Lab Animals Final

What preanesthetic is most commonly used in vet medicine?

atropine

what does xylazine and rompun lower?

heart and respiratory rate

ketamine is a...

controlled substance, tasteless, odorless, memory loss

what are the four periods to an anesthetic procedure

1) pre-anesthetic period

2) induction period

3) maintenance period

4) recovery period

analgesia

lack of pain sensation

amnesia

memory loss

SPO2 levels

close to 100% as possible

types of general anesthesia

1) injectables IM, SC/SQ, IP

2) injectables IV

3) gas agents

local anesthesia is really...

a local analgesia

surgical anesthesia

deep enough to provide muscle relaxation, painless without struggle

tranquilizers and sedatives

pre-anesthetics

what do pre-anesthetics do

- act on CNS to relax and calm

- may cause ataxia and prolapse the third eyelid

- given prior to general anesthesia

reasons to give pre-anesthetic drugs

- to tranquilize

- induce vomiting

- prevent seizures

- decrease side effects of the general anesthetic agent

- decrease amount of general anesthetic used

- decrease pain during surgery and in the post-op period

when atropine blocks the effects of acetylcholine the hear will

increase

when atropine blocks the effects of acetylcholine the GI tract

peristalsis decreases

when atropine blocks the effects of acetylcholine the Bronchi

dilates them

when atropine blocks the effects of acetylcholine the eye

dilates pupil

when atropine blocks the effects of acetylcholine the salivary glands

decreases saliva production

when atropine blocks the effects of acetylcholine the tear glands

decreases tear production

when should you use atropine or should you take caution

1) large animals

2) cats (use caution)

3) tachycardic animals

4) heart disease patients

5) constipated animals

what is the reversal drug for atropine

physostigmine

what is atropine used for beside anesthetics

diarrhea medications and eye exams

how is xylazine given

through IV, IM, or SQ

when is xylazine given

for minor surgeries

what are the positive effects of xylazine

1) sedation

2) analgesia for minor procedures

3) reduces the amount of general anesthesia used by 50-80%

what are the negative effects of xylazine

1) cardiovascular problems

2) decreases respiration

3) vomit

4) bloat

5) personality changes

6) profound sleep in some animals

7) temporary increase in blood sugar levels

8) caution with liver disease

what is the reversal drug for xylazine

yohimbine (yobine) given through IV

what happens during preanesthesia

the patient needs to have fasted and have had a physical exam that checks their weight, medical history, height, fam history

what happens during induction

the animal is given the anesthetic drug through inhalation or injection and they may experience, incoordination, relaxation, unconsciousness, intubation

what happens during maintenance phase

they strive for a stable level of anesthesia, they want surgical anesthesia, but they need to be cautious of depth because they may see respiratory depression

what happens during recovery for injectables

the anesthetic starts to leave the brain and the body as it's metabolized through the liver and excreted in the kidneys

what happens during recovery for inhalants

the anesthetic leaves through expiration in the lungs

what does ketamine produce

dissociative anesthesia or cataplexy

what does ketamine do to the CNS

it excited it

example of anesthetic that we use in class with animals

ketamine

some characteristics of ketamine

- rigid limbs

- sensitive to light/sound

- increased reflexes

- increased salivation

- cause tachycardia

- tough recovery

characteristics of gas anesthesia

- safest form of anesthesia

- need specialized equipment

- need knowledge of physical and chemical properties for safe use

advantages of has anesthesia

- primarily exhaled through lungs

- minimal metabolism through liver/kidneys

- good control

disadvantages of gas anesthesia

- need close monitoring due to rapid depth changes

- some gases are explosive

- increase cost over injectables

- air pollution

characteristics of ideal gas

- minimal toxicity to the patient

- easy to administer

- rapid/gentle induction and recovery

- depth is easily controlled

- good muscle relaxation

- safe to handle

- inexpensive

method of action for gas

1) gas inhales

2) goes to lungs

3) goes to alveoli

4) goes to blood

5) goes to brain

6) go to sleep

7) leaves brain

8) leaves blood

9) leaves alveoli

10) leaves lungs

11) wake up

what are the three properties of the drug that determines the speed of action

1) vapor pressure

2) solubility coefficient

3) MAC (minimum alveolar conc)

vapor pressure

determines how ready an agent is to go into the gas phase

solubility coefficient

describes the agents distribution between the 2 phases: gas and blood

low solubility agents

want to stay in gas form and do not want to go to the blood

MAC

- indicates an agent's strength

- the smaller the MAC, the more potent the gas

- MAC varies with dz, pregnancy obesity, other drugs on board, species, age, body temp, and BMR

a rapid induction agent has..

high VP, low solubility coefficient, low MAC

isoflurane

- most commonly used drug

- colorless liquid

- pleasant odor

- non-irritating to respiratory track

- good muscle relaxation

- give painkillers before recovery

- depresses respiration

- doesn't lead to arrhythmias

elimination of isoflurane

99% through the lungs and less than 1% through liver and kidneys

opiods (narcotics)

- derived from opium poppy

- very potent painkillers

- new synthetic ones have less tendency for addiction

- stimulate receptors in the CNS

stimulate all receptors

agonists

stimulate some receptors and block others

mixed agonists and antagonists

precautions of opiods

- controlled substances

- careful if five IV

- decrease respiratory function

- increase response to noise

- increase salivation

C1

most potent

C5

least potent

buprenorphine

- analgesic recommended for rats and mice

- 6-12 hrs of pain relief

- given sublingual, IM, SC

reversing agent for buprenorphine

naloxone