Most people who are choking automatically clutch at their throat. This is recognized as the universal distress signal for upper airway obstruction (fig. 10-1). The most common cause of upper airway obstruction in a conscious person is improperly chewed food.

PARTIAL OBSTRUCTION. When the victim coughs or when there is adequate air exchange, encourage the victim to continue with his own efforts to expel the foreign body. Do not interfere with the victim's

Figure 10-10.-Universal distress signal.

efforts to remove the obstruction. Observe the victim closely for increased distress, and be prepared to treat him for a completely blocked airway.

When there is inadequate air exchange, which is indicated by a weak or ineffective cough, high-pitched noises while the victim attempts to inhale, and bluish discoloration of the skin (especially around the nails and lips), handle the problem as though it were a complete airway obstruction.

COMPLETE AIRWAY OBSTRUCTION.

Complete airway obstruction is indicated by no air exchange and an inability to speak, cough, or breathe. If the victim is conscious, he may exhibit the universal distress signal, as identified above.

When the victim is unconscious, check for breathing. When the victim is not breathing, his tongue or some other object may be blocking the air passage. The airway may be opened by tilting his head back and lifting his chin. Or when his head should not be moved, in the case of neck injuries, his jaw may be thrust forward. These techniques are described below.