From the Research
Influenza-induced rhabdomyolysis is a serious complication of influenza infection that can lead to significant morbidity and mortality, and early recognition and aggressive management are crucial to prevent long-term sequelae. This condition occurs when influenza viruses directly invade muscle cells or trigger an excessive immune response, causing muscle damage, as reported in a case study published in the BMJ case reports in 2018 1. The clinical implications include acute kidney injury from myoglobin toxicity, electrolyte imbalances (particularly hyperkalemia), compartment syndrome, and disseminated intravascular coagulation. Patients typically present with muscle pain, weakness, dark urine, and elevated creatine kinase levels.
Mechanisms of Influenza-Induced Rhabdomyolysis
The exact mechanisms of influenza-induced rhabdomyolysis are not fully understood, but it is thought to be related to the direct invasion of muscle cells by the influenza virus or the triggering of an excessive immune response, as suggested by a study published in the Netherlands journal of medicine in 1995 2. A more recent study published in BMJ case reports in 2018 1 reported a temporal relation between fever spikes and subsequent increase in serum creatine kinase, suggesting a possible link between the two.
Clinical Implications and Management
Management of influenza-induced rhabdomyolysis includes aggressive intravenous fluid administration (typically isotonic saline at 200-300 mL/hour initially, adjusted based on response), with a goal of maintaining urine output above 200 mL/hour to prevent kidney injury, as recommended by a study published in Clinical nephrology in 2006 3. Electrolyte abnormalities should be corrected, particularly potassium levels. Antiviral therapy with oseltamivir (75 mg twice daily for 5 days) should be initiated if within 48 hours of symptom onset. In severe cases with acute kidney injury, renal replacement therapy may be necessary, as reported in a case study published in Anaesthesia in 2011 4. Monitoring should include serial creatine kinase levels, renal function tests, and electrolytes.
High-Risk Groups and Prevention
Clinicians should maintain a high index of suspicion for rhabdomyolysis in influenza patients presenting with muscle pain, weakness, or dark urine, especially in high-risk groups such as children, the elderly, and those with underlying medical conditions, as highlighted by a study published in Klinische Padiatrie in 2008 5. Early recognition is crucial as mortality rates can reach 8% in severe cases. Prevention measures, such as vaccination and early treatment of influenza infection, can help reduce the risk of developing rhabdomyolysis.
- Key points to consider in the management of influenza-induced rhabdomyolysis include:
- Aggressive intravenous fluid administration to prevent kidney injury
- Correction of electrolyte abnormalities, particularly potassium levels
- Antiviral therapy with oseltamivir if within 48 hours of symptom onset
- Monitoring of serial creatine kinase levels, renal function tests, and electrolytes
- Early recognition and management of high-risk groups, such as children, the elderly, and those with underlying medical conditions.