Drugs—ITE

Question 1

Reduced cardiac output has what effect on inhalational induction? Which gases are most affected?

Answer 1

Reduced cardiac output promotes a faster rate of induction. This is especially true with soluble volatiles.

Question 2

Solubility of volatiles is based on blood-gas coefficients. Is a volatile with low blood gas coefficient more or less soluble? List the gases from least to most soluble.

Answer 2

Low blood gas coefficient is less soluble.

Des < nitrous < sevo < iso < halothane

Question 3

Which volatile anesthetic undergoes the most extensive metabolism?

Answer 3

Sevoflurane. Despite elevations in serum fluoride in long cases, it has not been shown to cause fluoride induced nephrotoxicity.

Question 4

By what mechanism do volatiles potentiate neuromuscular blockade?

Answer 4

Volatiles potentiate NMB by decreasing the sensitivity of the post-junctional membrane to depolarization, increasing skeletal mm blood flow, and depressing upper motor neurons.

Question 5

Volatile anesthetics are thought to cause an uncoupling effect. What does this mean?

Answer 5

They decrease CMRO2 while increasing CBF via a direct vasodilatory effect.

Question 6

When a patient is administered 75% NO, the gas will rapidly diffuse from the blood into air filled cavities. How long does is take a pneumothorax to double in size with nitrous? To triple?

Answer 6

A PTX will double in 10m and triple in 30m

Question 7

Effect of L to R intracardiac shunt on inhalational induction speed? IV induction speed?

Answer 7

No effect on either

Question 8

R to L intracardiac shunt effect on inhalational induction speed? IV induction speed?

Answer 8

Decreased inhalational induction speed

Increased IV induction speed

Question 9

Effect of intrapulmonary shunt on inhalational induction speed? IV induction speed?

Answer 9

Decreased speed of inhalational induction

No effect on IV induction speed

Question 10

Factors decreasing MAC

Answer 10

Hyponatremia
Hypothermia
Hypoxia
Older age
Metabolic acidosis
Anemia hgb
Pregnancy
Acute EtOH use
Chronic methamphetamine use
Hypercarbia

Question 11

Factors increasing MAC

Answer 11

Red hair
Acute methamphetamine use
Chronic etoh use
Cocaine
Young age
Hypernatremia
Hyperthermia
Ephedrine
Levodopa
MAOIs

Question 12

Metabolic effects of epinephrine

Answer 12

—Hyperglycemia (increased gluconeogenesis, increased glycogenolysis, decreased insulin)
—increased free fatty acids
—hypokalemia

Question 13

Which volatile most significantly augments neuromuscular blockade?

Answer 13

Desflurane

Question 14

Glycopyrrolate MOA

Answer 14

Muscarinic anticholinergic in the periphery

Question 15

Neostigmine MOA

Answer 15

Anticholinesterase

Question 16

Side effects of anticholinesterase

Answer 16

Bradycardia, hypotension, bronchospasm, secretions, miosis, decreased intraocular pressure

Question 17

The onset of effect of local anesthetic is affected by what 4 factors?

Answer 17

1. Concentration (higher is faster)
2. Lipid solubility (higher is faster)
3. pKa (lower is faster; more unionized at physiologic pH)
4. Environmental pH (higher is faster; more basic)

Question 18

Physiologic changes associated with bicarbonate administration

Answer 18

Increased preload
Decreased contractility
Increased hgb affinity for oxygen
Increased lactate
*can cause intracranial hemorrhage

Question 19

Which opioid receptor does naloxone bind to most strongly?

Answer 19

Mu

Question 20

What is the preferred method of beta blockade in pts with reactive airway disease?

Answer 20

Beta 1 selective antagonists because they do not cause bronchoconstriction or vasoconstriction s/t sparing of beta 2 antagonism.

Question 21

List the ester local anesthetics

Answer 21

Procaine
Chlorprocaine
Tetracaine

(Preservatives Can Taint)

Question 22

Propofol should be used within what time frame of opening a vial?

Answer 22

12 hrs

Question 23

Terbutaline MOA and SFx

Answer 23

MOA: beta 2 agonist
SFx: hyperglycemia, tachycardia, hypokalemia

Question 24

Clopidogrel is a prodrug activated by what enzyme?

Answer 24

Cyp450

Question 25

Beta-1 selective blockers

Answer 25

``` Atenolol Bisoprolol Esmolol Acebutolol Metoprolol ```

Question 26

Non selective beta blockers

Answer 26

``` Carvedilol Timolol Labetalol Nadolol Propranolol Pindolol ``` Careful, This Lot’s Nor Particularly Picky

Question 27

Active metabolite of meperidine and SFX

Answer 27

The active metabolite of meperidine is normeperidine and it causes seizure activity.

Question 28

Metabolites of morphine and their SFX

Answer 28

Primary active metabolite is M6G, it is 100x more potent than morphine, and accumulation causes respiratory depression. Inactive metabolite is M3G and causes myoclonus and allodynia

Question 29

What is the best induction agent for pts with hypovolemic trauma at no risk for elevated ICP?

Answer 29

Ketamine

Question 30

Lithium effect on NMBDs

Answer 30

Prolongs action if NDNMBDs and depolarizing NMBDs

Question 31

What percent of platelet function is restored when an irreversible platelet inhibitor is held for one day?

Answer 31

10-15%

Question 32

Aspirin MOA

Answer 32

Blocks the formation of thromboxane A2 in platelets which prevents platelet aggregation.

Question 33

Succinylcholine effect on lower esophageal sphincter tone and on intragastric pressure

Answer 33

Increases both

Question 34

Which inhalational agent is associated with megaloblastic hematologic changes?

Answer 34

Nitrous oxide NO inhibits the vitamin B12-dependent enzymes methionine synthetase and thymidylate synthetase. Usually sub clinical effects in healthy pts but can cause neurologic and hematologic sequelae in critically ill and B12 deficient pts

Question 35

List the volatile anesthetics in order of NDNMB potentiation. Where does propofol fall on this spectrum?

Answer 35

Des>sevo>iso>halothane>propofol

Question 36

Treatment for delirium associated with scopolamine

Answer 36

Physostigmine

Question 37

List commonly tested medications that cause pain on injection

Answer 37

``` Prop Roc Etomidate Diazepam Methohexital ```

Question 38

List commonly tested medications that are not associated with pain on injection

Answer 38

``` Midazolam Opioids Ketamine Dexmedetomidine Fospropofol ```

Question 39

herbal supplements associated with increased risk of bleeding

Answer 39

Ginger, garlic, ginkgo, vitamin E

Question 40

Most common side effects of fospropofol

Answer 40

Parenthesias (general and perianal) and pruritis

Question 41

Chlorprocaine’s rapid onset of action is secondary to what characteristic of the drug?

Answer 41

Concentration

Question 42

Name the 4 potassium soaring diuretics

Answer 42

Spironolactone Eplerenone Amiloride Triamterene all can be associated with hyperkalemia

Question 43

Nicardipine metabolism and excretion

Answer 43

Metabolized by liver | Excreted by kidneys

Question 44

By what mechanism does etomidate cause adrenal suppression?

Answer 44

Inhibition of 11 beta hydroxylase