Induction Anesthetics

Question 1

Purpose of induction

Answer 1

Transition from a conscious/semiconscious animal to unconsciousness

Question 2

Injectable induction anesthetics

Answer 2

Dissociative anesthetics: ketamine, tiletamine, phencyclidine
Propofol
Barbituates: thiopental, pentobarbital
Imidazole derivatives: etomidate, metomidate
Neurosteroids: alphaxalone, alphadolone

Question 3

Ketamine cardiovascular effects

Answer 3

1. Direct negative inotropy

2. Catecholamine release: increases HR and contractility (if depleated, negative inotropy dominates)

Question 4

Ketamine respiratory effects

Answer 4

• minimal depression
• Apneustic breathing
• Bronchodilation
• Upper airway reflexes decreased

Question 5

Factors that increase cerebral blood volume

Answer 5

1. Hypercapnia, hypoxia
2. Hypertension
3. Drugs

Question 6

Ketamine CNS effects

Answer 6

1. Cerebral vasodilation (may increase ICP)
2. May worsen cerebral perfusion and cause herniation in cerebral injury
3. Cerebral metabolic O2 needs increase
4. May be seizurogenic (also used to treat seizures)

Question 7

Ketamine other effects

Answer 7

1. Increased salivation
2. Open eyes
3. Muscle tone retention (rigidity)
4. Increased IOP

Question 8

Indications for ketamine

Answer 8

1. Hypovolemic shock
2. Asthma
3. Risk patients will tolerate small doses
4. Aggressive animal sedation

Question 9

Contraindications for ketamine

Answer 9

1. Brain trauma or tumor
2. Perforating eye injury
3. HCM and mother other heart diseases
4. Epilepsy

Question 10

Telazol is a mix of which two drugs

Answer 10

Tiletamine and zolazepam

Question 11

Telazol is _____ acting than diazepam-ketamine.

Answer 11

Longer

Aggressive animals

Question 12

Propofol characteristics

Answer 12

1. Fast onset/duration/metabolism
2. No accumulation
3. Smooth induction and recovery
4. Ideal for TIVA
5. Give only IV
6. Does not contain preservative

Question 13

Propofol Cardiovascular effects

Answer 13

1. Vasodilation/hypotension
2. Mild negative inotropy
3. No reflex tachycardia

Question 14

Propofol respiratory effects

Answer 14

1. Respiratory depression (hypoventilation, apnea, decreased tidal volume)
2. No laryngeal paralysis

Question 15

Propofol CNS effects

Answer 15

1. Cerebral vasoconstriction
2. Increased ICP and blood volume
3. Metabolic O2 consumption decreased
4. Anti-epileptic
5. May cause muscle twitches

Question 16

Barbituate drugs w/ duration

Answer 16

Short acting: Thiopental

Middle duration: Pentobarbital

Long acting: Phenobarbital

Question 17

T/F: Thiopental has a slow metabolism rate and may accumulate after repeated dosages.

Answer 17

True

Question 18

T/F: Thiopental should not be given extravenously.

Answer 18

True

Question 19

Thiopental Cardiovascular effects

Answer 19

1. Negative inotropy
2. Vasodilation
3. Reflex tachycardia

Similar to propofol

Question 20

Etomidate characteristics

Answer 20

1. Propylene glycol or lipid emulsion
2. Fast onset, short duration
3. No cummulation
4. Minimal CV effects

Question 21

Etomidate cardiovascular effects

Answer 21

Almost none, best drug for hemodynamically unstable patients

Question 22

Etomidate other effects

Answer 22

1. CNS similar to propofol
2. Inhibit cortisol secretion
3. Vomiting
4. Excitement and twitching
5. Give soon after fentanyl
6. Difficult drug, needs experience

Question 23

Alfaxalone characteristics

Answer 23

1. Steroid anesthetic
2. Minimal CV effects
3. Slower onset than propofol, duration ~20min
4. Tough recovery at high doses
5. no allergic reaction
6. NEW