• Changes in relief from the sensation of breathlessness [ Time Frame: 7 days ] [ Designated as safety issue: No ]
  

• Changes in quality of life (QOL) [ Time Frame: 7 days ] [ Designated as safety issue: No ]
  
• Identification of patients who benefit from palliative oxygen [ Time Frame: 7 days ] [ Designated as safety issue: No ]
  
• Identification of side effects [ Time Frame: 7 days ] [ Designated as safety issue: Yes ]
  
• Documentation of costs of palliative oxygen [ Time Frame: 7 days ] [ Designated as safety issue: No ]
  

When further medical management will not relieve intractable breathlessness, palliative oxygen is often prescribed regardless of whether the person meets the common oxygen funding criteria of severely low blood oxygen levels. The results of this study will inform best practice in the care of people with advanced life-limiting illness and intractable breathlessness, aid in the development of rational funding guidelines, and answer an international debate on the role of palliative oxygen.

This study is a definitive international multi-center randomized double-blind controlled trial of oxygen versus medical air for the relief of breathlessness in participants with intractable dyspnea and PaO2>55mmHg (a measure of blood oxygen levels). Specific aims include demonstration of the effectiveness of oxygen versus medical air in relieving breathlessness in the palliative setting (Specific Aim 1) and improving QOL (Specific Aim 2). Additionally, we will seek to establish which patients derive the greatest benefit (Specific Aim 3), the risks of therapy (Specific Aim 4), and the costs of therapy (Specific Aim 5). The primary hypothesis is that oxygen therapy is superior to air in relieving the sensation of breathlessness for patients with intractable dyspnea due to life-limiting illness in the setting of PaO2>55mmHg.

All participants are enrolled as outpatients. The "eligibility visit" occurs about 5-7 days before starting the study and will include review of the consent form, a short interview, physical exam, and blood tests. The visit can occur in the home or clinic. The blood tests include regular venipuncture and also an arterial blood gas, if these studies have not been done in the preceding month. The "randomization visit" occurs 2 days before the study starts (Day -2) and includes a short interview and quality of life (QOL) questionnaire; this visit is usually done in the home but can also occur in the clinic. The oxygen or air concentrators are delivered to the home on Day 0 by a trained person from the oxygen company. On the same day there is also a brief home visit from the study nurse that includes a short interview and QOL questionnaire. The participant uses the oxygen or medical air gas each of 7 days (Days 0-6) for at least 15 hours each day. While using the oxygen/air the participant fills out a short diary form in the morning and evening, within 30 minutes of waking up or retiring. The diary focuses on the breathlessness, how the participant is feeling, and potential side effects of the gas. The study nurse conducts a "check-in" telephone call on Day 3 to make sure the participant is doing OK. On the last day (Day 6) the nurse visits the home to conduct a brief interview with a short QOL questionnaire. The oxygen company will pick up the concentrator, usually on Day 7.