Forced Alkaline Diuresis Dosing in Rhabdomyolysis
Current evidence does not support the routine use of forced alkaline diuresis with sodium bicarbonate in rhabdomyolysis, as it has not been shown to improve outcomes compared to aggressive crystalloid resuscitation alone. 1, 2
Evidence Against Alkaline Diuresis
The most recent high-quality guidelines explicitly recommend against using urinary alkalinization with bicarbonate for rhabdomyolysis treatment:
Kidney International guidelines clearly state that current evidence does not demonstrate benefit of active alkalinization over aggressive fluid resuscitation in preventing pigment nephropathy. 1
The Eastern Association for the Surgery of Trauma meta-analysis found that bicarbonate administration did not improve the incidence of acute renal failure or need for dialysis in patients with rhabdomyolysis. 2
The American College of Physicians recommends against bicarbonate use, as it did not reduce acute kidney injury or dialysis requirements. 1
Potential Risks of Bicarbonate Administration
If bicarbonate is used despite lack of evidence, clinicians must be aware of significant risks:
Large doses of bicarbonate can worsen hypocalcemia by decreasing free calcium levels, which is particularly dangerous in rhabdomyolysis patients who already have calcium dysregulation. 1
Bicarbonate adds extra volume without proven benefit, potentially contributing to fluid overload in vulnerable patients. 1
Recommended Approach: Aggressive Crystalloid Resuscitation
The evidence-based treatment is aggressive intravenous fluid resuscitation with isotonic saline, targeting a urine output of ≥300 mL/hour (approximately 3-5 mL/kg/hour for a 70 kg patient). 1, 3, 4
Fluid Resuscitation Protocol
Begin with 0.9% normal saline at 1000 mL/hour during initial resuscitation. 1
For severe rhabdomyolysis (CK >15,000-30,000 U/L), administer >6L of intravenous fluids per day. 1, 3
Early vigorous fluid resuscitation with ≥12L daily has been shown to reduce mortality from nearly 100% to <20% in crush syndrome cases. 5
Fluids to Avoid
Avoid potassium-containing solutions (Ringer's lactate, Hartmann's solution, Plasmalyte A) as potassium levels may increase markedly after reperfusion. 1
Avoid starch-based fluids due to association with increased acute kidney injury rates. 1
Limited Role for Bicarbonate
The only potential indication for sodium bicarbonate in rhabdomyolysis is:
Treatment of severe metabolic acidosis (as a general critical care principle, not specifically for myoglobin clearance). 6
Treatment of life-threatening hyperkalemia (bicarbonate aids potassium reuptake into cells). 6
In these specific scenarios, standard bicarbonate dosing for acidosis or hyperkalemia would apply, not a "forced alkaline diuresis" protocol.
Monitoring Parameters
Insert urinary catheter to monitor hourly urine output and urine pH. 6
Target urine output >2 mL/kg/hour (malignant hyperthermia context) or ≥300 mL/hour (general rhabdomyolysis). 6, 1
Monitor CK, creatinine, potassium, calcium, and phosphorus every 6-12 hours in severe cases. 3
Critical Pitfall to Avoid
Do not delay aggressive crystalloid resuscitation while attempting to alkalinize urine—delayed fluid resuscitation is associated with significantly higher risk of acute kidney injury and worse outcomes. 1, 3 The focus should be on achieving adequate urine output through volume expansion, not on manipulating urine pH.