What is the recommended treatment for rhabdomyolysis, including fluid resuscitation, electrolyte management, and indications for renal replacement therapy?

Treatment of Rhabdomyolysis

Aggressive intravenous fluid resuscitation with isotonic saline (0.9% NaCl) at 1 liter per hour is the cornerstone of rhabdomyolysis treatment, targeting a urine output of ≥300 mL/hour, while bicarbonate and mannitol are not recommended for routine use. 1, 2, 3

Immediate Fluid Resuscitation Protocol

Start aggressive IV fluid resuscitation immediately upon patient contact, even before complete assessment is finished. 1, 2

• Infuse 0.9% normal saline at 1000 mL/hour during the initial phase for adult patients to achieve rapid plasma volume expansion and promote myoglobin clearance 1, 2
• Reduce the infusion rate by at least 50% if the initial resuscitation extends beyond 2 hours to prevent volume overload 1, 2
• For severe rhabdomyolysis (CK >30,000 U/L or significant muscle injury), administer >6 liters of IV fluids per day to prevent acute kidney injury and need for dialysis 1
• For moderate rhabdomyolysis, administer 3-6 liters of IV fluids per day 1

Fluid Type Selection

Use isotonic saline (0.9% NaCl) exclusively as the primary crystalloid. 1, 2

• Avoid potassium-containing crystalloids (Lactated Ringer's, Hartmann's solution, Plasmalyte A) because reperfusion causes marked serum potassium elevations even with intact renal function 1, 2
• Avoid starch-based colloids due to their association with higher rates of acute kidney injury and bleeding complications 1, 2

Target Urine Output and Monitoring

Insert a bladder catheter immediately (unless urethral injury is suspected) and target urine output of ≥300 mL/hour or >2 mL/kg/hour. 1, 2, 4

• Monitor hourly urine output continuously to ensure adequate myoglobin clearance and prevent tubular precipitation 1
• Monitor CK, creatinine, potassium, calcium, and phosphorus every 6-12 hours in severe cases 1, 2
• Use point-of-care analyzers (e.g., iStat) when conventional laboratory services are unavailable, noting they require ambient temperature of 16-30°C for accurate operation 1

Electrolyte Management

Monitor and aggressively treat hyperkalemia, which is the most life-threatening complication. 2, 5

• Check serum potassium levels immediately and obtain an electrocardiogram to identify life-threatening hyperkalemia 5
• Treat hyperkalemia with standard protocols including calcium gluconate for cardiac membrane stabilization, insulin/glucose for intracellular potassium shift, and consider dialysis for refractory cases 2
• Monitor calcium and phosphorus closely, as hypocalcemia commonly accompanies rhabdomyolysis and can be worsened by bicarbonate administration 1

What NOT to Use: Bicarbonate and Mannitol

Do not routinely use bicarbonate for urinary alkalinization in rhabdomyolysis. 1, 3

• Current evidence shows no benefit of active alkalinization over aggressive saline resuscitation alone for preventing pigment-induced nephropathy 1, 3
• Large bicarbonate doses can worsen hypocalcemia by decreasing ionized calcium levels, which is already problematic in rhabdomyolysis 1
• Reserve bicarbonate only for life-threatening hyperkalemia or severe metabolic acidosis, following standard critical care dosing protocols 1, 2

Do not routinely use mannitol in rhabdomyolysis management. 1, 3

• Studies demonstrate minimal additional benefit compared to crystalloid resuscitation alone, and mannitol is potentially nephrotoxic 1, 3
• Mannitol may only benefit patients with markedly elevated CK (>30,000 U/L), though this benefit remains undefined, and it is contraindicated in patients with oligoanuria 1

Indications for Renal Replacement Therapy

Initiate dialysis early for the following indications: 1, 2

• Refractory hyperkalemia despite medical management 2
• Severe metabolic acidosis unresponsive to conservative measures 2
• Fluid overload despite conservative management 1, 2
• Persistently elevated CK levels after 4 days of adequate hydration 2

Use intermittent hemodialysis as the preferred modality, as it provides rapid clearance of potassium and allows treatment of multiple patients per day on the same machine 1

Compartment Syndrome Surveillance

Maintain high suspicion for compartment syndrome, particularly in trauma and electrical burn patients. 1, 2

• Perform early fasciotomy when compartment pressure exceeds 30 mmHg or when differential pressure (diastolic BP minus compartment pressure) falls below 30 mmHg 1, 2
• Perform escharotomy within 48 hours if circulatory compromise develops due to circumferential burns 1

Duration of Treatment and Medication Review

Continue IV fluids until all of the following criteria are met: 2

• CK levels are decreasing 2
• Urine output remains adequate 2
• Electrolytes normalize 2
• Renal function stabilizes or improves 2

Discontinue any medications or supplements that may worsen rhabdomyolysis, including statins, creatine monohydrate, and red yeast rice 2

Common Pitfalls to Avoid

• Delayed fluid resuscitation is associated with significantly higher risk of acute kidney injury - start fluids immediately upon recognition 1
• Failure to avoid potassium-containing fluids can exacerbate hyperkalemia, increasing risk of life-threatening cardiac arrhythmias 1
• Excessive fluid administration in patients with cardiac or renal compromise can cause fluid overload - monitor volume status carefully 1
• Using bicarbonate as primary therapy adds unnecessary fluid volume and carries risk without proven AKI-prevention benefit 1