S
AFETY
I
NFORMATION
R
EVISION
:
-
D
ATE
:
12/29/04
P
AGE
:
21
Copyright
2004 Glasair Aviation, LLC Arlington, Washington All rights reserved
symptoms of hypoxia are increased breathing rate, a light-headed or
dizzy sensation, tingling sensation, sweating, reduced visual field
(tunnel vision), sleepiness, blue coloring of the skin, fingernails or lips
(cyanosis), and behavior changes. Some people with hypoxia feel
clammy and cold.
A particularly dangerous feature of hypoxia is an increased sense of
well-being, called euphoria. It obscures a person’s ability and desire to
be critical of himself, slows reaction time and impairs thinking ability.
Consequently, a hypoxic individual often believes things are getting
progressively better as he nears total collapse.
The symptoms are slow but progressive, insidious in onset, and are
most marked at altitudes starting above 10,000 ft. Night vision,
however, can be impaired starting as low as 5,000 ft.
Use oxygen on flights above 10,000 ft. and at any time when
symptoms appear. Should symptoms occur that cannot definitely be
identified as either hypoxia or hyperventilation, try three or four deep
breaths of oxygen. The symptoms should improve markedly if the
condition was hypoxia (recovery from hypoxia is rapid).
Hyperventilation
Hyperventilation, or over-breathing, is a disturbance of respiration that
may occur in individuals as a result of emotional tension or anxiety.
Under conditions of emotional stress, fright or pain, breathing rate may
increase, causing increased lung ventilation. Since there is no
corresponding increase in the carbon dioxide output of the body cells,
carbon dioxide is “washed out” of the blood.