Cochrane: more evidence needed for NIPPV in stable COPD
medwireNews: The authors of a Cochrane systematic review say that they have failed to find evidence of a consistent beneficial effect of non-invasive positive pressure ventilation (NIPPV) in hypercapnic patients with chronic obstructive pulmonary disease (COPD).
While the technique is effective in treating acute exacerbations of the disease, after at least 3 months of nighttime treatment at home in stable patients there was no clinically or statistically significant change in a range of parameters including gas exchange, exercise tolerance, or lung function.
"However, the small sample sizes of these studies preclude a definite conclusion regarding the effects of NIPPV in COPD," the authors, Peter Wijkstra (University of Groningen, the Netherlands) and colleagues, note.
The review included seven randomized trials involving 245 people in which patients in the intervention group received NIPPV through a nasal or face mask for at least 5 hours during the night. Five studies were short term (3 months) and two were long term (12 months).
Meta-analysis showed that there were no statistically significant treatment effects with regard to arterial blood gas tensions, 6-minute walking distance (6MWD), health status, lung function, respiratory muscle function, sleep efficiency, or dyspnea, at either 3 or 12 months.
Despite the disappointing findings, the authors say that their review mainly highlights the dearth of adequate evidence for the treatment, rather than ruling it out as effective. In particular, they note that the wide confidence interval for the 6MWD was within the range of clinical significance, suggesting that NIPPV could benefit the walking of some stable patients.
"Additional studies with larger sample sizes that address participant selection, ventilator settings, training and NIPPV compliance should clarify the role of this treatment," Wikjstra and colleagues write in The Cochrane Library.
They add: "But moreover, a large trial also looking at the effect of NIPPV on survival, exacerbation frequency and admissions is needed."
Additionally, some studies used different questionnaires for the same outcome measures, making meta-analysis impossible.
"For future studies, it would be of great benefit if the same questionnaires were to be used making comparison and pooling of data possible," the authors comment.
Until further evidence is available, Wikjstra and colleagues therefore recommend that "long-term non-invasive ventilation for people with COPD should only be started in the context of a clinical trial."
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By Kirsty Oswald, medwireNews Reporter