LIFE-THREATENING PROBLEMS - Medicine for Mountaineering and Other Wilderness Activities - page 19

Evaluation and treatment of every ill or injured person begins with the ABC's: airway,
breathing, and circulation. The leading preventable cause of death from trauma is ob-
struction of the airway. Death resulting from failure of oxygen to reach the brain occurs
if a person does not have an open airway or does not breathe for approximately four
minutes—exceptforindividualswhoaremoderatelytoseverelyhypothermic.Inanuncon-
scious person, the tongue may obstruct the airway ( Figs. 3-1 and 3-2 ) . Opening the airway
may be as simple as repositioning the jaw ( Fig. 3-3 ) .
Once the airway is open, breathing should be evaluated. If the person is not breathing,
rescue breathing is necessary.
After an open airway and breathing are ensured, the next step is to evaluate the circula-
tion. If the person does not have a pulse, no effective circulation is present, and providing
cardiopulmonary life support (CPR) may be necessary for the person to survive.
Learning rescue breathing or CPR from a book is not advisable. Management of the
ABC's, including CPR, is taught in basic life-support classes available to the public. Parti-
cipants in wilderness activities should take one of these courses and a refresher every two
years.
Figure 3-1. Structures of the mouth, throat, and airway in a normal, conscious person
Figure 3-2. Position of the tongue and epiglottis in an unconscious person