Pre-anesthetic meds and induction agents

Pre-anesthetic meds are administered ____ or in _____ as a part of balance anethesia

alone or in combination

Commonly used meds:

Sedatives/Tranquilizers

opioids

anticholinergics

dissociative

oral meds

types of sedatives/tranquilizers

Acepromazine, Alpha-2 Agonists,

benzodiazepines, trazodone

The administration of pre-anesthetic agents and adjuncts to

calm or sedate

Purposes of pre meds

sedation and anxiolytics

analgesia

reduced required drug dosages

muscle relaxation

What is the effect of sedation and anxiolytics on fear, anxiety, and stress?

Reduces fear, anxiety, and stress

How do sedation and anxiolytics enhance safety?

Enhances safety for both animals and staff, less struggle with restraint

What benefit do sedation and anxiolytics provide for diagnostics or procedures?

Allows for more accurate diagnostics or procedures

How do sedation and anxiolytics improve pain management?

Better pain management

What is the effect of sedation and anxiolytics on anesthetic agents?

Reduce the required anesthetic agents, aid in calmer recovery

What is preemptive pain relief?

Pain management is covered prior to the noxious stimulus.

Why is preemptive pain relief critical?

It is critical for patient comfort.

What does preventing central sensitization involve?

Preventing central sensitization to tissue injury.

How do analgesics function in pain management?

Analgesics interrupt the process of pain amplification.

When is it important to decrease pain?

It is important to decrease pain before, during, and after procedures.

What is a benefit of reducing required drug dosages?

Lowers the necessary dose of induction and maintenance agents.

What is a potential advantage of using agents and adjuncts in drug therapy?

Provides better cardiovascular stability and reduces side effects.

What should one be aware of when using drug agents and adjuncts?

All agents and adjuncts cause undesirable side effects in addition to the desired action.

What is important to consider when using drug agents?

Must take the good with the bad.

What is essential for effective drug therapy?

Be knowledgeable.

What is a benefit of smoother inductions and recoveries in anesthesia?

Profound muscle relaxation

What is an important consideration for patient positioning during surgical procedures?

Know the procedure

What type of analgesics are used for long-lasting pain relief?

Long lasting analgesics

What phase do patients pass through during induction and recovery?

Phase II excitement

What can be dangerous to patients and personnel during induction and recovery?

Phase II excitement

What is a key procedure involved in anesthesia?

Intubation

Routes of administration for pre meds

¡Intramuscular (IM)

¡Intravascular (IV)

¡Subcutaneous (SQ/SC)

¡GV20

¡Orally (PO)

¡Oral Transmucosal (OTM)

¡Intranasal (IN)

¡Intraperitoneal (IP)

What varies with each pre med route

onset of action

duration

dose

slowest onset, longest duration

SQ/SC

somewhat faster onset and shorter duration than SQ

IM

¡Should be left undisturbed until peak action is reached

¡Excitement or stimulation can override the effects of the agents

IM administration

rapid onset, shorter duration than IM or SQ

Use with caution- potency and potential adverse effects increase

IV/GV20 admin

What is neuroleptanalgesia?

A state of central nervous system (CNS) depression and profound analgesia produced by the combination of a tranquilizer/sedative and an opioid.

What is the typical position of patients under neuroleptanalgesia?

Patients generally lie quietly in lateral or sternal recumbency.

What types of procedures is neuroleptanalgesia commonly used for?

Minor, mildly-painful procedures that require significant CNS depression and analgesia but not general anesthesia (e.g., FNA, radiographs, diagnostics).

What is a key safety feature of neuroleptanalgesia?

It provides a wide margin of safety in most patients.

What should be monitored when administering neuroleptanalgesia IV?

Care should be taken due to the risk of profound respiratory depression.

What should you be prepared to do when administering neuroleptanalgesia?

Be prepared to intubate if needed.

What is essential to do while a patient is under neuroleptanalgesia?

Monitor at all times!

What is a common example of a phenothiazine sedative?

Acepromazine

What effect do phenothiazines have on mood?

Calming and depression, sometimes causes agitation

How do phenothiazines affect the myocardium?

They protect against adrenaline (epinephrine) induced fibrillation

What is the antiemetic mechanism of phenothiazines?

Histamine blockade

Can phenothiazines be used for allergy testing?

No, they should not be used for allergy testing

What is a specific use of phenothiazines in equine post-operative care?

Equine post-op care

What condition can phenothiazines cause in stallions?

Paraphimosis

Do phenothiazines provide analgesia?

No, they do not provide analgesia

Are phenothiazines reversible?

No, they are not reversible.

Are phenothiazines ideal for sick or geriatric patients?

No, they are not ideal for sick or geriatric patients.

What effect do phenothiazines have on blood vessels?

They cause vasodilation and hypotension due to alpha-1 blockade.

How are phenothiazines metabolized?

They are metabolized by the liver.

Do phenothiazines cross the blood-brain barrier?

Yes, they cross the blood-brain barrier.

In what situations are phenothiazines ideal?

They are ideal in respiratory distress and for brachycephalic breeds.

What are some potential side effects of phenothiazines?

They can cause splenic enlargement, +/- platelet inhibition, and +/- seizures.

Which dog breeds may have issues with phenothiazines?

Boxers, Greyhounds, Giant breeds, and those with MDR1 mutation.

What routes can phenothiazines be administered?

They can be given PO, OTM, SQ, IM, IV, GV20, and IP.

What are examples of benzodiazepines?

Midazolam and diazepam (Valium)

What is a key benefit of benzodiazepines as a muscle relaxant?

They counteract muscle rigidity.

What is one of the uses of benzodiazepines?

They are used as an anticonvulsant.

Are benzodiazepines safe for cardiac patients?

Yes, they are safe for cardiac patients.

In which types of animals are benzodiazepines ideal?

Very young, sick, or geriatric dogs and cats.

In which animals are benzodiazepines commonly used?

Most large animals, small animals, birds, and reptiles.

What is the reversal agent for benzodiazepines?

Flumazenil.

What are the routes of administration for benzodiazepines?

OTM, SQ, IM, IV, GV20, IP, IN, per rectum.

What are examples of benzodiazepines?

Midazolam and diazepam (Valium)

What is a key consideration when using benzodiazepines in dogs and cats?

Caution with use in liver disease

How are benzodiazepines typically used in veterinary medicine?

Used in combination with other agents for induction

What is a characteristic of injectable diazepam?

It is mixed with 40% propylene glycol

Is injectable diazepam water-soluble?

No, it is not water-soluble

What can injectable diazepam not be mixed with, except for one drug?

Other drugs, except ketamine

What issue can arise with diazepam in plastic containers?

It will bind to plastic syringes, IV bags, and IV tubing

What is a potential effect of benzodiazepines on neonates delivered by C-section?

CNS depression due to crossing the placenta barrier

What are two examples of alpha 2 adrenergic agonists?

Dexmedetomidine and xylazine

What is a key benefit of using alpha 2 adrenergic agonists?

They provide very good sedation with a reliable and quick onset.

What effect do alpha 2 adrenergic agonists have on anesthesia requirements?

They reduce anesthesia requirements.

What caution should be taken when using alpha 2 adrenergic agonists?

Caution in patients with cardiac disease.

What is a common side effect of alpha 2 adrenergic agonists when given IM?

May cause vomiting.

What are some cardiovascular effects of alpha 2 adrenergic agonists?

Hypertension, bradycardia, and vasoconstriction.

In which types of animals are alpha 2 adrenergic agonists commonly used?

Most small animals, large animals, and exotic animals.

What are two reversal agents for alpha 2 adrenergic agonists?

Atipamezole and Yohimbine.

What are the routes of administration for alpha 2 adrenergic agonists?

OTM, IM, IV, SQ, and GV20.

What are Alpha 2 adrenergic agonists used for in large animals?

Reliable sedation

What are the signs of sedation in horses when using Alpha 2 adrenergic agonists?

Lowered head, droopy lip, soft eyes

What are the signs of sedation in cattle when using Alpha 2 adrenergic agonists?

Lie down, ataxia, fall over

Which large animal is more sensitive to Alpha 2 adrenergic agonists?

Cattle

How do animals typically react to sound while sedated with Alpha 2 adrenergic agonists?

They may jump or kick

What significant effect do Alpha 2 adrenergic agonists have on the cardiovascular system?

They can cause cardiac arrhythmias

What type of cardiac arrhythmias are most likely to occur with Alpha 2 adrenergic agonists?

1st and 2nd degree AV block

What respiratory caution should be taken with brachycephalic breeds when using Alpha 2 adrenergic agonists?

Caution due to hypoventilation

What should be considered when using Alpha 2 adrenergic agonists in horses?

Caution with airway obstruction

What type of drug is detomidine?

Alpha-2 adrenergic agonist

What is detomidine used for in horses?

To provide sedation, analgesia, and muscle relaxation

How does the duration of action of detomidine compare to xylazine?

Detomidine has twice the duration of action compared to xylazine

What is a common combination used with detomidine for standing sedation?

Butorphanol

What type of pain is detomidine used to provide analgesia for?

Colic pain

What are the similarities between detomidine and xylazine?

They produce similar beneficial and adverse effects

What are some examples of opioids?

Fentanyl, Hydromorphone, Methadone, Morphine, Butorphanol, Buprenorphine

What is the duration of action for opioids?

20 minutes - 4 hours, +/- 6-8 hours

What are opioids derived from?

Opium

What are the primary uses of opioids?

Analgesia, sedation, and in conjunction for anesthetic induction