MOD 20 - COURSE 2 - PT 2 - INJECTABLE

Question 1

the drug concentration in the blood doesnt correlate to…

Answer 1

anaesthetic depth based on subjective observations -
- can be differnet by differnet methodsof injection
(SC,IV,IM,IP)

Question 2

why does dose of anaesethic need to vary ebtween species

Answer 2

• anesthetic uptake, distribution, effect = givenered by pharmocokinetic adn dynamic proprtiers of anaesethic agent in that strain or species
• individual variation = also plays important role in biodisposition and pharamcokinestics as well as therapeutics
• variation includes - genotypes, stock strain, sex, age, body compositions, nutritional and disease statys

Question 3

what are the most common injectables used in the lab for anaesethics

Answer 3

• barbituates
• pentobarbital
• thipental
• methohexital
• coral hydrate
• xylazine/medetomidine
• ## phenothiazines and butirophenones

Question 4

what is the effects of barbituates

Answer 4

• effects - persisit several hours even with short acting barbituates
• readily absorbed from most sites i.e. GI tract - however - highly alkaline - so limited for IV administration
• considered good hypnotic agents but poot anaglesics

Question 5

what is the effects of pentobarbital

Answer 5

• severe cardiovascular resp system depression - poor anaglesic acitivyt
• causes pain if IP due to high Ph

Question 6

What are the effects of thiopental

Answer 6

• short acting barbiturate -useful - rapid induction of anaesethesia when administed intravenously - cause transient apnea
• irritant if injected perivascularly - diluted as much as practicable

Question 7

what are the effects of methohexital

Answer 7

• poor anaglesic acitivty - transient apnea ofent occurs
• muscle tremour during recovery unless suitable preanaesthetic medication = administred

Question 8

what is transient apnea

Answer 8

• breathing problems

Question 9

what is the effects of coral hydrate

Answer 9

• achieve medium - duration, light anaesthesia - minimal efect on cardiovascular function or relfexes
• poor anaglesic acitivty
• need high dose for surgey - can have severe repiraoty issue - not recommeneded

Question 10

what are the ffects of medetomidine / xylazine

Answer 10

used alone - sedative/anaglesic agent
- combined with other anaesthetic agents
- administed as constant rate at low doses for anxiolysis/analesia
- most effective if combined with opiods or dissociative anaesthetics i.e. ketamine
- are antagonist drugs - reverese the effect : tohimbine and atipamezole

Question 11

what antagonsits are there for xylazine and medetomidine

Answer 11

yohimbine and atipamezol

Question 12

what are the effects of phenothiazianes and butirophenones

Answer 12

• sedation - dont produce sleep, anaglesia or ananethesia even in increased dose - they causes decreased spontanous movement and complex behaviours , pscyhomotoe agitation, curiosity and apparent aggressiveness = reduced
• use ajunct with other anaestehtic i.e. opiods and ket

Question 13

what are some examples of phenothiazines

Answer 13

• chlorpromazine, promazine, acepromazine

Question 14

what are some exampels of butirophenones

Answer 14

• droperidol
• fluanisone

Question 15

what are some effects of benzodiazepines

Answer 15

• not true general anesethic state - awareness and relxation = not sufficnet for surgery
• not compatible alone to genral anaesetheitc- uses of preanaesethsia and anaesethsia induction
• used for their sedative, anxiolytic, relaxation and anticonvulsant activity

Question 16

wxamples of benzodiazepines

Answer 16

• diazepam, midazolam, zolasepam - (typically incombination with other agent i.e hypnotic or dissociative - for anaesthesia or anaesethic induction)

Question 17

how can you improve the quality of anaesethesia given to the aniamsl

Answer 17

• combination of 2+ drugs - balanced - improve saftey reduce dose adn corresponding side effect for each compoenent

Question 18

what are the 2 types of combinations most widely used for anaesetheis

Answer 18

• neuroleptoanaglesia
  ketamine combination

Question 19

what is neuroleptoanaglesia

Answer 19

• combination of opiod anaglesic (fentanyl) and a tranq

Question 20

what are some examples of transquilisers - used for neuroleptoanalgesia

Answer 20

• can be a dopaminergic receptor antagonist : fluanisone, droperidol, acepromazine
• or a benzodiazepine : midazolam and diazepam

Question 21

how can the effect of the combination be revered for neuroleptoanalgesia

Answer 21

• by admin or mu-opiod antagonist i.e. naloxone, nalbuphine or butorphal

Question 22

what is a ketamine combinations and what is its goal

Answer 22

• improved anaglesia, muscle relax, sedation, prolonged duration, decrease side efects
• mix ket toether with other anaesethic drugs to offset their side effects

Question 23

what are 2 common ketamine combinations

Answer 23

• ketamine and xylazine
• ketamine and diazepam

Question 24

whatelse can be used with ketamine to get the same effects as whe using ketamine mixed with xylazine

Answer 24

medetomidine

Question 25

what else cna be used in combination with ketamine to get the same effect as ketamine with diazepam

Answer 25

other benzodiazepines i.e. midazolam

Question 26

whats a local anaesthetic

Answer 26

- block sensory nerve endings - within tissue

Question 27

when is local anaesthetic used

Answer 27

- minot procedures - i.e blood samples rabbits ears, tail tip amputaiton in young mice - perioperative surgical anaglesic regiment in addition to systemic anaglesia i.e. intraoperative infiltration of wound margins - due ot thoractomoy - encouage breathing during recovery period

Question 28

what is thr routes of administraiton of local anaesthetic

Answer 28

- topic applicaiton to mucous memrbane i..e ksin eyes, - infiltration directly into tissues - without taking into consideration the course of cutaneous nerves - infiltration block - infiltration firectly into tissue while considering the course of cutaneous nerve to produce anaesethsia distally - field block

Question 29

what is a infiltration block

Answer 29

infiltration directly into tissues - without taking into consideration the course of cutaneous nerves

Question 30

what is a field block

Answer 30

infiltration firectly into tissue while considering the course of cutaneous nerve to produce anaesethsia distally

Question 31

what are some examples of common local anaesthetics

Answer 31

- chemcials ranging form alcohols, cocaine, complex toxins i.e. tetrodotoxin most common - aminoamides: lidocaine, bupivicaine, prilocain, lignocaine - alcohols: ethyl chloride

Question 32

what are some examples of topical preparations of local anaesthtics agents

Answer 32

- EMLA - mix of lidocain and prilocain - ethyl chloride - eyedrop of proparacaine and tetracain - injectable preparations - i.e. lignocaine

Question 33

when is EMLA used

Answer 33

- good anaesethis a0 minor procedures i.e. ear vein bleeding rabbits - refinement for venipuncture, skin contact 30-60 mins for effective use

Question 34

when is ethyl chloride use

Answer 34

- fairly fast acting - alcohol based topical - quiestionale analgesic effect - used for tail tip amputation in young mice - as t disinfects and chills

Question 35

what local anaesethics are used in eydrops

Answer 35

- proparacaine and tetracaine

Question 36

when are the inejctable preparations used

Answer 36

- lignocain - only lasts an oute - some prep use adrenaline - constrict blood vessel - retain anaesethic betters - buvacaine - lasts 6-8 hours or longer