The "Guedel" Style Oropharyngeal Airway

Created on Wed, 06/17/2015 - 20:36
Last updated on Wed, 06/17/2015 - 20:36

Once known as the "Guedel" airway, this is a simple airway adjunct which bypasses the oropharynx.

Anatomy of the oropharyngeal Guedel-style airway

 

oropharyngeal airway

Details of function

Essentially, this rigid tube offers a bite-resistant passage for air from the lips to the posterior pharynx.

The curved portion rests between the posterior pharyngeal wall and the tongue, keeping the epiglottis off the posterior pharyngeal wall (where it would normally be forced into by the flaccid collapse of the tongue).

Indications for use

  • To ensure airway patency:
    • Unconscious patient with loss of upper airway muscle tone
    • Unconscious patient with difficult bag/mask seal
    • Intubated patient, in whom the oropharyngeal airway acts as a bite block, preventing the kinking of the softer endotracheal tube
  • To improve airway hygiene:
    • Suctioning a patient with poor secretion clearance

Contraindications for use

  • Awake patient: An awake patient will not tolerate this airway, as it will stimulate their gag reflex.
  • Severe coagulopathy: this device, although possessing rounded edges, is still made of very hard plastic and it can still cause lacerations to the oral mucosa. If you have no platelets, you may end up with a lung full of blood from some sort of little posterior pharyngeal bleeder before anybody notices.

Methods of use/insertion

  • The tube is sized by placing it vertically, with the flange in the middle of the lips and the tip emerging at the angle of the mandible.
  • In adults it is inserted into the mouth upside-down, and rotated into the normal position once it is inserted about half way.
  • Lubricant may be useful if the mouth is excessively dry.

Safety features

  • The airways are colour coded to help recognise the sizes; the length of the tube is marked on the flange with a number (eg. "10" implies that the tube is 10cm long)
  • The flange limits the depth of insertion - so you cant accidentally lose the tube in somebody's airway
  • The reinforced bite block prevents occlusion of the airway by clenching of the teeth
  • The rigid construction is kink-resistant (although, if you really want, you can still kink it)
  • Available as a sterile product for single use; though most of the time the packaging is non-sterile (it tends to be cheaper that way, and one might make the argument that the oropharynx is not a sterile field anyway).

Complications of use

  • Gagging/vomiting, aspiration
  • Damage to oral mucosa, and bleeding
  • Damage to teeth, particularly if the patient bites down forcibly on the bite block.
  • Occlusion of the glottis by an inappropriately sized larger-than-needed tube
  • Failure of airflow due to an inappropriately small tube pushing the tongue into the posterior pharynx

Apocrypha

This airway was actually first developed by Arthur Ernest Guedel (1883–1956). The very same Guedel also proposed a system to classify the stages of anesthesia, which has been retained in classical anaesthetic training in spite of the fact that most modern agents will drop you within seconds, and nowadays the stages all blend into one.

But I digress. The early oropharyngeal airways were already flanged, but in 1933 they were made of hard metal, which (very likely) chipped and loosened many rotten post-Depression era teeth. Guedel's great advance was making them from rubber, which was a massive improvement over the cruel-looking all-metal Connell airway.

 

References

Guedel, Arthur E. "A nontraumatic pharyngeal airway." Journal of the American Medical Association 100.23 (1933): 1862-1862.

The best resource for this device, as always, is the site of the manufacturer. Unfortunately there is about a thousand manufacturers of these airways, or similar airways. All the products share the same features, mostly.