In a patient with extensive burns (>20% total body surface area) who has rhabdomyolysis (creatine kinase >5,000 U/L) or hemoglobinuria, what are the indications, timing, dosing regimen, monitoring parameters, and contraindications for initiating alkaline diuresis?

Alkaline Diuresis in Burn Patients with Rhabdomyolysis or Hemoglobinuria

Alkaline diuresis is not recommended in current burn management guidelines; instead, aggressive volume resuscitation with balanced crystalloids targeting urine output of 1–2 mL/kg/hour is the standard approach for preventing myoglobin-induced acute kidney injury in burn patients with rhabdomyolysis. 1

Primary Management Strategy

The cornerstone of preventing acute kidney injury from rhabdomyolysis or hemoglobinuria in burn patients is aggressive fluid resuscitation, not alkaline diuresis 1, 2:

• Initiate immediate volume repletion with balanced crystalloid (Lactated Ringer's preferred) using 3–4 mL/kg/%TBSA for electrical burns or burns with significant muscle damage 1
• Target higher urine output of 1–2 mL/kg/hour (rather than the standard 0.5–1 mL/kg/hour) to facilitate myoglobin clearance and prevent tubular precipitation 1
• Administer 20 mL/kg crystalloid bolus within the first hour for immediate hypovolemic shock management 1

Why Alkaline Diuresis Is Not Standard Practice

Current guidelines do not recommend alkaline diuresis because:

• Volume resuscitation alone is highly effective at reducing serum myoglobin by 41 ± 16% within 24 hours 2
• No beneficial pharmacologic agents have been identified for burn-related AKI prevention despite multiple investigations 3
• The primary pathophysiology of early burn AKI (0–3 days) is hypovolemia, poor renal perfusion, and direct cardiac suppression—all addressed by aggressive fluid therapy 3

Advanced Renal Support When Volume Resuscitation Fails

If oliguria persists despite adequate fluid administration:

• Initiate continuous veno-venous hemodiafiltration (CVVHDF) early (within 24 hours of diagnosis) using high-flux or high-cut-off membranes 2
• CVVHDF reduces serum myoglobin by 44 ± 20% and is effective at removing myoglobin when high-flux filters are used 2
• Early CVVHDF reduces the risk of ARF and mortality in burn patients with rhabdomyolysis 2

Monitoring Parameters

• Serum creatine kinase (CK) and myoglobin levels: Peak CK levels are more than two times higher and myoglobin levels more than four times higher in non-survivors compared to survivors 2
• Hourly urine output: Primary parameter for fluid adjustment, targeting 1–2 mL/kg/hour in the presence of myoglobinuria 1
• Serum creatinine and urine output per KDIGO criteria to stage AKI severity 3
• Arterial lactate concentration for adequacy of resuscitation 4

Timing Considerations

• Early fluid resuscitation is critical: Delayed resuscitation (4.4 ± 2.1 hours in non-survivors vs. 1.7 ± 1.0 hours in survivors) significantly increases mortality 5
• Initiate CVVHDF within 24 hours if renal injury progresses despite initial volume repletion 2

Albumin Administration

For severe burns (TBSA >30%) with rhabdomyolysis:

• Add 5% human albumin between 8–12 hours post-burn to reduce total crystalloid volume while maintaining adequate resuscitation 6, 4
• Target serum albumin >30 g/L with doses of 1–2 g/kg/day 6, 4
• Albumin reduces mortality (OR = 0.34; 95% CI 0.19–0.58; P < 0.001) and abdominal compartment syndrome from 15.4% to 2.8% 6, 4

Critical Pitfalls to Avoid

• Do not withhold fluids based solely on elevated creatinine; patients may be under-resuscitated despite abnormal laboratory values 6
• Do not delay CVVHDF when oliguria persists despite adequate volume resuscitation, as early initiation improves outcomes 2
• Avoid "fluid creep" (excessive crystalloid administration) by adding albumin early to limit total crystalloid volume while maintaining resuscitation goals 6, 4
• Do not initiate vasopressors before confirming adequate intravascular volume and cardiac function with echocardiography 6, 4
• Avoid nephrotoxic drugs in addition to burn injury to prevent compounding renal damage 7

Prognosis

• Mortality is 50% in burn patients with rhabdomyolysis who develop ARF 2
• Acute kidney injury occurs in >25% of severely burned patients and carries mortality as high as 80% 3, 7
• Sepsis is present in 96% of non-survivors vs. 44% of survivors, making infection prevention critical 5