The art and science of non-invasive ventilation

Abstract

SummaryNon-invasive ventilation (NIV) is one of the most relevant recent advances in the management of patients with severe acute respiratory failure (ARF). NIV is considered a standard of care for the management of hypercapnic ARF in patients with acute exacerbation of chronic obstructive pulmonary disease. With an appropriate selection of patients, NIV can reduce the need for invasive mechanical ventilation, mortality and length of stay. Patients with severe hypoxemic ARF have in general a lower likelihood to need tracheal intubation when NIV as a support for ARF is added to the standard medical treatment. However, the effects of NIV on mortality are less evident, and the heterogeneity of the different published studies suggests that the efficacy may be different among different populations. The optimal time for intubation after NIV failure remains a challenging issue due to increasing evidences on the relationship between delayed intubation and excess mortality in these populations. In intubated patients with preexisting lung disease, the use of NIV in order to advance extubation during difficult and prolonged weaning can result in reduced periods of endotracheal intubation, complication rates and improved survival. Moreover, NIV immediately after extubation is effective in avoiding respiratory failure after extubation and improving survival in patients at risk for this complication, particularly those with chronic respiratory disorders, cardiac co-morbidity, and hypercapnic respiratory failure.KEY WORDS: non-invasive ventilation, acute respiratory failure, weaning, hypoxemic respiratory failure, hypercapnic respiratory failure. IntroductionNon-invasive ventilation (NIV) is one of the most relevant recent advances in the management of patients with severe acute respiratory failure (ARF). Non-invasive ventilation is ventilatory support through the upper airways of patients with an interface, usually a mask; therefore, tracheal intubation or a tracheostomy is not needed. The benefits of NIV appear to be the consequence of avoiding tracheal intubation and the associated morbidity and mortality (1, 2). There are several potential advantages for the use of NIV. Some patients can be managed out of an intensive care unit (ICU), a particularly stressful environment, with additional benefits in reducing the occupation of ICU beds and related costs. Ventilatory support can be intermittent and therefore withdrawal of NIV can be gradual. These patients can cooperate in respiratory therapy; they can receive nebulised therapy, expectorate and communicate with staff and their relatives. However, there are limitations for NIV. Unnecessary delay in intubation of those patients who fail with NIV treatment is associated with worse outcome (3). Some patients do not tolerate the mask due to claustrophobia or other causes, and nasal bridge skin breakdown can occur and difficult the use of NIV. Non-invasive ventilation is now considered as a firstline intervention in selected patients with severe exacerbation of chronic obstructive...