Anesthesia

Question 1

What are some of the forms of anesthesia that used be used?

Answer 1

nitrous oxide
chloroform
ether (ether dome)

Question 2

What are the 3 objectives to general anesthesia? Are these satisfied by one or multiple drugs?

Answer 2

hypnosis, analgesia and paralysis

multiple

Question 3

What is conscious sedation? how is it usually accomplished? give an example.

Answer 3

hypnosis with an intact airway
ultra-short acting IV BDZs
Dental surgery or colonoscopy

Question 4

What is given pre-procedure? What should not be given?

Answer 4

anxiolysis - BDZ

hold any NSAIDS, anticoags

Question 5

What is managed in pre-op?

Answer 5

the patients physical and psych state, concurrent illnesses, drug therapy, IV access.

Question 6

What 3 kinds of meds are given in pre-op?

Answer 6

induction agents
meds to decrease aspiration risk - PPI, H2RAs, prokinetics
Drying agents - anticholinergics

Question 7

What meds are given for induction?

Answer 7

Opioid (fentanyl), then propofol

Question 8

If intubation is required, what else do you have to administer?

Answer 8

neuromuscular blocker for paralysis

Question 9

How do you maintain hypnosis?

Answer 9

volatile gas + O2, additional bolus doses of opioids and/or NMBs PRN
Total propofol anesthesia + fentanyl or remifentanyl

Question 10

What do you give the patient post-op?

Answer 10

Reverse paralysis - stigmine or Bridion

pain relief

Question 11

Where do the anesthetic agents generally act within the CNS?

Answer 11

RAS - midbrain

Question 12

What is MAC and how is it used?

Answer 12

Minimum alveolar concentration required to prevent movement in response to a standard surgical incision in 50% of test subjects
Lower the MAC, the more potent the anesthetic agent

Question 13

What 2 characteristics should volatile gases have?

Answer 13

non-irritating and non-flammable

Question 14

What is the potential risk of using volatile gases?

Answer 14

Malignant hyperthermia - life-threatening sudden release of Ca&raquo_space; muscle contractions, rhabdo, hypermetabolic state, hyperkalemia

Question 15

How do you manage MH?

Answer 15

Dantrolene + Insulin/D5W (insulin reverses hyperkalemia)

Question 16

How does dantrolene work to treat MH?

Answer 16

Direct acting skeletal muscle relaxer by blocking Ca

Question 17

Nitrous Oxide has what 3 qualities?

Answer 17

Sweet-ish smell, non-flammable, non-explosive

Question 18

T or F. Nitrous oxide produces deep anesthesia.

Answer 18

F - light

Question 19

What is used for rapid induction and recovery (~4 mins) but still has strong analgesic properties?

Answer 19

Nitrous oxide

Question 20

T or F. Nitrous oxide is cheap and rarely requires use of a second gas for general anesthesia.

Answer 20

F - $$$, used in conjunction with other gases, such as O2 (50-50)

Question 21

More than 4h of continuous exposure of nitrous oxide may lead to what?

Answer 21

megaloblastic changes to the bone marrow - anemia

Question 22

What is the most potent gas? least potent?

Answer 22

Halothone (MAC 0.74)

Desflurane (MAC 6)

Question 23

What IV med is most commonly used in induction AND general anesthesia? Brand name?

Answer 23

Propofol (Diprivan)

Question 24

What other indication does Propofol have?

What does it look like?

Answer 24

ICU agitation management

Milky - oil and water emulsion

Question 25

What is the advantage of Propofol over thiopental?

Answer 25

It doesn’t accumulate like thiopental did

Question 26

Describe the induction/recovery of general anesthesis when using propofol.

Answer 26

pleasant, within 30 seconds

rapid with little NV

Question 27

What vital sign should be monitored when using propofol?

Answer 27

BP - it causes reduced vascular tone - hypoTN

Question 28

What are 3 cons for using propofol (other than hypoTN).

Answer 28

$$$
Emulsion uses soy/eggs - allergy risk
CALORIES! 1 cal/mL

Question 29

What are the 3 drug classes that can affect anesthesia?

Answer 29

aminoglycosides - potentiate NMB
Anti-HTN - hypotension
K wasting Diuretics - hypokalemia may potentiate As

Question 30

What is the earliest local anesthetic used?

Answer 30

cocaine

Question 31

Name the ideal properties for local As.

Answer 31

water soluble
Sterilized by heat
rapid on/off
non-toxic on systemic absorption

Question 32

How do local As work?

Answer 32

they block transmission of nerve impulses

Question 33

How long do most local As take to work? duration? how can you prolong their duration?

Answer 33

5 mins
1-1.5 h
add vasoconstrictor - Epi

Question 34

Why don’t you use NE to prolong duration of local As?

Answer 34

it is too potent!
NE does not bind B2 (vasodilator), so it excites alpha 1 alone (vasoconstrictor)
Epi binds and excites both - less constriction

Question 35

What body parts should not receive local Epi?

Answer 35

fingers, nose, penis, toes

Question 36

Most every LA has _______ effects on the myocardium.

Answer 36

quinidine-like - arrhythmias `

Question 37

T or F. Topical agents can undergo significant systemic absorption.

Answer 37

T

Question 38

Name a topical LA that is used in derm and peds.

Answer 38

EMLA - eutectic mixture of prilocaine and lidocaine

Question 39

T or F. LA cannot be used for nerve blocks because they aren’t potent enough.

Answer 39

F

Question 40

Regional blockade almost always requires use of a _____ solution. Why does this matter?

Answer 40

Preservative free

most allergies are to the preservatives

Question 41

What is the preferred agent for local anesthesia?

Answer 41

lidocaine

Question 42

What is less toxic than lidocaine? Con?

Answer 42

Prilocaine - no longer comes as PF

Question 43

What is the long acting LA?

Answer 43

Bupivacaine (3h) slow on/off

Question 44

What is commonly used for regional blockade, such as epidurals?

Answer 44

Bupivacaine