Does home oxygen benefit people with chronic heart failure?BMJ 2011; 342 doi: https://doi.org/10.1136/bmj.d234 (Published 04 February 2011) Cite this as: BMJ 2011;342:d234
- Andrew L Clark, professor1,
- Miriam J Johnson, senior lecturer in palliative medicine1,
- Iain Squire, professor of cardiovascular medicine2
- 1Hull York Medical School, University of Hull, Cottingham HU16 5JQ, UK
- 2Department of Cardiovascular Sciences University of Leicester
- Correspondence to: A L Clark
Patients with chronic heart failure are often prescribed home oxygen therapy for intractable breathlessness, usually via a nasal cannula at a concentration of 24-28% oxygen. A Cochrane Review concluded that long term home oxygen therapy improved survival (although not quality of life) in patients with chronic obstructive pulmonary disease who had severe hypoxaemia (arterial PaO2 <55 mm Hg (8.0 kPa)).1 However, little evidence exists that patients with treated chronic heart failure have hypoxaemia. A complicating factor is that a third of patients with chronic heart failure may have episodic hypoxia overnight due to sleep disordered breathing,2 which might respond to nocturnal oxygen therapy. Sleep disordered breathing can be either obstructive sleep apnoea (common in patients with and without heart failure) or central sleep apnoea (common only in patients with chronic heart failure). Both types of sleep disordered breathing lead to episodic hypoxia, but only obstructive sleep apnoea responds well to continuous positive pressure airways support.3
What is the evidence of uncertainty?
A systematic review in 2004 identified only three randomised studies of oxygen therapy for breathlessness in patients with chronic heart failure.4 We searched PubMed, Medline, and Embase databases for randomised controlled trials comparing oxygen therapy with either placebo or no treatment in adults with chronic heart failure, using the search terms “oxygen”, “home” or “domiciliary” or “long-term”, and “heart (or cardiac) failure”, and we found no further studies.
Thus, despite the wealth of evidence supporting medical treatment in patients with chronic heart failure, unanswered questions remain about the …