling: For accurate uric acid measurement, blood samples should be immediately placed on ice and analyzed within 4 hours to prevent degradation 1

4. Blind finger sweeps: Never perform blind finger sweeps in pediatric patients with potential airway obstruction as this can worsen the situation 1

5. Medication errors: Avoid nephrotoxic medications, particularly NSAIDs, which can worsen renal function 2

6. Fluid overload: While aggressive hydration is necessary, monitor for signs of fluid overload, especially in younger children

By following this structured approach to pediatric rhabdomyolysis management, clinicians can significantly reduce the risk of acute kidney injury and improve outcomes for these patients.