Anaesthesia Critical Care Flashcards
What abnormalities in the mouth that may contribute to difficult airway management?
Anatomical: small mouth, receding chin, high arched palate, large tongue
Acquired: burns, tumours, abscess, radiotherapy injury, restrictive scars, beard
Poor dentition: loose teeth and crowns, protruding teeth, gaps in the front teeth
Mechanical: temporomandibular joint disease (reduced mouth opening)
What physical actions could be used to relieve airway obstruction?
Airway obstruction may be relieved by lifting the chin and/or pulling the jaw forward (jaw thrust)
How might the patency of an airway be improved?
Patency may be improved by:
* Insertion of an artificial airway (oropharyngeal (Guedel) airway, nasopharyngeal airway, laryngeal mask airway, tracheal tube)
* Turning the patient from the supine to the lateral position (recovery position)
What is the nasal cavity lined by?
Respiratory mucosa - pseudostratified ciliated columnar epithelium containing numerous mucous and serous glands
What is the widest part of the nasal airway
Below the inferior turbinate
What are the advantages of nasal intubation?
Nasal intubation leaves the oral cavity clear for oral surgery.
For patients in the Intensive Care Unit, nasal intubation is more easily tolerated than oral intubation and less sedation is required.
What are the disadvantages of nasal intubation?
More difficult than oral intubation, may cause nose bleed due to the rich blood supply to the nasal mucosa
May create a false passageway, e.g. beneath the nasal mucosa or, in basal skull fractures, into the cranium
Long term nasotracheal intubation - infection of the paranasal air sinuses.
What are the afferent and efferent nerves of Gag Reflex
Afferent = glossopharyngeal
Efferent = vagal
What may become a site of bleeding following nasal intubation in children.
The adenoids
List the sensory nerve supply to the tonsil
the glossopharyngeal, maxillary and mandibular nerves
Describe the anatomical location of palatine tonsils
Collections of lymphoid tissue between the palatoglossal and palatopharyngeal arches, the ‘pillars of the fauces’.
How is aspiration during swallowing prevented
Closure of the laryngeal sphincter
upward movement of the larynx behind the base of the tongue
Reflex inhibition of breathing and channelling of liquid/food laterally by the epiglottis into the piriform fossae. The epiglottis act as a ‘lid’ to the larynx to prevent substances entering the trachea.
Describe the anatomical landmark of the larynx
Midline, opposite the 4th to 6th cervical vertebrae
List the articulating cartilages and paired cartilages of the larynx
Articulating cartilages
* Thyroid
* Cricoid
* Epiglottis
Paired cartilages
* Arytenoid
* Corniculate
* Cuneiform
What do the extrinsic muscles of the larynx do?
Work with other muscles attached to the hyoid to move the larynx up and down during swallowing.
What do the intrinsic muscles of the larynx do?
Open the vocal cords during inspiration
Close the cords and laryngeal inlet during swallowing
Alter the tension of the cords during phonation
What do posterior cricoarytenoids do?
Abduct the vocal cords on inspiration
- pulls the posterior ends of the arytenoid cartilages together medially. The resulting pivoting movement abducts the anterior ends of the cartilages, to which the vocal cords are attached
What do lateral cricoarytenoids, transvere arytenoids do?
adductors of the cords and close the vocal cords
What do aryepiglottics, thyroepiglottics do?
Laryngeal sphincters and close the laryngeal inlet during swallowing
What do cricothyroids do?
Tensors of the cords, acting by tilting the cricoid cartilage (and the attached arytenoids) on the thyroid cartilage
What do the thyroarytenoids, vocalis
The thyroarytenoids are relaxors of the cords.
The vocalis are responsible for the fine adjustment of the cords
Describe the nerve supply to the larynx
Superior laryngeal nerve - above the vocal cords
* The external laryngeal branch - motor supply to the cricothyroid muscle.
* The internal laryngeal branch passes beneath the piriform fossa mucosa, and provides the sensory supply to the interior of the larynx as far as the vocal cords
Recurrent laryngeal nerve - below the vocal cords
How does laryngoscopy induce vagal reflexes
Stimulation of the internal laryngeal nerve, which provides the sensory supply to the vallecula.
What does damage to the superior laryngeal nerve result in:
A hoarse voice due to loss of function of the tensor of the cord (cricothyroid). The hoarseness is temporary as the muscle on the other side compensates
An increased risk of aspiration resulting from loss of sensation above the cords