Management of Acute Tubular Necrosis Following Rhabdomyolysis
Immediate aggressive intravenous fluid resuscitation with isotonic saline is the single most critical intervention for ATN from rhabdomyolysis, with early initiation (ideally within 6 hours) being essential to prevent irreversible kidney damage and reduce mortality. 1, 2
Immediate Fluid Resuscitation Protocol
Begin 0.9% normal saline at 1 liter per hour immediately upon diagnosis, even before complete diagnostic workup is finished 1, 3. This aggressive approach is non-negotiable and represents the difference between recovery and dialysis dependence 4.
Fluid Volume Targets by Severity
- Severe rhabdomyolysis (CK >30,000 U/L): Administer >6 liters per day of intravenous fluids 1, 5
- Moderate rhabdomyolysis: Administer 3-6 liters per day 1, 5
- Target urine output of 300 mL/hour (approximately 3-5 mL/kg/hour for a 70 kg patient), which is 6-10 times higher than standard oliguria thresholds 1, 5
Critical Timing Considerations
Delayed fluid resuscitation beyond 6 hours significantly increases the risk of acute kidney injury and mortality 1, 2. If you suspect rhabdomyolysis-induced ATN, start fluids immediately—do not wait for confirmatory laboratory values 4.
Fluid Type Selection
Use isotonic saline (0.9% NaCl) exclusively for initial volume expansion 1, 5, 3.
Fluids to AVOID
- Never use potassium-containing solutions (Lactated Ringer's, Hartmann's solution, Plasmalyte A) because potassium levels can increase markedly after reperfusion even with intact renal function 5, 3
- Avoid starch-based colloids due to their association with higher rates of AKI and bleeding complications 5, 3
Electrolyte Management
Monitor potassium levels every 6-12 hours in severe cases, as hyperkalemia can precipitate life-threatening cardiac arrhythmias and pulseless electrical activity 1, 3.
Specific Electrolyte Monitoring
- Check CK, creatinine, potassium, calcium, and phosphorus every 6-12 hours 1, 3
- Assess for metabolic acidosis, which commonly occurs 1
- Monitor for hypocalcemia and hyperphosphatemia 1
Treat hyperkalemia aggressively with standard protocols (insulin/glucose, calcium gluconate, albuterol, sodium polystyrene sulfonate) 3. Do not delay treatment waiting for repeat laboratory values if ECG changes are present.
Urinary Alkalinization: NOT Recommended
Do not routinely use sodium bicarbonate for urinary alkalinization in rhabdomyolysis-induced ATN 5. Current evidence from Kidney International guidelines shows no benefit of active alkalinization over aggressive saline resuscitation alone for preventing pigment nephropathy 5.
Limited Bicarbonate Indications
Reserve bicarbonate only for:
- Life-threatening hyperkalemia (as part of standard hyperkalemia protocol) 5
- Severe metabolic acidosis (pH <7.1) 5
Large doses of bicarbonate can worsen hypocalcemia by decreasing ionized calcium levels, which is already problematic in rhabdomyolysis 5.
Diuretics: Use With Extreme Caution
Diuretics are NOT recommended as primary treatment and may increase the risk of AKI unless adequate volume resuscitation has been achieved first 5.
When Diuretics May Be Considered
- Only after adequate volume expansion has been documented 1, 5
- Primarily for management of volume overload, not as treatment for rhabdomyolysis itself 5
- Mannitol is not recommended routinely as studies show little additional benefit over crystalloid resuscitation alone and it is potentially nephrotoxic 5
The KDOQI Work Group notes that osmotic diuretics like mannitol may only benefit patients with CK >30,000 U/L, though even this benefit remains undefined, and mannitol is contraindicated in patients with oligoanuria 5.
Monitoring Parameters
Insert a bladder catheter immediately to monitor hourly urine output unless urethral injury is suspected 1, 5, 3.
Hourly Assessment
Serial Laboratory Monitoring
- Plasma myoglobin, CK, and potassium measurements 1, 5
- Electrolyte panels every 6-12 hours in severe cases 1, 3
- Serial creatinine and BUN 1
Medication Review
Immediately discontinue all nephrotoxic medications and supplements including 1, 3:
- Statins
- NSAIDs
- ACE inhibitors/ARBs (especially in combination with NSAIDs and diuretics—the "triple whammy") 6
- Creatine monohydrate
- Red yeast rice
- Any other nephrotoxic drugs
Compartment Syndrome Surveillance
Maintain high suspicion for compartment syndrome, which can both cause and complicate rhabdomyolysis 1, 3.
Fasciotomy Indications
Perform early fasciotomy when 1, 3:
- Compartment pressure exceeds 30 mmHg
- Differential pressure (diastolic BP – compartment pressure) is <30 mmHg
Early signs include pain, tension, paresthesia, and paresis; late signs include pulselessness and pallor (indicating irreversible damage) 1. Do not wait for late signs—they indicate irreversible tissue damage.
Renal Replacement Therapy
Initiate RRT if CK remains persistently elevated despite 4 days of adequate hydration, as this indicates severe rhabdomyolysis with significant risk of irreversible kidney damage 1, 3.
Additional RRT Indications
- Refractory hyperkalemia despite medical management 1, 3
- Severe metabolic acidosis unresponsive to bicarbonate 1, 3
- Progressive acute kidney injury with rising creatinine 1
- Fluid overload despite conservative management 5
Intermittent hemodialysis is the preferred modality as it provides rapid clearance of potassium and allows treatment of multiple patients per day on the same machine 5.
Consider discontinuation of RRT when urine output recovers adequately (>100 mL/day) 1.
Duration of Treatment
Continue intravenous fluids until 3:
- CK levels decrease substantially
- Urine output remains adequate (≥300 mL/hour)
- Electrolytes normalize
- Renal function stabilizes or improves
This typically requires several days of intensive monitoring and fluid administration 4, 7.
Common Pitfalls to Avoid
Delaying fluid resuscitation is the single most common error and is associated with higher risk of acute kidney injury and worse outcomes 1, 4, 2. Start fluids immediately upon suspicion—do not wait for laboratory confirmation.
Inadequate fluid volume (using <6L/day in severe cases) may fail to prevent renal complications 1, 5. Be aggressive with volume—young, carefully monitored patients tolerate large positive fluid balances well 4.
Failure to monitor and correct hyperkalemia can lead to pulseless electrical activity and cardiac arrest where external defibrillation may be ineffective 1. Check potassium frequently and treat aggressively.
Using potassium-containing fluids can exacerbate hyperkalemia and precipitate fatal arrhythmias 5, 3. Always use 0.9% normal saline.
Missing compartment syndrome can result in irreversible muscle and nerve damage 1, 3. Maintain high suspicion and measure compartment pressures liberally.
Routine use of bicarbonate or mannitol adds unnecessary risk without proven benefit 5. Stick to aggressive saline resuscitation as the primary intervention.