Potential role of non-invasive ventilation by a face mask
In acute COPD exacerbations, non-invasive positivepressure ventilation (NPPV) decreases PaCO2 by unloading the respiratory muscles and supplementing alveolar ventilation. Several trials and meta-analysis support the use of NPPV by reducing ventilator associated pneumonia, intubation, duration of ICU stay, andmortality [13].The few studies on NPPV suggest that the response of middle-aged patients with acidotic COPD exacerbations to NPPV may extend to the geriatric population. In CHF, NPPV improves oxygenation, reduces work of breathing, and may prevent intubation,and decrease mortality [63]. One study demonstrated that,compared to medical treatment, continuous positive airway pressure (CPAP) decreased respiratory rate, decreased PaCO2, and improved oxygenation compared with baseline in elderly patients with hypoxaemic CHF [64]. However, the in-hospital mortality (28% versus 30%) was not different. There is no difference in outcome between NPPV and CPAP for CHF [65].