In this test, the subject is
asked to breathe as quickly and as deeply as possible. This does not
mean that the subject should pant (i.e. moving air back and forth in
the dead space of the upper airways at a very high rate.) Rather,
the subject must consciously attempt to breathe in as far as
possible, breathe out as far as possible, and try to execute these
movements as quickly as possible. Periods longer than 15 seconds
should not be allowed because prolonged hyperventilation leads to
fainting due to excessive lowering of arterial PCO2 and
H+. | |