Neuro: Inhalation Anesthetics

Question 1

Define MAC

Answer 1

MEDIAN ALVEOLAR CONCENTRATION:

• standard reference for inhaled anesthetics
• end-tidal concentration of inhaled anesthetics to eliminate movement in 50% of PTs
• ***median effective dose (ED50) of the anesthetic drug

Question 2

Nitrous Oxide

Answer 2

“laughing gas”

• used in combo with oxygen
• does not depress respiration
• maintains CV hemodynamics and muscular strength
• Can be used with inhalation agentf fg

Question 3

Malignant Hyperthermia

• exposure to waht causes this
• comon/uncommon?

Answer 3

uncommon–in small percent of PTs

• hapens when PT exposed to halogenated hydrocarbon anesthetics
• rare life threatening condition
• rxn only to the inhaled

Question 4

TX for malignant Hyperthermia?

Answer 4

Dantrolene–muscle relaxant

Question 5

IV anesthetics

-when to use

Answer 5

• when CO is reduced, body compensaties by diverting more cardiac output
• basically give a decreased dose of anesthetic when CO reduced

Question 6

What is the first choice for induction of general anesthesia and sedation

Answer 6

Propofol

Question 7

Propofol

• what is it
• onset of action
• half life
• what does it provide and not provide
• what can sometimes occur with it
• post-op complications?
• cleared?
• rely on tissue detistribution?
• excreted?

Answer 7

• IV sedative/hypnotic
• smooth induction–30-40 seconds
• T1/2: 2-4 minutes
• does NOT provide analgesia ** supplement this with some narcotics
• occasionally contributes to EXCITATORY PHENOM–muscle twitching, yawning, hiccups
• post-op complications of N/V is low
• not rely on tissue redistribution for recovery
• cleared: LIVER —not rely on tissue redistribution
• excreted KIDNEYS

Question 8

Benzodiazepines

• long medium or short acting?
• routes of admin
• induces what properties?
• what does it not produce
• what is it given with?
• anatgonist??

Answer 8

MIDAZOLAM: MC used 
-short acting CNS depressant 
-IV or rectal routes 
-Does not produce analgeisa 
-induces ***AMENSIA**** and sedation 
-given with neurmuscular blocking agents 
FLUMAZENIL---recepetor antagonist

Question 9

Which benzo is the MC used for induction of anesthesia

Answer 9

Midazolam—-Versed

Question 10

Opioids

Answer 10

-IND: analgeisa

MC one is fentanyl—if an analgesic is needed for GA

Question 11

what is standard reference for inhaled anesthetics

Answer 11

MAC

Medium Minimal Alveolar Concentration

Question 12

When is MAC less?

Answer 12

when intravenous anesthetics enhance inhibitory receptors and antagonize excitatory receptors

Question 13

POTENCY of the drug=

Answer 13

smallest alveolar concentration of drug that keeps the PT immobile

Question 14

MAC=

Answer 14

ED50

Question 15

MAC wil be small for what kind of anesthetics

Answer 15

potent ones

*and MAC»»for less potent

Question 16

The more lipid soluble an anesthetic….?

Answer 16

the lower the concentration needed to produce anesthesia

HIGHER THE POTENCY

Question 17

the higher the MAC means?

Answer 17

the PT is more resistant to the effects of the durg

Question 18

factors that raise MAC

Answer 18

hyperthermia
drugs that increase CNS catecholamines
chronic ETOH

Question 19

the lower the MAC means?

Answer 19

the PT is more sensitive to drug

Question 20

factors that lower MAC?

Answer 20

hypothermia 
age 
pregnancy 
sepsis 
acute intoxication 
concurrent IV anesthetics 
alpha 2 recp agonists

Question 21

what hapens to body during MH?

Answer 21

uncontrolled increase in skel muscle oxidative metabolism–>overhwlems body;s oxygen supply/removal of co2–>cannot regulate temp—–leads to circulatory collapse and death it not tx

Question 22

Dantrolene

Answer 22

muscle relaxant to tx MH

**blocks CA

Question 23

Susceptible PTs to developing MH

Answer 23

burn victs 
muscular dystrophy 
myopathy 
myotonia 
osteogenesis 
can be inherited as autosomal dominant disordr

Question 24

SE of opioids

Answer 24

Sedation 
Euphoria 
Dysphoria----depression anxiety unease 
Miosis 
constipation
urinary retention 
N/V
Mood changes 
incease pressure on gall bladder
RESP DEPRESSION*
*do not depress cardiovascular system 
but can cause: 
BRADY AND HYPOT

Question 25

``` Ketamine -___acting MOA drug class produces?? does not produce? recovery pd s/s? ``` Good for wht PTs?

Answer 25

short acting DISSOCIATE anesthetic produces good analgesia**** does not produce skel muscle relaxation MOA: -inhibits excitatory pathway via NMDA receptor, stimulates SNS (w/ incr BP and CO), BRONCHODILATOR (good for asthmatics) recovery PD can have vivid dreams and hallucinations

Question 26

MOA for local anesthetics | low vs high doses

Answer 26

LOW DOSES: -blocks nerve conduction of sensory impulses---reduces response to pain HIGHER DOSES: -blocks motor impulses from periphery to CNS---impairs motor nerve function VASODILATOR **

Question 27

what happens when you add Epinephrine to local anesthetic?

Answer 27

reduces the rate of the local anesthetic absorption and diffusion - -minimizes toxicity and increase DOA of anesthetic*** - --EPI IS A VASOCONTRICTOR!!

Question 28

List the ESTER local anesthetics

Answer 28

``` Benzocarine Procraine Chloroprocaine Tetracaine Cocaine ```

Question 29

AMIDE local anesthetics

Answer 29

``` Lidocaine Bupivacaine Prilocaine Ropivacaine Mepivacaine ```

Question 30

How to remeber estehr vs amide local anesthetics

Answer 30

ESTER----one "i" in each AMIDE---two "i" in each

Question 31

Amide or Ester has longer DOA

Answer 31

Amide

Question 32

Amide or Ester metabolized by LIver? Enzymes in skin/blood?

Answer 32

met by liver=amides enzymes in skin/blood=esters

Question 33

Onst of action is fast for ____anestetics and ____ for the other

Answer 33

FAST onset for AMIDES | SLOW onset for ESTER