Anesthesia Drugs

Question 1

How does local anesthesia work

Answer 1

interrupts pain impulses in specific regions of the body, without LOC

Question 2

what are the general side effects of anesthetics

Answer 2

CNS stimulation followed by drowsiness and sedation

HA

Paresthesias

Nausea

Cardiac depression, antiarrhythmic activity and wide QRS

blocks autonomic ganglia

C/I in myasthenia Gravis

Question 3

What are the differences in the types of local anesthetics

Answer 3

Esters: short-acting, metabolized by plasma esterases, used topically or infiltrative, more likeky to cause hypersensitivity reactions

Amides: longer acting, metabolized by the liver

Question 4

Rank the ester anesthetics from shortest actin to longest

Answer 4

1. procaine
2. tetracaine
3. cocaine
4. benzocaine

Question 5

Rank the amide anesthetics from shortest actin to longest

Answer 5

lignocaine

Mepivicaine

Prilocaine

Bupivicaine

Ropivicaine

Question 6

which general anesthetic is inhaled and what are the

side effects and contraindications

Answer 6

nitrous oxide

side effects: mild myocardial depression

increased pulmonary vessel resistance

c/i: pneumothorax and pulmonary HTN

Question 7

What are the volatile liquid general anesthetics

Answer 7

Halothane

Enflurane

Isoflurane

Desflurane

Sevoflurane

Question 8

the concentration of an inhaled anesthetic in a mixture of gasses is proportional to

Answer 8

its partial pressure

Question 9

what determines the speed of achieving steady-state of an inhalational anesthetic

Answer 9

ventilation rate

cardiac output

blood-gas partition coefficient

Question 10

what is the blood gas partition coefficient and what is its significance

Answer 10

ratio of anesthetic concentrations in the blood and alveolar space when partial pressure is equal

the higher the coefficient, the higher the solubility into blood and slower the action onset

the lower the coefficient, the faster the drug’s effect ceases

Question 11

what is the minimal alveolar concentration

Answer 11

concentration at which 50% of subjects are immobile when exposed to noxious stimuli

Question 12

what is the significance of the MAC

Answer 12

the lower the MAC, the more fat-soluble the drug is

Question 13

how are inhalational anesthetics eliminated

Answer 13

lungs

Question 14

steps of general anesthesia

Answer 14

1. neruons in the spine are prevented from firing
2. inhibition of inhibitory neurons causes paradoxical excitation
3. suppression of the reticular activating system, LOC and inhibition of spinal reflexes, muscle relaxation
4. can lead to cardiovascular collapse

Question 15

MOA of general anesthetics

Answer 15

1. drug binds to specific amino acid residues on transmembrane portions of GABAa receptor chloride channels
2. increased chloride influx and potassium efflux from neurons causes hyperpolarization and reduces membrane excitability
3. sodium and calcium influx is also reduced

Question 16

side effects specific to isoflurane

Answer 16

pungent odor

Question 17

side effects specific to desflurane

Answer 17

respiratory irritation:

coughing

salivation

bronchospasm

increased BP and HR

Question 18

side effects specific to sevoflurane

Answer 18

bronchodilation and nephrotoxicity

Question 19

which general anesthetic is metabolized by the liver

Answer 19

halothane

Question 20

which general anesthetic has the most rapid onset of action and recovery

Answer 20

desflurane

Question 21

Barbituates

MOA

side effects

contraindications

Answer 21

MOA: increases duration chloride channels are open, to hyperpolarized the neuron

side effects: hypotension, respiratory depression, laryngospasm, bronchospasm, myoclonus, painful injection, dependence, CYP450 inducer

contraindications: porphyria

Question 22

Benzodiazepines

MOA

side effects

contraindications

Answer 22

MOA: increases frequency of chloride channels opening to hyperpolarize the postsynaptic neuron

side effects: blunted/ hangover effect, muscle weakness, amnesia, tolerance, dependence, paradoxical excitability, increased appetite, CNS depression

contraindications: myasthenia gravis, ataxia, narrow-angle glaucoma, pregnancy, respiratory depression, drug dependence

Question 23

Propofol

MOA and Side Effects

Answer 23

MOA: acts at GABAa receptors and sodium channels of the reticular system

side effects: dose-dependent hypotension and respiratory depression, anaphylaxis with egg allergy, pain on injection, apnea, hypotonus

Question 24

which anesthetic drug causes the least amount of CVS symptoms and what is its MOA/ side effects

Answer 24

Etomidate

MOA: acts at GABA receptors of the reticular formation

Side effects: causes transient acute adrenal insufficiency, postop N/V, painful injection, myoclonus

Question 25

side effects of opioids

Answer 25

AMS

bilateral miosis

respiratory depression

seizure

decreased bowel sounds

decreased HR and BP

hypothermia

rhabdomyolysis

Question 26

how do opioids work

Answer 26

inhibit adenyl cyclase to increase potassium conductance and decrease calcium conductance to cause inhibition of neurotransmitter release from the central termination of small-diameter primary fibers and inhibition of membrane depolarization of dorsal horn noicireceptive neurons

Question 27

Ketamine

MOA

side effects

Answer 27

MOA: NMDA receptor antagonist

side effects: nystagmus, increased oxygen demand

increased pulmonary arterial pressure, increased ICP, hallucinations, nightmares, abnormal ECG, respiratory depression

Question 28

who do you give ketamine to

Answer 28

polytrauma patients with risk of hypotension

treatment-resistant asthma

pediatrics

Question 29

who is the best candidate for etomidate

Answer 29

patients with hemodynamic instability