Noninvasive positive-pressure ventilation

In their in-depth review of noninvasive positive-pressure ventilation in acute respiratory failure,1 Oscar Peñuelas and colleagues did not discuss the use of this treatment in patients with infections that are transmitted through aerosols. The efficacy of noninvasive positive-pressure ventilation in such patients has not been adequately tested, but anecdotal reports and observational studies have shown that this treatment can be successfully used in patients with acute respiratory failure resulting from human-adapted avian influenza, aspergillosis and varicella.2^–4 The use of noninvasive positive-pressure ventilation eliminated the need for intubation in most patients with severe acute respiratory syndrome.5^,6 When critical care resources are overstretched, such as during an influenza pandemic, noninvasive positive-pressure ventilation may be of value as an alternative to invasive ventilation or it may at least buy clinicians some time until invasive ventilation is available for their patient.

The available data on the risk to health care workers of acquiring infectious diseases through aerosols while they are performing noninvasive positive-pressure ventilation are conflicting and often methodologically flawed.5^,6 Indeed, in a recent set of World Health Organization guidelines this procedure was included as one of the aerosol-generating procedures for which the risk of pathogen transmission is still controversial or possible but not documented.6 Nevertheless, experience in the field mostly shows the use of noninvasive positive-pressure ventilation to be safe, if appropriate precautions are taken5^,6:infected patients should be placed in appropriate facilities and personal protective equipment should be worn. To further reduce the risk of pathogen diffusion, an exhalation port that generates round-the-tube airflow and a viral-bacterial filter interposed between the mask and the exhalation port should be used.6