3. Intubation

Question 1

What are endotracheal tubes?

Answer 1

flexible tube placed in the trachea
delivers anesthetic gases or oxygen directly from the anesthetic machine to lungs

Question 2

What are the differences btw murphy tubes and cole tubes

Answer 2

Murphy - beveled end and side holes, possible cuff
Cole - no side hole or cuff, abrupt dec in diameter or tube, used in exotics

Question 3

What are ubes made out of?

Answer 3

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

Question 4

What lengths do et tubes come in?

Answer 4

standard lengths
scale marks distance from patient end (in CM)

Question 5

What sizes do ET tubes come in?

Answer 5

Measured by internal diameter or ID
range from 1mm to 30 mm

Question 6

What are the different parts of an ET tube?

Answer 6

Valvue w/ syringe attached
pilot balloon, machine end, connector, tie, measure of length from patient end (CM), measure of internal diameter (MM), inflated cuff, patient end, murphy eye

Question 7

What is a laryngoscope?

Answer 7

used to inc visibility of larynx while placing an ET tube
Parts: handle containing batteries, blade to depress tongue, light source to illuminate the throat
Sizes: small anim 0-5; large anim to 18 in blade
Types: Miller blades or macintosh blade

Question 8

When are ET tubes placed? What do they do?

Answer 8

ET tube placed in patients airway after GA induction or during resp arrest
Conducts air or anesthetic gases directly from oral cavity to trachea
bypasses the nasal passages, oral cavity, pharynx and larynx - limits deadspace
can be connected to an anesthetic machine to maintain anesthesia or to an ambu bag for ventilation during cardiac arrest

Question 9

What are the benefits of ET intubation?

Answer 9

helps maintain an open airway - leave in place until swallowing in dogs, earflick in cats
With inflated cuff helps to prevent aspiration of vomitus, blood, saliva
Reduced 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 resp arrest

Question 10

What equipment do we need for ET intubation?

Answer 10

3 ET tubes of diff diameters (ex. 8 perfect, but lets bring 7.5 and 8.5)
lube, good light source
2’ lengths of IV tubing or rolled gauze to secure tube
gauze sponge to grasp tongue
10mL slip tip syringe to inflate cuff
stylet for narrow diameter tubes
lidocaine injectable solution, spray, or gel to control laryngospasm (fel)
laryngoscope with appropriate blade

Question 11

How do we select an appropriate ET tube for a patient?

Answer 11

Diameter: sm enough to not cause trachea injury, lg enough to provide a seal w/ inflated cuff, palpate the trachea to determine size, can use patient weight as guideline
Length: minimize mechanical deadspace - must reach thoracic inlet, not extend 2cm beyond end of muzzle
Patient: species, conformation and breed
Preparation - clean tube w/ no damage

Question 12

why do we intubate when patients are induced with an IV anesthetic?

Answer 12

unconscious, no voluntary movement, no pedal reflex, sufficient muscle relaxation, no swallowing when tongue is pulled

Question 13

What is the intubation procedure starting from gatheringering equipment and ending with monitoring

Answer 13

1. Gather all necessary equipment
2. Restrain patient in sternal recumbency w/ head extended and neck straight
3. Tongue pulled forward/slight downward
4. Use laryngoscope to light up larynx
5. Gently inster tube rapidly/correctly, giving it a small rotation as it is inserted (never force tube, when placed the curve of the tube should match curve of neck)
6. Roll patient into lat
7. Ensure proper placement
8. Secure tube/inflate cuff
9. Turn on O
10. Attach breathing circuit
11. Turn on anesthetic vaporizer
12. begin patient monitoring

Question 14

How can we check that we have proper tube placement?

Answer 14

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 tube connector as patient exhales
fogging of the tube during exhalation
unidirectional valve motion
Patient coughs during intubation
abilities of patient to vocalize indicates misplaced tube
connect a capnography to ET tube, will have proper waveform

Question 15

What is laryngospasm

Answer 15

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 16

How can we prevent laryngospasm?

Answer 16

2% injectable lidocaine or lidocaine gel - most commonly a lidocaine spray
adequate depth of anesthesia, wait for glottis to open before incubating, don’t force the tube

Question 17

How do we secure the tube and cuff inflation?

Answer 17

tie the ET tube securely w/o 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 reservoir bag, listen for gas leaks, inflate cuff until leaking just ceases at pressure of 20cm H20
OPEN THE POP OFF VALVE

Question 18

How do we extubate?

Answer 18

prepare by untying guaze and syringe ready to deflate cuff
DEFLATE CUFF
remove when:
Dogs: swallowing reflex returns
Cats: Ear twitch in response to stimulus
When signs of impeding arousal are present (voluntary limb, tail or head movements)
Remove tube in one slow, steady motion

Question 19

What are some complications of intubation?

Answer 19

vagus nerve stimulation, brachycephalic dogs or other breed deformities
overzealous intubation efforts
over inflation of cuff
obstructed ET tube
waiting too long to remove tube
improper cleaning and sanitizing btw uses
tracheal and/or laryngeal irritation leading to postsurgical cough - common

Question 20

What is a supraglottic airway device?

Answer 20

v-gels: species specific (rabbit and cat, working on canine)
trauma free high quality pressure seal around airway and oesophageal structures
V-gel is shaped to mirror the pharyngeal airway anatomical structures for each species of animal

Question 21

What are the benefits of V-gel

Answer 21

fast, easy, safe, and stress-free device insertions
no post-operative coughing or gagging
low airway breathing resistance due to lg airway channel within device
high quality pressure seal restricting leakage of volatile anes agents - improve health and safety in anes 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