It is that time of year again to be vigilant for cases of influenza
Influenza is not benign and causes > 40,000 deaths per year and is the 7th leading cause of death in the US
In the critically ill, the most severe disease occurs in patients > 65 and those with underlying cardiopulmonary disease
Critically ill patients with influenza can present with fever, cough, bilateral interstitial infiltrates, hypoxemia, and leukopenia
Other serious complications include myocarditis, encephalitis, and Reye syndrome
Amantadine and rimantadine should no longer be used, as the resistance has risen to > 90% in some populations
Oseltamivir (PO) and zanamivir (powder/inhalation) are the approved neuraminidase inhibitors; both decrease the severity and duration of illness; should be given as early as possible, preferably within 36 hours
Beigel JH. Influenza. Crit Care Med 2008;36:2660-6.