Injectable anesthetics

Question 1

Which injectable anesthetics uses:

Intravenous anesthetic — causing CNS depression ranging from drowsiness and mild sedation to coma

Control convulsive seizures by — depressing motor areas of the brain

Answer 1

barbiturates

Question 2

Which injectable anesthetics has this effect on vital systems:

1. May profoundly depress respiration; degree is related to the dose and rate of drug administration.
2. Apnea may result from rapid administration of high doses
3. Significant cardiovascular depression (seen in the first 10 minutes after IV injection)
4. Cardiac output and heart rate initially rise then decrease

Answer 2

barbiturates

Question 3

Other effects of this injectable anesthetics:

Excessive salivary secretion — coughing, hiccoughing, laryngospasm

Readily cross the blood-placental barrier causing respiratory depression of fetuses

Tissue irritation – bc highly alkaline and may cause tissue irritation when injected perivascularly

Excitement during induction and recovery

Increased potency in hypoproteinemic animals

Increased potency and duration of action in very thin animals including Sighthounds

Answer 3

barbiturates

Question 4

Identify the barbiturate (acc. to duration of action):

5-15 mins
— used to induce patients to surgical anesthesia

Answer 4

ultrashort-acting barbiturate

Question 5

Example of ultrashort-acting barbiturate

Answer 5

Methohexital Na

Question 6

Identify the barbiturate (acc. to duration of action):

45 mins to 1.5 hours
—used to produce general anesthesia

Answer 6

short-acting barbiturate

Question 7

Example of short-acting barbiturate

Answer 7

Thiopental Na (Pentothal Na)

Question 8

Identify the barbiturate (acc. to duration of action):

— 2 to 6 hours

Answer 8

Intermediate acting barbiturate

Question 9

Example of Intermediate barbiturate

Answer 9

Pentobarbital (Nembutal Na)

Question 10

Identify the barbiturate (acc. to duration of action):

8-12 hours
— not used as anesthetics
— anticonvulsants in humans

Answer 10

long-acting barbiturate

Question 11

example of long acting barbiturate

Answer 11

phenobarbital

Question 12

MOA of this injectible anesthetics

1. Disruption of nerve conduction pathways within the cerebrum and stimulation of the reticular activation center of the brain.
2. Suppress inhibitory neurons —> selective CNS stimulation —> dissociative anesthesia or catalepsy

Answer 12

Cyclohexamines

Question 13

the state where there is malleable rigidity of the limbs and the patient appears awake but is dissociated from or unaware of the environment; the animal tends to remain in any position of placement.

Answer 13

Catalepsy

Question 14

Provides significant analgesia to the skin but poor visceral and limb anesthesia

Answer 14

Cyclohexamines

Question 15

Injectable anesthesia that has this effects on vital systems:

1. Does NOT produce cardiorespiratory depression
2. Most animals exhibit tachycardia and elevated blood pressure
3. Animals exhibit apneustic breathing pattern in which the patient hold its breath for several seconds at the end of the inspiratory phase, which is followed by a quick expiratory phase.

Answer 15

Cyclohexamnes

Question 16

Other effects of this injectable anesthetics:

• May cause tissue irritation when given IM but do not cause tissue necrosis.
• Stimulates salivation and increase tracheo-bronchial mucous gland secretions
• May increase cerebrospinal fluid pressure and intraocular pressure
• Eye remains open with a central and dilated pupil
• May induce nystagmus (repetitive side-to-side motion of the eyeball)
• Recovering animals often show an exaggerated response to touch, light and sound
• Seizure-like activity and bizarre behavior may also be observed during recovery

Answer 16

Cyclohexamines

Question 17

Injectable anesthetics that have this contraindications:

1. Animals with history of seizures
2. Animals that have ingested strychnine, metaldehyde, marijuana, organophosphates and other toxins that affect the CNS

Answer 17

Cyclohexamines

Question 18

Identify the injectable anesthetics:

• Combination of an opioid and tranquilizing agent can also be used to induce general anesthesia in dogs when given by IV injection
• Not suitable for routine induction of anesthesia in healthy, young dogs
• May have a profound effect in high-risk or debilitated dogs and are useful and safe alternative to barbiturates or ketamine induction in these animals
• Seldom used to induce anesthesia in cats because of unacceptable side effects (excitement, mania)
• Rapid injection may cause CNS stimulation and profound respiratory depression

Answer 18

Neuroleptanalgesia

Question 19

Identify the injectable anesthetics:

• an ultrashort-acting, non-barbiturate IV anesthetic
• Dilution with saline or 5% dextrose in water allows more accurate dosing and helps to prevent respiratory and cardiovascular side effects in small animals
• In dogs, recovery is rapid and smooth, even with multiple injections

Answer 19

Propofol

Question 20

Injectable anesthetics that has this clinical uses:

1. Sole agent for brief procedures or for anesthetic induction before intubation and inhalant anesthesia
2. Maintenance of general anesthesia when combined with opioid analgesics or other sedative or other sedative-analgesic drugs

Answer 20

Propofol

Question 21

Injectable anesthetics that has this effect:

• Transient excitement and muscle tremors during induction
• Overall cardiovascular and pulmonary effects similar to barbiturates
• Minimal analgesia
• Moderate muscle relaxation
• Decreases intracranial and intraocular pressure

Answer 21

Propofol

Question 22

Identify the injectable anesthetic:

• Rapid-acting, ultrashort, IV anesthetics
• Sedative/hypnotic imidazole drugs that are occasionally used for induction of anesthesia in the cats and dogs
• Anesthesia is characterized by good muscle relaxation without analgesia

Answer 22

etomidate / metomidate

Question 23

Clinical uses of this injectable anesthetics:

1. short term (5-10 minutes) anesthesia in the dog and cat
2. induction agent of choice for difficult cardiac cases and animals in shock because of its minimal effect on cardiovascular functions

Answer 23

etomidate / metomidate

Question 24

Injectable anesthesia that has this effects:

• Mild respiratory depression, transient apnea
• produces good muscle relaxation
• IV injection is painful and may cause phlebitis
• Rapid injection may cause RBC hemolysis in cats
• Nausea, vomiting, and involuntary excitement may occur during induction or recovery, particularly in patients that have not been adequately premedicated.

Answer 24

etomidate / metomidate