What is the role of sodium bicarbonate (NaHCO3) in the management of rhabdomyolysis?

Role of Sodium Bicarbonate in Management of Rhabdomyolysis

Sodium bicarbonate is not recommended as a routine treatment in the management of rhabdomyolysis as it has not been shown to improve outcomes related to acute kidney injury or mortality. 1

Pathophysiology and Complications of Rhabdomyolysis

Rhabdomyolysis is characterized by rapid muscle breakdown and release of intracellular muscle components into the circulation. The most serious complication is acute kidney injury (AKI), which can significantly increase morbidity and mortality. The mechanisms of kidney injury include:

• Tubular obstruction from myoglobin precipitation
• Direct nephrotoxicity of myoglobin
• Renal vasoconstriction
• Intratubular cast formation

Evidence-Based Management Approach

First-Line Treatment: Aggressive Fluid Resuscitation

• Intravenous fluid resuscitation remains the cornerstone of therapy for preventing AKI in rhabdomyolysis 1
• Target urine output of >2 mL/kg/hr to maintain adequate renal perfusion
• Normal saline is the preferred fluid for initial resuscitation

Sodium Bicarbonate: Not Routinely Indicated

The most recent evidence strongly argues against routine use of sodium bicarbonate:

1. The 2022 Eastern Association for the Surgery of Trauma practice management guideline conditionally recommends against treatment with bicarbonate in patients with rhabdomyolysis 1

2. A 2022 propensity score-matched cohort study found that bicarbonate therapy was associated with:

   • Higher incidence of AKI
   • Higher rate of dialysis dependency
   • Higher 30-day mortality
   • Longer hospital stays
   • Greater volume overload 2

3. A comprehensive review in 2020 concluded that the use of sodium bicarbonate in practical situations is not entirely justified 3

When Sodium Bicarbonate Might Be Considered

Despite the general recommendation against routine use, sodium bicarbonate might be considered in specific scenarios:

• Severe metabolic acidosis (pH <7.15) 4
• Patients with compartment syndrome with rhabdomyolysis 5
• To alkalinize urine in patients with myoglobinuria, though evidence for this is limited 4

Monitoring and Additional Management

• Monitor serum creatine kinase (CK) levels
• Monitor electrolytes closely, particularly potassium, calcium, and phosphate
• Assess for compartment syndrome in patients with localized muscle swelling
• Consider renal replacement therapy if severe AKI develops despite preventive measures

Potential Risks of Sodium Bicarbonate

• Volume overload
• Electrolyte imbalances (particularly hypocalcemia)
• Paradoxical intracellular acidosis
• Metabolic alkalosis

Algorithm for Management

1. Confirm diagnosis of rhabdomyolysis (CK >5 times upper limit of normal)
2. Initiate aggressive IV fluid resuscitation with normal saline
3. Monitor urine output, targeting >2 mL/kg/hr
4. Monitor for and treat electrolyte abnormalities
5. Consider sodium bicarbonate only if:
   • Severe metabolic acidosis is present (pH <7.15)
   • Compartment syndrome is present
6. If AKI develops despite preventive measures, consider renal replacement therapy

In conclusion, while sodium bicarbonate has traditionally been used in the management of rhabdomyolysis, current evidence does not support its routine use. The focus should remain on early and aggressive fluid resuscitation with normal saline to prevent acute kidney injury.