inhalational agents - individual agents Flashcards by Linsley Lloyd

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

How well did you know this?

Not at all

Perfectly

Halothane: _____, ______ odor

sweet, nonpungent

How well did you know this?

Not at all

Perfectly

Halothane: stable in ____ ____, but decomposes _____ products and most ______

soda lime
rubber
metals

How well did you know this?

Not at all

Perfectly

Halothane: requires storage in _____ _____ and preservative ______, to prevent spontaneous oxidative decomposition

dark bottle
thymol

How well did you know this?

Not at all

Perfectly

Halothane: breaks down to (5)

hydrochloric acid
hydrobromic acid
chloride
bromide
phosgene

How well did you know this?

Not at all

Perfectly

Halothane cardiac: dose-dependent myocardial _____ ______ causes decreased _____ and decreased _____

contractility depression
CO
BP

How well did you know this?

Not at all

Perfectly

Halothane cardiac: 2 MAC causes

50% reduction in BP, CO

How well did you know this?

Not at all

Perfectly

Halothane cardiac: slows conduction through the AV node to cause _______ _______, _____ _____, and _______

junctional rhythms, wandering pacemaker, and bradycardia

How well did you know this?

Not at all

Perfectly

Halothane cardiac: inhibits ______ _____

baroreceptor reflex

How well did you know this?

Not at all

Perfectly

Halothane cardiac: sensitizes myocardium to ______

catecholamines

How well did you know this?

Not at all

Perfectly

with halothane: adults epi max dose _____, and when ______ is added it doubles dose of epi allowed

1.5 mcg/kg subq
0.5% lidocaine

How well did you know this?

Not at all

Perfectly

with halothane: children epi doses

more tolerant - 7.8-10 mcg/kg with and without lido

How well did you know this?

Not at all

Perfectly

Halothane: hypercarbia enhances

sensitization

How well did you know this?

Not at all

Perfectly

Halothane sensitization of heart thought to be due to effect on the _____ _____ of cardiac impulses through the _______ system

transmission rate
conduction

How well did you know this?

Not at all

Perfectly

Halothane resp: excellent _______ - reverses asthma induced _______

bronchodilator
bronchospasms

How well did you know this?

Not at all

Perfectly

Halothane resp - may be the best ______ of currently used inhaled agents

bronchodilator

but is likely there is no clinical significant difference between agents

How well did you know this?

Not at all

Perfectly

Halothane resp: works by inhibiting _____ _____ mobilization - bronchial smooth muscle

intracellular calcium

How well did you know this?

Not at all

Perfectly

Halothane resp: ________ inhalation induction

nonpungent

How well did you know this?

Not at all

Perfectly

Halothane CNS: direct cerebral _______, decreases ______

vasodilation
CMRO2

How well did you know this?

Not at all

Perfectly

Halothane CNS: cerebral autoregulation is _____

attenuated (DESTROYED)

How well did you know this?

Not at all

Perfectly

Halothane CNS: must _______ ______ to initiation of halothane

hyperventilate PRIOR

How well did you know this?

Not at all

Perfectly

Halothane CNS: at 1.1 MAC and MAP of 80, halothane increases CBF by _____

190% (more than iso)

How well did you know this?

Not at all

Perfectly

Halothane: MH ____ ____ trigger

most potent

How well did you know this?

Not at all

Perfectly

Halothane metabolism: ___-____ metabolized

15-40%

How well did you know this?

Not at all

Perfectly

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)

Desflurane: fat:gas solubility of ____ compared to _____ for isoflurane

13 70

Desflurane cardiac: RAPID increase in the concentration above ____ can cause sympathetic ______ with _______ HR and BP

6% stimulation

Desflurane cardiac: can double ___ and ___ with change from ___ to ___ in less than one minute

HR and BP 4% to 8%

Desflurane cardiac: HR and BP increase is accompanied by a significant increase in _____ _____ suggesting enhanced release from the _____ _____

plasma epinephrine adrenal gland

Desflurane cardiac: sympathetic stimulation most commonly seen in ____ _____ patients with little _____

young healthy patients opioids

Desflurane cardiac: SNS stimulation occurs both with _____ and without

N2O

Desflurane cardiac: SNS stimulation returns to normal within ______

5 mins

Desflurane cardiac: how do we limit change to HR and BP? _______ _____ PRIOR to increasing concentration

fentanyl 1.5 mcg/kg

Desflurane cardiac: how do we limit change to HR and BP? dont exceed ____ _____

6% desflurane

Desflurane cardiac: how do we limit change to HR and BP? Increase ______ to minimize change

SLOWLY (even above 6%)

Desflurane cardiac: how do we limit change to HR and BP? Drugs we can give (4)

1. alfentanil 2. sufentanil 3. clonidine 4. beta blockers

Desflurane cardiac: how do we limit change to HR and BP? _____ affects increase in HR but doesnt change BP

esmolol

Desflurane cardiac: how do we limit change to HR and BP? Lidocaine 1.5 mg/kg minimizes _____ response but not ____ response

HR BP

Desflurane cardiac: how do we limit change to HR and BP? _____ and _____ have no effect

propofol and N2O

Desflurane cardiac: ____ decreases but to a lesser extent with iso

SVR

Desflurane cardiac: decreased resistance to _____ ____ ____

coronary blood flow

Desflurane cardiac: ______ (____ ____) not seen when CAD is present

redistribution (coronary steal)

Desflurane respiratory: respiratory depression is similar to _____ up to _____

isoflurane 1.24 MAC of Des

Desflurane respiratory: profound resp depression to apnea at ___-___ ____

1.5-2 MAC

Desflurane respiratory: HPV is ______ as it is with sevo and iso

preserved

Desflurane respiratory: less effect on ____ ____ than other agents

hypoxic drive

Desflurane respiratory: 0.1 MAC of des decreased hypoxic drive response by ____ with _____

30% with hypercapnia (other volatiles 50-70% decrease)

Desflurane respiratory: causes _____ resistance with ______

increased resistance with smokers (less than 6% is less irritating, can give fent to help minimize irritation as well)

Desflurane neuromuscular: causes fade with tetanus at ____ to ____

3% to 12%

Desflurane neuromuscular: potentiated _____, ______, ______, and ____ in a dose-dependent manner

pancuronium, vecuronium, rocuronium, and succ

Desflurane neuromuscular: some studies say des has the greatest effect on ____

NMB

Desflurane CNS: EEG changes similar with ______

isoflurane

Desflurane CNS: burst suppression at ______, no _____ activity

1.24 MAC seizure

Desflurane CNS: ______ _____ at 1.5 - 2.0 MAC

isoelectric EEG

Desflurane CNS: cerebral blood flow similar with _____ during 1 and 1.5 MAC

isoflurane

Desflurane CNS: consider use during deliberate hypotension due to rapid ______ and reduction of ______ and _____

titratability CMRO2 CPP

Desflurane CNS: maintains ______ at 1 MAC

autoregulation

Desflurane metabolism: ____ metabolized at ____

least 0.02%

Desflurane metabolism: minute amount of ____ produced

TFA

Desflurane metabolism: no increase in serum ____ ____

inorganic fluoride

Desflurane metabolism: greenhouse effect (8 hr day using 1-2 L/min FGF) - Des - Sevo - Iso

- Des - 58-116 days worth of auto emission - Sevo - 4.3 days - Iso - 4.8-9.6 days

Sevoflurane - chemical name - blood:gas - MAC - MAC-awake - MW - Vapor pressure @ 20 C

- chemical name - fluoromethyl 2,2,2-trifluoro-1-(trifluoromethyl) ethyl ether - blood:gas - 0.69 - MAC - 1.8% - MAC-awake - 34% of MAC - MW - 200 - Vapor pressure @ 20 C - 170 torr

Sevoflurane: odor

nonpungent, sweet smelling

Sevoflurane: ___ solubility - blood:gas - fat:gas

low - blood:gas - 0.65 v. des 0.42 v. iso 1.4 - fat:gas - 37 v. des 13 v. iso 70

Sevoflurane: is _____ and can spontaneously degrade, must have _____ added as a preservative, bottles changed to _____

unstable water plastic

Sevoflurane: reactive with _____ to produce _____

CO2 absorbant compound A

Sevoflurane: potential for ____ with dry absorbant

fire

Sevoflurane cardiac: myocardial depression is comparable to _______ at _____ MAC concentrations

isoflurane equal

Sevoflurane cardiac: _____ decreased at 1/1.5 MAC and recovered at 2 MAC

Sevoflurane cardiac: increase ____ > 1.5 MAC

Sevoflurane cardiac: RARELY _______ but treat by ______ concentration

bradycardia

Sevoflurane cardiac: prolong ____ _____ - use with caution in pts with previously prolonged ____

QT interval QT

Sevoflurane cardiac: minimal effect on conduction of ____, ____, and _____ pathway

AV, SA, and accessory pathway

Sevoflurane cardiac: ______ suppression, prolongs _____ and _____ _____ - may affect arrhythmogenicity

autonomic QT action potential

Sevoflurane cardiac: _____ reduction is slightly less magnitude than iso

SVR

Sevoflurane cardiac: SVR reduction different mechanism than isoflurane - reduces resistance through aortic arch (arterioles at higher concentrations and abruptly), v. iso that reduces arteriolar resistance ____ and _____-_____

gradually and dose-dependently

Sevoflurane cardiac: ______ is preserved to a greater extent than with other agents

baroreflex

Sevoflurane resp: ______, stoelting says it causes the ____ ____ of airway irritation among available agents

bronchodilator least degree

Sevoflurane compared to Halothane for inhalation induction: sevo is better for 4 things -

1. slightly faster 2. less patient movement 3. quicker onset of mobility 4. fewer airway problems of course - other studies contradict

Sevoflurane: at ______ concentrations sevo causes less myocardial depression than halothane

HIGH

Sevoflurane inhalation induction: adult, healthy, unpremedicated, given vital capacity breaths of up to 7% sevoflurane (3)

1. loss of lash reflex in 1 min 2. acceptance of LMA in 1.7 mins 3. laryngoscopy, intubation in 4.7 mins

Sevoflurane HPV: ______ at clinically used concentrations

preserved

Sevoflurane neuromuscular: enhanced _____ and _____ of NMB, may prolong duration of _______ slightly longer than iso

intensity and duration rocuronium

Sevoflurane CNS: _______ preserved up to 1.5 MAC

autoregulation

Sevoflurane CNS: _____ _____ similar to that with iso

cerebral vasodilation

Sevoflurane CNS: EEG may have evidence of _____ _____ (__%)

seizure activity (7%)

Sevoflurane: _____ ______ inhibited more strongly than halothane due to suppression of ______ acid, probably due to inhibition of ______

platelet aggregation arachadonic cyclooxygenase

Sevoflurane metabolism: 5-8% of sevo is metabolized by ______ to produce _____ _____

CYP450 inorganic fluoride

Sevoflurane metabolism: levels of serum fluoride greater than 50 mcmol/L in 7% of patients; BUT....

no evidence of clinically significant renal dysfunction

Nitrous oxide - blood:gas - MAC - MAC-awake - MW - Vapor pressure @ 20 C - critical temp

- blood:gas - 0.46 - MAC - 104% - MAC-awake - 64% of MAC - MW - 44 - Vapor pressure @ 20 C - gas form - critical temp - 35.5 degrees C

Nitrous oxide: organic or inorganic?

inorganic

Nitrous oxide: ____ molecular weight

low

Nitrous oxide: odor

odorless (sweet smelling)

Nitrous oxide: ____ solubility, equilibrates _____

low rapidly

Nitrous oxide: ____ potency

low

Nitrous oxide: non______ but supports _____

nonflammable combustion

Nitrous oxide: stored in a ____-____ equilibrium @ ____ psi in blue cylinders

liquid-gas 745 psi

Nitrous oxide: stable with ____ ____

soda lime

Nitrous oxide: 4 impurities in Nitrous oxide

1. N2 2. NO 3. NO2 4. water vapor

Nitrous oxide: does not combine with _____, carried in solution in _____

Hgb blood

Nitrous oxide: hepatic enzymes are _____ by N2O

induced

Nitrous oxide: less than _____ is metabolized by ____ ____

0.004% intestinal flora

Nitrous oxide cardiac: ____ ____ on myocardial depression

direct effect

Nitrous oxide cardiac: young and healthy -

SNS stimulation and increased SVR due to increased endogenous catecholamines

Nitrous oxide cardiac - increased ____ (esp if already slightly elevated)

SVR (dont want to use with congenital heart kids)

Nitrous oxide cardiac: with pre-existing CVD, myocardial depression can be significant, ____% produces myocardial depression and adds to _____ ______

40% opioid anesthetic

Nitrous oxide respiratory: at concentrations < 50% no increase in PaCO2; it increases ____ more than other agents

Nitrous oxide respiratory: response to _____ is reduced with even small amounts of N2O

hypoxia

Nitrous oxide neuromuscular: does NOT potentiate _______ ______, but DOES potentiate ______, and increases muscle rigidity with _____

nondepolarizing NMB succinylcholine opioids

Nitrous oxide CNS: produces ____ and ____

analgesia and amnesia

Nitrous oxide CNS: analgesia due to increase in ______ _____

enkephalins produced

Nitrous oxide CNS: ______ occurs with 50% N2O

nystagmus

Nitrous oxide CNS: EEG effects similar to volatiles - _____ ____ and _____ _____

slowing frequency and higher voltage

Nitrous oxide CNS: cerebral vasodilation ____ than potent agents

less

Nitrous oxide CNS: increases _____

CMRO2

Nitrous oxide CNS: ____ ____ seen with nitrous may reflect acute nitrous dependence

withdrawal seizures

Nitrous oxide CNS: neuropathy/sensorimotor polyneuropathy - related to _____ effect on _____ atom of ______ ______

oxidizing effect cobalt atom vitamin B12

Nitrous oxide GI: gas in the bowel will...

increase in size with the use of nitrous

Nitrous oxide GI: increased incidences of _____ - controversial yet meta analysis of studies show increased incidence of ______

PONV PONV

Nitrous oxide uterine/reproductive: ____ _____ effect uterine tone

does not effect

Nitrous oxide uterine: weak ____ when used in high concentrations for prolonged time frame

teratogen

IMPORTANT Nitrous oxide Vit B12 dependent enzymes: inhibits ____ ____ which is necessary for _____ formation, and _____ ____ which is necessary for _____ _____

methionine synthetase myelin formation thymidylate synthesis DNA synthesis

Nitrous oxide Vit B12 dependent enzymes: prolonged exposure can result in ____ _____ depression - ______ anemia, and even ______ deficiencies - peripheral neuropathies and pernicious anemia

bone marrow depression - megaloblastic anemia neurological

Nitrous oxide: ENIGMA and ENIGMA II showed nitrous free anesthesia had decreased ____, _____ _____, _____, _______, _______

decreased PONV, wound infection, fever, pneumonia, atelectasis

Nitrous oxide: 59% increase in long term risk of ____; increased _____ levels

MI homocysteine (postop strokes/deaths NOT increased)

Nitrous oxide diffusion: ____ more soluble than _____ in the blood

34x nitrogen

Nitrous oxide diffusion: it is absorbed into air-filled spaces faster than nitrogen moves back into blood causing _____ of _____

expansion of bubble

Nitrous oxide diffusion: air expansion can affect...

- ears - pneumo - gastric/intestinal air - retinal detachment - intraocular gas bubble that serves as tamponade or splint

Nitrous oxide immunologic: affects chemotaxis and mobility of _______ ______ for ______ which is necessary for the inflammatory response to infection

polymorphonuclear leukocytes for phagocytosis

Nitrous oxide: diffusion hypoxia - N2O is so insoluble that it returns to alveoli so rapidly and in such volumes that it....

dilutes other gases including oxygen (this can be avoided by supplemental O2 for 5-10 mins after its dc'd)

Nitrous oxide: second gas effect - administering high concentrations of N2O will cause an increase of the _____ ______ of a _____ gas

alveolar concentration second gas (theoretically)

Nitrous oxide: when N2O is utilized, the ____ concentration must be _____

oxygen decreased

Nitrous oxide: care must be taken to avoid hypoxia especially in special populations such as...

c-section - common practice to deliver more than 50% N2O prior to delivery of infant (however with emergency cases youre worried about baby being deprived of O2)

Nitrous oxide: occupational risks - recent studies showed with scavenging and limited exposure....

it failed to show difference in fertility and birth defects with gen pop

Nitrous oxide: if substituted for a portion of a volatile agent, it (3)

1. decreases magnitude of BP decrease 2. less depression of ventilation (doesnt increase PaCO2) 3. MAC portion r/t N2O is not reduced due to decrease in temp

in summary: