Long-term reduction of hyperinflation in stable COPD by non-invasive nocturnal home ventilation

SummaryObjectiveThe role of non-invasive positive pressure ventilation (NPPV) in stable COPD with chronic ventilatory failure remains controversial. The impact of long-term home nocturnal NPPV treatment on deflation has not yet been evaluated in detail.MethodsRetrospective explorative study of 46 patients with stable COPD undergoing NPPV treatment. Effects of NPPV on bodyplethysmographic parameters, blood gas tensions and inspiratory muscle function after 6.2 (±1.7) and 12.7 (±2.1) months of treatment. Further, evaluation of 1-year survival, compliance and ventilation parameters.ResultsOne-year survival was 89.1%. The effectiveness of ventilation was proven by a significant reduction in nocturnal and daytime PaCO2. We observed a decrease in the ratio of residual volume (RV) to total lung capacity (TLC) on the average of 5.2±9.8% (or 15.2±29.7% pred.; P<0.01) at six and 3.9±9.0% (or 12.9±18.6% pred.; P<0.001) at 12 months. As a consequence, we found significant improvements in inspiratory capacity (IC), vital capacity (VC) and forced expiratory volume in one second (FEV1). For patients with the most severe hyperinflation (RV/TLC>75%), we found a significant positive correlation between inspiratory positive airway pressure (IPAP) and reductions in PaCO2 (r=0.56; P<0.05) and RV/TLC (r=0.50; P