[Devices used in non-invasive ventilation for obstructive sleep apnea associating COPD and/or morbid obesity]

Obstructive Sleep Apnea (OSA), COPD and morbid obesity are three medical conditions with increasing prevalence, and their association is not rare in clinical practice. Whereas CPAP remains the gold standard therapy of severe symptomatic OSA, non-invasive ventilation, often requiring additional oxygen therapy, could be necessary to achieve a satisfactory arterial oxyhaemoglobin saturation and carbon dioxide level, and is used on a long term basis for patients with OSA and COPD/morbid obesity. Thus, non-invasive ventilation is intended to increase the minute ventilation, and the devices used could achieve this either by providing a targeted volume as a result ofa pressure (barometric devices), or an actual volume (volumetric devices). In this paper are described the basic mechanisms, operating principle, the advantages and limitations of the most used devices for this kind of patients, in ambulatory settings.