Ch.9 Canine & Feline anesthesia Flashcards
What is the following list used to select
-Includes calculated dosages, routes, order of admin.
-Selected by Vet in charge
-Calculate, check, and recheck drug doses, oxygen flow rates, and fluid admin rates
-takes into account MPD, PE, and procedure
-Modified protocol for ill, pediatric, or otherwise comprised animals
an anesthetic protocol
What are the periods of anesthesia
-Premedication
-Induction
-Maintenance
-Recovery
What is the primary goal of premedication
calm patient, allows use of less induction agent
What is the primary goal of induction
rapid induction through excitement stage of anesthesia, gain control of airway
Goal of anesthetist is _ induction
rapid
Primary goal of maintenance
safely maintain patient in the surgical plane of anesthesia
Primary goal of recovery
extubation, provide analgesia, +/- thermal support
Induction agents may be given by what routes
IM, IV, inhalation
What routes may pre-medications be given
SQ, IM, IV
What are the desired effects of premedication or sedation
sedation, cholingeric blockage, analgesia, muscle relaxation
Premedication or sedation drugs are
tranquilizers, alpha 2 agonists, opioids, dissociative, anticholinergics
_ or _ may diminish the beneficial effects after an IM injection
stimulation or excitement
_ should follow immediately after desired effects of an IM injection are reached
Induction
_ induction is most common and takes animals through the excitement stage most rapidly
IV
_ induction results in smooth, gradual CNS depression with little apparent time spent in the excitement stage
IM
When administering IV sedatives, how should you administer the drug?
-Don’t administer the entire calculated dose all at once unless otherwise instructed
-Allow for individual patient response to anesthetic
IV induction produces up to _ -_ minutes of anesthesia
10-20
What is it called when IV drugs are given as a series of bolus injections and discontinued when desired effect is reached
Titration
The following are the benefits of what
-Use in animals which IV injections are difficult
-Young animals, aggressive animals, wild animals, captive animals in zoos
IM induction
The dose of a drug needed for IM induction is generally about _ the corresponding IV dose
twice
IM induction results in a longer recovery period because of a
longer metabolism time
Drugs used for inhalation induction
Isoflurane and sevoflurane
Patients induced by inhalation need higher oxygen flow rates than with endotracheal tube (30 times the tidal volume). How do you calculate the flow rate?
1-3L/min patients <10kg
3-5L/min patients >10kg
The following are cautions of using a _ for inhalation induction:
-Exposes personnel to waste anesthetic gas
-P struggling can lead to epi release
-Longer induction period, avoid in patients with poor respiratory function
-Intubate immediately when possible
-Always keep airway open
Facemask
_ is used for inhalation induction with patients <5-7 kg and aggressive
Chamber
Complications of using a chamber for inhalation induction
-Stress, trauma, vomiting, airway blockage
-Hard to monitor
-Exposes personnel to waste anesthetic gas
-Epinephrine release
IV injection and ultra short acting agents
Propofol, alfaxalone, etomidate
What does TIVA stand for
Total intravenous anesthesia
When using TIVA and ultra short acting agent, patient is induced to effect; additional boluses are administered every - minutes as needed to maintain surgical anesthesia
3-5
Anesthetist can increase depth but can’t _ depth if excessive
decrease
How is anesthesia maintained when using TIVA by CRI
constantly infusing small amounts of anesthesia via a syringe pump
Inhalent induction is _ than IM induction but _ than IV induction
faster; slower
Factors that affect delay time when using an inhalant agent
P respiratory drive
Agent used and carrier gas flow rate
Type and volume of breathing circuit
Dynamic elements of both IV and inhalant administration
-rapid induction
-good control over both increases and decreases in anesthetic depth
-rapid recovery
What is the most commonly used method of inducing and maintaining anesthesia in small animals
IV induction and inhalant maintenance
What are the benefits of endotracheal intubation
-helps maintain open airway
-efficient delivery of anesthetic gas than facemask
-w/ inflated cuff helps prevent aspiration of vomitus, blood, saliva
-reduces anatomic dead space
-ventilation can be supported manually or mechanically
How to determine diameter of ET tube
small enough to not cause trachea injury but large enough to provide a seal with inflated cuff
How to determine length of ET tube
must reach the thoracic inlet, must not extend beyond the end of the muzzle
You should not attempt intubation unless you can visualize the _
larynx
How to know if patient is induced enough to intubate
unconscious, no voluntary movement, no pedal reflex, sufficient muscle relaxation, no swallowing when the tongue is pulled
Steps after patient is intubated
lay lateral
secure tube
turn on oxygen
inflate cuff
attach breathing circuit
turn on anesthetic vaporizer
begin P monitoring
How to check for proper tube placement
-visualize larynx and confirm location
-watch reservoir bag as animal breathes
-feel for air movement from tube connector
-fogging of tube during exhalation
-unidirectional valve motion
-ability of patient to vocalize
-P coughing
-capnometer connection
What is the reflex closure of the glottis in response to contact with an object or substance called
laryngospasm
Laryngospasm is common in ,,_ in light plane of anesthesia
cats, swine, small ruminants
Laryngospasm during intubation may lead to
cyanosis or hypoxemia
Prevention of laryngospasm
-2% injectable lidocaine or lidocaine gel
-adequate depth of anesthesia
-wait for glottis to open before intubating
-dont force tube
Despite all precautions, many animals will develop a _ for 1-2 days after the use of an ET tube
cough
What should you do when turning a patient during an anesthetic procedure
disconnect tube temporarily
What should be done during anesthesia if one lung is disease in a patient
place normal lung up
What is anesthetic recovery
the period between the time the anesthetic is discontinued and the time the patient is able to stand and walk without assistance
Influencing factors of anesthetic recovery
-length of anesthetic period
-condition of patient
-type of anesthetic admin. and route
-patient body temp
-patient breed
In the recovery period, you should administer oxygen as necessary, especially in _ patients
shivering
When should the ET tube be removed
when swallowing reflex returns OR when signs of impending arousal are present (voluntary limb, tail, or head movements)
How long after a procedure should an IVC be removed?
until recovery is complete
What should be done in recovery to prevent hypostatic congestion
turning every 10-15 minutes
What can you do to hasten recovery
gentle stimulation (talking, rubbing gently moving ET tube)
Analgesics should be administer when
before the onset of pain
What does adequate analgesia look like
patient sleeps comfortably with minimal signs of discomfort
