Injected Anesthetics

What things should general anesthesia provide?

Loss of consciousness

Anxiolysis

Analgesia

Amnesia

Inhibition of reflexes

SK muscle relaxation

What type of anesthesia does Ketamine give?

Dissociative (cataleptic state)

What is an ideal general anesthetic?

Rapid induction and recovery

large TI

Few AE

Why do we use combinations of drugs for anesthesia?

Minimize toxicity,

Homeostasis

Minimize sx stress rxns

Why are A2 agonists, ACE, and benzos typically used as premeds?

Sedation

Amnesia

counteract CNS stimulation

What is a benefit of anticholinergic agents?

Decreased salivation and Bradycardia

What are the pharmacodynamics of Propofol?

GABAa receptor agonist (increases GABA effects - more cl-)

Some NMDA - anesthesia not pain

What are pharmacokinetics of Propofol?

Rapid onset and recovery

Highly lipid soluable

Glucoronidation/ pulmonary metal olism

What are AE of Propofol?

Resp depression (w/ opioids) Hypotension (vasodilation)

Baroreceptor reflex inhibited

Monoclonal twitching/ limb paddling

Transient apnea/ cyanosis

When would we used propofol over ketamine?

Pt w/ head trauma, decreases cerebral blood flow (neuroprotective)

Propofol can cause ___ when given w/ A2 agonists?

Hypoxemia

Propofol can cause ___ when given w/ Benzodiazepines?

Hypothermia

Propofol can cause ___ when given w/ St Johns Worts?

Cardiac collapse/ delayed recovery

Why does propofol have a short shelf life?

Milky emulsification = breeding ground for bacteria

Why can't we give propofol to cats repetedly?

They develop Heinz bodies

What are the pharmacodynamics of Etomidate?

Facilitates GABA transmission (hyper polarizing nerves)

Why would we use Etomidate over propofol?

Less depression of CV/ Hypotension

Less resp depression (but much doesn't last very long)

How is Etomidate metabolized?

Rapidly into the brain then rapid hepatic hydrolysis meaning it doesn't accumulate

What is Etomidate typically indicated for?

Induction in small animals

What are AE of Etomidate?

Pain on inj,

Monoclonus, Vomiting/ retching

Adrenocortical suppression (rare/life threatening)

What are the pharmacodynamics of Alfaxalone?

Synthetic neuroactive steroid that modulates GABAa receptors

Alfaxalone will provide ___ and ___ but no ____?

Anesthesia and muscle relaxation, No analgesia

Alfaxan is ___ meaning it can be used in cases of head trauma?

Neuroprotective

What are pharmacokinetics of Alfaxan?

Large TI,

Rapid onset

What is the indication for alfaxalone?

Induction/ maintenance of Gen anesthesia, in lots of animals

What are common AE of Alfaxalone?

Post induction apnea, psychomotor excitement

Hypotension - less Cardio effects

Hypothermia

What are the pharmacodynamics of Ketamine?

A noncompetitive antagonist of NMDA receptor complex

(binds inside ion channel and blocks it)

What nerve pathways does ketamine decrease?

Thalmic (pain)

Limbic

Reticular activating (consciousness)

What effect does ketamine have on the CV system?

Increase BP and HR

- Increase intracranial pressure and cerebral BF (NO HEAD TRAUMA)

What is important to be aware of when giving cats Ketamine?

It is excreted unchanged in the urine - careful w/ litter handling

What are the indications for Ketamine?

Chem restraint in cats

Induction

What are AE of Ketamine?

Mucle rigidity in horses/ dogs

Profuse salivation - cats

Tacycardia/ hypertension

Apneustic breathing patterns

What drug combinations should be given w/ ketamine in horses?

Xylazine - sedation,

Guanifenisen - muscle relax

Butorphanol - pain

What drug combinations should be given w/ ketamine in dogs and cats?

Benzos/ a2 - SK muscle relax, prevent seizures or delirium recovery

We combine midazolam and opioids for ____ and with ketamine for ____?

Neuroleptanalgesic

Muscle relaxation

What are important pharmacokinetics of Midazolam?

Water soluble

Crosses BBB

Glucocoronidated

Potent

High PPB

What are AE of Midazolam?

Cardiorespiratory depression

Paradoxical excitement/ dysphoria

Interactios due to high PPB

What are the pharmacodynamics of Tiletamine/ zolazepam?

Sim to benzos and ketamine

What are indications of Tiletamine/ zolazepam?

Short term anesthesia

Chem restraint of fractious cats

_____ is better tolerated in cats and allows for smooth recovery.

____ Causes delirium in dogs?

Tiletamine

Zolazepam