Can't answer your question as to why certain
groups of first aid people use high versus low
flow oxygen. (In anaesthesiology, we have a
saying that the correct dose is "enough".)
But thought you might find these numbers of
interest.
At sea level, the atmospheric pressure is
760 mm Hg (mercury), the partial pressure of
oxygen breathed into the nose and mouth is 159 mm
Hg, and the partial pressure of oxygen in the
blood is about 99 mm Hg (in a healthy person).
At a cabin altitude of about 6035 feet
(1829 metres), the atmospheric pressure is 609 mm
Hg, the partial pressure of oxygen breathed into
the nose and mouth is about 128 mm Hg, and the
partial pressure of oxygen in the blood is about
68 mm Hg (in a health person).
Hope this is of some help.
Jan
----------------------
J.M. Davies MSc MD FRCPC
Professor of Anaesthesia
Department of Anaesthesia
Foothills Medical Centre
1403 29th Street NW
Calgary, Alberta
CANADA T2N 2T9
tel: 403 - 670-1667
fax: 403 - 670-2425