What is the management approach for a patient with chronic kidney disease (CKD) who develops rhabdomyolysis?

Management of Rhabdomyolysis in Patients with Chronic Kidney Disease

Aggressive intravenous saline hydration is the cornerstone of treatment for rhabdomyolysis in CKD patients, and should be initiated immediately upon diagnosis to prevent progression to acute kidney injury, which occurs in 33-50% of rhabdomyolysis cases and carries significantly higher mortality. 1, 2

Immediate Assessment and Risk Stratification

Upon presentation, immediately assess the following parameters to determine AKI risk:

• Serum myoglobin levels - Values >8,000 U/L are strongly associated with severe AKI (stage 2-3) and long-term renal decline 1
• Creatine kinase (CK) levels - Values >16,000 IU/L significantly increase AKI risk; levels can reach 100,000-1,000 IU/L in severe cases 3, 4
• Serum phosphate, potassium, and bicarbonate at admission - These are strongly correlated with stage 2-3 AKI development 1
• Need for mechanical ventilation - This is associated with increased risk of severe AKI 1

Fluid Resuscitation Protocol

Initiate aggressive volume expansion with normal saline immediately - this is the single most important intervention to prevent AKI progression 2, 5:

• Target saline infusion rate of approximately 200-210 mL/hour during the first 60 hours 5
• Continue aggressive hydration until CK levels decline and urine output is adequate 2
• Monitor for volume overload, particularly critical in patients with pre-existing CKD 6

Adjunctive Therapies: Limited Evidence

The addition of mannitol and sodium bicarbonate to saline hydration does not appear necessary once appropriate saline expansion is provided 5:

• One study showed no difference in outcomes between saline alone versus saline plus mannitol and bicarbonate when adequate volume expansion (200+ mL/hour) was achieved 5
• Further studies are necessary to establish the importance of bicarbonate and mannitol in preventing AKI due to rhabdomyolysis 2

Medication Management During Acute Episode

Temporarily discontinue all potentially nephrotoxic medications immediately 6, 7:

• Stop statins immediately - Statins can cause rhabdomyolysis and must be discontinued if markedly elevated CK levels occur or myopathy is diagnosed or suspected 7
• Avoid NSAIDs completely - These are contraindicated in CKD patients with GFR <30 mL/min/1.73 m² and should be avoided in all CKD patients taking RAAS blocking agents 6
• Withdraw RAAS antagonists (ACE inhibitors, ARBs) temporarily during the acute illness 6
• Suspend metformin in patients who become acutely unwell, particularly if GFR <30 mL/min/1.73 m² 6

Renal Replacement Therapy Indications

Initiate hemodialysis or CVVH if the patient develops 1, 4:

• Stage 3 AKI (approximately 44% of severe rhabdomyolysis cases) 1
• Severe hyperkalemia unresponsive to medical management 2
• Severe metabolic acidosis 2
• Volume overload refractory to diuretics 1

Approximately 26.6% of patients with severe rhabdomyolysis require RRT 1

Monitoring Protocol

Monitor the following parameters closely:

• Serum CK levels - Should show rapid decrease toward normal values; CK >5,000 U/L confirms severe rhabdomyolysis 1
• Serum creatinine and eGFR - Measure at 48-96 hours and continue monitoring 6
• Electrolytes (particularly potassium and phosphate) - Check frequently during acute phase 1
• Urine output and color - Pigmenturia (tea-colored urine) indicates myoglobinuria 3

Long-Term Renal Outcomes

Assess for CKD progression 3 months after the rhabdomyolysis episode 1:

• Measure eGFR and compare to pre-rhabdomyolysis baseline 1
• A decrease in eGFR >20 mL/min/1.73 m² occurs in approximately 28.8% of patients 1
• Long-term renal decline is directly correlated to serum myoglobin levels >8,000 U/L at admission and severity of the initial AKI 1

Mortality Considerations

• Overall mortality rate is approximately 10% in rhabdomyolysis 3
• Mortality is significantly higher in patients who develop acute renal failure 3
• Early recognition and aggressive treatment are key to reducing mortality 2, 3

Prevention of Recurrence

Once the acute episode resolves, investigate underlying causes if this is recurrent rhabdomyolysis, particularly:

• History of exercise intolerance 3
• Family history of neuromuscular disorders 3
• Substance abuse (cocaine, alcohol) 4
• Medication-induced causes (statins, particularly in combination with other risk factors) 7

Before restarting statins in CKD patients, recognize that risk factors for statin-induced myopathy include age ≥65 years, uncontrolled hypothyroidism, renal impairment, and concomitant use with certain other drugs 7