Intubation

Question 1

Endotracheal tubes are

Answer 1

Flexible tube placed in the trachea
Delivers anesthetic gases or oxygen directly from the anesthetic machine to the lungs

Question 2

Types of ET tubes

Answer 2

Murphy tubes
Cole tubes

Question 3

Characteristics of cole tubes

Answer 3

No side hole or cuff
Abrupt decrese in diameter of tube
Used in birds and reptiles

Question 4

Characteristics of murphy tubes

Answer 4

Beveled end and side holes
Possible cuff

Question 5

Materials for et tubes

Answer 5

Polyvinyl chloride: clear and stiffer
* Red rubber: flexible and less traumatic, absorbent, and may kink or collapse
* Silicone: pliable, strong, less irritating, resist collapse

Question 6

Length of ET tubes

Answer 6

Standard lengths
* Scale marks distance from patient end (centimeters)

Question 7

Size of ET tubes are measured by

Answer 7

• Measured by internal diameter (ID)
• Range from 1 mm to 30 mm

Question 8

Parts of the ET tube

Answer 8

Valve with syringe attached
Pilot balloon
Machine end
Connector
Tie
Measurement of length from patient end (cm)
Measurement of internal diameter (mm)
Inflated cuff
Patient end
Murphy eye

Question 9

Laryngescope

Answer 9

Used to increase the visibility of the larynx while placing an ET tube
Parts
* Handle containing batteries
* Blade to depress tongue
* Light source to illuminate the throat
Sizes
* Small animal 0 to 5; large animal up to 18-inch blade
Types
* Miller blades
* Macintosh blade

Question 10

Why are ET tubes placed

Answer 10

Endotracheal tube is placed in the patient’s airway after general anesthesia induction or during respiratory arrest
* Conducts air or anesthetic gases directly from oral cavity to trachea
* Bypasses the nasal passages, oral cavity, pharynx, and larynx
* This limits dead space
* Can be connected to an anesthetic machine to maintain anesthesia or to an ambu bag for ventilation during cardiac arrest

Question 11

Benefits of endotracheal intubation

Answer 11

Helps maintain an open airway
* Leave in place until the swallowing reflex returns
* With inflated cuff helps prevent aspiration of vomitus, blood, saliva
* Reduces anatomic dead space
* Improved efficiency of gas exchange
* Decreased exposure of personnel to waste gas
* Ventilation can be supported manually or mechanically
* Especially useful for patients in cardiac or respiratory arrest

Question 12

Equipment for endotracheal intubation

Answer 12

Three endotracheal tubes of slightly different diameters
Lube for lubricating tube
Two-foot lengths of IV tubing or rolled gauze to secure tube
Gauze sponge to grasp tongue
10-mL slip tip syringe to inflate cuff
Good light source
Stylet for narrow diameter tubes
Lidocaine injectable solution, spray, or gel to control laryngospasm (cats)
Laryngoscope with appropriate blade

Question 13

How to chose the ET by diameter

Answer 13

Small enough to not cause trachea injury
* Large enough to provide a seal with inflated cuff
* Palpate the trachea to determine size
* Can use patient weight as a guideline

Question 14

How to chose ET length

Answer 14

minimize mechanical dead space
* Must reach the thoracic inlet
* Not extend 2 cm beyond the end of the muzzle

Question 15

Intubation procedure

Answer 15

*Know the anatomy of the throat
* Pharynx and larynx
*Know the proper restraint and positioning techniques
* Don’t attempt intubation unless you can visualize the larynx
*Have proper lighting
*Induce patient with IV anesthetic
* Unconsciousness, no voluntary movement, no pedal reflex, sufficient muscle relaxation, no swallowing when tongue is pulled

Question 16

Steps to intubation

Answer 16

1.Gather all necessary equipment
2. Restrain patient in sternal recumbency with head extended and neck straight
3. The tongue is pulled forward and slightly downward
4. Use the laryngoscope to illuminate the larynx
5. Gently insert tube rapidly and correctly, giving it a small rotation as it is inserted
a. Never force the tube
b. When placed the curve of the tube should match the
curve of the neck
6. Roll patient into lateral recumbency
7. Ensure proper placement
8. Secure the tube and inflate the cuff
9. Turn on the oxygen
10. Attach the breathing circuit
11. Turn on the anesthetic vaporizer if required
12. Begin patient monitoring

Question 17

How to check for proper tube placement

Answer 17

Palpate the neck
Re-visualize larynx and confirm the tube is in the correct location
Watch reservoir bag as animal breathes
Feel for air movement from the tube connector as patient exhales
Fogging of the tube during exhalation
Unidirectional valve motion
Patient coughs during intubation
Ability of patient to vocalize indicates misplaced tube

Question 18

Laryngospasm is and common ins

Answer 18

• Reflex closure of the glottis in response to contact with an object or substance
• Common in cats, swine, and small ruminants in light plane of anesthesia
• Makes intubation very difficult; larynx is easily damaged
• May lead to cyanosis or hypoxemia
• Not usually a problem with cardiac arrest

Question 19

Prevention of laryngospasm

Answer 19

• 2% injectable lidocaine or lidocaine gel
• Most commonly a lidocaine spray
• Adequate depth of anesthesia
• Wait for glottis to open before intubating
• Don’t force the tube

Question 20

How to secure the tube and inflate the cuff

Answer 20

• Tie the ET tube securely without compressing the tube
• Tie around muzzle, or behind head
• Cuff the tube
• Extend the patient’s head
• Have an assistant close the pop-off valve and compress the reservoir bag
• Listen for gas leaks
• Inflate the cuff until the leaking just ceases at a pressure of 20 cm H2O
• OPEN THE POP-OFF VALVE

Question 21

How to do extubation

Answer 21

• Prepare by untying gauze and syringe ready to deflate cuff
• Deflate cuff
• Remove when:
• Dogs –> Swallowing reflex returns
• Cats –>Ear twitches in response to stimulus
• When signs of impending arousal are present (voluntary limb, tail, or head movements)
• Remove the tube in one slow, steady motion

Question 22

Complications of intubation

Answer 22

• Vagus nerve stimulation
• Brachycephalic dogs or other breed deformities
• Overzealous intubation efforts
• Over inflation of cuff
• Obstructed endotracheal tube
• Waiting too long to remove the tube
• Improper cleaning and sanitizing between uses
• Tracheal and/or laryngeal irritation leading to postsurgical cough
• Very common!

Question 23

Supraglottic airway device

Answer 23

V-gels®; these are species specific
◦ Rabbit and cat
◦ Working on canine
Trauma-free high quality pressure seal around the airway and oesophageal structures.
V-gel® is shaped to mirror the pharyngeal airway anatomical structures for each species of animal.

Question 24

Benefits of V-gel

Answer 24

Fast, easy, safe, and stress-free device insertions.
No post-operative coughing or gagging.
Low airway breathing resistance due to the large airway channel within the device.
High quality pressure seal restricting leakage of volatile anaesthetic agents
◦ Improving health and safety in anaesthesia and overcoming patient sensitivity to smell – a common problem in rabbits.
Super soft contoured tip for a highly effective upper oesophagus seal.
◦ Prevents potential aspiration of reflux fluid.
Integral gas sampling port to reduce re-breathing dead-space.
◦ Makes high quality monitoring easier.
Integral bite block to stop patient damaging device and occluding the airway.
Materials safe for autoclave sterilization.