The study, lead investigator Dr. R. Douglas McEvoy told, is the first to show a survival advantage for night-time mask ventilation treatment in patients with severe COPD and chronic ventilatory failure.
Our enthusiasm for the treatment is somewhat tempered, however, by our finding that the patients randomized to the treatment had reduced quality of life and mood, he added.
Dr. McEvoy of Repatriation General Hospital, Daw Park, South Australia, and team reported the findings after studying 144 COPD patients with severe airflow limitation and stable hypercapnic ventilatory failure. The patients were randomized to long-term oxygen therapy with or without nocturnal noninvasive bi-level pressure support ventilation.
The combination therapy group patients had a median follow-up of 28.5 months and those who received oxygen alone had a median follow-up of 20.5 months.
A sleep study following in-hospital implementation of noninvasive ventilation in the treatment group showed little but significant increases in REM sleep and decreases in the frequency of disordered breathing events and a sleep-related rise in transcutaneous PCO2.
In addition, noninvasive ventilation treatment produced an improvement in survival (adjusted hazard ratio, 0.63). However there was no change in daytime arterial blood gas, lung function measurements, or hospitalization rates.
Moreover, disease-specific and general quality of life did not improve as a result of noninvasive ventilation treatment. On the contrary, write the investigators, it appeared that the addition of noninvasive ventilation to usual care in these severely disabled COPD patients resulted in deterioration in general and in mental health and some aspects of mood.
Thus, concluded Dr. McEvoy, A major challenge in this field is to find ways to further improve the level of ventilatory support at night and at the same time reduce the discomfort and long-term burden of the treatment to patients and their families.
Commenting on the findings, Dr. Mark W. Elliott, author of an accompanying editorial, told Reuters Health that the improvement in survival is encouraging, but the apparent worsening in quality of life is surprising.
Dr. Elliott of St. James’s University Hospital, Leeds, UK, also pointed out that the study provides important information that should help design future trials of domiciliary noninvasive ventilation in COPD, which are urgently needed.
