Cranston, J.M., Crockett, A., & Currow, D. (2008). Oxygen therapy for dyspnoea in adults. Cochrane Database of Systematic Reviews (Online), (3)(3), CD004769.

The objective of the study is to determine whether the administration of oxygen therapy alleviated dyspnea in adults with chronic end-stage disease versus breathing room air or placebo air in a non-acute care setting.

Databases searched were Cochrane reviews, OVID MEDLINE, CENTRAL, CINAHL (1982-2006), Cancer Lit (1975-2006), ACP Journal Club (1991-2006), Turning Research Into Practice (TRIP) (1997-2006), Dissertation Abstracts (ProQuest Digital Dissertations) (1985-2004), LILACS (1994-2006), Australasian Medical Index (National Library of Australia) (1990-2006) via Informit, LOCATOR plus (U.S. National Library of Medicine), EMBASE (1987-2006), PubMed (1950s-2006) (National Library of Medicine).

Search keywords oxygen, dyspnea, dyspnea, palliative, terminal, breathless, end-stage, and adult as either text words or mesh headings were used to search EMBASE Excerpta Medica, Australasian Medical Index, Latin American and Caribbean Health Sciences Literature (LILACS), and American College of Physicians (ACP) Journal Club and Dissertation Abstracts.

The Cochrane Library was searched using the terms oxygen and dyspnea or dyspnea and palliative or terminal.

Studies were included if they

• Were a randomized controlled trial (blinded or unblinded) performed in a non-acute care setting
• Included participants with chronic terminal illness (excluding chronic obstructive pulmonary disease) and breathlessness at rest or on mild exertion with or without hypoxemia
• Compared usual active treatment plus palliative oxygen therapy with a control groups
• Compared mean levels of dyspnea experienced by participants with a chronic terminal illness before and after administration of oxygen gas or room air/placebo
• Used a valid instrument to measure dyspnea.

Four hundred forty-six initial articles were retrieved. Only randomized controlled trials were considered for this review, with inclusion of unblended studies. Electronic databases were searched for predefined search terms. All studies were assessed for methodologic quality using a 0-5 scale based on the Oxford Quality Scale, and Quality of Concealment of allocation was rated.

Eight studies met inclusion criteria, for a final total sample of 144. Sample sizes across studies ranged from 12-45. Oxygen for dyspnea was evaluated in four studies among patients with cancer, three studies among patients with cardiac failure (CHF), and one study among patients with kyphoscoliosis. Of the sample, 99 were males and 46 were females. All were adults with listed comorbidities, some with or without domiciliary oxygen, with moderate to severe dyspnea.

Overall oxygen was not associated with reduction in the symptom of dyspnea.

Due to small number of research studies, variation in study methodologies, and small sample sizes among studies, evidence is still inconclusive regarding the short-term or long-term benefit of oxygen therapy over air inhalation in patients with cancer with dyspnea due to end-stage malignancy.

Newer, larger, well designed, controlled, randomized studies are needed with adequate power to detect variations in breathlessness with sufficient “washout” time between test gas inhalation times. Therefore, immense caution is suggested regarding the benefits of short-term oxygen inhalation over air inhalation for dyspnea relief in terminal care patients.