Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Anaesthesia Certificate > Breathing Systems > Flashcards

Breathing Systems Flashcards

(112 cards)

Start Studying
1
Q

factors influencing choice of breathing system (7)

A
  • Resistance
  • mechanical dead space
  • equipment drag
  • use of ventilation
  • Fresh gas flow requirement
  • use of nitrous oxide
  • valve position and scavenging
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Calculation to select appropriately sized reservoir bag

A

3 to 6 times the animals tidal volume

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

Function of the APL valve

A

Allow exhaled gases and excess fresh gas flow to leave the breathing system but to not allow room air to enter the breathing system

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

Coaxial configuration

A

One tube runs within the other

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

Theoretical advantage of coaxial breathing systems

A

Expired air warming inspired air

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

Disadvantage of coaxial breathing system

A

Risk of disconnection, fracture of kinking of the inner tube

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

Parallel configuration

A

Two tubes run parallel to one another

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

Advantages of parallel breathing systems

A

Damage to tubes more easily detected

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

Disadvantages to parallel breathing systems

A

No warming of inspired air, may exert more equiptment drag

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

Advantages of soda lime in rebreathing systems

A

Absorbs exhaled carbon dioxide and creates an exothermic reaction to help maintain the animals body temperature and humidify inspired gas

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

Exhausted soda lime produces

A

Carbon monoxide

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

When should soda lime be changed

A

When the capnograph shows rebreathing or when 50% of the granules have changed colour

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

What is the definition of tidal volume?

A

Volume of gas entering the lung with each inspiration

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

Halving the radius of the breathing system tubing increases the resistance by which factor ?

A

16 x

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

Why should gloved be worn when changing soda lime?

A

The prevent skin irritation/burns

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

What is Poiseuille’s law

A

Describes the relationship between the resistance of the tubing and the diameter and length of the tubing during laminar flow

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

Poiseuille’s law equation

A

R = 8ηl / πr4 where R is resistance, η is the viscosity of the substance, l and r are the length and radius of the tubing.

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

Summary of Poiseuille’s law equation explanation

A

The resistance to airflow is inversely proportional to the radius of the tubing, so halving the radius of the tubing increases the resistance 16 fold. Doubling the length of the tubing has a less profound effect and doubles the resistance

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

Hypercapnia may cause: (5)

A

Respiratory acidosis
Tachycardia
Increased blood pressure
Tachypnoea
Cardiac arrhythmias

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

How non-rebreathing systems remove expired carbon dioxide

A

Using relatively high fresh gas flow rates that get flushed into the scavenging

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

Advantages to using a non rebreathing system

A

Rapid changes in depths of anaesthesia possible
Can used nitrous oxide
Cheap to purchase and maintain
Lower resistance for small animals

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

Disadvantages of using a non-rebreathing system (4)

A

High fresh gas flows and volatile agent requirements
Heat and moisture lost
Not all systems can be used for prolonged ventilation
Flow rate may be impractically high for larger animals

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

Mucocilary escalator

A

The self-cleaning mechanism of the airways

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

Circuit factor for the Bain

A

2-3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Circuit factor for ayre’s t-piece
2-3
26
Circuit factor for the McGill
0.8 - 1
27
Circuit factor for lack
0.8 - 1
28
How to verify correct placement of ET tube
- Presence of a trace on the capnograph - Direct visualisation of the tube passing through the larynx - condensation on the inside of the tube during breathing - simultaneous movement of the thorax and reservoir bag
29
Recommended cuff pressure for ET tubes
20-30 cmH2O
30
Advantage of using a supraglottic airway device
Reducing trauma to the airway with repeated attempts to intubate
31
Disadvantages of supraglottic airway devices
They do not fully protect the airway against aspiration and it can be difficult to achieve an effective seal during IPPV. Capnography is required for monitoring
32
Straight laryngoscope blade
Miller blade
33
Curved laryngoscope blade
Macintosh blade
34
PaCO2 in conscious animals
35-45mmHg
35
Compliance (ventilation)
The volume change per unit pressure Classified into thoracic wall, lung or total lung compliance
36
Hysteresis
The inspiration curve is different to the expiratory curve on a graph of lung compliance
37
Produced by modern inhalant anaesthetics in desiccated soda lime
Carbon monoxide
38
When should soda lime be changed
Depending on the manufactures instructions, when 50% of the granules have changed colour or when rebreathing is seen on Capnography
39
Calculation for minute volume
Tidal volume x respiratory rate
40
Approximation for minute volume
200ml/kg/min
41
When using nitrous oxide what should be done at the end of anaesthesia?
The nitrous oxide turned off 5 minutes before the end and oxygen flow increased to 3L/min
42
Why should nitrous oxide be turned off 5 minutes before the end of anaesthesia?
To prevent diffusion hypoxia
43
Advantages of reducing fresh gas flows
Enable conservation of oxygen and anaesthetic gases Reduces atmospheric pollution
44
Weight range of the Bain circuit
8+kg
45
Circuit factor of Magill
1 to 1.5
46
Can a Bain be used for IPPV?
Yes
47
resistance of a Bain
Moderate
48
Drag on a Bain
Low
49
Dead space of a Bain
Low/moderate
50
Position of valves and scavenging on a Bain
Anaesthetic machine end
51
Position of the reservoir bag on the Bain
On the expiratory limb
52
classification of the Bain
Mapleson D
53
Classification of Ayres T-piece with Jackson Rees modification
Mapleson F
54
Weight range for Ayres t-piece
Up to 7.5-10kg
55
Can you do IPPV with an Ayres T-piece?
Yes
56
Dead space on an Ayres T-piece
Low
57
Drag on an Ayres T-piece
Low/Moderate
58
Classification of a Lack circuit
Mapleson A
59
Weight range for Lack
10+kg
60
Resistance for a coaxial lack
High
61
resistance for parallel lack
Lower than coaxial
62
Drag on a lack
Moderate
63
Dead space on a Lack
Moderate
64
Position of the valves and scavenging on a Lack
Anaesthetic machine end
65
Position of the reservoir bag on a Lack
On the inspiration limb
66
Can a Lack be used for IPPV?
No, not for prolonged IPPV although can be used for short periods if the crash gas flow is increased
67
Size range of the mini Lack
Up to 10kg
68
Classification of the Magill
Mapleson A
69
Weight range for the Magill
5+kg
70
Can a Magill be used for IPPV?
No
71
Resistance of the Magill
Moderate
72
Drag of the Magill
High
73
Dead space on a Magill
Moderate
74
Position of the valves on a Magill
Next to the patients head
75
Where does exhaled gas go in a rebreathing system?
Carson dioxide if absorbed by soda lime The remaining gases and anaesthetic vapour are recirculated into the breathing system, mixed with fresh gas and vapour from the anaesthetic machine to create a new minute of fresh gas and expired gas which is re-inhaled by the patient
76
Advantages to using a rebreathing system
Low fresh gas flows and volatile agent consumption Less was gases to contaminate the environment Heat and moisture conserved Easy to change between spontaneous ventilation and IPPV
77
Disadvantages of rebreathing system
Slower changes in depth of anaesthesia Nitrous oxide should not be used at low FGFR Higher resistance - problematic in smaller animals May contribute to patient hyperthermia
78
Calculation for approximations of metabolic oxygen consumption
5-10ml/kg/min
79
Oxygen used with closed rebreathing system
The animals metabolic oxygen requirement 5-10ml/kg/min
80
Advantages of using closed breathing systems
Preserves heat and moisture and is very economic
81
Disadvantages of using closed breathing systems
Very small margin for error Very accurate flow meters required Some vaporisers do not function as expected at very low flows The depth of anaesthesia is very slow to change Nitrous oxide cannot be used
82
ratio of nitrous oxide to oxygen when using open low flow rebreathing system
1:1
83
Advantages of using low flow rebreathing system
More achievable in practice Nitrous oxide can be used if inspired oxygen concentration is being measured
84
Disadvantages of low flow on rebreathing systems
Less heat and moisture is persevered compared to closed valve Less economic than closed systems Volatile agent no as accurate Depth of anaesthesia is slow to change
85
Denitrogenation
Higher fresh gas flows used at he start of anaesthesia for the first 10-15 minutes
86
Reasons for higher FGFR for the first 10-15 minutes of anaesthesia when using a rebreathing system
Enables the inhalant agent concentration to be established quicker during the uptake phase of anaesthesia. Higher flows can be used to change the depth of anaesthesia quickly after changing the vaporiser setting.
87
Adequate flow rate on a circle system for any animals weighing less than 50kg
500ml-1L/min
88
Can the circle be used for IPPV
Yes
89
Resistance of the circle system
Higher than non-rebreathing systems
90
Drag of circle system
Moderate/high
91
Valve and scavenging position on the circle
Away from the patient
92
Can IPPV be done using a to and fro system?
Yes but valve position make it inconvenient
93
Resistance of the to and fro system
Moderate
94
Drag of the to and fro system
High
95
Reasons to and fro system used less in veterinary practice
Older versions are difficult to scavenging Risk of chemical bronchiolitis Mechanical dead space increases over time and soda lime becomes exhausted Risk of gas ‘channeling’ over the top of soda lime if the canister is no in the horizontal position therefore carbon dioxide may not be removed
96
Mapleson ratings of the Humphrey ADE
A D and E
97
Features of the Humphrey ADE Stetson
Lower fresh gas flow needed than lack, t-piece and Bain so more economical Possible to attaché a removable soda lime canister so that it functions as a circle
98
Additional chest required to be done on a Bain
Check the integrity of the inspiratory inner tube by occluding the tube and observe the flowmeter bobbin dipping
99
IPPVs physiological effects
IPPV results in a reverse in interpleural pressures (Inspiration occurs when interpleural pressure is increases companies to spontaneous ventilation where inspiration occurs when interpleural pressure is decreased
100
Barotrauma
Caused by high airway pressures and characterised by air outside the alveoli and a consequence of alveolar rupture (pneumothorax)
101
Volutrauma
Causes alterations in gaseous exchange, thought to be caused by repeated stretch and overinflation of the alveoli
102
Risk of IPPV being performed with a face mask
Oxygen is forced into the stomach as well and the trachea and the distended viscus can press on the diaphragm compromising ventilation
103
Volume controlled ventilator
Delivers a constant flow of gas to the patient
104
Pressure controlled ventilator
Delivers a constant pressure of gas
105
Action of Volume-controlled and time cycled ventilation
Ventilators deliver a constant flow of gas to the animals lungs over a defined period of time. After the time has elapsed, expiration will begin.
106
Action of Volume-controlled and volume cycled ventilation
Deliver a constant flow of gas until the predetermined tidal volume (approx. 10ml/kg) is delivered. Increasing the flow will increase the respiratory rate and the pre-set tidal volume will be achieved quicker
107
Action of volume-controlled and pressure cycled ventilation
A constant flow of gas is delivered until a preset peak airway pressure (usually 10-15cmH2O in small animals) is reached at which point inspiration is terminated
108
Action of Pressure-controlled and time cycled ventilation
During inspiration, the pressure of the gas being delivered in maintained at a consistent level. Once the set pressure has been achieved the gas flow reduced to effectively “hold” the lungs at the pre-set pressure until the time that has been set has elapsed, at this point expiration begins
109
PEEP stands for
positive end expiratory pressure
110
CPAP stands for
Continuous positive airway pressure
111
Function of PEEP and CPAP
Aim to improve functional residual capacity by “holding the alveoli open” at the end of a breath.
112
Lung compliance definition
Volume change pre unit pressure change

Anaesthesia Certificate (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions