IV Anesthetics

Question 1

How does anesthesia work? Macroscopic?

Answer 1

CNS: disrupted transmission

Brain/SC: decerebration does not alter requirements

Question 2

How does anesthesia work? Microscopic?

Answer 2

Axon/synapse: axon disruption requires higher concern than synaptic disruption
Excitatory vs. inhibitory: blockage/enhancement
Pre vs. post synaptic: intracellular [Ca++] alters pre and other ions alter post

Question 3

How does anesthesia work? Molecule?

Answer 3

Membrane: Meyer-Overton rule- potency of anesthetic is proportional to lipid solubility
Lipid vs. protein: both involved

Question 4

GABA recepter

Answer 4

2 alpha, 2 beta, 1 gamma

Question 5

Central drug distribution

Answer 5

plasma & vessel-rich tissues- liver, brain, heart, kidneys (75% CO)
IV medications- sedatives/opioids

Question 6

Peripheral drug distribution

Answer 6

vessel-poor group (0.5% CO)- muscle (19% CO), bone, skin, fat (6% CO)

Question 7

What factors affect distribution?

Answer 7

1. Protein binding- albumin binds acidic drugs (BARBS), A1AG binds basic drugs (LA)
2. Protein availability- low albumin d/t liver, renal, CHF, CA or high A1AG d/t trauma, infect, MI, chronic pain
3. Lipid solubility
4. Ionization

Question 8

Vd

Answer 8

quantifies distribution of med b/t plasma and rest of body after dosing to produce observed drug concen