Exam 2 LA and general

Question 1

amides or esters better for LA?

Answer 1

amides - less allergenic, better tissue penetration and longer duration of action

Question 2

which local anesthetic has the longest duration of action?

Answer 2

bupivacaine (Marcaine)

Question 3

Islidocaine or procaine an amide or ester?

Answer 3

lidocaine = amide
procaine = ester

Question 4

what part of LA is hydrophilic or hydrophobic?

Answer 4

hydrophillic = amino group
hydrophobic = aromatic nucleus (lipophilic)

Question 5

why a decreased effect of LA if injected into an inflamed tissue?

Answer 5

LA is weak bases and inflamed tissue is acidic. So the inflamed tissues low pH will charge the drug and therefore the drug cannot cross the membrane as easily in healthy tissue

Question 6

general vs local anethetic mechanism

Answer 6

general

• CNS
• activate GABA A receptors (and glycine), blocks chlorine transfer

LA

• PNS
• basic and blocks Na+ channel; Na decreases and depolarization threshold increases

Question 7

charged or uncharged LA penetrate membranes better?

Answer 7

uncharged

Question 8

List esters and list amides

Answer 8

Esters (PABA)

• Procaine
• Tetracaine
• ethyl aminobenzoate
• benzocaine

Amides

• Lidocaine (xylocaine)
• bupivacaine
• mepivacaine
• prilocaine
• articaine (septocaine)

Question 9

more lipid soluable agents are more ____ with longer but take longer to?

Answer 9

more POTENT with longer duration of action but take longer to achieve clinical effect (bupivacaine is more lipid soluble)

Question 10

esters (such asprocaine) are metabolized into what that causes allergies?

Answer 10

PABA (para-aminobenzoic acid)

Question 11

what is the most important reason that LA is often combined with vasoconstrictors?

Answer 11

to INCREASE the duration of action of anesthesia

it also decreases blood flow, rate of systemic absorption and dose needed

Question 12

Why shouldn’t you warm injections?

Answer 12

This can deteriorate the epi and make it ineffective

Question 13

what LA is safest for pregnancy?

Answer 13

Lidocaine

Question 14

What is the only LA that causes vasoconstriction and can be used as topical?

Answer 14

cocaine is the only LA that cause vasoconstirction and can be used for topical for mucous membrane surgery

Question 15

if you see “methemoglobinemia” think?

Answer 15

benzocaine

Question 16

Lidocaine can be used as an?

Answer 16

antiarrhythmic agent

Question 17

cross allergies occurs in amides or esters?

Answer 17

ESTERS! (if you’re allergic to one ester LA you are probably allergic to the next one)

Question 18

Lidocaine should NOT be used for? why?

Answer 18

epidurals bc of transient neurological symptoms

Question 19

preservative allergies

Answer 19

methylparaben and metabisulfite (used in epi LA)

Question 20

If a patient has a sulfa allergy to preservatives, use?

Answer 20

mepivacaine 3% and prilocaine 4%

Question 21

use what to treat convulsions from toxicity?

Answer 21

benzodiazepinesie diazepam (Valium)

Question 22

what is OraVerse?

Answer 22

an anesthetic reversal agent that reduces time of numbness in half (1:1 ratio to epi)

Question 23

Hanaoka Seishu

Answer 23

first surgeon to use general anesthesia using Tsusensan

Question 24

Horace Wells

Answer 24

first dentist to use nitrous oxide for tooth extraction

Question 25

Oliver Holmes

Answer 25

drug induced reversible state of unconscious for surgery that patient doesn't feel

Question 26

Two types od general anesthetics?

Answer 26

1) complete (halothane, isoflurane, edsflurane)-can reach any stage 2) incomplete (nitrous oxide)- can reach stage 1

Question 27

describe stages of general?

Answer 27

1) induction - end marked by loss of consciousness - dental procedures 2) excitement - want to be super fast 3) surgical anesthesia - opoid used for pain control 4) asystole happens here... bad stage! recovery - opposite of induction emergence - regain consciousness

Question 28

5 primary effects of general?

Answer 28

``` 1 unconsciousness 2 amnesia (memory loss) 3 analgesia (no pain) 4 inhibition of autonomic reflexes 5 skeletal muscle relaxation ```

Question 29

most general are delivered via?

Answer 29

inhalation and IV injection

Question 30

T or F... no general achieve all 5 effects?

Answer 30

True. Combo of drugs is used

Question 31

two drugs for anterograde amnesia?

Answer 31

1) midaszolam- IV | 2) diazepam- IV or PO

Question 32

both H1 and H2 antagonist antihistamines are used to treat and prevent

Answer 32

allergic reactions (mainly H1)

Question 33

Name volatile and gasous general anesthetics?

Answer 33

volatile - halothane (Fluothane) - not used anymore, hepatitis - isoflurane (Forane) - - sevoflurane (Ultane) - most commonly used in hospital gaseous is nitrous oxide

Question 34

MAC (minimum alveolar concentration)

Answer 34

same as ED50 the LOWER the potency, the higher the # ** alveolar concentration of a gas necessary to prevent a skeletal muscle response to a standard surgical stimulus in 50% of subjects

Question 35

Ostwald Coeffecient Give example

Answer 35

describes the solubility of inhaled general in the blood (ratio IN blood to conc in GAS in contact with blood) * the more soluble to blood instead of air, the more it binds to plasma and the higher the conc. * * so large # means longer induction and recovery Ex: low solubility (nitrous oxide) = quick induction, less soluble in blood so gas gets to brain quicker --- high solubility takes awhile to get to brain bc it goes to all tissues

Question 36

List 5 general gaseous analthetics and major characteristic

Answer 36

``` 1) desflurane (supane) irritates airway 2) halothane (fluothane) most potent (smaller MAC=more potent) 3) isoflurane (forane) irritates airway 4) sevoflurance (ultane) widely used in adults and kids, best for lung disease 5) nitrous oxide least potent ```

Question 37

What is unique about Enflurane (Ethrane) in general?

Answer 37

does NOT cause liver probs such as a decrease in portal vein flow

Question 38

if you see malignant hyperthermia think?

Answer 38

dantrolene (dantrium) - heritable genetic disorder of skeletal muscle

Question 39

list intravenous general anesthetics

Answer 39

1) ketamine (Ketalar) - dissociative 2) Methohexital sodium (Brevital) - barbiturates 3) naloxone (Narcane) - drug antagonist 4) Propofol (Diprivan) - no analgesic effect - induction and maintenance of anesthesia - most pronounced decrease in BP 5) Midazolam (Versed) - used most for dental, work thru GABA 6) Flumazenil (Romazicon) - inhibits GABA - only benzodiazeprine reversal agent

Question 40

ketamine (Ketalar)

Answer 40

intravenous general anesthetic - blocks action of excitatory nuerotransmitter, produced state of dissociative anesthesia, children, no skeletal muscle relaxant required - side effects: increases lecrimation and salivation and causes hallucinations in adults

Question 41

Flumazenil (Romazicon)

Answer 41

- inhibits GABA | - only benzodiazeprine reversal agent

Question 42

Propofol (Diprivan)

Answer 42

NO ANALGESIC EFFECT (IV general) most frequently used drug for induction and maintenance of anesthesia --has replaced barbiturates * most pronounced decrease in BP