Pharm General Anesthetics

Front 1

Review the differences between "induction" "maintenance" and "emergence"

Back 1

page 209

Front 2

Since inhalational anesthetics are gases, how is the partial pressure of these gases useful as a measurement?

Back 2

partial pressure is proportional to concentration

Front 3

How are inhalant general anesthetics transferred from one compartment to another?

Back 3

passive diffusion down their partial pressure gradients

Front 4

Name the compartment inhalant general anesthetics pass through on their way to the CNS.

Back 4

inspired gas --> alveoli --> blood --> target CNS and other tissues

Front 5

What is the inhalent general anesthetic concentration in the CNS dependent upon?

Back 5

the final alveolar tension

Front 6

what 3 things govern the rate of induction of a general anesthetic?

Back 6

1. Rate of equilibration (which is dependent on the tension of the anesthetic of the inspired gas + pulmonary ventilation rate)… 2. Rate of blood equilibration (which is dependent on the blood solubility of the drug, where the lower the blood solubility coefficient = faster rate, because the more blood soluble the slower the induction and the slower the equilibration)... 3. Rate of Tissue Equilibration (which is dependent on tissue blood flow rates... brain>heart>lung... etc.)

Front 7

Which of the 3 things that govern induction rates of general anesthetic is most critical?

Back 7

blood solubility

Front 8

If general anesthetics are generally fat soluble, why do drugs take so long to equilibate in fatty tissue?

Back 8

poor blood flow to fatty tissues

Front 9

What governs rate of emergence?

Back 9

the same factors that govern induction

Front 10

T/F metabolism and renal clearance play a significant role in the elimination of inhalational anesthetics.

Back 10

FALSE… they play a minimal role

Front 11

What determines the potency of a inhalation anesthetic?

Back 11

it's lipid solubility

Front 12

T/F the more lipid soluble an inhalation anesthetic the less tension it require to produce anesthesia.

Back 12

TRUE

Front 13

Do lipid soluble inhalation anesthetics tend to have low or high blood solubility?

Back 13

they have high blood solubility, while they are more potent they tend to be slow inducers

Front 14

What does MAC stand for? (2 things)

Back 14

1. MAC = minimum alveolar concentration anesthetic needed to produce immobility in 50% of patients… 2. it's an index of potency…

Front 15

What is a good measure of brain tension for inhalation anesthetics?

Back 15

alveolar tension = brain tension

Front 16

T/F MAC can only be applied to inhalation anesthetics if they were nor a solid or liquid first.

Back 16

false all inhalation anesthetic are ranked by MAC

Front 17

T/F MAC is stable across a variety of conditions, e.g., gender, height, acid-base status.

Back 17

TRUE

Front 18

T/F MAC is additive for different inhalant anesthetics.

Back 18

TRUE

Front 19

Which is the most potent inhalational anesthetic? Which is the intermediate MAC? Which ihalent has the least potent?

Back 19

most potent = Halothane…Intermediate = Isoflurane... least potent = NO

Hint 19

None

Front 20

What is considered a potent MAC a large value or small value?

Back 20

small

Front 21

Which inhalational anesthetic cause a decrease in intracranial pressure (while the other cause an increase.)?

Back 21

Decrease = Isoflurane… increase = NO and Halothane

Front 22

Which inhalational anesthetic would require pretreatment to avoid airway irritation?

Back 22

Isoflurane, which is the the only inhalational anesthetic that causes airway irrititation

Hint 22

None

Front 23

Which inhalational anesthetic would you avoid if the patient has issues of low blood pressure?

Back 23

isoflurane and halothane, which both cause significant hypotension… use NO instead

Front 24

Between NO, halothane and isoflurane, which has the lowest blood solubilitiy? What is the consequence of this?

Back 24

NO… which makes it a rapid inducer… the other have a medium rate of induction

Front 25

T/F NO, halothane and isoflurane all have analgesic effects.

Back 25

TRUE

Front 26

which inhalation anesthtic will cause hypoxia at partial pressures of 70-80%?

Back 26

NO (diffusion hypoxia)

Hint 26

None

Front 27

In NO use, what happens during rapid emergence that causes a large drop in PaO2? And what is this effect called?

Back 27

NO saturates the alveoli… this is called the diffusion hypoxia effect

Front 28

Why is NO used as an adjuct with other inhalation anesthetics?

Back 28

becaues of its low potency and risk for hypoxia

Front 29

Rank the inhalational anesthetics in order of greater to least muscle relaxation effects.

Back 29

Isoflurane > halothane> NO (yes>minimal>none)

Front 30

Rank the inhalational anesthetics in order of greater to least respiratory system effects.

Back 30

Isoflurane (potent respiratory depressant) > Halothane (causes moderate reduction in rate) > NO (minimal effect)

Front 31

Which is the only inhalational anesthetic that comes in a gas form?

Back 31

NO.. The others are in volitile liquid form

Front 32

why is isoflurane a good choice for neurosurgery?

Back 32

isoflurane decreases cerebral blood flow and lowers intercranial pressure

Front 33

Which is the most potent inhalation anesthetic?

Back 33

isoflurane

Front 34

which inhalation anesthtic will cause liver nicrosis in adults, but is still used in pediatrics?

Back 34

halothane

Front 35

which inhalation anesthtic will cause coughing and layrngospams and requires premedication or use of thiopental as an induction agent?

Back 35

Isoflurane

Front 36

What is the advantage of IV general anesthetics?

Back 36

fast onset and ultra short acting… but moreover they are highly POTENT!!!!

Front 37

Why is the combination of IV general anesthetics and inhalation anesthetics useful?

Back 37

IV general anesthetics lowers the doses of inhalational anesthetics

Front 38

What properties do all IV general anesthetics share?

Back 38

all are IV injected and all are lipophilic (which makes sense in terms of potency)

Front 39

Why is the CNS preferentially targeted by IV general anesthetics?

Back 39

the CNS is highly perfused and lipophilic friendly

Front 40

What two things is the rate of induction for IV general anesthetics dependent upon?

Back 40

1. Lipid solubility of the IV general anesthetics… 2. The administered dose (i.e., one large bolus)

Front 41

where do IV general anesthetics redistribute after first going to the CNS?

Back 41

1. First, the less well perfused muscle and viscer… 2. Then the hydrophobic, but poorly perfused adipose tissues

Front 42

After redistribution, how are IV general anesthetics cleared from the body?

Back 42

liver metabolism and renal excretion

Front 43

Which is more responsible for emergence for IV general anesthetics, liver metabolism, renal excretion, or redistribution? (not continuous or intermittent use!!!)

Back 43

redistribution

Front 44

1. If the IV general anesthetics is used continuously or intermittently for a prolonged period, Which is more responsible for emergence for IV general anesthetics, liver metabolism, renal excretion, or redistribution?… 2. What then determines IV general anesthetics elimination half-life?

Back 44

1. Since the drug has equilibrated in all tissues, termination of drug action is now dependent on elimination from the body… 2. Infusion DURATION.

Front 45

What is the best example emergence being dependent upon infusion duration?

Back 45

a single bolus dose of thiopental has rapid emergence, while prolonged infusion takes a day to emerge

Front 46

How are IV general anesthetics measured?

Back 46

potency (lipophilicity) and dose

Front 47

Which IV general anesthetics is a barbiturate?

Back 47

Thiopental

Front 48

which IV general anesthetics is a phenol?

Back 48

Propofol

Front 49

Which IV general anesthetics is susceptible to bacterial contamination?

Back 49

propofol

Front 50

Which IV general anesthetics dissociates the thalamus from the limbic cortex?

Back 50

Ketamine

Front 51

Which IV general anesthetics have lipid solubility and high potency?

Back 51

all of them

Front 52

Which IV general anesthetics is a synthesized as a Na-salt from propylene glycol, alcohol and water?

Back 52

thiopental

Front 53

which IV general anesthetics is similar to PCP?

Back 53

ketamine

Front 54

Which IV general anesthetics increases CO, HR, and BP?

Back 54

ketamine

Front 55

which IV general anesthetics can increase the risk of seizure in epileptic patients?

Back 55

propofol

Front 56

which IV general anesthetics decreases intracranial pressure?

Back 56

thiopental

Front 57

Which of the IV general anesthetics offers analgesic properties?

Back 57

ketamine

Front 58

Which IV general anesthetics produce early airway irritation?

Back 58

thiopental

Front 59

which IV general anesthetics can allergic rxns in patients with a phenol allergy and has a high incidence of injection pain?

Back 59

propofol

Front 60

which IV general anesthetics can cause hypotention?

Back 60

thiopental can cause hyptension in hypovolemic patients… propofol can cause moderate hypotension

Front 61

Which IV general anesthetics can cause dose dependent respiratory depression?

Back 61

both propofol and thiopental

Front 62

which IV general anesthetics does not shows prolonged emergence due to prolonged infusion? What does this mean for its use as a maintenance anesthetic?

Back 62

propofol… quick emergence --> it's a good maintenance IV general anesthetics

Front 63

Which IV general anesthetics has a slow-long emergence?

Back 63

thiopental

Front 64

which IV general anesthetics can be titrated to achieve various levels of consciousness?

Back 64

propofol

Front 65

Which IV general anesthetics can produce severe pain and necrosis if accidental extravascular injection occurs?

Back 65

thiopental

Front 66

Which drug is has an active metabolite, is an analog of PCP, can develop tolerance, and is a potent broncho dilator?

Back 66

ketamine

Front 67

How do general anesthetics work?

Back 67

change activity of voltage gated and ligand gated channels (Ca), also GABA receptor have increased sensitivity… except NO is thought to depress the nervous system by inhibiting NMDA receptors

Front 68

which inhalent is sweet smelling?

Back 68

Halothane... used for kids