Eger Video #2

Question 1

2 modern inhaled anesthetics which differ only because they have a flurane substitued for another halogen which is chlorine

Answer 1

Isoflurane and Desflurane

Question 2

Formula for isoflurane

Answer 2

Question 3

formula for desflurane

Answer 3

Question 4

The flurane substitution on desflurane does what to desflurane? (6)

What is the boiling point of Desflurane?

Answer 4

increases vapor pressure
decreases boiling point
less biodegradable, more stable
less toxic
solubility decreases
potency decreases (MAC increases)

boiling point of des is 22.5 C

Question 5

In a closed circuit anesthesia system, the temperature in the absorbant is?

Answer 5

40-60 C
It is hotter than the OR room due to the exothermic reactions between the absorbant and the carbon dioxide, creating heat

Question 6

What is more stable in soda lime, des or iso?

Answer 6

desflurane has greater stability than isoflurane –> high absorbant temperatures caused isoflurance to break down more easily than desflurane

Question 7

degradation of soda lime is caused by what component of the soda lime?

Answer 7

Monovalent bases:
NaOH and KOH

Question 8

What are the degradation products from the modern inhaled anesthetics (iso/des/sevo)?

Answer 8

carbon monoxide (mainly from des, iso and enflurane)

Comound A from Sevo is NOT TRUE

Question 9

how much moisture is in soda lime and baralyme?

Answer 9

15% water

important because it can accelerate the reaction with CO2 and protects against the degradation of the inhaled anesthetics

Question 10

T/F: With moist absorbant, desflurane and isoflurane have no production of CO

Answer 10

true

CO is produced only if the absorbant is dry by > 90%.
Drying of the absorbant is caused by leaving the flow rate on along with removal of the reservoir bag, leads to production of CO.

Question 11

Issue with compound A?

Answer 11

attack on kidneys

Question 12

what is compound A?

Answer 12

vinyl ether

highly reactive compound that reactes with proteins in the body.
Disappears in the blood because it binds to the proteins in the blood

Question 13

what is the evidence of renal injury from compound A?

Answer 13

Albuminuria, enzymuria, glucosuria
Necrosis haven’t been tested in humans but necrosis is evident in rats.

Question 14

How to prevent drying of the absorbant?

Answer 14

keep low flow rates

Question 15

How to tell if absorbant is dry?

Answer 15

condensation, which is misleading (carbon dioxide in absorbant produces water)

Question 16

how to manage dry absorbants

Answer 16

add water or replace it

Question 17

Which anesthetic can spontaneously degrade? and under what circumstance?

Answer 17

sevoflurane.
2 circumstances: The aluminum of the bottle and the dry condition predisposes sevo to degradation

Now no longer an issue due to adding water to the bottle and producing a plastic liner for the bottle.

Question 18

Can inhaled anesthetics hurt the environment?

Answer 18

yes, due to the breakdown products such as chlorine.
isoflurance has chlorine
sevo and des don’t have chlorine

Question 19

Occupational exposures that are concerning in anesthesia

Answer 19

Nitrous oxide can lead to abortions, but that’s negligable due to the low amounts in the OR.
Amounts are low in the OR due to the scavenger system and high room air turn overs.

Question 20

What are the limits in inhaled anesthetics

Answer 20

2 parts per million for potent inhaled agents
25 parts per million for nitrous oxide

Question 21

Nitrous Oxide and occupational exposure

Answer 21

Involves the inactivation of thiamine synthase, B12
prolonged use can lead to aplastic anemia and death
however we breath low concentrations in the OR and nitrous oxide isn’t given that long in patients to lead to these risks

Question 22

What group of people are at high risk for injuries from the use of nitrous oxide?

Answer 22

B 12 deficiency, pernicious anemia