John: Hello, I'm John Hilton, editor of the Cochrane Editorial unit. The respiratory illness, chronic obstructive pulmonary disease, or COPD, is a major health burden for patients and healthcare systems, and there are several Cochrane Reviews examining the evidence for various ways to manage it. These were added to in July 2017 by the updating of a review last done in 2004 which looks at the evidence for the use of positive pressure breathing support during exacerbations. This was led by Dr. Christian Osadnik, from Monash University in Melbourne in Australia, who tells us what they found in this podcast.

Christian: When people with COPD experience an acute exacerbation, they might require hospitalisation and are at risk of developing respiratory failure characterised by high levels of carbon dioxide in the blood. This is called acute hypercapnic respiratory failure and it can be life-threatening. Positive pressure breathing support is one of the common therapies used to treat this condition. This can be delivered invasively using mechanical ventilation in conjunction with endotracheal intubation, which involves insertion of a tube to feed air directly into a person’s lungs, or more simply, by non-invasive ventilation or NIV which delivers air via a mask attached to a person’s face. There are several potential advantages of treating individuals via NIV, but some debate remains regarding its effectiveness and safety. We conducted our review to try and clarify this and found moderate quality evidence in favour of NIV.
We looked at the effects of the addition of NIV to usual care on mortality and the need for intubation, as well as the length of time people stayed in hospital and changes to their breathing. We were able to include 17 randomised trials involving more than 1200 participants from Europe, Asia and America.
The evidence points to benefits of NIV on both mortality and endotracheal intubation, such that its use for 12 people would reduce the number of deaths by one, while there would be one less intubation for every five patients using NIV. NIV use was also associated with a 3-day reduction in hospital stay, other benefits related to the one’s breathing and no obvious safety concerns.
In summary, we have compiled a strong body of evidence to support NIV as a first line treatment for patients who present to hospital with acute hypercapnic respiratory failure due to a COPD exacerbation. The benefits are large and of high clinical importance, and our subgroup analyses provide reassurance that they are broadly applicable across varying degrees of exacerbation severity and differing clinical environments in which the person is treated.

John: If you would like to look deeper into this compelling evidence, you can find links to the full review online by simply searching for 'Cochrane and COPD NIV'.