Noninvasive Ventilatory Support in Obstructive Disorders

Casanova et al., in a one-year study (145), randomized 52 COPD patients to standard care or standard care plus NIV with outcomes that included rate of acute exacerbations, hospital admissions, need for intubation and mortality at three, six, and 12 months. Bi-level positive pressure in spontaneous mode was implemented at an expiratory positive airway pressure of 4 cmH20 and an inspiratory positive airway pressure level of 12 cmH20, adjusted to decrease dyspnea and accessory muscle use. Five of the NIV group (total n = 26) did not tolerate it and the remainder used it for 6.2 hours per 24 hours, with only a few using it for less than 3 hr/day. One-year survival was similar between groups, as was the number of exacerbations. The breathlessness scores decreased in the NIV group, but only one psychomotor test improved. There was no evidence that the results were better in more hypercapnic patients (Paco2 7.3 kPa) or in those who used NIV for 5 hours per 24 hours. 

In an Italian multicenter trial (146), 122 stable hypercapnic COPD patients on LTOT for more than six months were randomized to continue LTOT alone, or LTOT plus NIV using a bi-level positive pressure device, over a two-year period. Although dropout rates were similar in both groups and compliance with NIV was impressive at 9 hours per 

24 hours, the authors showed only small differences between groups in dyspnea and Pac02. 

The studies do, however, suggest that primary end points of number of acute exacerbations and hospital admissions may be a more sensitive measure than mortality. Tuggey et al. (147) examined the economic impact of home NIV in COPD patients with recurrent exacerbations who responded well to NIV during these acute episodes. Good tolerance to home NIV resulted in a cost saving of 11,720 euros (5698-17,743 euros) per patient per year. The number of hospital admissions in the year on NIV compared to the previous year was reduced from five to three and hospital days decreased from a mean (SD) of 78 (51) to 

Abbreviations COPD, chronic obstractive pulmonary disease NIV, noninvasive ventilation LTOT, longterm oxygen therapy CPAP, continuous positive airway pressure. 

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