MSK: General and Local Anesthetics

Question 1

What is a common suffix of almost all inhaled anesthetics?

Answer 1

-urane

Question 2

What is the one inhaled anesthetic that doesn’t end in -urane?

Answer 2

Nitrous oxide

Question 3

How does a high blood:gas coefficient relate to onset of action?

Answer 3

High blood:gas coefficient=more soluble=slower onset

inversely related

Question 4

How does a low blood:gas coefficient relate to onset of action?

Answer 4

Low blood:gas coefficient=less soluble=faster onset

inversely related

Question 5

Whats an example of a drug with low blood:gas coefficient therefore quick onset of action?

Answer 5

Nitrous oxide

-very quick, I was out in like 10s when I got my wisdom teeth out

Question 6

Whats an example of a drug with high blood:gas coefficient therefore slower onset of action?

Answer 6

Halothane

-used for surgeries (not in US; hepatotoxic)

Question 7

What is the Minimal Alveolar Concentration (MAC) a representation of?

Answer 7

A measure of potency

-the dose at which 50% of subjects have anesthetic effects

Question 8

Is a higher MAC or lower MAC associated with greater anesthetic effects?

Answer 8

Lower

• if MAC 100%, it would mean pt would need 100% gas to feel it
• if MAC 70%, it would mean pt would only need 70% gas to feel it

Question 9

What is the most serious adverse effect of halothane?

Answer 9

Hepatotoxicity

-not used much in US; watch for question about pt having surgery in different country

Question 10

For those inhaled anesthetics that are combined with succinylcholine, what do you need to watch out for and how would you treat?

Answer 10

Malignant hyperthermia

-treat with dantrolene (ryr blocker)

Question 11

MOA of propofol

Answer 11

GABAa agonist

Question 12

What is the induction and recovery of propofol?

Answer 12

Rapid onset and rapid recovery

-poor solubility in water

Question 13

Clinical use of propofol

Answer 13

Can be used for induction and as continuous IV drip for maintenance

Question 14

Adverse effects of propofol?

Answer 14

CNS depression
Profound vasodilation=hypotension
Respiratory depressant

Question 15

MOA of etomidate

Answer 15

GABAa receptor agonist

Question 16

Which anesthetic drug is best for patients with cardiovascular and pulmonary issues?

Answer 16

Etomidate

-causes least amount of CV and pulm depression

Question 17

What is the induction and recovery of etomidate?

Answer 17

Rapid induction and moderate recovery

Question 18

Adverse effects of etomidate?

Answer 18

cerebral vasoconstrictor=decrease cerebral blood flow and ICP

Adrenocortical suppression

Question 19

MOA of ketamine

Answer 19

NMDA receptor antagonist

Question 20

Adverse effects of ketamine

Answer 20

Dissociated anesthetic
Hallucinations and bad dreams
CNS and CV stimulant
Nystagmus

Question 21

Which anesthetic causes profound analgesia, stimulation of Sym NS, bronchodilation and has minimal resp depression?

Answer 21

ketamine

Question 22

MOA of dexadetomide

Answer 22

a2 agonist that causes hypnosis

-works at locus caeruleus with analgesia at level of spinal cord

Question 23

MOA of midazolam and diazepam?

Answer 23

GABAa receptor agonist
-increase FREQUENCY of opening

-benzos

Question 24

MOA of fentanyl

Answer 24

μ opiate agonist

Question 25

Adverse effects of fentanyl and other opiates

Answer 25

CNS and resp depression

constipation

Question 26

MOA of thiopental and methohexital

Answer 26

GABAa receptor agonist
-increase DURATION of opening

Barbituates

Question 27

What drug is the antidote to benzodiazepine overdose?

Answer 27

Flumazenil

Question 28

What drug is often administered before surgery, especially surgeries where patient can keep “sedative” consciousness, ie colonoscopy or spinal surgery?

Answer 28

Midazolam

Question 29

What type of local anesthetic are:

Lidocaine
Dibucaine
Bupivacine
and Articaine?

Answer 29

Amides

-have two i’s in the name

Question 30

What type of local anesthetics are:

Benzocaine
Cocaine
Procaine?

Answer 30

Esters

-only one i in name and in in -caine

Question 31

MOA of the local anestetics?

Answer 31

Block voltage gated sodium channels to prevent spread of action potentials

Question 32

What fibers are blocked faster by local anesthetics: small or large?

Answer 32

Small

Question 33

What fibers are blocked faster by local anesthetics: myelinated or unmyelinated?

Answer 33

Myelinated

Question 34

What fibers are blocked faster by local anesthetics: large myelinated or small unmyelinated?

Answer 34

small unmyelinated

Question 35

What fiber types are especially sensitive to local anesthetics?

Answer 35

Type A Delta (pain, temp)
Type B (preganglionic autonomic)
Type C (pain and postganglionic)

Question 36

What type of drug are local anesthetics often paired with?

Answer 36

Vasoconstrictor (reduces bleeding)

-epinephrine

Question 37

What are some adverse effects of local anesthetics on CNS?

Answer 37

low doses: headache, light headedness, visual and audio disturbances

High doses: CNS depression and toxicity

Question 38

What are some adverse effects of local anesthetics on CV system?

Answer 38

Some can block Na conduction in heart, decreasing excitability
-bupivacine is most cardiotoxic

Question 39

What types of anesthetic are more likely to cause an allergic reaction: esters or amides?

Answer 39

Esters

-if pt has an allergic reaction to ester, switch to amide (lidocaine or other two i)

Question 40

Which local anesthetic has vasoconstrive properties?

Answer 40

Cocaine