Other causes of upper airway obstruction are typically categorized into one of four areas. They are:
Guedel inserted into patient
Anatomical causes
The anatomical causes include:
- Lesions of oral cavity
- Lesions of nasopharynx
- Lesions of the hypopharynx and larynx
- Lesions below the larynx (rarer)
Physiological causes
- Hypotonia
- Loss of protective airway reflexes
- Laryngospasm
Anaesthetic causes
There are many causes (other than those caused by the effect of drugs):
- Obstruction of anaesthetic circuit
- Incorrectly sized or misplaced Guedel airway
- The airway device e.g. LMA or tracheal tube used may be the wrong
size, damaged/kinked or be blocked/contain foreign bodies. In addition
the airway device may be:
- Over inflated - cuff herniation or pressure on vocal cords
- Misplaced - too superficial/deep or rotated
Others
- Secretions, blood or regurgitated gastric contents
- External compression of the airway e.g. surgical haematoma