Exam 3 Part III Flashcards
1
Q
liver receives ___________% of CO
A
25
2
Q
hepatic artery supplies ___________% of blood flow to the liver, and the portal vein supplies _______% of blood flow to the liver, both supplying ____% of O2
A
25; 75; 50
3
Q
prior exposure to _________________ can cause hepatitis with a current exposure to another (different) volatile
A
halothane
4
Q
what is volatile induced hepatotoxicity
A
- 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
5
Q
T/F: all volatile inhalational agents have very little liver metabolism
A
TRUE
6
Q
s/sx of volatile induced hepatotoxicity
A
- fever 2. jaundice 3. increased LFTs
7
Q
volatile induced hepatotoxicity is aka __________________
A
halothane hepatotoxicity
8
Q
all volatile anesthetics produce a ___________________ relaxation of skM EXCEPT ___________ which may cause skM rigidity
A
dose-dependent ; N20
9
Q
all volatile anesthetics _______________ the effects of DMR and NDMR
A
potentiate
10
Q
mechanism at which volatiles produce skM relaxation
A
- decrease neural activity within the CNS 2. decrease effect at the NMJ (Predominantly post-synaptic membrane)
11
Q
NDMR doses are decreased by _______________% in the presence of a volatile gas
A
15-50
12
Q
time dependent potentiation of NDMR via volatile agent begins in ___________ min
A
10-May
13
Q
after 30 minutes of exposure to sevoflurane, recovery from vecuronium to 25% of baseline is prolonged __________%
A
89
14
Q
after 60 minutes of exposure to INH agent, the recovery from NDMR to 25% of baseline is prolonged by ________%
A
100
15
Q
effects of Iso on: CO SVR MAP HR
A
CO - decreased SVR - decreased MAP - decreased HR - increased
16
Q
effects of Sevo on CO SVR MAP HR
A
CO - maintained SVR - decreased MAP - decreased HR - maintained
17
Q
effects of desflurane on: CO SVR MAP HR
A
CO - maintained SVR - decreased MAP - decreased HR - increased
18
Q
effects of N20 on: CO SVR MAP HR
A
CO - decreased SVR - increased MAP - maintained HR - increased
19
Q
ISO, SEVO, and DES ______ MAP, CO, CI via a ______ in SVR 2/2 ________________
A
decrease; decrease; reduction in intracellular free Ca
20
Q
Halothane decreases MAP by?
A
direct myocardial depression
21
Q
which volatile inhalational agent is SUPPORTIVE of HD
A
N2O
22
Q
inhalational agents will cause dose dependent depression of what cardiac activity?
A
- myocardial contractility 2. peripheral vascular smooth muscle 3. inhibition of ANS activity
23
Q
HR effects of inhalational agents
A
- antagonism of SA node automaticity 2. modulation of the baroreceptor reflex 3. SNS activation
24
Q
which INH agent increases HR the most
A
desflurane
25
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
26
inhalational agents, esp ____________ should be cautioned in those with ________ 2/2 HR effects
des; CAD
27
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
28
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
29
_________________ will block the increase in HR but not the decrease in MAP with inhalational agents
esmolol
30
INH agents effects on coronary blood flow
1. produce vasodilation 2. cause coronary steal syndrome in diseased coronarys
31
which INH agent causes vasodilation the LEAST
sevo
32
which INH agents may be used in pts with hx of ischemic heart disease
1. iso 2. sevo 3. des
33
common arrhythmias with inhalational agents
bradycardias and AV conduction abnormalities
34
which INH agents produce arrhythmias the most
sevo and halothane
35
sevo and halothane are c/i if the patient has what arrhythmias
2nd degree AV block type II, complete heart block
36
what is "sensitization" (with arrhythmias)
reduction in catecholamine threshold necessary to produce arrhythmias
37
_______________ may protect the myocardium from coronary steal syndrome
50% N20
38
what is hypoxic pulmonary vasoconstriction
1. 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
39
when are INH agents at risk of decreasing hypoxic pulmonary vasoconstriction?
in one lung situations
40
Enflurane CNS effects
1. increase CBF 2. increase ICP 3. increase CSF 4. produces seizure activity
41
MAC of enflurane
1.7
42
B: G solubility of enflurane
1.9
43
Vapor pressure of enflurane
175
44
% of enflurane that is metabolized
8-Feb
45
enflurane is toxic to the _______________
kidneys
46
T/F: enflurane is stable and not effected by light, has no preservatives
TRUE
47
which agent causes coronary vasodilation more than any other INH agent?
isoflurane
48
which agent causes coronary steal more than any other agent
isoflurane
49
which INH agent is the most potent (of commercially available agents in US)
isoflurane
50
______________ increases CBF and ICP @ 1 MAC
isoflurane
51
which agent increases CBF less than any other INH agent
isoflurane
52
which agent decreases CMRO2 less than any other INH agent
isoflurane
53
which INH agent is considered cerebral protective
isoflurane (means the CBF at which ischemic changes occur on EEG is lower with isoflurane than other agents)
54
respiratory effects of isoflurane
1. decrease TV 2. increase RR (slight) 3. decrease MV 4. increase PaCO2 5. bronchodilator
55
what is the most widely used INH agent
isoflurane
56
metabolism of isoflurane
0.20%
57
isoflurane _________ RBF --> ______ GFR and UOP
decrease; decrease
58
what is the only volatile that undergoes reductive metabolism
halothane
59
which agent decreases MAP from direct myocardial depresson
halothane
60
which agent increases the incidence of ventricular arrhythmias
halothane
61
which agent has NO impact on SVR
halothane
62
which agent increases the arrhythmic potential of epi
halothane
63
respiratory effects of halothane
1. bronchodilator 2. increased RR 3. decreased TV 4. decreased response to CO2 (less than other agents) 5. hypoxic drive severely depressed
64
CNS effects of halothane
1. increased CBF 2. increased ICP (more than all other agents) 3. decreased CMRO2 4. autoregulation is blunted and completely abolished at high concentrations
65
which INH agent increases ICP the MOST
halothane
66
which INH agent is metabolized more than any other agent
halothane (20%)
67
which agent is the most hepatotoxic
halothane
68
which inhalational agent is metabolized via oxidation/reduction reactions
halothane
69
______________ is added as preservative to halothane to enhance stability
thymol
70
major metabolites of halothane
1. trifluoroacetic acid (TFA) 2. free bromide 3. free chloride
71
T/F: metabolism of halothane increases with repeated exposures
true - 20% first exposure, increases from there
72
which inhalational agent is the LEAST potent
desflurane
73
which INH agent is the least soluble
Desflurane
74
which INH agent (other than N2O) has the highest MAC
desflurane
75
which INH agent is the most expensive
desflurane
76
CV effects of desflurane
1. rapid increase in des --> transient increase in HR 2. does NOT increase coronary artery blood flow
77
why does desflurane require a special heated and pressurized vaporizer
because vapor pressure is so high (664) and close to atmospheric, it is a gas at room temperature
78
____________________is pungent, airway irritant that has high risk of coughing and laryngospasm if administered while pt is awake
desflurane
79
__________________ is a great gas for pts who are super morbidly obese and/or have liver dz
desflurane
80
which INH agent is the LEAST irritating to the airway
sevoflurane
81
sevoflurane is __________% metabolized
5-Feb
82
metabolites of sevoflurane
1. inorganic fluoride 2. hexafluoroisopropanol
83
what gas is a methyl isopropyl ether
sevoflurane
84
sevoflurane will spontaneously degrade in _______________ bottles, so must be kept in ___________ or __________ bottle
glass; plastic; metal
85
what is the MAC of Xenon
71%
86
what is the B:G solubility of Xenon
0.14
87
why is xenon not able to be used as an inhalational anesthetic
because MAC = 71% so you would only be able to use 29% O2
88
induction and emergence with xenon is _________________ x faster than desflurane or sevoflurane
4-Mar
89
xenon advantages as inhalational agent
1. non-explosive 2. minimal cardiac depression 3. no metabolic effects 4. not harmful to the environment
90
disadvantages of xenon as inhalational anesthetic
1. potential risk of recall 2. extremely high cost 3. MAC of 71%
91
________________________ has hindered the acceptance of xenon into clincial practice
extremely high cost
92
anesthetic effects of N2O and other volatile agents are _________________
additive
93
N2O usually used in concentrations of __________ - ___________% to reduce the requirement of more potent agents
50; 70
94
basic characteristics of N2O
1. stored as a liquid and a gas in pressurized tanks (@ 50 atm) 2. Non flammable 3. BUT DOES support combustion 4. least potent of all gases 5. minimal toxicity 6. stable at room temperature 7. does not react with soda lime or other anesthetic drugs 8. almost entirely eliminated through the lung
95
analgesic effect of 50% N20 is approximately equal to __________
10 mg morphine
96
approximately __________% of N20 undergoes metabolism
1
97
absolute c/i of N20
1. known deficiency of enzyme or substrate in methionine synthase pathway 2. potential toxicity from expansion of gas filled space (emphysema, pneumothorax, middle ear surgery, pneumocephalitis, air embolus, bowel obstruction)
98
relative C/I to use of N20
1. increased ICP 2. pulmonary HTN 3. prolonged anesthetic (> 6 h) 4. first trimester of pregnancy 5. high risk PONV
99
CNS effects of N2O
1. increased CBF- potent cerebral vasodilator (not good for neuro cases) 2. minimal increase in CMRO2 3. minimal EEG changes 4. no effect on cerebral autoregulation 5. big increase in PONV (d/t activation of CTZ and vomiting center)
100
CV effects of N20
1. no effect on HR, CO, BP 2. no significant changes in EKG 3. mild, transient, stimulation of SNS 4. increase PVR (issue with pulm htn)
