A Meta-Analysis Of Long Term Noninvasive Positive Pressure Ventilation In Stable COPD

[Objective]The potential treatment effect on stable chronic obstructive pulmonary disease (COPD) patients with noninvasive positive pressure ventilation (NIPPV) is still not very clear. There are some contradictory results in previous studies, and most studies are of small sample size. So we undertook a meta-analysis of randomized controlled trials (RCTs) that compared NIPPV with conventional therapy in stable patients with COPD to explore the influence on respiratory function, quality of life and survival rate.[Methods]The studies included in the meta-analysis are randomized controlled studies (RCTs) that compared the effect of treatment group (NIPPV combined with conventional therapy) with control group (conventional therapy) for stable COPD patients.The outcomes were respiratory function, quality of life and survival rate. The foreign language search terms included pulmonary disease. Chronic obstructive, stable, noninvasive ventilation. BiPAP, NIPPV; Chinese search terms were COPD, chronic obstructive pulmonary disease, stable, noninvasive ventilation. Comprehensive search of PubMed database, China National Knowledge Infrastructure (CNKI) and Chinese Biomedical Literature Database (CBM). Two evaluators independently screened the literatures, extracted data, evaluated the quality and cross-checked. Use RevMan5.1statistical software for statistical analysis of the data, to evaluate the effect of NIPPV on respiratory function [daytime arterial carbon dioxide partial pressure (PaCO2), daytime arterial oxygen tension (PaO2), forced expiratory volume in one second (FEV1), forced vital capacity (FVC), one second forced expiratory volume in percentage of predicted value (FEV1%pre)], quality of life and survival rate.[Results]This study included16studies,16RCTs, including756patients with stable COPD. Meta-analysis results are as follows.1.Respiratory functionNIPPV for3months can reduce PaCO2in patients with severe COPDfweighted mean difference (WMD) for-5.19,95%confidence interval (CI)-6.16to-1.78]. Nocturnal noninvasive positive pressure ventilation with high IPAP (≥14cmH2O) for6months can reduce patients’ PaCO2(WMD-8.30,95%CI-9.90to-7.11).NIPPV for3months can improve PaO2in patients with severe COPD(WMD3.78,95%CI0.01to7.55). Nocturnal noninvasive positive pressure ventilation with high IPAP (≥14cmH2O) for6months can increase patients’ PaO2(WMD5.04,95%CI3.05to7.03).NIPPV therapy for2years in patients with COPD can improve PaO2significantly(WMD7.47.95%CI5.88to9.06).Three months of NIPPV treatment can not improve patients’ FEV1(WMD0.04,95%CI-0.02to0.10). But after1year the patient’s FEV1increased (WMD0.12, 95% CI0.07to0.17).NIPPV treatment for three months does not improve FVC (WMD0.04,95% CI-0.06to0.14). The treatment for two years can delay the decline in FVC(WMD0.14,95% CI0.07to0.21).NIPPV can not improve FEV1%pre of patients.2.Quality of life6MWD in patients can be increased with NIPPV(March, WMD19.62,95% CI9.55to29.69; June, WMD46.83,95% CI33.47to60.20; one year, WMD81.50,95%CI59.60to103.40; two years,WMD87.39.95%CI69.49to105.29).The treatment of NIPPV can improve the degree of dyspnea and some neurophysiological functions.It also improve the health-related quality of life from different aspects. However, the roles of NIPPV on mood, sleep, and the incidence are not sure.3.Survival rateAccording to present studies, the role of NIPPV on survival rate can not be determined.[Conclusion]NIPPV can improve the patient’s blood gas levels, reduce PaCO2and increase PaO2. Severe COPD patients with CO2retention, nocturnal NIPPV, high IPAP (≥14cmH2O) noninvasive positive pressure ventilation may be better. The longer the application of NIPPV, the better blood gas level may become.NIPPV can not reverse the process of disease, has no significant effect on patients’FEV1%pre. Long-term application of NIPPV may delay the deterioration of FEV1and FVC.NIPPV can improve the6MWD. With time, the improvement is more obvious.The treatment of NIPPV can improve the degree of dyspnea and some neurophysiological functions.It also improve the health-related quality of life from different aspects. However, the roles of NIPPV on mood, sleep, the incidence and survival rate can not be determined.