Use of Premedicants & Sedative drugs Flashcards by Rebecca Hancorne

What is the difference between sedation and premedication?

Sedation: the use of drugs to allay anxiety and cause some drowsiness or immobility; used to allow minor procedures to be carried out without a general anaesthetic
Premedication: the administration of drugs prior to general anaesthesia

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Sufficient sedation requires relatively…

high individual doses

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What medications make up a pre-med?

Combo of sedative + analgesic +/- anticholinergics +/- antihistamines, antinausea, gastroprotectants

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What is specific when it comes to the level of flatness in premedication?

You do not want the same level of flatness in premed that you get in sedation EXCEPT in dangerous animals

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What are the 5 aims of premedication?

To make the patient easier to handle/ safer/ calmer
provide analgesia
decrease the dose of induction agent
to reduce the dose of maintenance agents
make the recovery smoother if possible

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Sedation is NOT

premedication

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GA can be achieved with smaller dosages thus there is…

less need for drugs

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Which is more safer? GA or sedation?

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What are some reasons for using anaesthetic pre-med?

To calm & control nervous P’s
to provide pre-emptive analgesia
To facilitate smooth induction of anaesthesia & reduce the dose of the induction agent
To reduce the amount of anaesthetic required to maintain anaesthesia
To provide smooth recovery from anaesthesia
to reduce side effects of anaesthetics
to prevent other anaesthetic or procedural complications

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What are the 4 main classes of sedatives?

Phenothiazines
Alpha-2 agonists
Benzodiazepines
Butyrophenones

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Which sedative drugs have a wide therapeutic index?

Benzodiazepines

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What sedatives have minimal cardiovascular system side effects?

Benzodiazepines

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What sedatives have minimal respiratory side effects?

Acepromazine & Butyrophenones

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What sedatives are considered reliable?

Alpha 2 agonists

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What sedatives have analgesic properties?

alpha 2 agonists

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What sedatives have multiple routes of administration?

Benzodiazepines
Alpha 2 agonists
Acepromazine

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What sedatives are not painful or irritants?

Benzodiazepines

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What sedatives have antagonists available?

Benzodiazepines
Alpha 2 agonists

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What sedatives are considered hazardous to humans?

Benzodiazepines
Alpha 2 agonists

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What is a caution to remember of alpha-2 agonists?

it can provide what LOOKS like super deep sedation, but these animals can still be completely aware & aroused easily, therefore they can STILL BE DANGEROUS

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Why do you not use an alpha 2 with an opioid?

can be dangerous in a dangerous patient

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what level of medication is required to provide analgesia from an alpha-2?

high dosages

Some benzos can cause pain on IM injection. How do you know?

Check the bottle/makeup

What occurs in regards to alpha-2 antagonism and analgesia?

When high doses of alpha-2s are used for analgesic effects and then an antagonist is used, it reverses the analgesic effect so you need to ensure other analgesics are on board prior to reversing an alpha 2

what makes alpha-2s harmful to humans

Can lead to severe hypertension

what makes benzos harmful to humans?

can be abused

What is required to achieve the 5 goals of premed?

combo of 2-3 drugs, with 1 always being a sedative

Acepromazine is licensed in what animals?

horses dogs/cats

What are the main uses of acepromazine in dogs/cats?

sedation & premed of healthy animals travel sickness

What are the main uses of acepromazine in horses?

sedation & premed of healthy animals cardioprotection in a premed post-op myopathy

What is important to remember of acepromazine in horses?

It is contraindicated in very sick patients & colics

What are some cautions of acepromazine?

- Vasodilation (avoid in hypotensive, hypovolaemic, shocky patients) - avoid in liver dz, hypoalbuminaemia

What dogs require special attention when using acepromazine? Why?

- Giant breeds, boxers, brachycephalics require reduced doses - Collies (MDR1 mutation) undergo excessive sedation because it increases the BBB permeability so reduce doses or do not use - avoid in epileptics

What is important to remember when using Acepromazine in stallions?

It can cause priapism & penile prolapse so it should be avoided in breeding stallions

When should you use allometric scaling of drugs?

At all times so use lower doses based on surface area: vol ratio

What are the main uses of alpha-2 agonists in dogs/cats/rabbits?

- Sedation & premed of health (& sick) or vicious animals - Intra-op CRI to reduce inhalation agent & provide vasoconstriction & analgesia - Post-op CRI for sedation

What are the main uses of alpha-2 agonists in horses & farm animals?

- only reliable sedation & premed agents - standing sedation in equines - intra-op CRI to reduce inhalation agents - Triple drip to maintain anaesthesia (Eq)

What are the main cautions with alpha-2 agonists?

- reduction in cardiac output - not for small kittens/puppies < 3 mos old - avoid in very sick animals - analgesia requires higher plasma levels than sedation - alpha-2 agonist-induced bradycardia does not need to be treated unless it leads to hypotension (if so, use anticholinergics)

What is Vatinoxan? What is it used for? In what species?

- Premix w/ medetomidine for DOGS ONLY (DO NOT USE IN CATS) - Peripheral alpha-2 agonist that does not cross BBB - only licensed for sedation, NOT premed in EU/ not noted in USA - may be safer sedation in geriatric and sick dogs

What species are benzodiazepines licensed in?

Dogs/cats horses

what are the main uses of benzodiazepines in dogs/cats?

- sedation & premed of very young, very old & sick P's - co-induction agent w/ propofol, ketamine or alfaxalone - treatment of seizures

What cautions are there when using benzodiazepines in dogs/cats ?

- not great in young, healthy patients - can cause paradoxic excitation in healthy animals

What are the main uses of benzodiazepines in horses (with a passport)?

- co-induction agent w/ ketamine to improve muscle relaxation & conditions for endotracheal intubation - effective sedation of foals

What is the main butyrophenone? What animal is it used in? What is it used for?

Azaperone Used in pigs/zoo med For sedation & premed

What is atipamezole? What is it used for?

- Alpha-2 antagonist - To reverse medetomidine & dexmeditomidine sedation - Left on board after GA for analgesia effects

When does alpha-2 agonist bradycardia require treatment? How do you treat it?

- if it leads to hypotension - treat w/ anticholinergics

What is flumazenil?

- reversal of benzodiazepines

What are the main anticholinergic agents?

Atropine, glycopyrrolate

what are the main uses of anticholinergics?

- to treat bradycardia & associated hypotension caused by opioids & other anaesthetics OR vagal stimulation during a procedure

Bradycardia caused by hypothermia does not respond to

anticholinergics

there is a high risk of cardiac arrhythmias if anticholinergics are given with

an alpha-2 without hypotension

What other uses are there for anticholinergics?

- pupil dilation - to treat some types of heart block - to reduce saliva production - during CPR

What cautions are present with anticholinergics?

- pre-existing tachycardia - glaucoma - paralytic stasis of the gut causing colic in horses/equines - do not pre-emptively give w/ alpha-2 agonists

What four questions are essential to ask before choosing sedation over GA for a procedure?

1. Will the sedated patient be safe? 2. Does the patient (or procedure) require analgesia? 3. How long will the effects last? 4. Is sedation to be followed by general anaesthesia?