Test 3: 39 TIVA

Question 1

what 5 things need to happen for anesthetics to be successful

Answer 1

immbolity
unconsciousness
analgesia
muscle relaxation
inhibition of autonomic reflexes

Question 2

pharmacokinetic vs pharmacodynamic

Answer 2

kinetic: what body does to drug (breaksdown in liver)

dynamic: what drug does to body (cause bradycardia)

Question 3

3 independent pharmacokinetic variables

Answer 3

volume of distribution
clearance
target plasma concentrations

Question 4

how to measure volume of distribution

Answer 4

measure tissue distribution of a drug

Vd= (amount of drug administered)/ (amount of drug found in plasma)

Question 5

how to predict loading dose needed

Answer 5

desired plasma concentration x volume of distribution

Question 6

how to determine maintenance dose

Answer 6

clearance= dose/AUC

CRI dose = desired plasma concentration (Cpt) x Cl

Question 7

what characteristics do you want for TIVA drugs

Answer 7

• Fast onset
• Short duration
• High therapeutic index
• Minimal or no side effects
• Insensitive context half life (no accumulation)
• Low cost
• Long shelf life

Question 8

what drugs are used for small animal TIVA

Answer 8

• Propofol
• Alfaxalone
• Opioid (morphine, fentanyl, remifenntanil)
• Lidocaine
• Dexmedetomidine
• Ketamine

Question 9

what drugs are used for large animal TIVA

Answer 9

• Ketamine
• GG, Benzodiazepines
• Alpha 2 agonists (xylazine, detomidine, dexmedetomidine, romifidine)
• Lidocaine

Question 10

what can happen with intermittent multiple boluses for TIVA

Answer 10

Question 11

example of small animal intermittent multiple boluses TIVA

Answer 11

Example for short procedure (skin biopsy)
1. Premedication Methadone 0.2 mg/kg IV
2. Propofol bolus until loss of righting reflex IV
3. Evaluate anesthetic depth ( eye position, strength of palpebral reflex, jaw tone) top up if needed 0.5 mg/kg of propofol
4. Provide oxygen (face mask)
5. Have ability to intubate & ventilate if patient stops breathing (too deep)

Question 12

how to do CRI for TIVA

Answer 12

do loading dose to get to theraptutic level quickly, then maintain with CRI

Question 13

what is a triple drip

Answer 13

CRI for large animal

GKX (GG 10%, Xylazine 1mg/ml, ketamine 2 mg/ml) add 1g of ketamine, 500 mg of xylazine to 500 ml of Guaifenesin 5 or 10%

Question 14

problems with TIVA

Answer 14

• dosage based on models of healthy animals
• context sensitive 1/2 life- takes longer to recover
• IV access problematic in very small patients (birds, rodents, etc)
• Not possible to measure real time plasma drug levels (only predict)
• Cost of drugs

Question 15

advantages of tiva

Answer 15

• No pollution
• No need for anesthesia machine
• Cardiovascular stability
• Propofol reduces ICP
• Suitable for prolonged sedation