Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Ocular Pharmacology > Anesthetics > Flashcards

Anesthetics Flashcards

1
Q

What is the chemical structure of an anesthetic?

A

lipophilic synthetic aromatic or heterocyclic residue, intermediate ester or amide linkage and a weakly basic tertiary amine terminal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why is lipophilicity of key component of anesthetics?

A

it can penetrate cells (corneal layers), skin, CNS, and blood brain barrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does myelin do to anesthetics?

A

enhances its sensitivity independent of diameter (lipid myelin attracts lipophilicity)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Are small diameter nerves more or less sensitive than large diameter nerves?

A

small (highly active) are more sensitive to anesthetics = fire more rapid and has repeated opportunity to bind drug (large = recover quicker - usually have life giving functions)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the order of effects for anesthetic targets?

A

pain > cold > warmth > touch > deep pressure > motor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what does the intermediate chain linkage on an anesthetic link?

A

a lipophilic aromatic residue with a hydrophilic amino group - longer linkage enhances potency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Is the receptor on the nerve lipophilic or hydrophilic?

A

hydrophilic - the more lipophilic the more effective (potency)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How are ester linkage anesthetics metabolized?

A

locally by pseudocholinesterase (PChE)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 3 parent structures in the ester group? and which anesthetics are in those groups?

A

PABA (tetracaine, procaine, benzocaine, and benoxinate), MABA (proparacine), and BA (cocaine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How are the amide linked anesthetics metabolized?

A

hepatic metabolism, urinary and biliary excretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the most common eye-care amide anesthetic?

A

lidocaine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the difference in action between esters and amides?

A

amides are longer acting, have greater systemic effects and readily cross the blood brain barrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How do anesthetics increase absorption and intercellular permeability?

A

break the corneal epithelium tight junctions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the schirmer I test?

A

without anesthetic = measures basal tearing + reflex tearing

with anesthetic = measures basal tearing (neurogenic reflex tearing is suppressed)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the best anesthetic to use when collecting cultures?

A

Preservative free proparacine - least antibacterial/antifungal effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are proparacine and tetracaine used for?

A

tonometry, gonio, sutures, nasolacrimal massage, ultrasound

17
Q

what is an advantage of proparacine over tetracaine?

A

proparacaine has less sting - but has potential to increase corneal thickness (cause swelling) and affects goldmann and pachymetry

18
Q

what is an advantage of tetracaine over proparacaine?

A

tetracaine has greater corneal toxicity but penetrates more than proparacaine

19
Q

Which ester anesthetic produces the least amount of corneal compromise but has the potential to increase thickness?

A

benoxinate

20
Q

what is the onset and duration for topical anesthetics?

A

(mainly esters) - 30sec onset and about 15min duration (procaine is longer)

21
Q

Why are amide anesthetics usually longer lasting and take longer to take effect?

A

they are not locally metabolized - need to go to liver

22
Q

How can you double lidocaine duration?

A

use with epinephrine for vasoconstriction

23
Q

If a patient has a red eye following anesthetic use - are they allergic to the drop?

A

not necessarily - vasodilation of lidocaine may relax nerves responsible for vascular tine and if it was a long half-life anesthetic they may have a red eye

24
Q

Why would you pair an anesthetic with a vasoconstrictor?

A

reduce absorption and systemic toxicity, reduce metabolism, keep effect localized, and reduce bleeding at injection site

25
Q

What is the only anesthetic that vasoconstricts instead of vasodilates?

A

cocaine

26
Q

what are the systemic adverse effects of cocaine?

A

excitement, convulsions, rapid palpitations, nausea, and delirium

27
Q

what are the ocular adverse effects of cocaine?

A

desquamation, mydriasis, lid retraction (unilateral)

28
Q

Why do TCADs, MAOIs, epinephrine, phenylephrine, Guanethidine, and Reserpine cause adverse reactions with cocaine?

A

these drugs also excite the sympathetic nervous system - amplify the effects of cocaine and cause serious damage

29
Q

what are some adverse effects of cocaine on ocular tissues?

A

desquamation, corneal edema, conjunctival hyperemia, allergic conjunctivitis, and lacrimation

30
Q

who is more susceptible to desquamation?

A

patients over age 50 - reduced blink rate (cells die), reduced tear production, and increased evaporation

31
Q

How do you determine if your patient has conjunctival hyperemia vs. allergic conjunctivitis from an anesthetic?

A

allergic conjunctivitis will itch (both will be red eyes)

32
Q

Why do you need to know what anesthetics your patient may have been on for surgeries or procedures?

A

they may have nystagmus or visual hallucinations from long lasting (long half-life) anesthetics

33
Q

what are the cardiovascular anesthetic adverse effects (except from cocaine)?

A

decreased excitability, decreased cardio force/conduction –> hypotension = cardio collapse

34
Q

what are some anesthetic cautions?

A

cholinesterase deficiency, hyperthyroidism, cardiac disease, allergy history, and sensitivity to similar drugs

35
Q

What is the primary sign of anesthetic abuse syndrome?

A

yellow-white stromal ring at the active site

36
Q

What are some signs and symptoms of anesthetic abuse syndrome?

A

corneal epithelium defect (stromal edema and descemet’s folds), disciform stromal infiltrates, KP, hypopyon, hyphema, lid edema, neovascularization, discharge

37
Q

What are some non-anesthetic alternatives (allergy to amide/esters)?

A 
Injectable = 1% Benadryl or saline
Topicals = EMLA, lidoderm patch, or iontophoresis

Ocular Pharmacology (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions