Nitrous/Sevoflurane

Question 1

What is the MAC value of Nitrous?

Answer 1

104%

Question 2

What is the metabolism rate of Nitrous?

Answer 2

0.004%

Question 3

In a Nitrous tank when the pressure begins to decrease, about how much is remaining in the cylinder?

Answer 3

~400 L

Question 4

What is the BGPC of Nitrous?

Answer 4

0.46

Question 5

What property does Nitrous have that no other VA shares with it?

Answer 5

prominent analgesic effects—>10% nitrous = 7.5 mg morphine

Question 6

Can Nitrous cause skeletal muscle relaxation?

Answer 6

No actually can cause rigidity

Question 7

What is the mechanism of action related to the analgesic effects of Nitrous?

Answer 7

N2O produces analgesia via opioid like neurons in the periaqueductal gray matter of the brain stem. These neurons project to the dorsal horn of the spinal cord where they act through alpa-2B adrenergic receptors inhibiting nociception

Nitrous provides analgesia by inhibition of the dorsal horn nociceptive neurons

Question 8

Nitrous may increase motor activity with ___ and ___.

Answer 8

clonus and opisthotonus

Question 9

Substitution of nitrous for a portion of VA ___ the magnitude of BP decrease produced by the same MAC {} of the VA alone.

Answer 9

decreases

Question 10

Is PHT contraindicated for N2O administration?

Answer 10

yes due to increased CVP secondary to increased PVR

Question 11

Which type of shunt patient should not receive N2O?

Answer 11

those with Right to Left shunts

Question 12

Nitrous do’s:

Answer 12

hastens inhalation induction-second gas effect
lower VA MACS
deeper levels of anesthesia
Hasten emergence with Iso/Sevo
Analgesia

Question 13

Nitrous don’ts:

Answer 13

laparoscopic cases
bowel cases
cases with potential for air emboli
PONV patients
Vitamin B12/folate metabolism deficiencies
Pneumothorax
abuse
Muscle relaxation
potential for hypoxia
free flaps
hasten Desflurane emergence
PHT
R to L shunts

Question 14

What is the BGPC of Sevoflurane?

Answer 14

0.69

Question 15

What agent is in Sevo making it nonflammable?

Answer 15

Fluorines—>they replace the hydrogens

Question 16

What is the MAC value of Sevo?

Answer 16

2.1%(or 1.8% in some text)

Question 17

What is the MAC BAR of Sevo(blocked autonomic reflex)?

Answer 17

1.5 x MAC

Question 18

On how much MAC Sevo can you intubate?

Answer 18

2 x MAC

Question 19

Hyperthermia reduce or increase the amount of VA needed?

Answer 19

reduce

Question 20

Patients with lower cardiac outputs will take longer or be faster to put to sleep?

Answer 20

Lower CO faster to sleep

Question 21

What percentage of the body mass is the VRG?

Answer 21

10%

Question 22

What percent of the body’s CO goes to the VRG?

Answer 22

75%

Question 23

At what percentage does the cerebral metabolic oxygen requirements begin to decrease on Sevo?

Answer 23

0.4 MAC

Question 24

At what level does EEG activity cease while on sevo?

Answer 24

2 MAC

Question 25

At what MAC does Sevo cause EEG burst suppression?

Answer 25

1.5 MAC

Question 26

At what MAC does Sevo cause increased blood flow to the brain—>increased ICP?

Answer 26

0.6 MAC

Question 27

Sevo circulatory effect will disappear in about ___ hours?

Answer 27

5 hrs

Question 28

Sevo neuro alterations will disappear in about ___ hours

Answer 28

4 hrs

Question 29

In contrast to Iso and Des, neurocirculatory responses do not accompay…..?

Answer 29

abrupt increases in Sevo concentrations. Sevo is smoother

Question 30

Can Sevo cause Halothane hepatitis?

Answer 30

Sevo cannot form trifluoracetylated protein antibodies resulting in immune mediated hepatotoxicity. The chemical structure of sevo does not allow metabolism to an acetyl halide

Question 31

Should Sevo be avoided in patients with ESRD?

Answer 31

yes

Question 32

What % Sevo is metabolized?

Answer 32

5%

Question 33

Compound A can be caused from ?

Answer 33

HGF
LGF
closed circuits
Metabolism rates
Higher temps

mostly LGF and minimal flow anesthesia

Question 34

Is Sevo a triggering agent for MH?

Answer 34

yes