Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharm > Inhaled Anesthetics > Flashcards

Inhaled Anesthetics Flashcards

1
Q

Nitrous oxide

A

Molecular weight: 44

Boiling point:

Vapor pressure (mmHg 20°C): gas

Odor: sweet

Preservative necessary: No

Stability in soda lime (40°C): Yes

Blood:gas partition coefficient: 0.46

MAC w/ 100% O2 (middle age healthy pt): 104

MAC w/ 60-70% N2O:

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Halothane

A

Molecular weight: 197

Boiling point: 50.2

Vapor pressure (mmHg 20°C): 244

Odor: Organic

Preservative necessary: Yes

Stability in soda lime (40°C): No

Blood:gas partition coefficient: 2.54

MAC w/ 100% O2 (middle age healthy pt): 0.75

MAC w/ 60-70% N2O: 0.29

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Enflurane

A

Molecular weight: 184

Boiling point: 56.5

Vapor pressure (mmHg 20°C): 172

Odor: Ethereal

Preservative necessary: No

Stability in soda lime (40°C): Yes

Blood:gas partition coefficient: 1.90

MAC w/ 100% O2 (middle age healthy pt): 1.63

MAC w/ 60-70% N2O: 0.57

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Isoflurane

A

Molecular weight: 184

Boiling point: 48.5

Vapor pressure (mmHg 20°C): 240

Odor: Ethereal

Preservative necessary: No

Stability in soda lime (40°C): Yes

Blood:gas partition coefficient: 1.46

MAC w/ 100% O2 (middle age healthy pt): 1.17

MAC w/ 60-70% N2O: 0.50

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Desflurane

A

Molecular weight: 168

Boiling point: 22.8

Vapor pressure (mmHg 20°C): 669

Odor: Ethereal

Preservative necessary: No

Stability in soda lime (40°C): Yes

Blood:gas partition coefficient: 0.42

MAC w/ 100% O2 (middle age healthy pt): 6.6

MAC w/ 60-70% N2O: 2.83

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Sevoflurane

A

Molecular weight: 200

Boiling point: 58.5

Vapor pressure (mmHg 20°C): 170

Odor: Ethereal

Preservative necessary: No

Stability in soda lime (40°C): No

Blood:gas partition coefficient: 0.69

MAC w/ 100% O2 (middle age healthy pt): 1.80

MAC w/ 60-70% N2O: 0.66

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Alveolar partial pressure is an index of?

A

1) depth of anesthesia
2) recovery from anesthesia
3) anesthetic equal potency (MAC)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Minute ventilation

A

Sum of all exhaled gas volumes in 1 min

Tidal volume x breaths/min= 5L/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Alveolar ventilation

A

Volume of inspired gases actually taking part in gas exchange in 1 min

(Tidal volume-dead space) x breaths/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Dead space

A

Any volume of inspired breath that does not enter the gas exchange areas of the lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Time for equilibration (time constant)=

A

Amt of inhaled anesthetic dissolved in tissue/ tissue blood flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

For volatile anesthetics, 3 time constants =

A

5-15 min for brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Lower tissue:gas ratios indicate?

A

The gas is relatively insoluble in tissues thus emergence will be more rapid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Stage I

A

Begins with induction of anesthesia

Ends with loss of consciousness (no eyelid reflex)

Still can sense pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Stage II

A

Delirium excitement

Uninhibited excitation

Pupils dilated, divergent gaze

Potentially dangerous response to noxious stimuli: breath holding, muscular rigidity, vomiting,laryngospasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Stage III

A

Surgical anesthesia

Centralized gaze with constriction of pupils

Regular respirations

Anesthesia depth is sufficient for noxious stimuli when the noxious stimuli does not cause increase sympathetic response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Stage IV

A

Stay away from. Too deep

Apnea

No reactive dilated pupils

Hypotension resulting in complete CV collapse if not monitored closely

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does nitrous cause diffusion hypoxia?

A

Once d/c’d the nitrous diffuses rapidly out of tissues and into the blood and alveoli. Rapid flood into alveoli dilutes alveolar gas and displaces O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

EEG effects

A

<0.4 MAC = increase in frequency & voltage similar for all volatile anesthetics

0.4 MAC= shift of voltage activity from posterior to anterior portions of brain.
Decrease in cerebral O2 requirements-may reflect transition from wakefulness to unconsciousness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

_______ has fast frequency and high voltage on EEG indistinguishable from changes produced by seizure activity; twitching of facial muscle occurs and can be initiated from repetitive auditory stimuli

A

Enflurane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

No seizure activity on EEG, suppress convulsants properties

A

Iso, des, sevo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Volatile anesthetics > 0.6 MAC produce what effect on CBF?

A

Cerebral vasodilation, decreased cerebral vascular resistance, dose-dependent increase in cerebral blood flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

At 1.1 MAC cerebral blood flow increases (greatest to least)

A

Halothane> Enflurane > Isoflurane=Desflurane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Cerebral Metabolic O2 Requirements dose dependent decrease (greatest to least) & how

A

Isoflurane= Desflurane= Sevoflurane > Halothane

Decrease metabolic requirement- decrease CO2 production- vasoconstriction that decreases CBF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Decreased metabolic requirement =

A

Decreased CO2 production, vasoconstriction that decreases CBF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

I’m CEA, CBF ischemic changes are lower with ____

A

Isoflurane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Increased ICP is parallel to

A

Increased CBF produced by volatile anesthetics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What opposes the tendency for increased ICP

A

Hyperventilation of lungs to decrease PaCO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Cause similar dose dependent decreases in MAP due to decrease in SVR

A

Iso (most profound)> des > sevo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Causes decrease in MAP due to decrease in myocardial contractility

A

Halothane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Effects of N2O on MAP

A

No change or modest increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Increase HR (greatest to least)

A

Des (most) > Iso > Sevo

sevo only >1.5 MAC

33
Q

What effect does halothane have on HR?

A

No change

34
Q

Halothane effect on CO/stroke volume

A

Dose dependent decrease CO

35
Q

Effect of iso, des, sevo on CO/SV

A

No real effect

36
Q

Sevo decreases CO up to ___ MAC; ____ MAC CO recovers

A

2; >2

37
Q

N2O ____ CO slightly

A

Increases

38
Q

N2O _____ PVR and is exaggerated in?

A

Increases; pulm. HTN, neonates, congenital heart disease

39
Q

Coronary steal syndrome

A

Maldistribution of blood flow from ischemic to nonischemic areas

40
Q

Coronary vasodilation (greatest to least)

A

Halothane, enflurane < Isoflurane < adenosine

41
Q

To decrease risk of MI pretreat with?

A

Opioids or a beta blocker

42
Q

______’s solubility characteristics make it a good choice to treat abrupt increases in systemic BP and HR associated w/ changes in intensity of surgical stimulation

A

Desflurane

43
Q

Neurocirculatory response does not occur with abrupt increase in concentration of ________

A

Sevoflurane

44
Q

_____ is the most potent of the volatile gases in clinical uses and is a potent coronary vasodilator

A

Isoflurane

45
Q

Dose limit for exogenous Epi:

A

6mcg/kg for Iso, Des, Sevo

46
Q

______ increases frequency of breathing at concentrations up to __ MAC, then no further increase occurs

A

Isoflurane; 1

47
Q

_____ produces most profound decrease in SVR

A

Isoflurane

48
Q

_______ selectively interferes with intercostal muscle function resulting in loss of chest wall stability

A

Halothane

49
Q

________ has direct relaxing effects on airway smooth muscle (decreases _____ nerve traffic from CNS)

A

Halothane; vagal

50
Q

______ causes modest increase in PVR

A

Nitrous oxide

51
Q

Volatile anesthetics _______ PVR. Except for ______ which ____ PVR at MAC of 1.6

A

Decrease; Desflurane; increases

52
Q

______ inhibits hypoxia pulmonary vasoconstriction (HPV)

A

Nitrous oxide

53
Q

_______ acts as a hepatic circulation vasoconstrictor

A

Halothane

54
Q

Hepatic effects greatest to least

A

Halothane > Enflurane > Isoflurane > Desflurane

55
Q

Fluoride-Induced Nephrotoxicity sx

A

Polyuria, hypernatremia, hyperosmolarity, increased serum creatinine, inability to concentrate urine

56
Q

Sevo effects on renal

A

No renal damage in pt without preexisting renal disease

57
Q

Enflurane has greater _____ metabolism; Sevoflurane has greater ______ metabolism

A

Intrarenal; hepatic

58
Q

Sevo and soda lime/Baralyme

A

CO2 absorbents react and eliminate hydrogen fluoride from its isopropyl moiety to form breakdown products- Compound A- nephrotoxin

Use at least 2L/min fresh gas flow rate to minimize concentration of compound A accumulating in breathing circuit

59
Q

_______ most potent trigger for MH of all VA

A

Halothane

60
Q

Patho of MH

A

Increase and continuous leaking of Ca from Ryanodine receptors of SR

61
Q

Earliest sign of MH

A

Succinylcholine induced masseter muscle rigidity (MMR)

62
Q

Late sign of MH

A

Hyperthermia; can raise temp 1 degree C every 5 min

63
Q

Other symptoms of MH

A

Rhabdomylosis, tachycardia, increased metabolism, HTN, mottled cyanosis, arrhythmia, dark urine

64
Q

Most sensitive indicator of MH

A

Doubling or tripling of ETCO2

65
Q

MH labs

A 
Hyperkalemia
Hypermagnesemia
Reduced mixed venous O2 sat
Increased serum myoglobin
Increased creatinine kinase (CK) (peak 12-18 hrs later exceeding 20,000 IU/L)
66
Q

Treatment for MH

A 
Dantrolene 2.5mg/kg (max 10mg/kg) every 5 min until stops (after episode: 1mg/kg q 6 hrs for 24-48 hrs)
Stop gas and succ immediately
Change machines and bag/mask 100% O2
Correct acid-base/electrolyte imbalance
No CCB!
Cool pt til 38C
67
Q

Dantrolene supply

A

20mg lyophilized order to be dissolved in 60ml sterile water. Takes 86 sec to reconstitute (new version 20 sec)

Half life is 6 hrs

68
Q

N2O metabolism

A

Very little metabolism, mainly by anaerobic bacteria in GI tract

O2 concentration > 10% inhibits metabolism

69
Q

Halothane metabolism

A

15-20% CYP450

70
Q

Enflurane metabolism

A

3% CYP450

71
Q

Isoflurane metabolism

A

0.2% CYP450

72
Q

Desflurane metabolism

A

0.02% CYP450

73
Q

Sevoflurane metabolism

A

5% CYP450

74
Q

Carbon monoxide toxicity order

A

Desflurane > Enflurane > Isoflurane

Halothane and Sevo have no CO production

75
Q

___ of a MAC should produce MAC awake for volatiles

A

1/10

76
Q

MAC BAR

A

Blunt Autonomic Responses to noxious stimuli

77
Q

Factors that increase MAC

A 
Hyperthermia
Red hair
Cocaine/methamphetamine/amphetamine
Cyclosporine
Hypernatremia
78
Q

Factors that decrease MAC

A 
Hypothermia 
Increasing age
Preop meds
Drug induced decrease catecholamine
Alpha 2
Acute alcohol
Pregnancy/postpartum
Lidocaine
Neuraxial opioids
PaO2 <38
MAP < 40
Cardiopulmonary bypass
Hyponatremia

Pharm (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions