Noninvasive Ventilation in COPD Impact of Inspiratory Pressure Levels on Sleep Quality

Background: Although high-intensity noninvasive positive pressure ventilation (HI-NPPV) is superior to low-intensity noninvasive positive pressure ventilation (LI-NPPV) in controlling nocturnal hypoventilation in stable hypercapnic patients with COPD, it produces higher amounts of air leakage, which, in turn, could impair sleep quality. Therefore, the present study assessed the difference in sleep quality during HI-NPPV and LI-NPPV. Methods: A randomized, controlled, crossover trial comparing sleep quality during HI-NPPV (mean inspiratory positive airway pressure 29 +/- 4 mbar) and LI-NPPV (mean inspiratory positive airway pressure 14 mbar) was performed in 17 stable hypercapnic patients with COPD who were already familiar with HI-NPPV. Results: Thirteen patients (mean FEV1 27% +/- 11% predicted) completed the trial; four patients refused to sleep under LI-NPPV. There was no significant difference in sleep quality between the treatment groups (all P>.05), with a mean difference of -3.0% (95% CI, -10.0 to 3.9; P=.36) in the primary outcome, namely non-rapid eye movement sleep stages 3 and 4. However, nocturnal PaCO2 was lower during HI-NPPV compared with LI-NPPV, with a mean difference of -6.4 mm Hg (95% CI, -10.9 to -1.8; P=.01). Conclusions: In patients with COPD, high inspiratory pressures used with long-term HI-NPPV produce acceptable sleep quality that is no worse than that produced by lower inspiratory pressures, which are more traditionally applied in conjunction with LI-NPPV. In addition, higher pressures are more successful in maintaining sufficient alveolar ventilation compared with low pressures. Thus, HI-NPPV is a very promising new approach, but still requires large, longer-term trials to determine the impact on outcomes such as exacerbation rates and longevity.