Background: Non-invasive ventilation (NIV) is increasingly being used to treat episodes
of acute respiratory failure not only in critical care and respiratory wards, but also in emergency
Aim: Aim of this review is to summarize the current indications for the management of NIV for respiratory
Methods: Current literature about the topic was reviewed and critically reported to describe the rationale
and physiologic advantages of NIV in various situations of respiratory failure.
Results: Early NIV use is commonly associated with the significant decrease in endotracheal intubation
rate, the incidence of infective complications (especially ventilatory associated pneumonia),
Intensive Care Units and the length of hospital stay and, in selected conditions, also in mortality
Severe acute exacerbation of chronic obstructive pulmonary disease (pH<7.35 and relative hypercarbia)
and acute cardiogenic pulmonary oedema are the most common NIV indications; in these
conditions NIV advantages are clearly documented. Not so evident are the NIV benefits in hypoxaemic
respiratory failure occurring without prior chronic respiratory disease (De novo respiratory
failure). One recent randomized control trial reported in hypoxaemic respiratory failure a survival
benefit of high-flow nasal cannulae over standard oxygen therapy and bilevel NIV. Evidence
suggests the advantages of NIV also in respiratory failure in immunocompromised patients or chest
Use during a pandemic event has been assessed in several observational studies but remains controversial;
there also is not sufficient evidence to support the use of NIV treatment in acute asthma exacerbation.
Conclusion: NIV eliminates morbidity related to the endotracheal tube (loss of airway defense
mechanism with increased risk of pneumonia) and in selected conditions (COPD exacerbation,
acute cardiogenic pulmonary edema, immunosuppressed patients with pulmonary infiltrates and hypoxia)
is clearly associated with a better outcome in comparison to conventional invasive ventilation.
However, NIV is associated with complications, especially minor complications related to interface.
Major complications like aspiration pneumonia, barotrauma and hypotension are infrequent.