Is diuresis safe in patients with rhabdomyolysis?

Diuresis in Rhabdomyolysis: Safety and Management

Diuresis is generally not recommended as a primary treatment strategy in rhabdomyolysis, as it may increase the risk of acute kidney injury unless adequate volume resuscitation has first been achieved. 1

Initial Management Approach

• Early and aggressive fluid resuscitation with isotonic saline (0.9% NaCl) is the cornerstone of rhabdomyolysis management to prevent acute kidney injury 2, 3
• For severe rhabdomyolysis (CK >15,000 IU/L), volumes greater than 6L of fluid per day may be required; for moderate cases, 3-6L per day is typically sufficient 2, 3
• Initial fluid resuscitation should be started as early as possible, as delayed treatment is associated with higher risk of kidney injury 3

Diuretics in Rhabdomyolysis

• The KDOQI Work Group specifically addressed diuretics in rhabdomyolysis, noting that osmotic diuretics like mannitol may only benefit patients with markedly elevated creatine kinase levels (>30,000 U/L), though even this benefit remains undefined 1
• Mannitol should be administered with caution and is contraindicated in patients with oligoanuria 1
• Diuretics should only be considered after adequate volume expansion has been achieved, and primarily for the management of volume overload rather than as a primary treatment for rhabdomyolysis 1

Monitoring Parameters

• Close monitoring of urine output is essential to ensure adequate kidney perfusion 3
• Repeated bioassessment should include plasma myoglobin, creatine kinase, and electrolytes, particularly potassium 2
• Monitor urine pH, which should ideally be maintained at approximately 6.5 3

Evidence on Fluid Management

• A retrospective analysis showed that progression to established renal failure can be avoided with prophylactic fluid treatment 4
• When comparing saline alone versus saline plus mannitol and bicarbonate, the study found that once appropriate saline expansion is provided, the addition of mannitol and bicarbonate may be unnecessary 4
• There is limited high-quality evidence to support the routine use of bicarbonate-containing fluids, mannitol, and loop diuretics in rhabdomyolysis 5

Potential Complications and Precautions

• Excessive diuresis without adequate volume replacement can worsen renal hypoperfusion and increase the risk of acute kidney injury 2
• Electrolyte abnormalities, particularly hyperkalemia, can lead to life-threatening cardiac arrhythmias and must be closely monitored 2
• Patients with cardiac or renal compromise are at risk of fluid overload with aggressive fluid administration, requiring careful monitoring 3

Special Considerations

• In patients who develop acute kidney injury despite fluid resuscitation, renal replacement therapy may be necessary 6
• Forced alkaline diuresis has been found useful in some cases of non-traumatic rhabdomyolysis-associated acute kidney injury 6
• Continuous hemofiltration with super-high-flux membranes has shown efficacy in removing circulating myoglobin in severe cases 7

In conclusion, while diuretics have a role in managing volume overload in patients with rhabdomyolysis, they should not be used as a primary treatment strategy and should only be considered after adequate volume expansion has been achieved. The priority remains early and aggressive fluid resuscitation to prevent acute kidney injury.