Test 3 Notes: Janet Flashcards
Define induction
taking patient from a conscious to an unconscious state
2 Methods of induction
Injection
Inhalation
4 Benefits of ET intubation
Establish pt. airway
Prevent aspiration
IPPV
Decrease gas exposure to personnel
3 Types of ET tubes
Murphy tubes
Cole Tubes
Cuffless ET tubes
Cole Tube
Used for small animals & exotics
Skinny end inserted into trachea
Tie behind ears so wider part creates seal
Are easily dislodged
Murphy Tube
Beveled end (easier to insert) Murphy eye (prevents complete blockage) Cuff Pilot line with balloon Radiopaque strip
What are 3 benefits to using a cuffed ET tube
Prevents aspiration
Prevents leakage of gas to room
Prevents animal from breathing in room air
Cuffs do NOT ____, they create a ____
Hold the ET tube in place, they create a seal
How are ET tubes measured?
french scale= external diameter
How do you choose an ET tube size?
Use a chart based on weight
Palpate trachea
Measure tube diameter in comparison to nasal opening
How is the length of the ET tube measured?
From the tip of the nose to the thoracic inlet
What could happen if the ET tube is too long?
Endobronchial intubation
Increased resistance to respiration
How should a patient be restrained for placement of the ET tube?
Sternal recumbency
Restrainer holds top jaw
Extend neck and raise head
Intubator will pull tongue down to open mouth
Medical term for vocal folds
arytenoid cartilages
How do you restrain a ET tube?
Muzzle gauze
Rubberbands/ties
IV tubing
What is the best way to know the ET is in the trachea?
- *To visualize it
- use fingers to feel for tube between vocal folds
- feel air with exhalation
- res. bag movement
How would you know the ET tube is NOT properly placed?
You hear vocalization
What are 2 ways to know how much air to use in cuff
Back pressure in syringe
Use pressure manometer
What numbers do you look at when using the pressure manometer to inflate the cuff?
Hear slight leak at 20cmH2O
No leak at 15cmH2O
What could happen if you over-inflated the cuff?
Compression of the tube
Pressure necrosis of trachea
Tracheal rupture/tear
Why are cats more difficult to intubate?
Small trachea diameter
Larynx sits deeper in neck (harder to visualize)
Laryngospasms
Vocal folds cover more of the glottis
How would you intubate a cat?
Using a stylet or by putting lidocaine on the vocal folds
How much lidocaine would you put on the vocal folds?
0.1ml
one drop on each vocal fold
Succinylcholine properties
For feline intubation
IV
Lasts 5-10min.
Relaxes jaw tone and prevents spasms
What is the instrument that depresses the base of the tongue and has a light source?
Laryngoscope
What are some complications associated with ET intubation?
Pressure necrosis of lining of trachea Plugged ET tube (mucus plug) Kinked tube Stimulation of vagus nerve Trauma Animal could chew tube during recovery
How long do you leave the cuff inflated when extubating the patient?
Until you see 2 good swallows or you see signs of recovery
What do you do if the animal vomits with an ET tube in?
Deflate the cuff 1/2 way and remove (the cuff acts a squeegee)
How are ET tubes cleaned?
With dilute antiseptic (like chlorhexadine)
OK to submerge under water
Inflate cuff to remove all mucus
Use brush or pipe cleaner to clean inside
Rinse and hang to dry with cuff inflated
What should you be aware of if lasers are being used during surgery?
The laser mixed with the high oxygen could start a fire
Wrap ET tube with duct tape
Use a special laser safe ET tube
What is the Corneal reflex
touch cornea with sterile swab, animal should blink and withdraw eye, should be present during surgical plane, more common in equine
What is the Ear flick reflex
Gently touch hairs on inside of ear and look for “flick” could be absent or present during surgical plane
More reliable in cats
What is the Palpebral reflex
Gently tap medial canthus of the eye and observe blinking reflex
Should be gone during surgical plane
What is Jaw tone
Open jaw and observe muscle tone, should have some tone but mostly relaxed
Puppies and kittens have weak jaw tone
Eye position & Pupil size
Usually eyes will rotate ventromedial during surgical plane but can also be central
Pupils should be slightly dilated during surgical plane
10 Common vital signs to monitor during anesthesia
Heart rate Pulse ECG Resp. rate MM color CRT Temp Blood pressure O2 saturation ETCO2
Stage 1
Voluntary excitement phase- induction Immediately after admin of injectable or inhalant (usually rougher and longer) Animal is conscious, but disoriented HR & RR can be normal or increased All reflexes present
Stage 2
Involuntary excitement phase
Begins with loss of consciousness, all reflexes present, animal is able to chew and swallow
May have rapid movement of limbs, vocalization, struggling etc.
Shorter stage 2 = better!
Stage 3, plane 1
Light plane of anesthesia
Can be intubated
Relaxed jaw tone
NOT able to withstand sx.
Stage 3, plane 2
Medium plane of anesthesia
Suitable for most surgical procedures
Slight response to surgical stimulation
Patient is unconscious and immobile
What is the normal RR during Stage 3, plane 2?
8-30rpm
Stage 3, plane 3
Deep plane of anesthesia
Significant depression of circulation and respirations
Excessively deep for most sx procedures
Good plane for very painful surgery
Marked muscle relaxation & slack jaw tone
NO surgical response
Stage 3, plane 4
Anesthetic overdose
Patient is too deep
Drop in HR, BP, CRT and pale MM
Stage 4
Death
CPCR necessary to save patient
Turn off vaporizer
What are the 6 injectable anesthetic agents?
Barbiturates Cyclohexamines (dissociatives) Propofol Etomidate Neuroleptanalgesia Guaifenesin
What are the 2 main uses for Barbiturates?
Anticonvulsants (Pheno)
Euthanasia (Pento)
What is the ultra-short acting barbiturate?
Methohexital, thiopental
death row drug
Primary use of Phenobarbital
(Barbiturate)
Anticonvulsant
Primary use of Pentobarbital
(Barbiturate)
Euthanasia solution
ONLY DOUBLE THE ANESTHESIA DOSE!
Barbiturates properties
Controlled
NOT reversible
NO analgesia
IV admin only
4 effects of barbiturates
1.CNS depression
anti-convulsants
excitement during induction and recovery (Prolonged stage 2)
2.Potent respiratory depression
apnea with rapid admin or high doses
decreased RR and depth
3.Cardiovascular depression
decreased BP and cardiac output
4.Tissue irritation
IV admin only
What breeds have increased potency with barbiturates?
Sighthounds & lean animals
Thiopental properties
(Pentothal) -Barbiturate
Ultra-short acting
Used to be used as induction agent
No longer made in the US
Methohexital properties
(Brevital) -Barbiturate
Ultra-short acting
Best for use in sighthounds
Death row drug
What are the 2 Cyclohexamines?
Ketamine (Ketaset, Ketalar, Vetalar)
Tiletamine (in Telazol)
Cyclohexamine uses and properties
Induction agent Controlled NOT reversible Some analgesia IV or IM admin.
Cyclohexamine mode of action
CNS STIMULATION
Disrupts or scrambles nervous system pathways so they never make it to the brain
“Trance-like” anesthesia- appears awake, but immobile and unaware
CNS effects of Cyclohexamines
- Increased CSF, intracranial pressure, and intraocular pressure
- Lowers seizure threshold
- Increased sensitivity to sound
- Hallucinations
What drug combined with Cyclohexamines can help decrease the rough recovery?
Benzodiazepine tranquilizers
Cardiovascular effects of Cyclohexamines
Tachycardia
Combine with Glycopyrrolate instead of Atropine
Apneustic respirations
What are apneustic respirations
Breath holding, prolonged pause after inspiration
Other effects of Cyclohexamines
Catalepsy (increased muscle tone) Spastic reflexes Open, dilated eyes Nystagmus (mainly cats) Ptyalism (increased salivation)
What is ptyalism & what can help this?
Increased salivation
Anticholingergics can decrease this
How are Cyclohexamines metabolized?
Dogs- metabolized by the LIVER, then excreted
Cats- excreted by the KIDNEYS only
Ketamine general properties
Most common induction agent
Can be used for short procedures
Can squirt into the mouths of aggressive cats (takes 5-10mins)
Advantages of IV Ketamine
Faster onset and recovery
Decreased dose compared to IM
No tissue irritation