Chapter 2 Flashcards
Addition of ____ made modern inhaled anesthetics differ from the previous ones
changing the physical properties of anesthetic compounds.
Fluorine
Isofluorine contains what in its formula?
Chlorine on alpha ethyl group
To change Isofluroine to desflurane, requires the substitution of what element?
substitute chlorine for a fluorine
What does the change of adding fluorine to desfluorine do to its physical properties?
increases vapor pressure
Makes it more resistant to degradation –> more stable and less toxic
decrease solubility
decrease potency ( increase MAC)
_____of fluorinated anesthetics is greater than the presence of absorbance
Stability
What does this show?
Desflurane is more stable/ less degradable than Isoflurane
Sevoflurane is only halogenated with fluorine and is degraded by soda lime at higher temperatures to higher extend.
Degradation of Soda Lime is caused by
Monovalent bases (NaOH, KOH) and Divalent bases
Which monovalent bases do most od the degradation?
NaOH and KOH
What is AMSORB ?
new absorbent that does not contain any Na/KOH.
Does not degrade the anesthetics.
Costly
Absorbent capacity (CO2) is half of that of regular soda lime.
Degradation product of mainly Isoflurane, desflurane and enflurane is__________
CO - carbon monoxide
Why is it important that Soda Lime is 15% water by weight?
Important b/c:
1. Can accelerate rxn with CO2.
2. Protects against degradation of inhaled anesthetics.
Only when the absorbent is dry by ______, you get CO production.
90 percent or more
What are the causes of dry absorbent?
leave O2 flow on for extended periods of time AND remove the reservoir bag→production of CO
Compound A is
a vinyl ether
Compound A causes
Kidney toxicity
Old School: Per Package of Label of Sevoflurane
Does this still hold true?
Back then:
Don’t use Sevo at less than 1 L/min and if you use it, then only for 2 MAC hours and after that you have to increase Sevo for up to 2L/min.
o ↓flow rate will cause increased temp in the absorbent→ ↑production of compound A.
BUT ALL FALSE NOW
How can we ensure the absorbent won’t get dry to avoid the issue w/ CO?
Check canister on a regular basis - can’t really tell
Condensation is misleading
Color change?
Making sure high flow is not going through the system when it is unused.
When drying of of the absorbent occurs, what should one do?
Add water ( to the bottom) or replace the absorber!
Which anesthetic can spontaneously degrade
Sevofluraneo
It is no longer an issue, as components of the bottle changed!
T:F UV light can cause degradation of any anesthetic
True
Can inhaled anesthetics hurt environment
Yes
For every one of chlorine atom that is released, it goes to destruct the ozone layer.
o Isoflurane is the ONLY chlorinated anesthetic
N20 and abortions
- Occupational exposure: N2O could possibly cause abortions but the amounts are negligible thanks to the scavenging system.
o Also due to high air turnover in the room: 10-15 turnovers per hour
Dental offices and office based anesthesia have a higher chance
- N2O given at high concentrations for prolonged periods of time (for tetanus pts)
Can cause what?
decrease the pain and spasms of muscles can cause aplastic anemia and death.
Who are at higher risk of injury for prolonged periods of NO2 at high concentrations?
Patients with Vitamin B12 deficiency (pernicious anemia, real vegetarians) are at higher risk of injury from N2O.
Why don’t we use absorbents that do not have Na/K OH in them?
Money and less capacity.
T: F
Addition of H2O to Sevoflurane does not alter its potency
T
