Noninvasive nocturnal ventilatory support in advanced lung disease from cystic fibrosis

Respiratory failure is the most common cause of death among people with cystic fibrosis (CF). The role of noninvasive positive-pressure ventilation (NPPV) in severe but stable lung disease from CF has not been adequately determined. We therefore sought to determine the tolerability and efficacy of NPPV in people with advanced lung disease from CF.

We studied 13 patients with CF, severe air flow limitation (mean +/- SD forced expiratory volume in the first second 0.8 +/- 0.3 L), and chronic respiratory failure (mean +/- SD P(aO2) 67 +/- 19 mm Hg and P(aCO2) 51 +/- 8 mm Hg). All patients were awaiting lung transplantation. NPPV was prescribed for 2 months. Overnight polysomnography, arterial blood gas values, pulmonary function, exercise capacity, and health-related quality of life were evaluated at baseline, after 2 months of NPPV, and again after a 1-month wash-out period off NPPV.

Eight patients completed the study and tolerated NPPV extremely well. These patients subjectively noted improvement in their symptoms and requested that they restart NPPV after completing the protocol. Nevertheless, NPPV did not improve objective measures of sleep quality, daytime blood gas values, pulmonary function, respiratory muscle strength, or exercise tolerance. All 8 patients were continued on NPPV and underwent successful lung transplantation.

NPPV is well tolerated by most patients with CF and severe lung disease and may be a useful bridge to support CF patients awaiting lung transplantation. However, despite subjective improvement, standard objective measures did not improve and cannot explain the reduced symptoms reported by these patients.