IV Anesthetics

Question 1

What is the triad of general anesthesia?

Answer 1

1) Need for unconsciousness (Hypnosis)
2) Need for analgesia
3) Need for amnesia

Question 2

What is anesthesia?

Answer 2

The abolition of all sensation

Question 3

What is analgesia?

Answer 3

The abolition of pain sensation

Question 4

What are pharmacokinetics?

Answer 4

How the body processes the drugs

Question 5

What are pharmacodynamics?

Answer 5

How a drug causes physiological and pharmacological reactions within the body

Question 6

What are the key components of pharmacokinetics?

Answer 6

1) Administration (absorption)
2) Distribution
3) Drug metabolism
4) Drug excretion

Question 7

What are the key components of pharmacodynamics?

Answer 7

Reponses on receptors at the cellular level

Question 8

Which route of administration requires higher doses? Why?

Answer 8

Enteric administration; because of first pass metabolism

Question 9

What is free fraction and protein binding?

Answer 9

Drugs bound to drugs = therapeutically inactive
Drugs not bound to drugs (free drugs) = therapeutically active

Question 10

What is vd?

Answer 10

Total dose of drug given divided by plasma concentration

Question 11

What is drug redistribution?

Answer 11

Some drugs will quickly distribute into certain parts of the body (brain and heart) and slowly into adipose tissue. Once more and more distribution occur into adipose tissue however, equilibrium will force them out of brain and heart, leading to less therapeutic effect.

Question 12

What are high perfusion (vessel-rich) organs? Give examples.

Answer 12

Organs takes up disproportionately large amount of the drug; the brain

Question 13

What are some examples of low perfusion organs?

Answer 13

1) Muscles
2) Fat
3) Vessel-poor groups

Question 14

What is responsible for termination of effect of many anesthetic drugs?

Answer 14

The redistribution from the vessel-rich group to the vessel-poor group

Question 15

Most drug excretion occurs through which organs?

Answer 15

1) Liver
2) Kidneys
3) Lungs

Question 16

What is zero-order kinetics?

Answer 16

When drugs are metabolized at a fixed rate, regardless of concentration

Question 17

What is first-order kinetics?

Answer 17

When rate of drug metabolism is proportional to concentration

Question 18

What is potency?

Answer 18

The dose of the drug required to achieve a therapeutic effect

Question 19

What is efficacy?

Answer 19

The maximum effect achievable with the drug

Question 20

When does drug toxicity occur?

Answer 20

When undesirable side- effects of its administration occur

Question 21

What is the therapeutic index?

Answer 21

The ratio of the dose producing a toxic effect to that producing a therapeutic effect

Question 22

What are the most commonly used IV anesthetics?

Answer 22

1) Propofol
2) Etomidate
3) Ketamine
4) Thiopental (Barbiturate)

Question 23

What is the mode of action of IV anesthetics?

Answer 23

Either
1) Stimulates inhibitory neurons
or
2) Inhibits excitatory neurons

Question 24

What is the primary mechanism for most IV anesthetics?

Answer 24

Potentiation of GABA receptors = Increased chloride conductance across membrane and into postsynaptic neuron = hyperpolarization = inhibits neuronal signaling = a sedative and hypnotic effect

Question 25

What is GABA?

Answer 25

The primary inhibitory neurotransmitter in the CNS

Question 26

What is the primary mechanism of Ketamine?

Answer 26

Inhibits NMDA receptor

Question 27

What is the primary mechanism of Dexmedetomidine?

Answer 27

Alpha-2-receptor activation