Can infection cause rhabdomyolysis?

Can Infection Cause Rhabdomyolysis?

Yes, infection is a well-established cause of rhabdomyolysis and should be considered in any patient presenting with muscle breakdown, particularly in the context of viral or bacterial illness. 1

Mechanisms by Which Infection Causes Rhabdomyolysis

Infections trigger rhabdomyolysis through multiple pathophysiologic pathways:

• Direct viral invasion of muscle tissue leading to myocyte injury and breakdown 1
• Systemic inflammatory response that damages muscle cells through cytokine-mediated mechanisms 2, 3
• Sepsis-related multi-organ failure with associated muscle tissue hypoperfusion 1
• Electrolyte derangements (particularly hypokalemia and hypophosphatemia) secondary to infection 1, 4
• Prolonged immobilization during severe illness, especially when patients are unable to call for help after falling 1

Specific Infectious Causes

Viral Infections

Influenza is a recognized cause of rhabdomyolysis, with documented cases following both seasonal and pandemic strains including H1N1 1, 5. The mechanism involves direct viral-mediated muscle injury and systemic inflammatory response 5.

COVID-19 infection causes rhabdomyolysis as one mechanism of acute kidney injury, alongside volume depletion, multi-organ failure, and thrombotic processes 1.

Coxsackie B virus has been documented to cause severe rhabdomyolysis with acute renal failure, though this complication is rare 6. Serological testing may reveal the diagnosis when rhabdomyolysis follows a viral illness 6.

Bacterial Infections

Legionella pneumophila is a recognized but uncommon cause of rhabdomyolysis with high morbidity and mortality when extrapulmonary involvement occurs 7. Physicians should specifically consider Legionella in patients presenting with the triad of respiratory symptoms, rhabdomyolysis, and renal failure 7.

Rickettsial and Other Infections

Anaplasmosis can present with rhabdomyolysis as a severe manifestation, though this is less frequent than with other tickborne rickettsial diseases 1.

Clinical Recognition and Diagnosis

Key Clinical Features

When evaluating for infection-related rhabdomyolysis, look for:

• Muscle pain, weakness, and swelling in the context of recent or active infection 2, 3
• Dark or tea-colored urine indicating myoglobinuria 4
• Fever and systemic symptoms of the underlying infection 7, 5
• History of prolonged immobilization during illness, particularly in elderly patients who may have fallen and been unable to get help 1

Laboratory Confirmation

Creatine kinase (CK) elevation is the hallmark diagnostic finding, with levels often exceeding 3,000-5,000 U/L in clinically significant cases 4. In severe infection-related cases, CK can reach extremely high levels (>50,000 U/L) 7.

Essential initial laboratory workup includes:

• CK levels (repeated measurements as levels peak 24-120 hours after onset) 4
• Serum creatinine and electrolytes, particularly potassium 4
• Urinalysis showing myoglobinuria (positive for blood without RBCs) 4
• Complete blood count to assess for leukocytosis suggesting infection 1

Etiology-specific testing should include:

• Viral studies when viral myositis is suspected 4
• Legionella urinary antigen in patients with pneumonia and rhabdomyolysis 7
• Blood cultures if bacterial sepsis is suspected 1

Management Priorities

Immediate Interventions

Aggressive fluid resuscitation is the cornerstone of treatment, with isotonic crystalloid (0.9% normal saline) as the initial fluid of choice 4, 3. For severe rhabdomyolysis (CK >15,000 IU/L), volumes greater than 6L may be required; for moderate cases, 3-6L per day is typically sufficient 4.

Early initiation of fluid therapy is critical, as delayed treatment significantly increases the risk of acute kidney injury 4.

Electrolyte Management

Monitor potassium levels closely and correct hyperkalemia emergently, as it can precipitate life-threatening cardiac arrhythmias 4. Obtain ECG to identify cardiac complications of hyperkalemia 3.

Trend CK, creatinine, and electrolytes daily until CK is declining and renal function is stable 4.

Infection-Specific Treatment

Treat the underlying infection appropriately with antimicrobials when indicated 7. For Legionella pneumonia complicated by rhabdomyolysis, azithromycin and levofloxacin are appropriate choices 7.

Do not delay antibiotic therapy in patients with suspected bacterial infection, as treating the infection may prevent or ameliorate acute kidney injury 1.

Critical Pitfalls to Avoid

Do not overlook infection as a cause when evaluating rhabdomyolysis, particularly in patients with recent viral illness or pneumonia 7, 5, 6.

Do not use NSAIDs for pain management in patients with rhabdomyolysis, as they increase nephrotoxicity risk in patients already vulnerable to acute kidney injury 4. Use acetaminophen as first-line analgesia instead 4.

Do not wait for peak CK levels before initiating treatment - begin aggressive hydration immediately based on clinical suspicion, as CK levels may not peak until 24-120 hours after onset 4.

Consider compartment syndrome in patients with severe infection-related rhabdomyolysis, particularly those with prolonged immobilization 4. Early fasciotomy is indicated when compartment pressure exceeds 30 mmHg 4.

Prognosis and Complications

Early diagnosis and appropriate treatment of both the infection and rhabdomyolysis are essential to improve outcomes 7. Timely intensive care management, including judicious use of dialysis when complicated by acute renal failure, leads to good outcomes even in severe cases 7.

Monitor for progression to chronic kidney disease after acute kidney injury from rhabdomyolysis, with appropriate follow-up after hospital discharge 1.