Airway Obstruction

An airway obstruction is a blockage somewhere along the respiratory tract, decreasing or preventing the flow of air through it. The location of the blockage may be in the pharynx, larynx, trachea or bronchus. The severity of the obstruction varies, depending on whether it is a partial obstruction or a complete obstruction.

Obstruction by a Foreign Object
Obstruction could be caused by a foreign object entering into the respiratory tract. This is called “foreign body aspiration”, more commonly known as choking. The most common cause for this is during eating, if the food enters into the trachea instead of being swallowed into the esophagus.

If the patient has an effective cough, they should be encouraged to do so. If they have an ineffective cough, then back blows should be performed. Back blows are firm hard blows with the heel of the hand, directed between the patients scapula. If unsuccessful, or if the patient is unable to breathe, then the Heimlich maneuver can be performed on adults.

Obstruction by the Tongue
The most common type of airway obstruction is obstruction by the tongue in an unconscious person. This is because the muscles relax in an unconscious person. The tongue is composed of muscles, so it also relaxes. As the tongue relaxes, it can then fall back and down the throat, causing obstruction of the airway.

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For this reason, the unconscious patient needs to be continually monitored, ensuring that the airway remains open. Head tilt chin lift, as well as the jaw thrust maneuver, are both maneuvers that lift the tongue up from the throat, clearing the airway.

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An oropharyngeal airway (sometimes called a “guedel”) can also be used in patients that are deeply unconscious. Oxygen saturation should be frequently monitored.

Obstruction due to Angioedema
Airway obstruction can also occur because of an allergic reaction. Signs and symptoms of allergic reactions vary, although sometimes angioedema can occur causing swelling of the tongue, lips, eyelids or larynx. The severity of the swelling varies, from mild to severe. Severe swelling of the larynx can progress to complete airway obstruction. Laryngeal angioedema should be suspected in any patient that experiences an acute onset of throat tightness, voice changes or difficulty breathing.

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The treatment for allergic laryngeal angioedema is oxygen and intramuscular adrenaline, and intravenous antihistamine (such as Cimetidine). Further treatment includes intravenous corticosteroids (such as Hydrocortisone). Corticosteroids have a slow onset, and so are not beneficial in the emergency situation, however they reduce the possibility of relapse, and so should be given once the above medications have been administered.

If the airway edema is not responding to treatment then tracheal intubation may be required.

Patients with only mild symptoms of allergic angioedema can be treated with oral antihistamine (such as Cimetidine) and oral corticosteroid (such as Prednisolone).

Obstruction due to Smoke Inhalation
Airway obstruction can also occur due to smoke inhalation. Inhaling hot smoke from a fire can cause a burn of the airway. Swelling of the tissue can then occur, which has the potential to obstruct the airway.

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Fires in enclosed spaces are much more likely to cause significant airway burns. The following signs indicate significant airway burns:

  •  respiratory distress
  •  burns to the face or neck
  •  soot in the nostrils, mouth or sputum
  •  blistering or edema in the mouth
  •  hoarse voice

Tracheal intubation is justified if any of the above signs are present in a patient exposed to fire. A few hours of high flow oxygen should be given to all patients who have been exposed to smoke inhalation.