Airway Disease: Recognition and Diagnosis

Question 1

What is the most obvious clinical sign of a dyspnoeic cat?

Answer 1

Mouth breathing

Question 2

What questions would you ask for a relevant history regarding? (6)

Answer 2

About breathing
GI?
Exercise/activity level
Sleep
Heat tolerance
General

Question 3

For upper airway respiratory disease, sleeping disorders may be related to:

Answer 3

Nasal obstruction

Question 4

What is acute weight loss with resp dx suggestive of?

Answer 4

Underlying neoplastic cause such as nasal lymphoma or a laryngeal tumour.

Question 5

Why may patients with hormone disease deteriorate with resp dx?

Answer 5

Some hormonal diseases, such as hyperadrenocorticism, can reduce muscle tone. An animal that can cope with some degree of obstruction may deteriorate if muscle tone reduces.

Question 6

Any disease that compromises breathing for any length of time can result in weight loss. Why?

Answer 6

to difficulty in breathing whilst eating

Question 7

How does obesity effect tidal volume and why?

Answer 7

Obesity decreases tidal volume in animals, due to decreased thoracic wall movement and space occupying disease.

Question 8

Other than the effect on tidal volume. Obesity may compress what? (4)

Answer 8

Components of the upper airway such as the nasopharynx or pharynx, larynx or trachea.

Question 9

Full clinical examination is required paying particular attention to the following points (7)

Answer 9

Hormonal conditions

Any signs of myopathy or neuropathy;

Hepatomegaly

Mucous membrane colour and refill time;

Temperature ;

Short neurological assessment;

Cardiac disease can manifest as dyspnoea.

Question 10

Hepatomegaly may be associated with what resp condition. Why?

Answer 10

tracheal collapse (thought to be related to fatty deposits in the liver);

Question 11

Resp dx; what do you examine on CE? (5)

Answer 11

Respiratory rate and effort: look for abdominal muscle movement, thoracic inlet ballooning;

Nostrils: assess movement, stenosis and any movement of the skin behind the nostrils;

Breathing noise;

Stance:

Mucous membrane colour.

Question 12

Why look at stance on resp exam? What does it mean

Answer 12

elbows abducted is often a sign of dyspnoea (often pneumonia);

Question 13

We generally listen to the lower airway by auscultating over several places on both sides of the thorax and the upper airway by gentle auscultating over the side of the larynx with the head in a what position.

Answer 13

neutral

Question 14

What areas of the nostrils should be examined on CE? (30

Answer 14

• Movememnt
• Stenosis
• Movement of skin behind nostrils

Question 15

Define stertor

Answer 15

a low-pitched noise that is usually associated with vibration of soft tissues in the nasal cavity or nasopharynx.

Question 16

Define stridor

Answer 16

higher pitched noise - like ‘sawing wood’ which is usually associated with air being sucked through a narrowed opening - typically the larynx.

Question 17

The diagnosis is generally achieved using imaging techniques: (4)

Answer 17

Ultrasonography (can evaluate laryngeal movement in a non-invasive manner)

Laryngoscopy under a light plane of anaesthesia

Radiography

Advanced imaging (usually CT or fluoroscopy).

Question 18

Some animals that have severe dyspnoea and cyanosis will require emergency treatment on admission.

Answer 18

O2
Monitor temp
Sedation
Corticosteroids

Question 19

What O2 flow in emergency?

Answer 19

Aim for 6-10 L/ minute flow by/nasal prongs/incubator or oxygen cage

Question 20

Resp distress:
A) What sedation used?(4)
B) BE prepared to..

Answer 20

A) Butorphanol; IV, IM or SC: Dexmedetomidine IV or IM, Acepromazine IV, IM or SC: Diazepam IV
b) Intubate

Question 21

When are steroids used for resp dx?

Answer 21

Obstruction

Question 22

What steroid choice for resp dx?

Answer 22

Dexamethasone

Question 23

Once stabilised, what monitoring would you use? (6)

Answer 23

Respiratory rate and effort

Pulse oximeter

Respiratory noise

Mucous membrane colour

Blood gas analysis

Temperature.

Question 24

Dog with laryngeal stridor, particularly pugs, it is worth nebulising with?

Answer 24

0.05 mg/kg epinephrine diluted in 0.9% saline using a quiet mesh nebuliser.

Question 25

How to improve airflow in the rima glottis

Answer 25

pulling the tongue forward will remove bulk from the caudal pharynx

Question 26

A ‘cannot intubate, cannot oxygenate’ situation may occur secondary to (5)

Answer 26

severe BOAS,
laryngeal oedema,
laryngeal or pharyngeal trauma,
foreign body
pharyngeal or laryngeal tumour.

Question 27

REsp obstruction; ideally access within how long?

Answer 27

300 secs

Question 28

What is the easiest way to supplement oxygen and bypass a laryngeal or upper airway obstruction in a dog that is difficult to intubate?

Answer 28

Cannulation of the cricothyroid ligament

Question 29

With cricothyroid cannulation, the easiest technique to facilitate ventilation may be to pass what through the cricothyroid ligament

Answer 29

a small bore (3.0-4.5) cut down ET tube

Question 30

Steps to cricothyroid cannulation

Answer 30

1. Find larynx by superficial palpation under the angle of the jaw.
2. Cranial to the cricoid cartilage is the thyroid cartilage and the ligament between the two is the access point- with the cannula directed caudally
3. Stabilise larynx in non-dominant hand.
4. Stab incision with 11 blade into cricothyroid ligament.
5. Place a urinary catheter through the cut down ET tube and slide next to the scalpel blade.
6. Feed ET tube over the catheter.

Question 31

What is the cricoid cartilage?

Answer 31

The cricoid cartilage is a fixed ring attaching to the trachea.

Question 32

How to check the placement of cricothyroid cannulation?

Answer 32

Capnography