[Ventilatory assist therapy].

NPPV has been shown to improve arterial blood gas values, prevent symptoms resulting from alveolar hypoventilation, and decrease hospitalization in patients with chronic respiratory failure with COPD. Regarding acute exacerbation of COPD, the utility of NPPV has been established so NPPV will be regarded first-line therapy as ventilatory assist therapy. On the other hand, with respect to chronic stable COPD, the utility of NPPV isn' t established yet. However NPPV cases have been increasing rapidly in these years, as new home respiratory care technique. From now on, we have to evaluate the objective utility of NPPV from the standpoint of evidence.