inhalational agents - individual agents Flashcards
Halothane
- blood:gas
- MAC
- MAC-awake
- MW
- Vapor pressure @ 20 C
Halothane
2-bromo-2-chloro-1,1,1-trifluroethane
- blood:gas - 2.4
- MAC - 0.76%
- MAC-awake - 55% of MAC
- MW - 197.4
- Vapor pressure @ 20 C - 244 torr
Halothane: _____, ______ odor
sweet, nonpungent
Halothane: stable in ____ ____, but decomposes _____ products and most ______
soda lime
rubber
metals
Halothane: requires storage in _____ _____ and preservative ______, to prevent spontaneous oxidative decomposition
dark bottle
thymol
Halothane: breaks down to (5)
- hydrochloric acid
- hydrobromic acid
- chloride
- bromide
- phosgene
Halothane cardiac: dose-dependent myocardial _____ ______ causes decreased _____ and decreased _____
contractility depression
CO
BP
Halothane cardiac: 2 MAC causes
50% reduction in BP, CO
Halothane cardiac: slows conduction through the AV node to cause _______ _______, _____ _____, and _______
junctional rhythms, wandering pacemaker, and bradycardia
Halothane cardiac: inhibits ______ _____
baroreceptor reflex
Halothane cardiac: sensitizes myocardium to ______
catecholamines
with halothane: adults epi max dose _____, and when ______ is added it doubles dose of epi allowed
1.5 mcg/kg subq
0.5% lidocaine
with halothane: children epi doses
more tolerant - 7.8-10 mcg/kg with and without lido
Halothane: hypercarbia enhances
sensitization
Halothane sensitization of heart thought to be due to effect on the _____ _____ of cardiac impulses through the _______ system
transmission rate
conduction
Halothane resp: excellent _______ - reverses asthma induced _______
bronchodilator
bronchospasms
Halothane resp - may be the best ______ of currently used inhaled agents
bronchodilator
but is likely there is no clinical significant difference between agents
Halothane resp: works by inhibiting _____ _____ mobilization - bronchial smooth muscle
intracellular calcium
Halothane resp: ________ inhalation induction
nonpungent
Halothane CNS: direct cerebral _______, decreases ______
vasodilation
CMRO2
Halothane CNS: cerebral autoregulation is _____
attenuated (DESTROYED)
Halothane CNS: must _______ ______ to initiation of halothane
hyperventilate PRIOR
Halothane CNS: at 1.1 MAC and MAP of 80, halothane increases CBF by _____
190% (more than iso)
Halothane: MH ____ ____ trigger
most potent
Halothane metabolism: ___-____ metabolized
15-40%
Halothane hepatitis: ___ ____ mechanism
no clear
Halothane hepatitis: likely an _______ that binds to hepatocytes previously exposed to halothane, has been isolated from _____ of patients with halothane-induced _____ _____
antibody
70%
hepatic dysfunction
Halothane hepatitis: this antibody response may involve microsomal proteins that have been modified by ______ _____ as the triggering antigens
trifluoroacetic acid
Halothane hepatitis: incidence is __ in _____ fatal, hepatic ____ (1 in 10,000 ____)
1 in 35,000
necrosis
jaundice
Halothane hepatitis: hepatitis due to other inhaled agents ___ in ____ _____
1 in 1 million
Halothane hepatitis: incidence is higher if halothane exposure _____ within ____ ____
repeats within 28 days
Halothane hepatitis: risk factors (5)
- sepsis
- obesity
- age > 40 yrs
- female
- enhanced metabolism/induced enzymes
Halothane hepatitis: rarely reported with _______ _______ even with pre-existing liver disease
pre-pubescent children
Halothane hepatitis: similar hepatitis can be induced with other volatiles but ______
rarely
Halothane hematology: like sevo, halothane may cause a _____ in _____ ____ and increases _____ time
decrease in platelets
increases bleeding time
Halothane immune: unlike the other three potent agents, halothane depresses the defense against _____, the _____ _____ response of ______
infection
oxidative burst response of neutrophils
Isoflurane
- chemical name
- blood:gas
- MAC
- MAC-awake
- MW
- Vapor pressure @ 20 C
Isoflurane
- chemical name - 1-chloro-2,2,2-trifuoroethyl-difluoromethyl ether
- blood:gas - 1.4
- MAC - 1.17%
- MAC-awake - 38% of MAC
- MW - 184
- Vapor pressure @ 20 C - 240 torr
Isoflurane: ______, _____-type smell
pungent, ether
Isoflurane: isomer of ______
enflurane
Isoflurane: stable, ________
nonflammable
Isoflurane: no ________ necessary
preservative
Isoflurane cardiac: minimal _____ ______; decreased oxygen demand more in ______ than _____ _____
myocardial depression
heart
other organs
Isoflurane cardiac: cardiac output preserved by increased _____ related to _______
HR
baroreceptors
Isoflurane cardiac: _____ decreases but _____ remains nearly constant due to compensation
SV
CO
Isoflurane cardiac: rapid increase in concentration causes increases in ____, _____, and _______
HR, BP, and norepinephrine
Isoflurane cardiac: different from other agents due to ____ _____-_____ _____ properties
mild beta-adregnergic agonist
Isoflurane cardiac: decreases coronary vascular _______ with coronary blood flow ______ or _______
resistance
increased
unchanged
Isoflurane cardiac: unlike nitroglycerin, isoflurane dilates small ______ ______ ______ within the heart muscle
endocardial coronary arteries
Isoflurane cardiac: coronary artery steal - the studies suggest that with the steal, the _____ fell significantly; other studies suggest that steal doesnt occur
MAP
Isoflurane cardiac: ____ is decreased based on dose; this is mainly due to _____ reduction
BP
SVR
Isoflurane: carotid sinus baroreceptor reflex is maintained at _______ but depressed at ______
1 MAC
2 MAC
Iso - studies differ - abolish at 1.25 MAC v. some response at 1.5 MAC
Isoflurane: Accessory pathway conduction - increases the ________ of accessory pathways and the _____ _______ system
refractoriness
AV conduction
Isoflurane: accessory pathway conduction - interferes with interpretation of confirming success of _____ _____
ablation procedures (suppression of SVT re-entry tachycardia)
Isoflurane ablations: prolong action-potential duration, delay _____ and _____ ________, decrease ________ inducibility
atrial and vent repolarization
tachyarrythmia
Isoflurane ablations: enhance automaticity of secondary _____ ______ causing ectopic atrial rhythms
atrial pacemakers
Isoflurane: ____ prolongation in healthy patients, may not be seen in pts with idiopathic long _____
QT
QTc
Isoflurane resp: causes greater resp depression than ______
halothane
Isoflurane resp: tachypnea is ____ ____ resulting in enhanced reduction in _____ _____
less pronounced
minute ventilation
Isoflurane resp: _____ and _____ to some airways; however, overall good ______
pungent and irritating
bronchodilator
not as good as halothane
Isoflurane CNS: at concentrations greater than 1 MAC, iso increases _____ and _____
CBF
ICP
Isoflurane CNS: ________ that accompanies the introduction of iso can minimize the effect on ______
hyperventilation
ICP
Isoflurane CNS: when iso is used for deliberate hypotension, it ______ _____ _____ ______
decreases cerebral oxygen demand
Isoflurane CNS: at 2 MAC, iso results in an _______ ______; this provides _____ protection during episodes of ______ ischemia
isoelectric EEG
brain
cerebral
Isoflurane hepatic: hepatic oxygenation is better maintained because……
hepatic artery perfusion and hepatic venous oxygen saturation are preserved
Isoflurane hepatic: iso is metabolized to ______ ions, _____, and _____ acid, but there are no real concerns for ______ ______ levels
fluoride
TFA
formic
inorganic fluoride levels
Isoflurane hepatic: ICU pt on iso for 30 MAC hours had a max inorganic fluoride level of ______ and _____ ______ of renal failure
37 mcgmol/L
no evidence
Isoflurane hepatic: metabolized ___
0.2%
Desflurane
- chemical name
- blood:gas
- MAC
- MAC-awake
- MW
- Vapor pressure @ 20 C
Desflurane
- chemical name - difluromethyl 1-fluoro 2,2,2-trifluroethyl ether
- blood:gas - 0.42
- MAC - 6.6%
- MAC-awake - 34% of MAC
- MW - 168
- Vapor pressure @ 20 C - 669 torr
- boiling point - 22.8 degrees C
Desflurane: differs from iso only in the substitution of a ______ atom for a _____ atom on the alpha ethyl carbon
fluorine
chlorine
Desflurane: ____ boiling point and _____ vapor pressure require _____-controlled vaporizer
low
high
temperature
Desflurane: stable in _____ absorbant
moist
Desflurane: requires no _______
preservatives
Desflurane: odor
pungent (the worst!)
Desflurane: bc Des is less potent, there are ranges of MAC values in different age groups -
- 0.6-0.7 years
- 25 years
- 36-49 years
- 65 years
- 0.6-0.7 years - 9.96%
- 25 years - 7.25%
- 36-49 years - 6.0%
- 65 years - 5.17%
Desflurane: blood gas solubility (0.42) very similar to ____ (___)
N2O (0.46)