Feasibility and effects of non-invasive ventilation during pulmonary rehabilitation in patients with hypercapnic interstitial lung disease

Background Aim of this study was to investigate the feasibility and the effects of non-invasive ventilation (NIV) during pulmonary rehabilitation (PR) in hypercapnic patients with interstitial lung disease (ILD). Methods In this retrospective analysis hypercapnic (NIV initiated) and normocapnic ILD-patients admitted to a specialized PR were analyzed. Standardized PR was performed in all ILD-patients. Pulmonary function tests, blood-gas analysis, 6-min walk distance (6MWD) and a health-related quality of life (HRQL) (SF-36) were assessed on admission and discharge. Results Data of 29 ILD-patients with NIV (PR for 25±19 days) were compared with those of 319 normocapnic ILD-patients (PR for 25±13 days). In contrast to the normocapnic group, NIV patients were initially more impaired regarding PaO 2 , PaCO 2 , vital capacity (all p<0.0001), total lung capacity (p=0.012) and O 2 demand (p=0.041). PR was associated with an improvement in 6MWD of 64 meters (95% CI [45 - 84], p<0.0001) in NIV patients, and of 43 meters (95% CI [37 - 49], p<0.0001) in the non NIV-patients (difference 21 meters, 95% CI [0.5, 41.8], p=0.045). In NIV-patients pCO 2 levels dropped slightly from 50.6±9.0 to 49.0±6.4 mmHg during PR. PR with NIV improved mental health summary score (SF-36) (9.3, 95% CI [4.8 - 13.9], p<0.0001) but not physical summary score (0.7, 95% CI [-2.1 - 3.4], p=0.63). There was no difference between the two groups with regard to changes in HRQL. No adverse events were registered in patients with NIV during PR. Conclusions NIV during PR in ILD-patients seems to be feasible and safe. It may improve exercise capacity and HRQL even in patients with hypercapnic ILD.