The purpose of this study is to evaluate the efficacy of high-intensity non invasive mechanical ventilation (during one year to reduce the severity and frequency of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in patients with frequent AECOPD (frequent exacerbations defined more two or more AECOPD) and in GOLD IV stage (very severe COPD). The design is a randomised, double blind and controled with placebo (sham maneuver) clinical trial.

Background:

• There are many previous studies (no controlled trials or observational studies)that demonstrated minimal benefits (on gas exchange and marginal effect over exacerbations frequency) with the use of non invasive mechanical ventilation, in BiPAP modality with IPAP pressures <18H2ocm (low intensity), in COPD patients.
• In subsequent years there were controled trials that concluded that there was no benefits with the use of non invasive mechanical ventilation on BiPAP mode in COPD patients ( It should be mentioned that in most trials were used low inspiratory pressure levels, that is called low-intensity non invasive mechanical ventilation).
• However, there are other recent studies that described some benefits of high intensity Bilevel modality of non invasive mechanical ventilation (inspiratory pressures >18cmH2O) specially on gas exchange, quality of life and functional status.
• There are some issues that do not yet have a clear answer like the optimal inspiratory pressure (IPAP) or the ventilation modality (BIPAP or other) to obtain the maximal benefit on COPD patients. Additionally, is not clear also if the use of non invasive mechanical ventilation on COPD patients helps to reduce the frequency and severity of acute exacerbations of COPD (AECOPD).

This study have some characteristics that are different to the previous reports:

• The inclusion of patients with frequent exacerbations phenotype (and therefore worst prognosis patients)that there are no included in previous trials
• The intervention maneuver that is bilevel modality of non invasive mechanical ventilation at hig-intensity pressure (>18H2Ocm and <24H2Ocm)
• The use of placebo maneuver (CPAP "Sham")
• The home titration in three phases, over a week
• The long-term use of the intervention and sham maneuver

Inclusion Criteria:

• Clinical and spirometric diagnosis for COPD (FEV1/FVC <70%)
• Clinical phenotype of frequent exacerbations
• Must sign the informed consent
• Former smokers
• Stable COPD
• FEV1 <35%
• Optimal medical treatment

Exclusion Criteria:

• OSAS diagnosis
• Other indications for non invasive mechanical ventilation
• Arterial pressure for dioxide carbon >45mmHg
• Lung cancer
• Impossibility for doing spirometry or going to the medical visits
• Be included in another study