LEARNING OBJECTIVE: Recall basic life support techniques for upper airway obstruction, respiratory failure, and cardiac arrest.

Basic life support is the emergency technique for recognizing and treating upper airway obstruction and failures of the respiratory system and heart. The primary emphasis should be on the ABCs of basic life support: maintaining an open airway to counter upper airway obstruction; restoring breathing to counter respiratory arrest; and restoring circulation to counter cardiac arrest.

UPPER AIRWAY OBSTRUCTION
The assurance of breathing takes precedence over all other emergency measures. The reason for this is simple: If a person cannot breathe, he cannot survive.

Many factors may cause a person's airway to become fully or partially obstructed. Avery common cause of obstruction with both adults and children is improperly chewed food that becomes lodged in the airway (an event commonly referred to as a "cafe coronary"). Additionally, children have a disturbing tendency to swallow foreign objects while at play. Another cause for upper airway obstruction occurs during unconsciousness, when the tongue may fall back and block the pharynx (fig. 4-1). When the upper airway is obstructed, the heart will normally continue to beat until oxygen deficiency becomes acute. Periodic checks of the carotid artery must be made to ensure that circulation is being maintained.

Partial Airway Obstruction
The signs of partial airway obstruction include unusual breath sounds, cyanosis, or changes in breathing pattern. Conscious patients will usually make clutching motions toward their neck, even when the obstruction does not prevent speech. Encourage conscious patients with apparent partial obstructions

Figure 4-1.-Tongue blocking airway.

to cough. If the patient is unable to cough, begin to treat the patient as if this were a complete obstruction. (This also applies to patients who are cyanotic.)