RE Chapter 8

Question 0

Anesthetic effect is lost if carbon atom chain exceeds ______ carbon atoms

Answer 0

4 or 5 (5 angstroms)

Question 1

All commonly used inhalation agents are (select two)
A. Ethers
B. Amides
C. Esters
D. Aliphatic hydrocarbons

Answer 1

A & D

Question 2

Halogenation of ethers and hydrocarbons influences what 4 things?

Answer 2

1. potency
2. arrythmogenic properties
3. flammability
4. chemical stability

Question 3

What is the rate of inhaled anesthetic degradation?

Answer 3

sevo=iso > des > N2O

Question 4

How are all inhaled anesthetics biodegraded?

Answer 4

Hepatic metabolism through oxidation (phase 1 reaction)

Question 5

What is the Meyer-Overton rule?

Answer 5

Lipid solubility is directly proportional to potency.

Question 6

What is the definition of “general anesthesia”?

Answer 6

A drug’s capacity to induce and sustain unconsciousness, amnesia, analgesia, and immobility.

Question 7

What is the definition of MAC?

Answer 7

The minimum concentration at equilibrium in which 50% of subjects will not respond to a painful stimulus.

Question 8

Isoflurane MAC in 60-70% N2O

Answer 8

0.56

Question 9

Desflurane MAC in 60-70% N2O

Answer 9

2.38

Question 10

Sevoflurane MAC in 60-70% N2O

Answer 10

0.66

Question 11

What are factors that reduce MAC?

Answer 11

Increased age, hypothermia, depressant meds, alpha2 agonists, acute alcohol intox, hypoxemia, anemia, hypotension, pregnancy,

Question 12

What are factors that increase MAC

Answer 12

young age, hyperthermia, hyperthyroidism, chronic ETOH consumption, acute amphetamine admin, red-headed females.

Question 13

What is the effect of volatile anesthetics on CMRO2?

Answer 13

Decreases in a dose-dependent manner.

Question 14

What is uncoupling in relation to CMRO2 and CBF?

Answer 14

When decreases in CMRO2 are accompanied by increases in CBF

Question 15

What is the effect of N2O on CBF & CMRO2

Answer 15

Increases both CBF & CMRO2

Uncoupling still occurs because increase in CMRO2 exceeds increase in CBF

Question 16

Which evoked potentials are the most and least sensitive to volatile anesthetics?

Answer 16

Most: visual evoked potentials
Least: brainstem-evoked potentials

Question 17

A ______(increase / decrease) in latency and a _________ (increase / decrease) amplitude reflect ischemia or secondary to volatile anesthetic.

Answer 17

increase in latency

decrease in amplitude

Question 18

Which two volatile anesthetics are linked to emergence delirium in children?

Answer 18

Sevoflurane & Desflurane

Question 19

Which volatile anesthetic decreases MAP the least?

Answer 19

Isoflurane

Question 20

Of desflurane, isoflurane, & sevoflurane which decreases SVR the least?

Answer 20

sevoflurane

Question 21

What does N2O do to SVR?

Answer 21

Activates the SNS leading to an increase in SVR, this may lead to increases in CVP and ABP

Question 22

When N2O is used with volatile anesthetics it may support but may cause cardiac depression when used with opioids because it produces what effect?

Answer 22

Negative inotropic

Question 23

What are inhaled anesthetics three mechanisms for altering HR?

Answer 23

1. antagonism of SA node automaticity
2. modulation of baroreceptor reflex activity
3. SNS activation via activation of tracheopulmonary systemic receptors.

Question 24

What is coronary steal?

Answer 24

reduction of perfusion from ischemic myocardium and improvement of blood flow to non ischemic tissue

Question 25

What is ischemic preconditioning?

Answer 25

A cascade of cellular events that protect the myocardium from ischemic and reperfusion insult.
Volatile anesthetics do this.

Question 26

What are two mechanisms of preconditioning?

Answer 26

1. improves contractile function

2. reduces calcium overload by preventing down-regulation of major sarcoplasmic reticulum Ca+ protiens.

Question 27

How does N2O affect pulmonary vascular resistance?

Answer 27

increases it

-Only small increases with normal PVR, more notable in patients with pulmonary HTN

Question 28

How do volatile anesthetics affect PVR?

Answer 28

Most decrease it

Desflurane at 1.6 MAC increases