Brainscape's Knowledge GenomeTM

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


See full index

Anesthesia Equipment > Pressure-Volume & Flow-Volume Loops > Flashcards

Pressure-Volume & Flow-Volume Loops Flashcards

0
Q

Simple changes to what 3 things can create discrepancies between set and delivered TVs?

A
  1. Fresh gas flow (FGF)
  2. Respiratory rate (RR)
  3. I:E ratio
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

Compliance of the breathing circuit: For every 1 cm H20 pressure in the circuit ______ ml of volume is lost per breath r/t tubing distention and compressible volume.

A

2-8 ml

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

The greatest TV augmentation occurs at the ….?

A
  • Highest FGF (10L/min)
  • Highest I:E (1:1)
  • lowest RR (8)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The lowest TV augmentation occurs at the …?

A
  • Lowest FGF (0.25 L/min)
  • Lowest I:E (1:3)
  • Highest RR (16)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The magnitude of delivered TV augmentation is ____________?

A
  • Independent of the volume control TV setting

* Thus, the percent increase is much larger for pediatric settings

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

What 2 methods increase TV accuracy?

A
  1. Fresh gas decoupling

2. Fresh gas compensation

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

What is fresh gas decoupling?

A
  • Fresh gas is diverted by a decoupling valve to the manual breathing bag, and is thus not added to the delivered tidal volume.
  • This helps ensure that the set and delivered tidal volumes are equal.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is fresh gas compensation (volume/flow sensors)?

A

The volume and flow sensors provide feedback which allows the ventilator to adjust the delivered tidal volume so that it matches the set tidal volume in spite of changes in the total fresh gas flow.

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

How is MV (Minute Ventilation) calculated?

A

MV = RR x TV

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

A pause at the end of inspiration is a ventilator option to…?

A
  • Benefit alveolar gas distribution from the compliant to the less-complaint alveoli while maintenance of lower airway pressures.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the usual I:E ratio?

A

1:2

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

Longer inspiratory times generally improve oxygenation by:______?

A
  1. Increases the mean airway pressure (longer period of high pressure increases mean airway pressure over entire respiratory cycle)
  2. Allows re-distribution of gas from more compliant alveoli to less compliant alveoli
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the disadvantages of longer inspiratory times?

A
  1. Increases the risk of gas trapping, intrinsic PEEP, and barotrauma by reducing expiratory time
  2. Less well tolerated by the patient - requires deeper sedation levels
  3. Decreases peak pressure by decreasing inspiratory flow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is compliance?

A
  • change in volume/change in pressure
  • measurement (ml/cmH2O) of how well the lung-thoracic system can change its total volume as changing pressure is applied
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Compliance = ?

A
  • Expiratory TV / (pressure at the end of inspiration - pressure at the end of expiration)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is normal adult compliance?

A

35-100 ml/cmH2O

16
Q

What is normal pediatric compliance?

A

> 15 ml/cmH2O

17
Q

Compliance can easily be viewed via ___________?

A

Pressure-Volume Loops

18
Q

How will decreased compliance be represented on pressure-volume loops?

A
  • The slope of the pressure-volume loop will move toward the horizontal/x-axis (more pressure is required to fill the lungs to a given volume)
19
Q

How will increased compliance be represented on pressure-volume loops?

A

The slope of the pressure-volume loop will move towards the vertical/y-axis (less pressure is required to fill the lungs to a given volume)

20
Q

What is resistance (Raw)?

A
  • The relationship between the pressure difference across the airway (between the mouth and the alveoli) and the rate at which gas flows through the airway
21
Q

What is the most probable reason for a non-closing loop on the Flow-Volume Loop?

A

Leak

22
Q

On a Pressure-Volume Loop, spontaneous ventilation is represented how?

A
  • negative pressure
23
Q

What do pressure-volume loops provide?

A
  • information on dynamic trends of respiratory compliance
24
Q

What do flow-volume loops provide?

A
  • information on dynamic trends of respiratory resistance
25
Q

Pressure-Volume Compliance Loop: Static?

A
  • ICU vents can provide rapid airway occlusion at end-inspiration. During the pause, flow rapidly drops to zero and TV is briefly trapped inside the lung, at this point static airway pressure can be measured.
  • Absence of flow equals alveolar pressure, which reflects the elastic retraction of the entire respiratory system
26
Q

Pressure-volume compliance loop: Quasi-static?

A
  • Obtained when inspiratory pause is shorter than 2 seconds & does not always reflect alveolar pressure
27
Q

Pressure-volume compliance loop: Dynamic?

A
  • Obtained without flow interruption
28
Q

What is static compliance?

A
  • Mirrors the elastic features of the respiratory system

- Only affected by variations in volume and/or complaince

29
Q

What is dynamic compliance?

A
  • Provides information on both elastic & resistive (flow-dependent) components of the airways and endotracheal tube
  • Affected by variations in volume, compliance, airway secretions, bronchospasm, diameter of OET
30
Q

Plateau pressures greater than _____ cm H2O are associated with shear lung damage.

A

35

31
Q

What is normal lung and chest compliance?

A

50-80 ml/cm H2O

32
Q

What are the advantages of PEEP?

A
  • Improved PaO2
  • Reduces right –> left intrapulmonary shunting (PEEP expands collapsed, but perfused alveoli)
  • Increases FRC through maximal alveolar recruitment
  • Prevents airway & alveolar closure at end-expiration
33
Q

What are disadvantages of PEEP?

A
  • Excessive distention of alveoli may cause compression of pulmonary vasculature
  • decreased preload
  • increased CVP
  • increased risk for barotrauma
  • redistribution of pulmonary blood flow
  • promotion of pulmonary edema-impeding lymphatic drainage from lungs
34
Q

What is “Best” PEEP?

A
  • level of PEEP that produces maximal PaO2 with an FiO2 less than or equal to 0.5 with the least decrement in CO and over distention of alveoli

Anesthesia Equipment (14 decks)

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