Airway devices - anaesthetics

Question 1

Face mask

Answer 1

Rubber or silicone masks that cover the mouth and nose of the pt.
- Used to deliver 02, N20-02 and other inhalation agents.

Question 2

Oropharyngeal airway

Answer 2

Also known as a Guedel.
- Flat section rests on tongue, preventing it from falling into the pharynx and resulting in obstruction.
- Size must be large enough to go beyond the back of the tongue, but shouldn’t press on the posterior pharyngeal wall since this may stimulate the gag reflex.

Question 3

Nasopharyngeal Airway

Answer 3

Used when a oropharyngeal airway is contraindicated.
- Traumatic and can cause bleeding and swelling if incorrectly inserted.

Question 4

Laryngeal mask airway (LMA)

Answer 4

Designed to be left in place until the return of the protective reflexes of the airway such as the gag reflex.
- Used to provide supplemental oxygen via a T-piece system or a Bain’s circuit.
- Device of choice for supraglottic airway ventilation.

Question 5

Factors affecting difficult supraglottic airway:

Answer 5

• Restricted mouth opening
  
  • Upper airway obstruction or below the level of the larynx
• Stiff cervical spine

Question 6

Proseal LMA

Answer 6

A LMA incorporating a second tube lateral to the airway tube.
- Second tube is intended to separate the alimentary and respiratory tracts.
- Permits access to or escape of fluids from the stomach and reduces the risk of gastric insufflation and pulmonary aspiration.

Question 7

Supreme LMA

Answer 7

Differs from a standard LMA as it has two seals.
- First is the oropharyngeal seal
- Second is an upper oesophageal sphincter seal.
- Second seal is important as it minimises gastric insufflation and reduces the risk of aspiration.

Question 8

LMA Fastrach

Answer 8

Specifically designed to improve blind and endotracheal intubation through a LMA.
- Useful in difficult intubation cases on their own or in conjunction with the fibreoptic-intubating laryngoscope.

Question 9

Endotracheal tubes (ETT)

Answer 9

Placed between the vocal cords through the trachea.
- Serves to provide oxygen and inhaled gases to the lungs
- Protects lungs from contamination - including gastric contents and blood.

Question 10

Performed tubes

Answer 10

Manufactured with a pre-existing bend that can be straightened during intubation.
- Most common - ring-elwin (RAE) tube that allows the ETT once placed to be angled away from the face to facilitate access during surgeries around the head and neck.

Question 11

Reinforced (armoured) tubes

Answer 11

Reinforced tubes provide strength and reduce kinking of tube.
- Useful in surgeries that require unusual patient positioning and potential compression of the tube.
- Bite blocks are recommended to prevent tube from breaking.

Question 12

Stylet

Answer 12

Designed to fit inside an ETT so it maintains its predetermined shape.

Question 13

Bougies

Answer 13

Used to help the intubator identify anatomical landmarks and to direct the head of the tube into the correct place.
- ETT is placed over the bougie.

Question 14

Laryngoscope

Answer 14

Used to directly view the larynx and adjacent structures
- Comprises of a blade and handle.

Question 15

Miller blade

Answer 15

Miller laryngoscope is a straight blade designed to obtain a view of the vocal cords by directly lifting the epiglottis.
- Useful application in floppy airways making it popular within paediatric anaesthesia.

Question 16

Macintosh blade

Answer 16

• Tip of the blade is compressed into the angle formed by the base of the tongue and the epiglottis, indirectly raising the epiglottis.