Breathing supplemental oxygen reduces breathlessness during exercise in patients with chronic obstructive pulmonary disease (COPD). Replacing nitrogen with helium reduces expiratory flow resistance and may improve lung emptying. Combining these treatments should be independently effective.
Respiratory Medicine, Royal Hallamshire Hospital, Department of General Practice and Primary Care, ScHARR, Biomedical Sciences, University of Sheffield, Sheffield, UK. e.a.laude@sheffield.ac.uk
