Influenza Virus-Related Critical Illness

Prevention, Diagnosis, Treatment

Eric J. Chow; Joshua D. Doyle; Timothy M. Uyeki


Crit Care. 2019;23(214) 

In This Article


Influenza vaccination can reduce the risk of complications from influenza, including reducing illness severity and the risks of hospitalization, ICU admission, and death. The elderly, young children, pregnant women, and those with underlying medical conditions are most at risk for severe complications of influenza. A diagnosis of influenza should be considered in critically ill patients admitted with complications such as exacerbation of underlying chronic comorbidities, community-acquired pneumonia, and respiratory failure during influenza season. Influenza molecular assays are recommended for testing upper respiratory tract specimens in patients without signs of lower respiratory tract disease. However, because critically ill patients with lower respiratory tract disease may have cleared influenza virus in the upper respiratory tract, but have prolonged influenza viral replication in the lower respiratory tract, an endotracheal aspirate (preferentially) or bronchoalveolar lavage fluid specimen (if collected for other diagnostic purposes) should be tested by molecular assay. Antiviral treatment with standard-dose oseltamivir delivered orally or enterally by oro or naso-gastric tube is recommended as soon as possible for patients with suspected influenza without waiting for testing results. Corticosteroids should not be routinely administered for treatment of influenza and should only be given for other indications (e.g., exacerbation of asthma or chronic obstructive pulmonary disease, or septic shock), because of the risk for prolongation of influenza viral shedding and ventilator-associated pneumonia in critically ill influenza patients with respiratory failure. Future directions for treatment of influenza in critically ill patients include novel antiviral compounds, combination antiviral treatment with drugs with different mechanisms of action, immunomodulatory agents, and strategies for multi-modality, combination antiviral, and host-directed immunomodulatory therapies.