General Anesthetics

Question 1

How do anesthetics work?

Answer 1

GABAa chloride channel IPSP

GABA stimulates chloride channel to open making cell hyperpolarized (inhibiting APs)

Question 2

What is MAC?

Answer 2

minimal alveolar concentration at 1ATM that prevents movement during skin incision in 50%

Question 3

What is the MAC formula to achieve preventing movement in 95% people?

Answer 3

1.3 x MAC

Question 4

What 3 factors influence MAC?

Answer 4

temp
age
prescriptions

Question 5

What 4 factors do NOT influence MAC?

Answer 5

sex
O2
pH
BP

Question 6

As cardiac output increases, what happens to induction with inhalation anesthetics?

Answer 6

GETS SLOWER

inverse relationship with CO

Question 7

What is the equation for anesthesia?

Answer 7

FA/FI

end-tidal/inspired

Question 8

True or false: the faster the agent gets from one compartment to the next, the slower it reaches equilibrium

Answer 8

TRUE

Question 9

What 3 factors determine GA uptake from the blood?

Answer 9

1) solubility
2) partial pressure difference
3) cardiac output

Question 10

Define FA

Answer 10

the end tidal partial pressure is the brain partial pressure

Question 11

Which drug is more soluble in the blood, NO or Halothane?

Answer 11

HALOTHANE

Question 12

Which achieves equilibrium faster, NO or halothane?

Answer 12

NO (blood cannot hold that much NO)

Question 13

Which blood compartment is larger, NO or halothane?

Answer 13

halothane (holds more since drug is more soluble)

Question 14

What does a larger blood/gas partition coefficient mean?

Answer 14

more soluble
takes longer to reach equilibrium
larger blood compartment

Question 15

What are the vessel rich organs? BHLK

Answer 15

brain
heart
lung
kidney

Question 16

Increased blood flow near alveolus _______ (slows/speeds up) equilibrium because it increases uptake

Answer 16

slows

remember: cerebral blood flow is regulated so an increase in CO should not bring extra agent to brain

Question 17

What effect does GA have on lungs?

Answer 17

bronchodilation

Question 18

What happens to the brain during GA?

Answer 18

uncoupling

increased blood flow but decreased O2 consumption

Question 19

What IV anesthetic is used for induction, maintenance, sedation in the OR or ICU?

Answer 19

propofol

mechanism: IPSP

increases intracranial pressure

Question 20

What was the most used induction agent before propofol?

Answer 20

thiopental

arterial vasoconstrictor

Question 21

What are some of the good effects of ketamine?

Answer 21

1) dissociative anesthesia
2) bronchodilator, keep breathing
3) increase BP and HR
4) increase ICP and cerebral blood flow

Question 22

What is the hallmark of etomidate?

Answer 22

least cardiovascular side effects