W b saunders co ltd Baillière Tindall, in association with the British Thoracic Society
Respiratory Medicine vol:102 issue:12 pages:1827-1829
Hypoxemic patients with chronic obstructive pulmonary disease (COPD) are at risk of carbon dioxide (CO2) retention during oxygen therapy and hypercapnia in COPD is associated with an ominous prognosis. Rebreathing with oxygen mask is possible in practice and possibly affects CO2 retention due to an increased inspired fraction of CO2. Its effects on arterial partial pressure Of CO2 during oxygen supply have, to the best of our knowledge, never been studied. We measured the inspired fraction Of CO2 in eighteen non-hypoxemic stable COPD patients with a capnograph during a 5 min trial with two different modes of oxygen supply (oxygen mask without reservoir bag and nasal prongs, respectively at a flow of 10 l/min and 2 l/min). We found no significant increase in inspiratory CO2 concentration. These findings suggest that inspired fraction Of CO2 does not increase markedly during controlled oxygen therapy. (C) 2008 Published by Elsevier Ltd.