Noninvasive ventilation in long-term treatment of COPD

There are some data that noninvasive ventilation (NIV) could be useful in long-term treatment of some patients with chronic obstructive pulmonary disease (COPD). Apart from the information from arterial blood gas analysis, which data should we use to decide which stable hypercapnic patients with COPD will benefit most from NIV? Is there a subgroup of patients in whom this treatment should be routinely used?

Andreas Freitag: I think that is a good question and I am glad to see that that whole question is being reexamined or reasked. Up to 2014 there was a Cochrane analysis, there was a bunch of other studies, which really showed no significant benefit in terms of using NIV for patients with underlying severe COPD, and we thought that was the end of it. Having said that, I think people started to challenge that and because as we saw advances in technology in terms of noninvasive mechanical ventilation and as we got better at titrating the pressures, we started to notice in the intensive care unit that there is a lot of these patients that respond to noninvasive mechanical ventilation, and the issue is, “If they are like this here in the hospital, maybe we can do this in the home environment, where they are much better.”

There were two studies that looked at that. One was a negative study, one was a positive study, initially looking at blood gases. When the patient presented with hypercapnic respiratory failure related to an exacerbation of COPD before they went home, they were tried on noninvasive versus conventional treatment. When they followed the patients along, they really saw no confirmed benefit. Once again, it was what we saw historically. But a more recent study that looked at stable patients, patients that are at home but are chronically hypercapnic, with pCO₂ >55 mm Hg or >6 kPA. These individuals clearly have got chronic ventilatory failure, they are in a stable situation and definitely could benefit from noninvasive mechanical ventilation. And indeed, when they actually applied that technology – let’s say, supplemental oxygen – and they could demonstrate a reduction in terms of morbidity and mortality and improvement in quality of life. So I do not think that we have closed the book completely on noninvasive mechanical ventilation for patients with COPD.

Having said that, where do we use it today? Once again, I think that is the situation. You have patients that have got chronic severe hypercapnic hypoxemic respiratory failure who clearly are struggling or are breathless, and you have tried all the other modalities. This may be helpful in terms of scrubbing off CO₂, reducing the work of breathing, improving their ability to sustain gas exchange in the longer term.

The second option might still be – and I believe this is for – the younger COPD patients that are actually thinking of lung transplantation. We definitely have used noninvasive mechanical ventilation in the setting of severe end-staged emphysema COPD in anticipation of lung transplantation.