Exam 3 Part III Flashcards
liver receives ___________% of CO
25
hepatic artery supplies ___________% of blood flow to the liver, and the portal vein supplies _______% of blood flow to the liver, both supplying ____% of O2
25; 75; 50
prior exposure to _________________ can cause hepatitis with a current exposure to another (different) volatile
halothane
what is volatile induced hepatotoxicity
- decrease hepatic blood flow + increased O2 demand of enzyme induction –> liver dysfunction 2. develops 2/2 decreased hepatic blood flow 3. can occur hours - days post anesthetic
T/F: all volatile inhalational agents have very little liver metabolism
TRUE
s/sx of volatile induced hepatotoxicity
- fever 2. jaundice 3. increased LFTs
volatile induced hepatotoxicity is aka __________________
halothane hepatotoxicity
all volatile anesthetics produce a ___________________ relaxation of skM EXCEPT ___________ which may cause skM rigidity
dose-dependent ; N20
all volatile anesthetics _______________ the effects of DMR and NDMR
potentiate
mechanism at which volatiles produce skM relaxation
- decrease neural activity within the CNS 2. decrease effect at the NMJ (Predominantly post-synaptic membrane)
NDMR doses are decreased by _______________% in the presence of a volatile gas
15-50
time dependent potentiation of NDMR via volatile agent begins in ___________ min
10-May
after 30 minutes of exposure to sevoflurane, recovery from vecuronium to 25% of baseline is prolonged __________%
89
after 60 minutes of exposure to INH agent, the recovery from NDMR to 25% of baseline is prolonged by ________%
100
effects of Iso on: CO SVR MAP HR
CO - decreased SVR - decreased MAP - decreased HR - increased
effects of Sevo on CO SVR MAP HR
CO - maintained SVR - decreased MAP - decreased HR - maintained
effects of desflurane on: CO SVR MAP HR
CO - maintained SVR - decreased MAP - decreased HR - increased
effects of N20 on: CO SVR MAP HR
CO - decreased SVR - increased MAP - maintained HR - increased
ISO, SEVO, and DES ______ MAP, CO, CI via a ______ in SVR 2/2 ________________
decrease; decrease; reduction in intracellular free Ca
Halothane decreases MAP by?
direct myocardial depression
which volatile inhalational agent is SUPPORTIVE of HD
N2O
inhalational agents will cause dose dependent depression of what cardiac activity?
- myocardial contractility 2. peripheral vascular smooth muscle 3. inhibition of ANS activity
HR effects of inhalational agents
- antagonism of SA node automaticity 2. modulation of the baroreceptor reflex 3. SNS activation
which INH agent increases HR the most
desflurane
INH (ether) agents reduce intracellular free calcium this has what effect on the myocardium and peripheral vasculature
depression of myocardium and dilation of peripheral vasculature
inhalational agents, esp ____________ should be cautioned in those with ________ 2/2 HR effects
des; CAD
increase in HR with inhalational agents can be modulated (but not ablated) with ______________ 5 min prior to induction before an increase in desflurane concentration
fentanyl
what dose of fentanyl can give up to 70% modulation of increase in HR prior to increase desflurane concentration
1.5-4.5 mcg/kg
_________________ will block the increase in HR but not the decrease in MAP with inhalational agents
esmolol
INH agents effects on coronary blood flow
- produce vasodilation 2. cause coronary steal syndrome in diseased coronarys
which INH agent causes vasodilation the LEAST
sevo
which INH agents may be used in pts with hx of ischemic heart disease
- iso 2. sevo 3. des
common arrhythmias with inhalational agents
bradycardias and AV conduction abnormalities
which INH agents produce arrhythmias the most
sevo and halothane
sevo and halothane are c/i if the patient has what arrhythmias
2nd degree AV block type II, complete heart block
what is “sensitization” (with arrhythmias)
reduction in catecholamine threshold necessary to produce arrhythmias
_______________ may protect the myocardium from coronary steal syndrome
50% N20
what is hypoxic pulmonary vasoconstriction
- natural compensatory mechanism in response to hypoxia or atelectasis 2. pulmonary arterioles constrict w/ alveolar hypoxia –> diversion of blood flow away from poorly ventilated alveoli 3. reduces pulmonary shunt, reduces V/Q mismatch
when are INH agents at risk of decreasing hypoxic pulmonary vasoconstriction?
in one lung situations
Enflurane CNS effects
- increase CBF 2. increase ICP 3. increase CSF 4. produces seizure activity