Brainscape's Knowledge GenomeTM

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


See full index

Module 14 > Getting Gas to Patient: Breathing Systems > Flashcards

Getting Gas to Patient: Breathing Systems Flashcards

1
Q

what are non-rebreathing systems (3)

A
  1. lack
  2. T-piece
  3. bain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are re-breathing systems

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

what are hybrid systems

A

humphrey ADE

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

what are the functions of breathing systems (4)

A
  1. deliver oxygen to patient
  2. deliver anesthetic gas and/or vapour to patient
  3. remove exhaled carbon oxide
  4. provide a means to ventilate patient
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is tidal volume

A

volume of gas exhaled in 1 breath (10-20 ml/kg)

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

what is minute respiratory volume

A

volume of gas exhaled in 1 minute

tidal volume x respiratory rate ~ 200ml/kg

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

what is rebreathing

A

inhalation of previously exhalged gas

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

what are the two types of rebreathing systems

A
  1. rebreathing of exhaled gas from which CO2 has been removed by an absorbent is not detrimental
  2. rebreathing of unchanged exhaled gas leads to build up to CO2 (hypercapnia) –> detrimental
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is apparatus dead space

A

volume of breathing system that may contain exhaled gas that could be rebreathed during subsequent breath

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

what are the breathing system components (5)

A
  1. tubing
  2. reservoir bag
  3. adjustable pressure limiting (APL) valve
  4. carbon dioxide absorbent (soda lime)
  5. unidirectional valves
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the function of tubing

A

conveys gases to and from pateint

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

why are tubes corrugated

A

resist kinking

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

how do tubes reduce resistance of air flow

A

smooth internal bore reduces resistance

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

what are the two arrangements of tubing

A
  1. parallel: tubes arranged side by side
  2. coaxial: 1 tube inside the other
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the functions of reservoir bag

A
  1. reservoir
  2. visual aid
  3. means of assisting ventilation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are APL valves and what is their function

A

adjustable pressure limiting valve

“pop off” or “spill” or “expiratory valve”

provides a means of escape for excess fas preventing pressure build up

connects to scavenging system for disposal of waste gases

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

what is an open APL valve

A

slight increase in pressure during expiration lift disc and open valves

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

what are closed APL valves

A

tension in spring opposes lifting of disc and valve remains closed

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

how do you open an APL valve

A

anti-clockwise open

lefty loosey

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

how do you close an APL valve

A

clockwise close

righty tighty

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

when should you have the APL valve open

A

should always be fully open during spontaneous ventilation

only adjusted during intermittent positive pressure ventilation (IPPV) –> when we want to manually inflate the patients lungs

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

what can occur when the APL valve is closed

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

how are breathing systems classified (4)

A
  1. rebreathing or non-rebreathing
  2. with or without CO2 absorbent
  3. conway classification
  4. mapleson classification
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what are non-rebreathing systems

A

no rebreathing of exhaled gases occurs

high fresh gas flow flushes out exhaled gases before the next inspiration

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

what are rebreathing systems

A

exhaled gases are rebreathed after removal of CO2 by an absorbant

allow use of lower fresh gas flows

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

what does removal of exhaled gases in non-rebreathing systems depend on

A

adequate fresh gas flow (FGF)

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

what are the advantages of non-rebreathing systems

A
  1. patient inspires fresh gas
    - patient breathes gas of known composition
    - anesthetic depth can be changed rapidly
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what are the disadvantages of non-rebreathing systems (2)

A
  1. high fresh gas flow (FGF)
    - increased cost
    - increased potential for environmental pollution
  2. fresh gas is cold & dry
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what are the two ways to calculate FGFs

A
  1. use minute resp volume (MRV)
  2. use ml/kg/min
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

how do you calculate FGF using MRV

A

MRV = resp rate x tidal volume (10-20 ml/kg)

FGF = MRV x circuit factor

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

what are circuit factors for lack, ayre’s t-piece, bain

A

lack: 0.8-1

ayre’s t-piece: 2.5-3.5

bain: 1-3.5

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

how do you calculate FGF using ml/kg/min

A

lack: 150-200 ml/kg/min

ayre’s t-piece: 400-600 ml/kg/min

bain: 200-600 ml/kg/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

why are FGFs not always sufficient

A

noraml ventilatory pattern: inspiration, expiration & then expiratory pause

the expiratory pause is crucial –> fresh gas flushes expired gas out of system, if too short there is insufficient time for expired gas to be removed & rebreathing occurs

so increase FGF in patients with rapid resp rates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what are the classifications of the mapleson A systems

A
  1. parallel
  2. coaxial
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what system is this

A

parallel lack

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

describe how the gas flows through this system

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what system is this

A

parallel lack

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what system is this

A

coaxial lack

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what are the differences between the parallel and coaxial lack

A

coaxial: damage/disconnection of central tube leads to marked rebreathing of CO2 or if there is a leak
parallel: more bulky but probably safer, more widely used

41
Q

is the lack system suitable for IPPV

A

no

the reservoir is on the inspiratory limb –> rebreathing & hypercapnia develop during prolonged IPPV

can be reduced but not eliminated by increasing FGF

42
Q

what patients is the parallel lack used for

A

10kg & over

43
Q

what is the recommended FGF in the parallel lack

A

160-200 ml/kg/min

44
Q

what is the minilack

A

for smaller patients

undre 10kg

45
Q

what is the FGF for the miniLack

A

200 ml/kg/min

46
Q

what is the basic ayre’s t-piece

A

mapleson E

47
Q

does the basic ayre’s t-piece have an APL valve

A

no

low resistance

48
Q

what are the problems with basic ayre’s t-piece

A

no reservoir bag so difficult to observe ventilation

49
Q

can IPPV be done on the basic ayre’s t-piece

A

yes but exposes lungs to high pressure

occlude the tube with thumb

50
Q

what system is this

A

basic ayre’s t-piece

51
Q

what is the jackson-rees modification of the basic ayre’s t-piece

A

addition of open ended bag

52
Q

what system is this and describe how air flows through it

A

jackson-rees modification

53
Q

what is the jackson-rees modification classified as

A

mapleson F

54
Q

what are the benefits of the jackson-rees modification

A
  1. allows observation of respiration
  2. allows more control during IPPV
55
Q

what is a disadvantage of jackson-rees modification

A

difficult to scavenge

56
Q

what system is this

A

jackson-rees

57
Q

what is the mapleson D t-piece

A

adaptation to facilitate scavenging

includes closed reservoir bag & APL valve

58
Q

what is this system and describe the airflow through it

A

mapleson D t-piece

59
Q

what system is this

A

mapleson D t-piece

60
Q

what size of patients can the t-piece be used for (modified/basic/mapleson D)

A

up to 10kg

61
Q

what is the FGF of t-piece be used for (modified/basic/mapleson D)

A

400-600 ml/kg/min

62
Q

if the t-piece be used for (modified/basic/mapleson D) suitable for IPPV

A

yes

63
Q

what is the bain system

A

mapleson D

modification of T-piece –> parallel or coaxial (most common)

64
Q

what system is this and describe how air flows through it

A

coaxial bain system

fresh gas passes up inner tube and expired gas out via outer tube

65
Q

what system is this and how does gas pass through it

A

fresh gas passes up the outer tube and expired gas out via inner tube

66
Q

what are the disadvantages of coxaxial bain

A

damage/disconnection of central tube leads to marked rebreathing

but we can test integrity of inner tube in coaxial bain –> always check prior to use

67
Q

what size of patient is the bain system suitable for

A

up to 10kg and above

68
Q

what is the FGF of the bain system

A

200-600 ml/kg/min

69
Q

is the bain system suitable for IPPV

A

yes

70
Q

what is the bain modification t-piece used for

A

larger patients

FGF 400-600 ml/kg/min

slower resp rate and longer expiratory pause

71
Q

what are the features of rebreathing systems (3)

A
  1. exhaled gases are rebreathed after removal of CO2 by an absorbent
  2. relatively low FGF can be used
  3. patient inspires a mixture of fresh gas & exhaled gas
72
Q

what are the advantages of rebreathing systems

A
  1. lower gas flow –> more economical, less environmental contamination
  2. gases are warmed and humidified
73
Q

what are the disadvantages of rebreathing systems (4)

A
  1. greater resistance to breathing (soda lime canister, unidirectional valves)
  2. unsuitable for small patients
  3. patient inspires a mixture of fresh gas & exhaled gas (composition of mixture unknown)
  4. more difficult to alter anesthetic depth
74
Q

what is the usual absorbent of CO2

A

soda lime

80% calcium hydroxide

4% sodium hydroxide

14-20% added water

indicator dye

75
Q

how do indicator dyes in CO2 absorbents

A

pH of soda lime changes reveals exhaustion

-exothermic reaction

76
Q

what are the classification of rebreathing systems

A
  1. closed systems
  2. semi-closed systems (low flow)
77
Q

what are the features of closed systems

A

oxygen supplied is just sufficient to meet the patient’s metabolic oxygen requirement ~5-10 ml/kg/min oxygen

no gas exits via the APL valve

78
Q

what are the problems of closed systems (3)

A
  1. flowmeters may be inaccurate
  2. vaporizers may be inaccurate
  3. marked dilutional effect
79
Q

what is the dilutional effect

A

inspired concentrations of inhalant & oxygen may differ from those set

80
Q

can the anesthetic depth be altered quickly in closed system

A

slow to adjust

81
Q

what are the features of semi-closed systems

A

use higher FGF than for closed systems but still less than in non-RB systems

excess gas spills via APL valve

82
Q

what is the minimum FGF of semi-closed systems

A

20ml/kg/min O2

83
Q

what are the differences between closed and semi-closed systems

A
  1. flowmeters should be accurate
  2. vaporizers should be accurate
  3. less dilution effect (though it still occurs) –> easier to adjust anesthetic depth, N2O can be used safely
84
Q

how do you denitrogenate after post-induction in rebreathing systems

A

use high FGF for the first 10-15 min of anesthesia with closed or semi-closed rebreathing systems (4L/min O2)

after this lower FGF to closed/semi-closed levels (1L/min O2)

85
Q

what is the concern of using nitrous oxide in rebreathing systems

A

N2O accumulates reducing O2 concentration

don’t use in closed systems without monitoring FiO2

can use in semi-closed systems in 1:1 mixture with O2

86
Q

what system is this

A

to & fro system

87
Q

what are the components of circle system (3)

A
  1. soda lime canister
  2. reservoir bag
  3. unidirectional valves (flow through soda lime is unidirectional)
88
Q

what size of patients are circle systems used for

A

>15 kg (pediatric circles available)

89
Q

what system is this and how does the gas flow through them

A
90
Q

what system is this

A

circle

91
Q

describe the main differences between non-RB and RB systems

A
92
Q

what system should you use for patients <10kg

A

T-piece or miniLack

93
Q

what system should you use for patients 10-15kg

A

bain, lack, (circle)

94
Q

what system should you use for patients <15kg

A

bain, lack or circle

95
Q

what is a hybrid system

A

humphrey ADE system

96
Q

what is a hybrid system used for

A

patients 10kg and over

97
Q

how does a hybrid system work for paitents 10kg and over

A

use a soda lime canister used as a circle

98
Q

how does a hybrid system work for paitents <10kg

A

remove soda lime canister & use in non-RB mode

with lever up for spont breathing = miniLack

with lever down for IPPV = bain/T-piece

99
Q

what are the pros and cons of humphrey ADE

A

pros: easy to change from spont breathing to IPPV + suitable for wide range of patient sizes + economical to run
cons: expensive to purchase

Module 14 (29 decks)

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