Inhaled Anethetics

Question 1

Why chloroform bad/good

Answer 1

Bad: hepatotoxic, cv depressant, deaths assoc, hard to admin
Good: good odor, nonflammable

Question 2

First halogenated hydrocarbon anesthetic, why taken off market

Answer 2

Fluroxene. Organ tox

Question 3

Methoxyflurane: pro and con

Answer 3

Pro: potent, mac 0.16, soluble
Bad: vasopressin resistant high output renal failure

Question 4

Guedel stages of anesthesia

Answer 4

1- amnesia/analgesia
2- delirium/excitement
3- surgical anes 4 planes
4- OD

Question 5

N20
Mac
Blood gas partition coefficient

Answer 5

105%. 0.47

Question 6

Balanced technique=

Answer 6

N20 + induction agent + muscle relaxant + opioids +/- volatile agent

Question 7

N20
Effective ___
70% n20 + 02 ___ mac for halothane, Enflurane, ISO, sevo, and des

Answer 7

Analgesic

Reduces

Question 8

Contraindications to N2O

Answer 8

Air embolism, ptx, intestinal obstruction (acute), intracranial air, pulm air cysts, intraocular air bubbles, tympanic membrane grafting. Others: 1st tri preg, b12 def, CAD

Question 9

Drug consid w N2O

Answer 9

Can’t use alone (high MAC), decreases MAC reqs of other agents, potentiates NMB

Question 10

Halothane
VP
B/G
MAC %

Answer 10

VP 243
B/G 2.3
MAC .74

Question 11

Enflurane
VP
B/G
MAC

Answer 11

VP 175
B/G 1.8
MAC 1.68

Question 12

Isoflurane
VP
B-G
MAC

Answer 12

VP 239
B-G 1.4
MAC 1.15

Question 13

Des
VP
B-G
MAC

Answer 13

VP 664
B-G 0.69
MAC 6

Question 14

Sevo
VP
B-G
MAC

Answer 14

VP 157
B-G 0.69
MAC 2.05

Question 15

N20
VP
B-G
MAC

Answer 15

38, 770
0.47
104

Question 16

Factors that dont affect MAC 6

Answer 16

Variable stimuli, species, gender, duration of anesthesia, acid-base disturbances, Pa02 (40-500 torr)

Question 17

Factors that decrease MAC

Answer 17

Inc age, hypothermia, low Na, BP <40, pregnancy, 02 <38, anemia 4.3, opioids, ketamine, benzos, clonidine, A2 agonists, LAs, ETOH acute

Question 18

Factors that increase MAC

Answer 18

Hyperthermia, CNS stimulants, under 1 year old

Question 19

___% move at 1 MAC

Give what to avoid movement when no muscle relaxant given

Answer 19

50%

Give 10-30% above 1 mac (1.3)

Question 20

MAC awake

Concentrations you have to give of anesthetics

Answer 20

1/3: des, sevo, iso
1/2: halothane
60%: n20

Question 21

Which inhaled agent decreases BP the least

Answer 21

N20- no change

Sevo- mild decrease

Question 22

Which inhaled agents increase HR

Answer 22

Methoxyflurane, enflurane, isoflurane, Des (or no change)

Question 23

Which inhaled agents decrease or dont affect hr

Answer 23

N20 (n/c), halothane decreases, sevo (inc or n/c), sevo (n/c)

Question 24

Which agents drastically decrease SVR

Answer 24

Isoflurane, desflurane

Question 25

Which agents mildly decrease SVR

Answer 25

Enflurane, sevoflurane

Question 26

Which agents decrease CO

Answer 26

Halothane, methoxyflurane, isoflurane (the most), des (or n/c), sevoflurane

Question 27

Which agents decrease TV a lot

Answer 27

Halothane, methoxyflurane, enflurane, isoflurane

Question 28

Which agents decrease TV a little

Answer 28

N2O, desflurane, sevoflurane

Question 29

Which agents inc RR a lot

Answer 29

Halothane, methoxyflurane, enflurane

Question 30

Which agents inc rr a little

Answer 30

N20, isoflurane, desflurane, sevoflurane

Question 31

Which agents inc paco2 the most

Answer 31

Enflurane and desflurane

Question 32

Which agent inc cerebral bf the most

Answer 32

Halothane

Question 33

Which agents inc ICP the most

Answer 33

Halothane, enflurane

Question 34

Which agents dec cmro2 the most

Answer 34

Isoflurane, desflurane, sevoflurane

Question 35

Which agent inc seizures

Answer 35

Enflurane (all others decrease them)

Question 36

Which agent inc NMDR 1 on scale of 1-3

Answer 36

N20

Question 37

Which agent inc NMDR 2 on scale of 1-3

Answer 37

Halothane, methoxyflurane, sevoflurane

Question 38

Which agents inc NMDR the most

Answer 38

Enflurane, isoflurane, desflurane

Question 39

Which agents dec renal bf the least

Answer 39

Desflurane and sevoflurane

Question 40

Which agents dec hepatic bf the most

Answer 40

Halothane, methoxyflurane, enflurane

Question 41

Metab % Halothane Enflurane

Answer 41

15-20% | 2.5-3%

Question 42

Metab % Sevoflurane Isoflurane

Answer 42

2-5% | 0.2-2%

Question 43

Metab % Desflurane N20

Answer 43

0. 02% | 0. 004% (gi tract)

Question 44

When to not use halothane

Answer 44

``` CAD Arrhythmias, epi use Hepatotoxicity (esp prev halothane exposure) Hypovolemia AS Pheochromocytoma MH- most potent trigger ```

Question 45

Halothane drug interac

Answer 45

Myocardial dep w/: bb and ccb. TCAs and MAOI may cause BP instability. Aminophylline- v dysrhythmias

Question 46

When to not use enflurane

Answer 46

Seizures, renal disease, MH trigger

Question 47

Isoflurane contraindications

Answer 47

Peds (laryngospasm), CAD (coronary steal), MH

Question 48

When to not use Des

Answer 48

Not used for inhalation in peds bc of smell, neurosurgery, MH

Question 49

Sevo | When to use/not use

Answer 49

Good for peds. Fast on/off. | Not: kidney function dec, MH