Sevo Flashcards
1
Q
Increase or decrease MAC
- temperature
- age
- benzos, opiates, alpha 2 agonists
A
Decreases
2
Q
Adding 1% N2O decreases MAC by what
A
1%
3
Q
ETOH use acute and chronic effect on MAC
A
Acute = decreased MAC
Chronic = increased MAC
4
Q
MAC awake of Sevo
A
0.6%
5
Q
MAC BAR Sevo
A
3%
6
Q
MAC intubation Sevo
A
4%
7
Q
Sevo MAC
A
2%
8
Q
Alveolar concentration =
A
Brain Concentration
9
Q
Sevo BGP
A
0.69
10
Q
Low solubility of sevo facilitates what
A
Rapid elimination
11
Q
Rate of decrease of ET concentrations following termination of anesthesia
A
Rate of elimination
12
Q
To hasten emergence of volatile anesthetic
A
- Oxygen
- Ventilate more
- turn off sooner
- high FGF (decreases reinspiration)
13
Q
Is Sevo an airway irritant
A
NO
14
Q
Sevo Vapor pressure
A
197
15
Q
Is Sevo soluble in water
A
Yes
16
Q
Sevo BGPC
A
0.69
17
Q
Sevo OGPC
A
53.9
18
Q
MAC highest for Sevo at what age?
How different from other volatiles
A
Highest in newborns
- others around 1 year
19
Q
Lower CO =
A
Faster to go to sleep
20
Q
Primary factor determining FA/FI
A
BGPC
21
Q
Sevo uptake factors
A
Solubility X CO X alveolar to venous partial pressure
22
Q
Tissue uptake depends on
A
- Tissue solubility
- Tissue blood flow
- Arterial to tissue anesthetic partial pressure difference
23
Q
VRG gets how much CO?
% of body mass
A
10% body mass
75% of CO
24
Q
Muscle % of body mass
% of perfusion received
A
50% body mass
19% CO
25
Fat % of body mass
| % of CO
20%
6% CO
26
VPG is what % body mass
| Get what % of CO
20% mass
| 0% CO
27
VRG equilibrates with Sevo in how much time
4-8 minutes
28
How long until sevo equilibrates in muscle and skin
2-4 hours
29
Sevo equilibration in fat takes how long
30 hours
30
Durations of sevo anesthesia affects
Recovery times
31
Residual gases in anesthetic circuit can affect
Recover times
32
Sevo emergence correlates with
Fall in alveolar concentration
33
Sevo and retrograde amnesia
No retrograde amnesia (not remembering what happened before given)
34
Sevo and long term impairment of intellectual function and mental function
Can cause long term development impairment
35
Sevo and ICP
Potential to increase in pt with space occupying lesion
36
Ketamine and long term intellectual impairment
Does cause
37
Sevo at _____ increases frequency and voltage of EEGs
<0.4 MAC
| <0.8%
38
Counteract increased ICP with what
Hyperventilation
39
Goal of ETCO2 fro hyperventilation
25- 35
Correlate with blood gas
40
CMRO2 decreases at what MAC of sevo
0.4 MAC.
41
At what MAC value does sevo begin to maximally suppress CMRO2
..
42
As sevo dose approaches 1 MAC what happens to EEG
Frequency decreases and maximum voltage occurs
43
Sevo causes burst suppression on EEG at
1.5 MAC
44
EEG activity ceases at what MAC of sevo
2 MAC
45
Does Sevo produce convulsive activity on EEG
Does not
46
Does sevo suppress convulsive activity
Yes
47
Sevo an evoked potential monitoring
Cause dose dependent decrease in amplitude and increased latency of evoked potentials
48
Sevo effect on
- cerebral vasodilation
- cerebral vascular resistance
- CBF
- increased vasodilation
- decreased resistance
- increased CBF
49
Sevo and ICP
Increases ICP
50
How to decrease tendency of sevo to increase ICP
Hyperventilate decreasing PaCO2 to 30
51
Sevo and BP r/t what
Decreased MAP rt decreased SVR
52
Sevo and increased HR begins at what MAC
1.5 MAC
53
Increased loss of body heat with sevo caused by
Increased cutaneous blood flow
54
Is there potentiation of NMB’s with volatile agent administration
YES
55
Sevo and RAP
Does not significantly alter RAP
56
Sevo and PVR
No effect on PVR
57
Sevo and doses of epi
Does not alter dose of epi needed
58
HR decrease more with
Spontaneous ventilation as opposed to mechanical ventilation
59
Abrupt increase in iso and des cause what to BP and HR
Why
Transient increases in HR and BP r/t increased SNS and RAA
60
Sevo and contractility of myocardium
Decreases in normal and failing cardiac muscle
61
Sevo produces dose dependent effect on
- pattern of breathing
- ventilatory response to CO2
- ventilatory response to arterial hypothermia
- airway resistance
62
Pattern of breathing with sevo
Increased RR, decreased TV, increased deadspace
63
Sevo produces apnea
Bw 1.5-2 MAC
64
Pre- existing lung disease and ventilatory depressant effects of sevo
Worsens vent depression
65
As duration of sevo anesthesia increases, ventilatory effects
Decrease
66
Sevo interferes with what during spontaneous breathing
- intercostal muscle function
| - resulting in loss of chest wall stabilization
67
Best way to treat hypoxemia and hypercarbia with pt breathing sevo
Put on vent or squeeze bag more
68
Sevo effect on smooth muscle related to what
Relaxant effects r/t decrease in vagal nerve control
69
Which decreases airway resistance more iso or sevo
Sevo
70
Best for inhalation inductions
Sevo
71
Sevo to what for inhalation induction
8%
72
Sevo and metabolism of drugs
Drug metabolism decreased
73
Sevo metabolism and liver
No effect
74
Sevo and renal blood flow, GFR, UOP
Dose dependent decreases
75
How to decrease reduction in renal function
Pre-hydrate
76
Safety of sevo and ESRD
Not established
77
Sevo metabolism rate
3-5%
78
Sevo and skeletal muscle relaxation
Produces relaxation
79
Sevo effect on NMD
Dose dependent enhancement of NMB effect
80
Is sevo triggering agent for MH
YES
81
Sevo degredation enhanced by
Higher absorbent temps
High sevo concentration
Low FGF
Desiccated CO2 absorbent
82
Sevo depredation via path 1
Deflourination pathway: - Loss of hydrogen fluoride to form compound A
- results from extraction of acidic proton in presence of strong base
- KOH or NaOH form Compound A from sevo
83
Concentration of degradents is ____________ to FGF rate
Inversely proportional
84
Temp increase of absorbent is determined by what
Quantity of CO2 absorbed
85
Quantity of CO2 absorbed by absorbent depends on
- FGF in circuit
- Pt metabolic rate
- pt ventilation
86
Minimum FGF to prevent compound A formation
2 liters
87
Concentration of Compound A in circuit increases with what
- concentration of sevo given
| - duration of sevo anesthesia
88
Second pathway of Sevo depredation
- occurs in presence of desiccated CO2 absorbent and dissociation of sevo to HFIP and formaldehyde
- formaldehyde can degrade to methanol and formate
- formate can form carbon monoxide
- methanol can form Compound B
89
HFIP
Inactive and rapidly cleared by liver eliminated in urine
90
Fluoride ion concentration influenced by
- duration of anethesia
- sevo concentration used
- composition of anesthetic gas mixture
91
Sevo metabolism rate
3-5%
92
CO2 absorbent containing _________ and _________ produce much higher concentration in Compound A concentration from sevo
KOH
| NaOH
93
Absorbent containing neither KOH or NaOH and produces lower concentration of Compound A
Absorb
94
Incidence of post op agitation with sevo
Greater with sevo than with other volatile agents
95
Sevo produces what effect on uterine smooth muscle contractility and blood flow
Don’t give more than _____
Decreases
Don’t give more than 1 MAC
96
Sevo and placenta
Easily crosses placenta but quickly exhaled by newborns
97
Sevo and K+
Most vulnerable
Rarely ass with increase in K+
Duchesse muscular dystrophy more vulnerable
98
Sevo and total body O2 requirements
Reduces requirement
99
Solubilization of sevo may cause
Redistribution of membrane lateral pressures surrounding ion channels
100
Sevo and CBF autoregulation
Does not alter
101
Sevo produces ______________ in cerebral metabolic oxygen requirements.
Maxes out when ____________
- dose dependent decrease
| - isoelectric EEG obtained
102
Abrupt increases in iso and des may cause ___________ in HR and BP r/t _______
Transient increase due to increased SNS and Renin angiotensin activity
103
sevo minimally __________ myocardial contractility in normal and failing cardiac muscle
Decrease
104
Sevo and RR
Dose dependent increase in RR
105
Apne threshold with sevo
Apnea threshold 3-5mmHg less than PaCO2 in spontaneous breathing
106
Sevo is metabolized by ________ to _______
Cytochrome P-450 to HFIP with release of inorganic fluoride and CO2
107
How much sevo metabolized
5%
108
Peak inorganic fluoride concentrations occur ________ and return to baseline _____
Within 2 hours
| Within 48 hours from end of sevo admin
109
Post op agitation and sevo
Incidence is greater with sevo than other volatile agents
110
Sevo and uterine smooth muscle contractility and blood flow
Effect minimal at ____ and significant at ____
Decreases
0.5 MAC significant at 1 MAC
111
Sevo _______ cross placenta.
Easily crosses
Quickly exhaled by newborn
112
Sevo and MH
Less than halothane but greater trigger than nitrous
113
Sevo and total body oxygen requirements
Decreases
