Avoidance of high concentration oxygen in chronic obstructive pulmonary disease

In this editorial by B Ronan O’Driscoll and Richard Beasley an error occurred in the second paragraph (BMJ 2010;341:c5549, doi:10.1136/bmj.c5549). We wrongly referred to alveolar carbon dioxide tension; we should have said a mean difference in arterial carbon dioxide tension. However, alveolar carbon dioxide tension is also mentioned later, in the fourth paragraph, where it is correct.