1. INTUBATION OF DOGS AND CATS
A&A Page 245

2. Intubation
Flexible tube, placed inside trachea of an anesthetized patient, used to transfer gases directly from anesthesia machine to patient’s lungs.
Usually after induction
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3. Advantages Patient airway is assured
Free from obstruction
Artificial ventilation can be provided
Flow of O2 and iso from the machine will fill the reservoir bag, which can be used to provide a breath
When should this be done other than emergencies?
Dead air space reduced  increase efficiency of gas exchange
Dead air space describes the breathing passages that contain air but no gas exchange can occur

4. More advantages
“Cuffed” ET tubes reduces the risk of vomit/saliva/water being aspirated
Where would water come from? Vomit?
Secretions can be removed with suction catheter through the ET tube
Efficient delivery of inhalant anesthetics
Gas rates can be lowered (safe personnel)
Anesthetic gas stays in the system, not the sx suite
Drugs can be easily administered in emergency
Must give double the IV dosage

5. PROBLEMS Difficult to intubate certain patients
Brachycephalic, tiny animals, bull dogs
Overzealous efforts to intubate can
damage larynx, pharynx, soft palate
Cats especially with small glottis
Blind intubation (esophagus)
Tubes can be inserted too far
Ventilation of only one lung
Pressure necrosis from over inflation

6. Murphy eye-beveled, with a side hole
Types of ET Tubes
PVC, red rubber, or silicone
Non-cuffed
Used in birds/reptiles due to their
tracheal rings
Cuffed
Balloon type structure on the lower half of tube
Inflated with air in a syringe AFTER tube
has been placed in the trachea
Need a designated “cuff inflator”
Murphy eye-beveled, with a side hole

7. Purpose of Cuff on Tube Positive pressure ventilation
Easier achievement of anesthesia
P isn’t breathing in room air too
Prevent foreign material from entering lungs
Less waste gases in room
*Inflating the cuff should not take the place of using a larger tube

8. Responsible for maintenance: batteries/charging and light bulbs
Laryngoscope
Responsible for maintenance: batteries/charging and light bulbs
Blade
Light source
Handle

9. DOGS = based on weight (table in A&A book)
Selecting an ET Tube
DIAMETER
Should be a snug, easy fit
Should not “fall” in OR be forced into trachea
The cuff being inflated will “seal” the trachea
General ideas:
CATS = mm
DOGS = based on weight (table in A&A book)
Remember: 20 kg = mm

10. Tips for Tube Size Weight based is a guideline
Always prep 3 tubes (choice,1 smaller, 1 bigger)
Brachycephalics may need smaller than you think
Long soft palate with extra tissue and narrow tracheas
Use width of space between the
nostrils as a guide

11. Selecting an ET Tube LENGTH
Extend from the tip of the nose to the thoracic inlet
ABOVE THE TRACHEAL BIFURCATION
If you extend into only one lung:
Hypoventilation and hypoxemia
???
If you extend tube too far past
patient’s nose
Increased dead space

12. Prior to Intubation
Check several tubes for loose connectors, excessive wear, cuff leaks, debris
Cuff leak check: inflate cuff fully and let it sit Remember to deflate cuff completely prior to intubation
Apply lubrication- very small amount and optional
Larger tubes – KY jelly or saliva
Do not allow it to dry on tube
Smaller tubes (<4.0mm) – water or saliva
Check patient jaw tone
Swallow reflex

13. Intubation Techniques
1. Visual
Preferred technique for dog and cat
Direct visualization of larynx minimizes possibility of traumatic or improper intubation
Position: Sternal, Dorsal, Lateral recumbency
Position is preference

14. Visual Technique
Assistant holds hand placed on the muzzle with fingers behind front canine teeth (like you would for pilling) pulling upward to open the mouth
Neck should be slightly extended and in line with body
Pull out tongue to
visualize back of throat
May need gauze to
hold tongue- slippery

15. Under direct vision, tube is passed through tracheal opening
Tongue is pulled forward and off to the side, then held in place with thumb – moves epiglottis forward and down
Tongue can be held by you or restrainer
Move soft palate up and out of the way with ET tube and at the same time…
Move epiglottis down out of the way with the tube – this brings tracheal opening into view
Under direct vision, tube is passed through tracheal opening
Tech note: You may need to wait for a breath or stimulate animal’s body to inhale to see opening

16. With laryngoscope RIGHT HANDED PERSON Hold laryngoscope w/ left hand
Hold ET tube in right hand
Press blade against pulled out tongue, exposing trachea
Can be used to hold epiglottis down
Lightly!
Blade too far forward will obstruct view

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19. With Stylet Stylet runs inside the ET tube Made of strong wire/metal
Stiffens the tube and molds the tube
Sticks out past the ET tube
Provides smaller, blunt point to first pass through the vocal cords
Allows larger ET tube to slide into trachea
Stylet should be longer than ET tube!
Why?

20. Intubation Techniques
2. Blind
Used in dogs and horses
NOT suitable for cats, very small dogs, or patients with edema, swelling or trauma
Lateral recumbency (RIGHT lateral in dogs)
Head and neck extended and mouth open
Advance tube with bevel parallel to vocal cords
Move soft palate up and out of the way and epiglottis down
Advance upon expiration
Rotating tube to follow curve and point tip down

21. Intubation Techniques
3. Tactile
Cattle, large exotics, a few large dogs
Finger holds down the epiglottis
Slide tube into trachea using your finger as a guide

22. Feline Intubation More difficult Small mouth and sensitive larynx
Dome shaped vocal cords tend to close and push tube to side
Swallowing reflex or contact with end of tube causes laryngospasm

23. Feline Intubation Laryngeal sensitivity
Can be reduced by application of topical anesthetic
Apply 0.1 cc of 2% Lidocaine soln. on glottis (without the needle!)
Or use cotton swab
Can also coat the end of the tube w/ lidocaine gel

26. Tips for cats Sternal recumbency Good light source
Use direct visualization technique-must be able to see vocal cord opening before inserting tube
Stylet is helpful!
Cats often cough – don’t let go!

30. How Do You Know You’re In?
Condensation seen in ET tube
Feel air through tube
Place something light or metal
at end of ET tube
Palpate throat
One tube – you’re in
Two tubes – you’re in esophagus
Normal breathing sounds
No gurgling
Patient can not vocalize

31. How Do You Know You’re In?
Using Machines
Give a breath = chest should rise
(stomach should NOT)
Listen to BOTH lung sounds
Rebreathing bag and flutter valve should move with respirations
Capnograph should give appropriate reading
Radiographs

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33. Paper tape-birds/reptiles
Secure Tube in Place
Roll gauze
Rubber Band
IV line
Paper tape-birds/reptiles
Tie around tube first, then around patient
Do not include small tube used for cuff inflation
ALWAYS use a bow tie, not a knot
ALWAYS disconnect the patient from the anesthetic tubes when moving OR repositioning

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35. Cuff Inflation Cats: 1 – 2 cc of air Dogs: 2 – 10 cc of air
Valve port should inflate, but not be maximally full of air
If more than 10 cc needed:
Leak or need a larger ET
tube

36. Cuff Inflation
Recheck every 30 min of surgery – especially after moving or repositioning patient
If you are running anesthesia for longer than 2 hours reposition the tube slightly so pressure necrosis does not happen.
Must deflate cuff before moving tube!

37. Extubation Your patient will be in recovery
Sternal or lateral recumbency
Head and neck extended
Deflate the cuff when the patient shows signs of waking up
Remove ET tube after un-stimulated swallowing has returned
Prevent obstruction of airway with tongue by pulling tongue forward during and after pulling the tube
*Waiting too long can cause patient to bite tube in half*

38. Extubation Note
Brachycephalic animals – should be head up, chewing on tube before it is pulled

39. Post-op Advice to Owner
Patients may cough for 1 – 2 days post operatively
Should not be severe or continue to get worse
Advising owner will avoid phone calls and later explanations!

40. ET Tube Cleaning Inflate cuff and leave inflated until dry
Wash inside AND outside of endotracheal tube
Use warm soapy water to get mucus off
Commercial brushes available, cotton swabs, pipe cleaners
Rinse
Disinfect for minimum of 15 minutes in Ultra Sonic Cleaning soln. with DILUTE chlorhexidine
Rinse VERY well
Hang upright to dry over night
Deflate cuff