An acute upper airway obstruction is a blockage of the upper airway, which can be in the trachea, voice box (laryngeal), or throat (pharyngeal) areas.

Causes of acute upper airway obstruction include:

• Allergic reactions in which the trachea or throat swell closed, including allergic reactions to a bee sting, peanuts, antibiotics (penicillin), and blood pressure medications (ACE inhibitors)
• Chemical burns and reactions
• Croup
• Epiglottitis
• Fire or burns from breathing in smoke
• Foreign bodies -- such as peanuts and other breathed-in foods, balloon fragments, buttons, coins, and small toys
• Infections with viruses or bacteria
• Peritonsillar abscess
• Retropharyngeal abscess
• Trauma

Symptoms vary depending on the cause, but some symptoms are common to all types of obstruction.

• Agitation or fidgeting
• Bluish color to the skin (cyanosis)
• Changes in consciousness
• Choking
• Confusion
• Difficulty breathing
• Gasping for air
• Panic
• Unconsciousness
• Wheezing, crowing, whistling, or other unusual breathing noises indicating breathing difficulty

Physical examination may show:

• Decreased breath sounds in the lungs
• Rapid, shallow, or slowed breathing

Tests are usually not necessary, but may include:

• Bronchoscopy
• Laryngoscopy
• X-rays

If the person has a complete obstruction and is unable to speak or breathe, the Heimlich maneuver may be lifesaving.

Treatment depends on the cause of the blockage.

• Objects lodged in the airway may be removed with a laryngoscope or bronchoscope.
• A tube may be inserted into the airway (endotracheal tube or nasotracheal tube).
• Sometimes an opening is made directly into the airway (tracheostomy or cricothyrotomy).

Prompt treatment is often successful. However, the condition is dangerous and may be fatal, even if treated.

Inability to relieve the obstruction can cause:

• Brain damage
• Breathing failure
• Death

Airway obstruction is an emergency. It is a good idea to learn how to clear an airway of a foreign body by using a method such as the Heimlich maneuver.

Diseases in which airway obstruction develops over a period of hours will allow time to get to a hospital. If an acute airway obstruction occurs, call 911 or your local emergency number for medical help. Do what you can to maintain breathing until medical help arrives.

Prevention depends on the cause of the upper airway obstruction. See the individual diseases in the above section for more information.

The following methods may help prevent an obstruction:

• Eat slowly and chew food completely.
• Don't drink too much alcohol before or while eating.
• Keep small objects away from young children.
• Make sure dentures fit properly

Manno M. Pediatric respiratory emergencies: upper airway obstruction and infections. In: Marx J, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 6th ed. Philadelphia, Pa: Mosby Elsevier; 2006: chap 166.

Thomas SH, Brown DFM. Foreign bodies. In: Marx J, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 6th ed. Philadelphia, Pa: Mosby Elsevier; 2006: chap 57.