Primary Outcome Measures:
- Patient preference for gas
Secondary Outcome Measures:
- Patient ratings of dyspnoea on visual analogue scales
Dyspnoea is a devastating symptom in patients with advanced cancer. Management strategies are limited and include behavioural therapies such as relaxation, and pharmacological therapies such as opioids and anxiolytics. The latter are associated with problematic side effects in many patients. Inhalational oxygen is frequently administered but there are few studies in this population which define its role and benefits.
Main Aim: To compare patient preference for inhalational oxygen versus air for relief of dyspnoea.
Specific aims:
- To compare the patient preference for inhalational oxygen versus compressed air in the relief of dyspnoea.
- To compare the response to oxygen and air in improvement of dyspnoea in patients with advanced cancer.
- To compare the response to oxygen and air in improvement of dyspnoea in those patients with advanced cancer with documented hypoxia.
- To identify factors other than hypoxia which impact on the sensation of dyspnoea and its relief, when patients are administered oxygen and air.
Hypotheses
- Oxygen improves dyspnoea in patients with cancer more than compressed air.
- Patients with cancer who are hypoxic are more likely than those who are not hypoxic to have improvement of dyspnoea with oxygen administration.
- The cause of the dyspnoea may affect whether dyspnoea improves more with oxygen than with air.
Using a randomised, double blind, crossover study design, patients will be adminstered air and oxygen for 15 minutes and be asked to rate dyspnoea scores before and after each gas. Measures of oxygen saturation will be simultaneously measured, and finally the patient preferences for the gases will be sought at trial completion.