Non-invasive ventilation for critically ill patients with pandemic H1N1 2009 influenza A virus infection

We read with interest the study reported by Rello and colleagues [1]. The authors described the first 32 documented patients with pandemic influenza A H1N1 (PIAH1N1) virus infection hospitalized in an intensive care unit (ICU) in Spain. Twenty-four patients (75.0%) had refractory hypoxemia and required advanced mechanical ventilation. Eight patients (33.3%) received noninvasive mechanical ventilation at ICU admission. Six of these patients (75%) required further orotracheal intubation and invasive mechanical ventilation and two (33%) died. Non-invasive ventilation (NIV) is not recommended for patients with PIAH1N1 virus infection complicated by pneumonia, acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) because although NIV temporarily improves oxygenation and reduces the work of breathing in these patients, it does not necessarily change the natural disease course. On the other hand, NIV may increase the risk of respiratory pathogen transmission [2] and there is not enough evidence to support the treatment of ALI/ARDS with NIV. To date, three studies have suggested that NIV has not been successful in critically ill patients with hypoxemic respiratory failure attributable to PIAH1N1 virus infection [1,3,4]. In these studies a total of 76 patients received NIV, but 64 (84.2%) of these patients required subsequent intubation and invasive ventilation. Considering the high failure rate of NIV therapy in patients with PIAH1N1 virus infection and ALI/ARDS, the treatment of ARDS associated with the PIAH1N1 virus infection should be based upon published, evidence-based guidelines for sepsis-associated ARDS. Standard lung-protective ventilation strategies are appropriate initially [2,5].