Would you use a diuretic, such as furosemide (Lasix) or mannitol, to treat rhabdomyolysis?

Management of Diuretics in Rhabdomyolysis

Diuretics should not be used to treat rhabdomyolysis except in cases of volume overload after adequate fluid resuscitation has been achieved. 1, 2

Pathophysiology and Treatment Priorities

Rhabdomyolysis involves the breakdown of skeletal muscle with release of intracellular contents into circulation, potentially leading to acute kidney injury (AKI). The management focuses on:

1. Early aggressive fluid resuscitation

   • Cornerstone of treatment
   • Restores renal perfusion
   • Dilutes nephrotoxic substances
   • Increases urine flow

2. Avoidance of nephrotoxic agents

   • Including diuretics in early management

Evidence Against Diuretic Use in Rhabdomyolysis

The KDOQI Work Group specifically addresses diuretics in rhabdomyolysis:

• Loop diuretics do not prevent AKI and may increase risk 1
• Osmotic diuretics (mannitol) have limited evidence:
  • May only benefit patients with severe rhabdomyolysis (CK >30,000 U/L) 1
  • Even in severe cases, true benefit remains undefined 1
  • Recent guidelines conditionally recommend against mannitol use 2

Management Algorithm

1. Initial Management:

   • Administer aggressive IV fluid resuscitation with 0.9% saline 1, 3
   • Target rate: 1-2 L/hour initially, then adjusted based on clinical response 1, 3
   • Monitor for adequate urine output (>0.5 mL/kg/hr)

2. Ongoing Management:

   • Continue IV fluids to maintain urine output
   • Monitor electrolytes, renal function, and fluid status
   • Treat underlying cause of rhabdomyolysis

3. When to Consider Diuretics:

   • Only after adequate fluid resuscitation
   • Only if volume overload develops (pulmonary edema, hypertension)
   • Furosemide 0.5-2 mg/kg IV may be considered 1

4. Contraindications to Diuretics:

   • Hypovolemia
   • Hypotension
   • Oliguria without adequate fluid resuscitation
   • Electrolyte abnormalities (especially hypokalemia)

Special Considerations

• Mannitol: Despite theoretical benefits (antioxidant properties, potential to reduce compartment pressure), current evidence does not support routine use 2, 4, 5

• Bicarbonate: No established benefit over crystalloid fluid resuscitation alone 2, 4

• Monitoring Parameters:

  • Urine output
  • Serum creatinine and BUN
  • Electrolytes (especially potassium)
  • Creatine kinase levels
  • Fluid balance

Common Pitfalls to Avoid

1. Premature diuretic administration before adequate fluid resuscitation, which can worsen renal hypoperfusion and increase AKI risk

2. Excessive focus on diuresis rather than addressing the underlying cause of rhabdomyolysis

3. Failure to recognize compartment syndrome, which requires surgical intervention regardless of medical management

4. Overlooking electrolyte abnormalities, particularly hyperkalemia, which can be life-threatening

5. Delaying renal replacement therapy when indicated by severe electrolyte disturbances or refractory volume overload

Conclusion

The evidence clearly demonstrates that diuretics should not be used routinely in the management of rhabdomyolysis. Early aggressive fluid resuscitation remains the cornerstone of therapy to prevent AKI. Diuretics should be reserved only for cases with volume overload after adequate fluid resuscitation has been achieved.