Chapter 2 - Airway And Ventilatory Management

Question 1

What is the definition of a definitive airway?

Answer 1

A cuff inflated below the level of the vocal cords, connected to an O2-enriched source of ventilation, and secured with tape

Question 2

What 2 things do you do if there are gastric contents in an airway?

Answer 2

Suction (Yankauer) and rotate patient to lateral position

Question 3

What 3 things do you see in MaxFax fractures? What is the main concern in a bilateral mandibular fracture?

Answer 3

3 things = Haemorrhage, dislodged teeth, increased secretions.
Bilateral mandibular fractures can cause loss of normal airway structural support, leading to airway obstruction when supine.

Question 4

Blunt/penetrating neck injuries can disrupt larynx/trachea - what is the main concern?

Answer 4

Obstruction or bleeding into the tracheobronchial tree, necessitating a definitive airway (even if obstruction is partial)

Question 5

What are the 3 signs of (albeit rare) larynx fracture? What is the treatment? What other main structures can be damaged?

Answer 5

Hoarseness, Subcut Emphysema, and a palpable fracture.
Try flexible endoscopic intubation; if it fails, do tracheostomy - but even this may be difficult, so cricothyroidotomy may be lifesaving.
Damage may occur to oesophagus/carotids/jugular veins.

Question 6

Assuming no alcohol, when assessing behaviour, agitation = ? and obtundation = ?
When listening, stridor/snoring = ?, hoarseness = ?

Answer 6

Agitation = Hypoxia
Obtundation = Hypercarbia
Stridor/snoring = Partial pharynx/larynx occlusion
hoarseness = Laryngeal obstruction

Question 7

What are the causes of decreased ventilation?

Answer 7

1. Airway obstruction,
2. Pre-existing pulmonary disease
3. Intracranial injury
4. Chest trauma (causing pain and therefore rapid shallow breathing)
   5 C-spine injury sparing phrenic nerves, which causes abdominal breathing and paralysis of intercostal muscles.

Question 8

What are 2 signs of decreased ventilation? Why is pulse oximetry unhelpful when assessing ventilation?

Answer 8

1. Asymmetric chest movements (eg flail chest)
2. Decreased air entry on one or both sides
   Pulse Oximetry measures oxygenation/perfusion, but not ventilation, for which you need end-tidal CO2.

Question 9

What does LEMON stand for, and what is it?

Answer 9

It’s the way to assess airway difficulty.
L = Look for C-spine injury, severe arthritis, obesity, overbite, significant maxfax trauma etc
E = Evaluate 3-3-2 rule
M = Mallampati
O = Obstructive conditions (eg epiglottitis, peritonsillar abscess)
N = Neck mobility - patients in a hard spinal collar can’t move neck at all, therefore intubation is hard.

Question 10

What are the Mallampati classifications?

Answer 10

I = Soft palate/uvula/fauces/pillars visible; II = soft palate/uvula/fauces visible; III = soft palate and base of uvula visible; IV = Hard palate only

Question 11

What is the 3-3-2 rule?

Answer 11

To allow simple intubation, you need:
3+ finger breadths between the patient’s top and bottom incisor teeth (with mouth open)
3+ finger breadths between the hyoid bone and chin (with mouth closed).
2+ finger breadths between thyroid notch and floor of mouth (with mouth closed).

Question 12

What equipment is needed when preparing for the arrival of a patient with a possible obstructed airway?

Answer 12

Suction, O2, OP/NP airways, bag-mask, laryngoscope, bougie, extra-glottis devices, surgical/needle cricothyroidotomy kit, ET Tube, pulse oximetry, CO2 detection device, drugs

Question 13

Why shouldn’t you put an OP airway in a conscious patient?

Answer 13

Gagging –> Aspiration.

Question 14

What’s the important thing to remember about putting an OP airway in children?

Answer 14

Don’t rotate it 180 degrees, as you can damage the mouth/pharynx.

Question 15

Name 4 types of Extra/Supraglottic devices.

Answer 15

Laryngeal Mask Airway (LMA), Intubating LMA (ILMA), Laryngeal Tube Airway (LTA), or Multilumen Oesohageal Airway.

Question 16

What are the three types of airway? What are the Airway, Breathing and Disability criteria for needing them?

Answer 16

3 types = orotracheal, nasotracheal or surgical (cricothyroidotomy or tracheostomy).
Airway criteria = Inability to maintain patent airway (eg inhalation injury, facial fracture, retropharyngeal haematoma)
Breathing criteria = Inadequate oxygenation by face mask, or apnoea.
Disability = GCS < 8, sustained seizure or to protect against aspiration.

Question 17

What are two main complications of NASOtracheal airways?

Answer 17

Sinusitis and pressure necrosis. And if patient is apnoeic, orotracheal intubation is mandatory.

Question 18

What 4 types of fracture are relative contraindications to NASOtracheal intubation?

Answer 18

Facial, frontal sinus, basilar skull and cribriform plate fractures (as evidenced by raccoon eyes, battle’s sign, rhinorrhoea or otorrhoea).

Question 19

What manoeuvre helps to visualise the vocal cords?

Answer 19

Backward, Upward, Rightward Pressure (BURP) on thyroid cartilage ( you need extra hands to do this!).

Question 20

When passing a Bougie blindly, should the angled tip be positioned anteriorly or posteriorly?
How is tracheal position confirmed when passing it?

Answer 20

Anteriorly.
Confirm position by feeling a ‘click’ of the distal tip rubbing along the cartilaginous tracheal rings (felt in 65-90% of bougie placements).

Question 21

What 3 checks should be made to confirm an ET Tube is in the right place?
What complications should you look for once ventilating?

Answer 21

1. Auscultate for equal breath sounds bilaterally plus NO borborygmi (stomach gurgling sounds).
2. CO2 detection device
3. CXR
   Look out for tension pneumothorax (due to positive pressure) and gastric distension, which can cause the stomach to press on the vena cava, causing hypotension and bradycardia.

Question 22

What diameter ET Tube should be used to pass over a bougie? If the tube gets stuck at the epiglottic folds, what manoeuvre should be carried out?

Answer 22

6cm.

Withdraw the tube slightly, and turn it 90 degrees before advancing.

Question 23

What are the 10 steps of Rapid Sequence Induction?

Answer 23

1. Plan in case of failure! (surgical airway kit nearby)
2. Ensure suction and positive pressure ventilation are ready.
3. Preoxygenate with 100% O2.
4. Apply pressure over cricoid.
5. Administer induction agent (e.g. Etomidate 0.3mg/kg) or sedate.
6. Administer 1-2mg/kg succinylcholine (or equivalent)
7. Intubate
8. Inflate cuff, auscultate, check end CO2.
9. Release cricoid pressure.
10. Ventilate and CXR to confirm position.

Question 24

What is the advantage of Etommidate?

What is the main thing to watch out for when using Succinylcholine?

Answer 24

Etomidate doesn’t affect BP or intracranial pressure (but can suppress adrenals).
Succinylcholine can cause hyperkalaemia (so use with caution in burns/electrical/crush injuries, or CKD).

Question 25

What are 4 indications for a surgical airway?

Answer 25

1. Failed ET Tube
2. Oedematous glottis
3. Fractured larynx
4. Oropharyngeal haemorrhage.

Question 26

What size cannula should be used in Needle Cricothyroidotomy? How long can this airway last and why? What flow rate of O2 should be used?

Answer 26

12-14 gauge (adults) or 16-18 (children).
It lasts 30-45 minutes as there is gradual accumulation of CO2.
Use 5-7Lmin as persistent glottis obstruction can cause an increase in pressure, leading to pulmonary rupture and tension pneumothorax.

Question 27

What are 7 complications/side-effects of a Needle Cricothyroidotomy?

Answer 27

Aspiration (of blood), Oesophageal laceration, Haematoma, Thyroid Perforation, Pneumothorax, Subcut Emphysema, Poor ventilation.

Question 28

What is the lower age limit for Surgical Cricothyroidotomy and why?

Answer 28

12 years old; it can damage the cricoid cartilage which is the only support for the upper trachea in young children.

Question 29

What are 5 complications of a Surgical Cricothyroidotomy?

Answer 29

Aspiration, False Passage, Laryngeal/Subglottic Stenosis, Laceration of trachea/oesophagus, Vocal cord paralysis.

Question 30

What level of Pulse Oximetry saturation is suggestive of adequate oxygenation?
When is Pulse Ox unreliable?

Answer 30

95% = PaO2 > 9.3 (approx.).

Pulse Ox is unreliable in severe vasoconstriction (eg hypovolaemia), CO poisoning, HB < 5 or Temp < 30 degrees