Supraglottic airways

Question 1

What is the glottis?

Answer 1

Opening between the vocal folds

Question 2

When might you use an NP?

Answer 2

Conscious patients, with intact gag reflex - to aid BVM and assist suction.

Question 3

Contraindication to NP?

Answer 3

Epistaxis, facial trauma.

Question 4

Contraindications to OP?

Answer 4

Soft tissue damage, gagging/vomiting, aspiration

Question 5

Problems with supraglottic airways?

Answer 5

Not definitive - simply create a seal without entering the trachea, theoretically higher aspiration risk.

Question 6

Dates of different types of LMA?

Answer 6

• LMA: 1981. Inflatable cuff on top of glottis to prevent aspiration.
• Combitube 1987. First of the dual cuffs, distal end sits in the oesophagus and inflated to prevent rising gastric contents rising/can suction contents.
• LMA fasttrack: 1997 more rigid tube, and an ET tube guiding ramp. Eg bridge to ET.
• Laryngeal tube 1997. Same concept of combitube, apparently curvature makes tracheal placement impossible.
• I-gel 2003. Only HEMS carried SA. No cuff - thermoplastic polymer seals around glottis. Less risky and can be used as bridge to ET.
• LMA supreme: 2007. Bite block and gastric aspiration added.

Question 7

I-gel vs combitube for ET bridge?

Answer 7

I-gel: quicker insertion/less damage therefore better rescue device
Combitube: better

Question 8

Advantages of supraglottic airway?

Answer 8

Disposable/sterile packaging
Gastric suctioning
ET conduit
Biteblock
Non-inflatable cuff (for i-gel only)

Question 9

Complications related to cuff inflation?

Answer 9

aspiration pneumonitis (n=31),
 pulmonary aspiration (n=16),
 pneumothorax (n=6), 
upper airway bleeding (n=4),
 esophageal laceration (n=3), sc 
emphysema (n=2), 
esophageal perforation
mediastinitis (n=2)

Question 10

Priorities in routine anaesthesia?

Answer 10

High rates of insertion when used by experts.
Ability to ventilate
Few complications

Question 11

Key message for what supraglottic device is best - research?

Answer 11

Semi-meaningful comparisons from efficacy trials (speed of insertion/first time success). However in terms of survival in CPR context, not enough studies/patients yet.

Question 12

Key priorities for airway control in pre-hospital CA?

Answer 12

Speed of insertion
-Success without expert training 
-Ability to ventilate
-Stability in the airway once placed 
-Lessening the risk of aspiration 
(though less prioritised than in routine anaesthesia)

Question 13

Most secure SA?

Answer 13

Combitube

Question 14

Reasons suggested from Japanese study into why ET more survival than supraglottic airways?

Answer 14

• ?Better ventilation via ET

- LMA cuff inflation reduced carotid artery floe

Question 15

Why are ET tubes optimum management in CA?

Answer 15

Enables ventilation without stopping compressions
Reduced risk of gastric aspiration
Frees up hands for other tasks

Question 16

Disadvantages of ET inCA?

Answer 16

Oesophagal intubation/ dislodgement unacceptably high.
CPR mustn’t be significantly interrupted for intubation.
Paramedics who don’t regularly perform intubation are more likely to fail

Question 17

What about in traumatic arrest?

Answer 17

Probably ET, due to extra risk to airway