who are not investigators to engage with the ethos of
the study, as well as the difficulty in using clinical trials
to bring about change in management practices. The
British Thoracic Society’ s guidelines on the management of acute exacerbation of chronic obstructive pulmonary disease recommend that all patients should
have arterial blood gas sampling.8 The audit by Wijesinghe et al found that about a third of patients who had
a blood gas measurement had respiratory failure,
defined as an arterial carbon dioxide pressure of
45 mm Hg and a pH below 7.35, illustrating the importance of this recommendation.20 Ideally, for our study,
a member of the research team would have been available to take arterial blood samples on arrival of the
study patients, but unfortunately this was not practical.
In this study, we could not determine any effect of
prehospital management on in-hospital management
or differentiate the effects of prehospital and in-hospital oxygen management on measured outcomes.
Review of the hospital records did not provide any
further insight into the treatment after arrival in hospital. Titrated oxygen is the recommended treatment for
breathless patients with a history or risk of chronic
obstructive pulmonary disease at the Royal Hobart
Hospital, but in practice, especially at the time of the
trial, many of these patients received high flow oxygen
on admission to hospital. However, any change in oxygen treatment that occurred after arrival in hospital
would have reduced the differences between the treatment arms, thus underestimating the risk associated
with high flow oxygen. Unfortunately, collection of
data on in-hospital management was beyond the
scope of the study, so we cannot dissect the effect of
prehospital and in-hospital oxygen administration