Plain language summary
Non-invasive positive pressure ventilation (ventilators) used at night by people with stable chronic obstructive pulmonary disease (COPD)
Background: Non-invasive positive pressure ventilation (NIPPV) is a method to assist or replace spontaneous breathing (or normal breathing) with the aid of a machine called a ventilator. A mask is fitted over the nose or mouth, or both and air is pushed into the lungs. It can be used as a short-term measure, during critical instances in the hospital, but also at home for longer periods in people who have raised levels of carbon dioxide in their blood. We wanted to discover whether using NIPPV at home during the night alongside standard therapy was better or worse than standard therapy alone in people with chronic obstructive pulmonary disease (COPD). COPD is a progressive disease that makes it hard to breathe. In 2002, we published our original Cochrane review looking at this. It is important to check if new studies have been published that could be added to the existing studies in the review. In this review, we performed a new search and found new studies and, therefore, this is an update of the review published in 2002.
What is individual patient data? In this review we used individual patient data. This means we collected original research data for each participant from the original researchers who performed the studies. We used this information to perform our calculations.
Review question: What is the effect of NIPPV in people with COPD on blood gases, six-minute walking distance, health-related quality of life, lung function, respiratory muscle function and sleep efficiency.
Study characteristics: The evidence is current to August 2012. We found seven studies that reported the effects of NIPPV at home. Five of these studies looked at the effects after using NIPPV compared to regular treatment (without NIPPV) for at least three months. Two studies looked for a longer period of time, for at least 12 months. The mean age of all participants included in our meta-analysis was 67 years. All studies included men and women, but 77% of participants were men. We used data from 245 people for our meta-analysis.
Results: NIPPV during the night for 3 and 12 months in people with COPD who had raised levels of carbon dioxide had no clinically or statistically significant effect on gas exchange, six-minute walking distance, health-related quality of life, lung function, respiratory muscle strength and sleep efficiency. This means we found little or no difference in the outcomes.
Quality of the results: Because some trials had very small numbers of participants, our confidence in the quality of evidence is moderate when looking at the effects on gas exchange. All seven trials measured this outcome. Other outcomes were not always measured or available leading to a lower quality of evidence for the other outcomes such as six-minute walking distance, health-related quality of life, lung function, respiratory muscle function and sleep efficiency.