Oxygen may not help breathlessness in patients with refractory dyspnoea

January 01, 0001

Oxygen may not help breathlessness in patients with refractory dyspnoea

Palliative oxygen therapy is widely used for treatment of dyspnoea in individuals with life-limiting illness who are ineligible for long-term oxygen therapy. The researchers assessed the effectiveness of oxygen compared with room air delivered by nasal cannula for relief of breathlessness in this population of patients. Adults from outpatient clinics at nine sites in Australia, the USA, and the UK were eligible for enrolment in this double-blind, randomised controlled trial if they had life-limiting illness, refractory dyspnoea, and partial pressure of oxygen in arterial blood (PaO2) more than 7.3 kPa. Participants were randomly assigned in a 1:1 ratio by a central computer-generated system to receive oxygen or room air via a concentrator through a nasal cannula at 2 L per min for 7 days. Participants were instructed to use the concentrator for at least 15 h per day. 239 participants were randomly assigned to treatment (oxygen, n=120; room air, n=119). 93% patients assigned to receive oxygen and 83% assigned to receive room air completed all 7 days of assessments.

From baseline to day 6, mean morning breathlessness changed by -0.9 points in patients assigned to receive oxygen and by -0.7 points in patients assigned to receive room air (not significant). Mean evening breathlessness changed by -0.3 points in the oxygen group and by -0.5 in the room air group (not significant). The frequency of side-effects did not differ between groups. Extreme drowsiness was reported by 10% of patients assigned to receive oxygen compared with 13% of patients assigned to receive room air. 2% of patients in the oxygen group reported extreme symptoms of nasal irritation compared with 6% in the room air group. One patient reported an extremely troublesome nose bleed (oxygen group).

The researchers concluded: "Since oxygen delivered by a nasal cannula provides no additional symptomatic benefit for relief of refractory dyspnoea in patients with life-limiting illness compared with room air, less burdensome strategies should be considered after brief assessment of the effect of oxygen therapy on the individual patient."

An interestingly example of the benefit of using evidence for something usually done routinely. Also a reminder that dyspnoea is distinct from breathlessness.

For the full abstract, click here.

The Lancet 376(9743):784-793, 4 September 2010 © 2010 Elsevier Limited
Effect of palliative oxygen versus room air in relief of breathlessness in patients with refractory dyspnoea: a double- blind, randomised controlled trial. Amy P Abernethy, Christine F McDonald, Peter A Frith et al. Correspondence to Amy Abernethy: [email protected]

Category: R. Respiratory. Keywords: palliative, oxygen, room air, relief, breathlessness, refractory, dyspnoea, double-blind, randomised controlled trial, journal watch.
Synopsis edited by Dr Stephen Wilkinson, Melbourne, Australia. Posted on Global Family Doctor 1 October 2010

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