Airway Anatomy and Obstruction
The image shows a sagittal view of the adult airway. Partial or complete obstruction can occur at any point.
Patients with a reduced conscious level are vulnerable to airway obstruction through relaxation of their smooth muscle. Relaxed smooth muscle causes: occlusion of the nasopharynx by the soft palate, occlusion of the oropharynx by the tongue and occlusion of the laryngopharynx by the epiglottis.
Airway obstruction can also occur through other mechanisms (see table below)
Table 1: Causes of airway obstruction
| In the lumen | In the wall | From outside the airway |
| Vomit | Infection, including: – Tonsillitis – Peritonsillar abscess – Retropharyngeal abscess – Floor of the mouth infection – Epiglottitis | Penetrating neck injury |
| Secretions | Trauma to larynx (blunt and penetrating) | Tumour |
| Blood | Tumour | Oesophageal foreign body |
| Foreign body | Anaphylaxis | |
| Angio-oedema |