SN4 SHORT NOTE 5M

Describe Oropharyngeal & Nasopharyngeal Airways in detail.

General Surgery · Final Professional

Purpose

Oropharyngeal and nasopharyngeal airways are simple airway adjuncts that hold the upper airway open by preventing the tongue falling back against the posterior pharyngeal wall — the commonest cause of airway obstruction in the unconscious patient. They are used with a face mask to aid ventilation.

Oropharyngeal (guedel) Airway

A rigid, curved plastic device inserted over the tongue into the oropharynx. It is sized from the incisors to the angle of the mandible. Because it stimulates the gag reflex, it is only tolerated in the deeply unconscious patient — in a lightly anaesthetised or semi-conscious patient it can provoke gagging, vomiting or laryngospasm.

Nasopharyngeal Airway

A soft tube passed through the nostril into the nasopharynx, sized from the nostril to the tragus of the ear. It is better tolerated in the semi-conscious patient than an oral airway. It is avoided in base-of-skull fracture (risk of intracranial placement) and used cautiously where there is coagulopathy (epistaxis).

CLINICAL PEARL

Choose by conscious level: the rigid oropharyngeal (Guedel) airway for the deeply unconscious (it triggers the gag reflex), and the soft nasopharyngeal airway for the semi-conscious — but avoid the nasal route with a suspected base-of-skull fracture.

Complications of Adjuncts

Although simple, these adjuncts have hazards: an oropharyngeal airway that is too large can push the epiglottis down and worsen obstruction or provoke laryngospasm, while one that is too small is ineffective; a nasopharyngeal airway can cause epistaxis and, in the presence of a base-of-skull fracture, has been reported to pass intracranially. They are therefore correctly sized, inserted gently, and chosen with the patient’s conscious level and injuries in mind, and they never substitute for proper positioning and jaw support.

CLINICAL PEARL

Pick the adjunct by conscious level — Guedel for the deeply unconscious, nasopharyngeal for the semi-conscious — size it correctly, and never pass a nasal airway when a base-of-skull fracture is suspected.

DANGER / REMEMBER

An incorrectly sized oropharyngeal airway is worse than none: too long it can reach the larynx and provoke laryngospasm or push the epiglottis over the glottis, too short it folds the tongue back and worsens obstruction — so it is always measured (incisors to the angle of the mandible) before insertion.

Oropharyngeal airway in a semi-conscious patient provokes laryngospasm.

KEY POINT

Key points TO remember

Adjuncts hold the airway open by preventing the tongue obstructing the pharynx.
Oropharyngeal (Guedel): sized incisors–mandibular angle; only for the deeply unconscious (gag reflex).
Nasopharyngeal: sized nostril–tragus; better tolerated when semi-conscious.
Avoid nasopharyngeal airway in base-of-skull fracture; caution with coagulopathy.

EXAM TIP

Sources: Morgan & Mikhail’s Clinical Anesthesiology; Miller’s Anesthesia; Ajay Yadav’s Short Textbook of Anaesthesia.

All questions in Airway Management

Every General Surgery chapter →