Airflow relieves chronic breathlessness in people with advanced disease: an exploratory systematic review and meta-analyses: Airflow relieves chronic breathlessness in people with advanced disease

Background: Chronic breathlessness is a neglected symptom of advanced diseases. Aim: To examine the effect of airflow for chronic breathlessness relief. Design: Exploratory systematic review and meta-analysis. Data sources: Medline, CINAHL, AMED and Cochrane databases were searched (1985 – 2018) for observational studies or randomised controlled trials of airflow as intervention or comparator. Selection against pre-defined inclusion criteria, quality-appraisal and data extraction were conducted by two independent reviewers with access to a third for unresolved differences. “Before and after” breathlessness measures from airflow arms were analysed. Meta-analysis was carried out where possible. Results: 16/78 studies (n=929) were included; 11 randomised controlled trials of oxygen vs medical air, four randomised controlled trials and one fan cohort study. Three meta-analyses were possible: i) Fan at rest in three studies (n=111) offered significant benefit for breathlessness intensity (0-100mm Visual Analogue Scale and 0- 10 Numerical Rating Scale), mean difference -11.17 (95% confidence intervals -16.60 to -5.74), p=0.06 I² 64%. ii) Medical air via nasal cannulae at rest in two studies (n=89) improved breathlessness intensity (visual analogue scale), mean difference -12.0mm, 95% confidence intervals -7.4 to -16.6, P<0.0001 I² =0%. iii) Medical airflow during a constant load exercise test before and after rehabilitation (n=29) in two studies improved breathlessness intensity (mBorg, 0-10) mean difference -2.9, 95% confidence intervals -3.2 to -2.7, p<0.0001 I² =0%. Conclusion: Airflow appears to offer meaningful relief of chronic breathlessness and should be considered as an adjunct treatment in the management of breathlessness.