A&A Pages 97-99 & 245-251. Page2 Flexible tube, placed inside trachea of an anesthetized patient,...
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Transcript of A&A Pages 97-99 & 245-251. Page2 Flexible tube, placed inside trachea of an anesthetized patient,...
Endotracheal Intubation of Dogs and Cats
(Anesthetist)A&A Pages 97-99 & 245-251
Endotracheal Intubation
Page 2
Flexible tube, placed inside trachea of an anesthetized patient, used to transfer gases directly from anesthesia machine to patient’s lungs.
Usually after induction
Advantages Patient airway is assured
◦ Free from obstruction
Artificial ventilation can be provided◦ Manual or mechanical◦ Flow of O2 and iso from the machine will fill the
reservoir bag, which can be used to provide a breath
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
3
“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
More advantages
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
◦ More so in cats
PVC◦ Transparent◦ Rigid
Red rubber◦ Flexible/floppy◦ Absorbs disinfectants
Silicone- happy medium but expensive
Types of ET Tubes
Types of ET Tubes Cole tubes
◦ Non-cuffed◦ Used in birds/reptiles due to their tracheal rings…what about them?
Murphy tubes◦ Balloon type structure on the lower half of tube◦ Inflated with air in a syringe AFTER tube has been
placed in the trachea *Once inflated, DO NOT move tube◦ Need a designated “cuff inflator”
Murphy Eye
Purpose of Cuff on Tube
Positive pressure ventilation Efficient delivery of inhalant anesthetics◦P isn’t breathing in room air too◦Less waste gases in room
Prevent foreign material from entering lungs
*Inflating the cuff should not take the place
of using a larger tube
Laryngoscope
Light source
Blade
Handle
Responsible for maintenance:
batteries/charging and light bulbs
*Handle must match blade
http://www.youtube.com/watch?v=cK8fdHHyCPY&NR=1 - visual of epiglottis
http://www.youtube.com/watch?v=3EDRvvGpOZk&NR=1 - intubation of a dog
http://www.youtube.com/watch?v=CGjGTfP_Bs0 – intubation with cuff
Videos
DIAMETER (measured in mm) 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 = 3.0-4.5mm
DOGS = based on weight (table in A&A book)Remember: 20 kg = 9.5-10 mm
Selecting an ET Tube
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
Tips for Tube Size
Use width of space between thenostrils as a guide
LENGTH (measured in centimeters) Extend from the tip of the nose to the thoracic inlet
◦ ABOVE THE TRACHEAL BIFURCATION
If you extend into only one bronchus:◦ Hypoventilation and hypoxemia???
If you extend tube too far past patient’s nose
Increased dead space
Selecting an ET Tube
Prior to Intubation Check several tubes for loose connectors,
excessive wear, cuff leaks, debrisCuff leak check: inflate cuff fully and let it sit Remember to deflate cuff completely prior to intubation
Immediately before intubating: 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
Intubation Techniques Procedure 8-6 on Page 260
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
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 extended and in line with body
Pull out tongue to visualize back of throat
◦ May need gauze to hold tongue- slippery
17
Move soft palate up and out of the way with ET tube and at the same time…
Move epiglottis down and out of the way with the ET tube (or blade of laryngyscope)◦ This brings tracheal opening into view
Under direct vision, ET 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
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 can obstruct view
Page 21
With Stylet Stylet runs inside the ET tube Made of strong wire/metal
◦ Stiffens the tube and molds the tube Can stick 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?
Intubation Techniques2. 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)
3. Tactile Cattle, large exotics, a few large dogs Finger holds down the epiglottis Slide tube into trachea using your finger as a guide
More difficult Small mouth and sensitive larynx Dome shaped vocal cords tend to quickly
close and push tube to side Swallowing reflex or contact with end of
ET tube causes laryngospasm
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
Feline Intubation
Tips for cats
Sternal recumbency, neck extended 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!
How Do You Know You’re In?
Condensation seen in ET tube Feel air through tube
◦ Place something light or metalat 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
Using Machines
Give a breath = chest should rise (stomach should NOT)◦ Listen to BOTH lung sounds
Rebreathing bag and flutter valves should move with respirations
Capnograph should give appropriate reading
Radiographs
How Do You Know You’re In?
Page 34
Cuff Inflation Cuff is attached to a pilot balloon with a
spring loaded inflation valve Must depress spring in order to inflate Cuff should inflate, but not be maximally full
of air
*If more than 10 cc of air needed: Leaky cuff or need a larger ET
tube
Cuff Inflation
Recheck every 30 min of surgery – especially after moving or repositioning patient◦ Most important for which type of procedure??
If you are running anesthesia for longer than 2 hours, you can reposition the tube slightly so pressure necrosis does not happen.◦ Must deflate cuff before moving tube!
*Even in emergencies
Secure Tube in Place Roll gauze
Rubber Band IV line tubing
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
A LW A Y S disconnect the patient from the anesthetic tubes when moving OR repositioning
Page 38
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 such as??
Remove ET tube after 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*
Brachycephalic animals – should be head up, chewing on tube before it is pulled
Extubation Note
Bulldog video
Post-op Advice to Owner
Patients may cough for 1 – 2 days post-op◦ Should not be severe or continue to get worse
Advising owner will avoid phone calls and later explanations!
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 in Ultra Sonic Cleaning soln. or
DILUTE chlorhexidine Rinse VERY well Hang upright to dry over night Deflate cuff
Unclean equipment (we reuse ET tubes!)◦ Disease transmission ex. Kennel cough
Leaky cuff◦ Check before use, during surgery, and while cleaning
Complications Before You Even Start
Complications While Placing
Tube too small◦ Failure to achieve desired depth of anesthesia
“light”◦ Like breathing through a straw increased resp.
effort◦ Easily become blocked with mucus
Tube too large◦ Damage to anatomy
Tube is too long◦ Hypoxemia and atelectasis decreased tissue
perfusion and difficulty breathing on recovery
Over-inflation of cuff◦ Necrosis, anatomical damage
Under inflating cuff = No seal created◦ Breathing room air light◦ Staff breathing iso high◦ Aspiration likely, especially if dental procedure
Vagus nerve stimulation◦ Parasympathetic response bradycardia, apnea,
cardiac arrhythmias ◦ What class of premed can help prevent this
response?
Complications While Placing
Dislodged tube◦ Not tied securely◦ Coughs out (cats)◦ Not disconnected while repositioning◦ Weight of hoses & machine pulls out
Restricted air flow◦ Bevel against wall of trachea, reason for
additional “Murphy eye” on other side◦ Kinks- extreme head position, over edge of table,
floppy tube used
Complications During Ax