Nocturnal noninvasive positive pressure ventilation in stable COPD: a systematic review and individual patient data meta-analysis.

INTRODUCTION The effects of nocturnal noninvasive positive pressure ventilation (NIPPV) in patients with stable chronic obstructive pulmonary disease (COPD) remain controversial. METHODS The Cochrane Airways group Register of Trials, MEDLINE, EMBASE and CINAHL were searched up to August 2012. Individual patient data from randomised controlled trials on NIPPV outcomes were selected for two separate meta-analyses: the first with follow-up of 3 months and the second with 12 months of follow-up. Additionally, subgroup analyses within the NIPPV group comparing IPAP levels, compliance and levels of hypercapnia on change in PaCO2 after 3 months were performed. RESULTS Seven trials (245 patients) were included. All studies were considered of moderate to high quality. No significant difference was found between NIPPV and control groups after 3 or 12 months of follow-up when looking at PaCO2 and PaO2, 6-minute walking distance, health-related quality-of-life, forced expiratory volume in 1 s, forced vital capacity, maximal inspiratory pressure and sleep efficiency. Significant differences in change in PaCO2 after 3 months were found for patients ventilated with IPAP levels of at least 18 cm H2O, for patients who used NIPPV for at least 5 h per night as well as for patients with baseline PaCO2 of at least 55 mm Hg when compared to patients with lower IPAP levels, poorer compliance or lower levels of hypercapnia. DISCUSSION At present, there is insufficient evidence to support the application of routine NIPPV in patients with stable COPD. However, higher IPAP levels, better compliance and higher baseline PaCO2 seem to improve PaCO2.