Ventilator Graphics

Ventilator Graphics

Charles Williams RRT, AE-C

v3.0

Learner Objective Objectives s

   

Understand the importance of monitoring and interpreting ventilator graphics. Learn the basic shapes of waveforms. Identify the different types of waveforms and loops available on most ventilators. Learn to use the graphics to identify patient/ventilator problems, and make the appropriate adjustments.

Why do we monitor ventilator graphics and waveforms? 

   

Allows practitioners to evaluate and troubleshoot the patient’s response to the ventilator. Monitor proper ventilator function. Monitor the patient’s disease status (Compliance and Airway Resistance). Assess response to therapy. Allow fine tuning of ventilator ventilator to decrease WOB, optimize ventilation, and maximize m aximize patient comfort.

Ventilator graphics graphics are waveforms waveforms that that reflect the patient-ventilator system and their interaction. interaction.

Learning to analyze and interpret ventilator ventilator graphics can be a very useful tool for respiratory therapists. The graphics can assist therapists in making recommendations and necessary adjustments to the ventilator ventilator..

Practitioners can use ventilator graphics to assess the condition of a patient’s patient’s lungs in the same way a cardiologist uses the graphics of an EKG to view the condition of the heart.

Puritan Bennett 840 ®

Hamilton Galileo ®

Drager Evita ® Respironics Esprit ®

The graphics display will have different appearances and configurations, depending on the make and model of ventilator.

Basic Shapes of Waveforms

Scalars Time

Loops

Basic waveforms waveforms that plot pressure, flow, or volume against time. Time is on the x-axis. Waveforms that combine pressure or flow, with volume. (P/V or F/V). There is no time component.


Generally, Generally, The ascending and descending ramps can be considered the same as exponential ramps, So you really only need to remember three shapes: Square,, Ramp Square Ramp,, and Sine waves.


Squares

Ramps

Sine

Squares represent fixed, constant, or set parameters. For example, pressure setting in Pressure Control mode. Ramps represent variables. Will vary with changes in lung characteristics. Ramps can be accelerating or decelerating.

Sine waves are seen with spontaneous, spontaneous, unassisted breathing.

Basic Shapes of Waveforms Question: What are the three basic shapes of waveforms? Answer: 

Square  Ramp  Sine

Types of Waveforms

3

Each time the ventilator delivers a breath, there are waveforms waveforms that are displayed on the graphics screen: Pressure, Flow, Flow, and Volume.

Types of Waveforms

(20)

The pressure scalar displays the amount of pressure generated generated with each breath. The scale is located on the left side in cmH20. The peak pressure of these breaths are about 22 cmH20.

Types of Waveforms

The flow scalar displays the flowrate, or speed associated with each breath. In this example, the breath begins at a fast flowrate and then decreases during inspiration.

Types of Waveforms

(375 ml)

(250 ml)

Volume in

Volume out

The volume scalar displays the amount of volume inhaled and exhaled with each breath. The scale is located on the left side in ml’s. These breaths are about 370 ml.

Types of Waveforms Question: What 3 waveforms are displayed on the graphics screen? Answer: Pressure  Flow  Volume 

Types of Waveforms

Pressure Modes

Volume Modes

Pressure

Pressure

square

Flow

Flow

square

Volume

Volume

Volume Control SIMV (Vol. Control)

Pressure Control *PRVC SIMV (PRVC) SIMV (Press. Control)

Pressure Support *Volume Support

* Considered Considered a “dual-mode” of ventilation

Types of Waveforms Volume Modes

Pressure Modes

Pressure

Pressure

Flow

Flow

Note: Some ventilators ventilators allow you select the desired flow pattern for for different modes.

Types of Waveforms SIMV (Vol. Control) + Pressure Support

Volume Breath

Pressure Breath

Pressure Breath

Volume Breath

For combination combination modes, such as SIMV/PS SIMV/PS,, the graphics can show both volume breaths and pressure breaths.

Pressure Waveform Pressure Modes

Volume Modes

Pressure

Pressure

square

Flow

Flow

square

Volume

Volume


Pressure Control PRVC SIMV (PRVC) SIMV (Press. Control)

Pressure Support Volume Support

Pressure Waveform The pressure waveform can be used to assess: 

Breath Type (Pressure vs. Volume)



Air trapping (auto-PEEP)



Airway Obstruction



Bronchodilator Bronchodilator Response



Respiratory Respiratory Mechanics (Compliance/Raw)



Active Exhalation



PIP, Pplat



CPAP, PEEP



Asynchrony



Triggering rigger ing Effort

Pressure Waveform Volume Modes

Pressure Modes

If the ventilator delivers a volume breath, the shape of the pressure waveform will be a ramp.

If the ventilator delivers a pressure breath, breath, the shape of the pressure waveform will have a square shape.

square

Ramp = variable

Square = constant

Pressure Waveform Volume Modes

Pressure Modes

This means that pressure will vary, depending on lung characteristics; (compliance, airway resistance, etc.)

This means that pressure will remain the same during inspiration.

Ramp = variable

Square = constant

Pressure Waveform Pressure waveform

Pressure waveform with “inspiratory pause” PIP

Pplat

Raw

Setting an inspiratory inspiratory pause time or performing an insp. hold maneuver, will create a plateau on the waveform. The plateau allows for easy visualization of PIP, Pplat, and Raw. Adding an inspiratory pause time may improve distribution of ventilation.

Pressure Waveform I-time Peak Inspiratory Pressure (PIP) Plateau Pressure (Pplat) Alveolar Distending Pressure

Elastic Recoil Pressure

= Mean Airway Pressure (MAP)

Pressure Waveform

10 5

PEEP

PEEP No patient effort

PEEP Patient triggered breath

The baseline for the pressure waveform will be higher, when Positive EndExpiratory Expiratory Pressure (PEEP), is added. PEEP is also a component of mean airway airway pressure (MAP). With patient triggered breaths, there will be a negative deflection just before the waveform.

Pressure Waveform

I-time

Peak Inspiratory Pressure (PIP)

Pressure Waveform Increased Airway Airway Resistance Resistance (Raw) PIP

Decreased Compliance PIP

(Increased Raw) Pplat

(Normal Raw) Pplat

Increased airway resistance (Raw) will cause the PIP to increase. The Pplat pressure remains normal. Decreased lung compliance will cause the entire waveform to increase in size. The difference difference between PIP and Pplat will remain normal.

Pressure Waveform Air-Trapping Air-Trapping (auto-PEEP)

“Expiratory hold” maneuver

PEEP

auto-PEEP (trapped air) PEEP

auto-PEEP Set PEEP

Total-PEEP

+9 +5 +14

While performing an expiratory hold maneuver, maneuver, trapped air will cause the waveform to rise above the baseline. An acceptable amount of auto-PEEP should be < 5cm H2O.

Pressure Waveform Label the parts: A B C =G

E

F

A= Inspiratory Time

D= Airway Resistance (Raw)

B= Peak Insp. Pressure (PIP)

E= Alveolar Distending Pressure

C= Plateau Pressure (Pplat)

F= Elastic Recoil Pressure

G= Mean Airway Pressure (MAP)

Pressure Waveform Question: What does this pressure waveform waveform show?

Answer: Increased airway resistance

Flow Wavefor Waveform m Pressure Modes

Volume Modes

Pressure

Pressure

square

Flow

Flow

square

Volume

Volume




Flow Wavefor Waveform m If a volume breath is delivered, the shape of the waveform will be a square. This means that the flowrate stays the same during inspiration.

If a pressure breath is delivered, the shape of the waveform will be a ramp. This means that the flowrate starts out high and then decreases during inspiration.

Square = constant

Ramp = variable

Flow Wavefor Waveform m The flow waveform can be used to assess: 

Air trapping (auto-PEEP)



Airway Obstruction



I-Time adjustment



Bronchodilator Bronchodilator Response



Active Exhalation



Breath Type (Pressure vs. Volume)



Inspiratory Inspiratory Flow



Asynchrony



Triggering riggeri ng Effort

Flow Wavefor Waveform m Volume Modes

I-time

Pressure Modes

I-time Set Flowrate

E-time

PEF

PIF

E-time

PEF

Flow Wavefor Waveform m

The decelerating flow pattern may be preferred over the constant flow pattern. The same tidal volume can be delivered, but with a lower peak pressure.

Flow Wavefor Waveform m Airway Obstruction PIF

Inspiratory flow takes longer to return to baseline

= Normal PEF

In patients with severe airway obstruction, the flow waveform can become a plateau. This can become a problem in flow-cycled modes, such as Pressure Support. (asynchrony, W.O.B.)

Flow Wavefor Waveform m Auto-Peep (air trapping)

Expiratory flow does not return to baseline

= Normal

Start of next breath

If the expiratory portion of the waveform doesn’t return to baseline before the start of the next breath starts, there could be air trapping. (emphysema, improperly set I:E ratio).

Flow Wavefor Waveform m Bronchodilator Response Pre-Bronchodilator

Post-Bronchodilator

I-time

Prolonged E-time

Normal E-time

Reduced PEF Improved PEF

To assess response to bronchodilator therapy, you should see an increase in peak expiratory flow rate. Also, the expiratory portion of the curve should return to baseline sooner.

Flow Wavefor Waveform m

Pressure Control, PRVC (Time-cycled)

Adjusting I-Time

Pressure Support, Volume Support (Flow-cycled)

Pressure

Flow

Inspiration should end when flow reaches baseline

Inspiration ends before flow reaches baseline

Volume

In Pressure modes that are time-cycled (Pressure Control), the flow waveform should return to baseline. In Pressure modes that are flow-cycled (Pressure Support), the flow waveform does not return to baseline. (Adjustment is made with Insp. Cycle Off %)

Flow Wavefor Waveform m Adjusting I-Time I-time

I-time

(Too short)

(Too long)

Inspiration should end here

Not here

Inspiration should end here

Not here

Remember, this applies to Control modes with a decelerating flow (ramp). This includes Pressure Control, PRVC, SIMV (Press. Control), and SIMV (PRVC). Volume Control and SIMV (Vol. Control) have a constant flow.

Flow Wavefor Waveform m Question: What does this flow pattern show?

Answer: Air trapping (auto-PEEP)

Flow Wavefor Waveform m Question: To assess improvement after a breathing treatment you should see what? Pre-Bronchodilator

Post-Bronchodilator

I-time

Normal E-time

Improved PEF

Answer: Improved PEF and shorter E-time

Volum olume e Waveform Waveform Pressure Modes

Volume Modes

Pressure

Pressure

square

Flow

Flow

square

Volume

Volume




Volum olume e Waveform Waveform Volume Modes

The Volume waveform will generally have a “mountain peak” shape regardless of what mode, of ventilation.

Pressure Modes

There may also be a small plateau at the top of the volume waveform

Volum olume e Waveform Waveform The volume waveform can be used to assess: 

Tidal Volume  Active Exhalation  Asynchrony  Airway Resistance 

Air trapping (auto-PEEP)  Leaks

Volum olume e Waveform Waveform

Inspiratory Tidal Volume

Exhaled volume should return to baseline

Volum olume e Waveform Waveform Air-Trapping or Leak

Volume Loss

If the exhalation side of the waveform doesn’t return to baseline, it could be from air-trapping (improperly set I-time, emphysema), or there could be a leak (ET tube, vent circuit, chest tube, etc.)

Volum olume e Waveform Waveform Increased Airway Resistance = Normal

Exhaled volume taking longer to get out

If there is an increase in airway air way resistance, resistance, it will take longer for the exhaled volume to return to baseline. This is more commonly seen with a damp or blocked expirat expiratory ory filter/valve.

Volum olume e Waveform Waveform Question: The volume waveform waveform is most commonly used to assess ass ess which two situations?

Answer: Air trapping and leaks

Is it Volume Volume or Pressure? Pressure Modes

Volume Modes

Pressure

Pressure

Flow

Volume

square

square

Flow

Volume

Here is an easy way to tell what type of mode (or type of breath) this is, just by looking at the graphics. Look at the pressure waveform and remember the letter “ P”.

With Pressure breaths…The Pressure waveform…will have a Plateau.

Is it Volume Volume or Pressure? The pressure waveform has a plateau

The flow waveform doesn't return to baseline

Is it a Volume or Pressure mode? (Hint: look at the pressure waveform) Is it a Control mode or Support mode? (Hint: look at the flow waveform)

Volume Modes

Pressure Modes

Ventilat entilator or Graphics Graphics

PressureVolume Loops

Pressure-V PressureVolume Loops

• Volume is plotted on the y-axis, Pressure on the x-axis. • Inspiratory curve is upward, Expiratory curve is downward. • Spontaneous breaths go clockwise and positive pressure breaths go counterclockwise. counterclockwise. • The bottom of the loop will be at the set PEEP level. It will be at 0 if there’s no PEEP set.

• If an imaginary line is drawn down the middle of the loop, the area to the right represents inspiratory inspiratory resistance and the area to the left represents expiratory expiratory resistance.


The Pressure/Volume Pressure/Volume Loop can be used to assess: 

Lung Overdistention  Airway Obstruction  Bronchodilator Response  Respiratory Respiratory Mechanics (C/Raw)  Flow Starvation  Leaks  WOB  Triggering rigger ing Effort Effort


Volume Modes

In Volume modes, the P/V loop will normally have a “football” shape.

Pressure Modes

In Pressure modes, the P/V loop will have a “square” appearance.


Dynamic Compliance (Cdyn)

500

250

5

10

15

20

If PEEP is added, the loop will begin at the set PEEP level. The top part of the P/V loop represents Dynamic compliance (Cdyn). Cdyn = Δvolume/Δpressure


500

Plateau

250

10

20

Pressure modes deliver a set “constant” pressure during inspiration, creating a plateau on the pressure waveform. This will also create a plateau on the P/V loop.

Pressure-V PressureVolume Loops Overdistention

“beaking”

500

250

10

20

Pressure continues continues to increase with little or no change in volume, creating a “bird beak”. Fix by reducing amount of tidal volume delivered.

Pressure-V PressureVolume Loops Triggering Effort

WOB

tail

If the patient is triggering the breath, you will see a “crossover” “crossover” or “tail”, “tail”, at the beginning of the loop. As WOB increases, the tail will become larger.

Pressure-V PressureVolume Loops Airway Resistance 500

Increased expiratory resistance: secretions, bronchospasm, etc.

250

Increased inspiratory resistance: 10

20

ETT size too small, tube kinked, patient biting tube, etc.

As airway resistance increases, the loop will become wider. An increase in expiratory resistance is more commonly seen.


Increased Compliance

Decreased Compliance

Cdyn 500

500

250

250

Cdyn

10

20

10

20

Cdyn = Dynamic Compliance Examples: Examples: (Δvolume/Δpressure) Emphysema, ARDS, CHF, CHF, Post Surfactant Therapy Atelectasis, Pleural Effusions


Increased Compliance

Decreased Compliance

600/12 Cdyn = 50 ml/cmH20

600

500

500

Increased volume

300/22 Cdyn = 14 ml/cmH20

300

250

250 Decreased volume

12

Decreased pressure

10

22

20

10

Increased pressure

20

VT – ) Examples: Examples: Cdyn = PIP - PEEP Emphysema, ARDS, CHF, CHF, Post Surfactant Therapy Atelectasis, Pleural Effusions (Tubing compliance

Pressure-V PressureVolume Loops A Leak 500

250

10

20

The expiratory expiratory portion of the loop does not return back to baseline. This indicates indicates that there is a leak.

Pressure-V PressureVolume Loops point of alveolar collapse

Upper Inflection Point Third Inflection Point

500

250

Lower Inflection Point 10

point of alveolar opening

20

Inflection Points Some lung protection strategies strategies for treating ARDS, suggest setting PEEP just above the lower inflection point, to hold the alveoli open.


500

250

10

20

Question: What does this loop show? Answer: Decreased lung compliance. (ARDS, CHF, Atelectasis)


500

250

5

15

30

Question: What is happening when there is a bird beak appearance on the P/V loop? Answer: Lung overdistention. Pressure continues to increase, with no increase in volume.


Question: What does this P/V loop show? Answer: Increased expiratory airway resistance (Raw).

Ventilat entilator or Graphics Graphics 40

20 200 0

20

FlowVolume Loops

40

600

Flow- Volume Loops

• Flow is plotted on the y axis and volume on the x axis • Flow volume loops loops used for ventilator graphics are the same as ones used for Pulmonary Function Testing, (usually upside down). • Inspiration is above the horizontal line and expiration is below. below. • The shape of the inspiratory portion of the curve will match the flow waveform. • The shape of the exp flow curve represents passive exhalation. • Can be used to determine the PIF, PEF, and Vt • Looks circular with spontaneous breaths

Flow-Volume Loops The Flow/Volume Flow/Volume Loop can be used to assess:         

Air trapping Airway Obstruction Airway Resistance Bronchodilator Response Insp/Exp Flow Leaks Water Wa ter or Secretion accumulation Flow Starvation Asynchrony

Flow-Volume Loops 60

40

20

0

Begin Inspiration 200

Begin Expiration 400

600

-20

-40

-60

Peak Expiratory Flow (PEF)

Flow-Volume Loops Constant Flow

0

Variable Flow

0

The shape of the inspiratory inspiratory portion of the curve will match the flow waveform.

Flow-Volume Loops PEF

Airway Obstruction Reduced PEF “scooping”

0

PFT view

0

With conditions that cause airway obstruction (asthma), you will see a lower peak expiratory flow (PEF). You should also see “scooping” on the expiratory portion of the loop. *Scooping means that the volume is being exhaled at a slower rate because of obstruction.

Flow-Volume Loops Airway Obstruction

0

Ventilator graphic view

0

“scooping”

Reduced Peak Flow (PEF)

The F-V loop appears “upside down” on most ventilators.


Air Trapping or Leaks 40

20

0 200

400

600

-20

loss of volume -40

= Normal -60

If there is air-tr a ir-trapping, apping, or a leak, the loop will not meet at the starting point where inhalation starts and exhalation ends.

Flow-Volume Loops Water or Secretions

If there is a collection of water in the ventilator circuit or a build up of secretions, you you will see a jagged, “sawtoothed ” pattern.

Flow-Volume Loops

20

0

Begin Inspiration 200

-60

400

Begin Expiration 600

Peak Expiratory Flow (PEF)

What points on this F/V loop do the arrows indicate?


40

20

0 200

400

600

-20

-40

-60

Question: What does this F/V loop show? Answer: There is air-trapping or a leak. (ETT cuff, vent circuit)

Flow-Volume Loops

0

0

Question: What What is the term used to describe the part of the loop indicated by the arrow? What causes it? Answer: This is known as “scooping”. It’s caused by small airway obstruction.

Asynchrony (out of sync)

Flow Starvation

The inspiratory portion of the pressure waveform shows a “dip”. Because of an inadequate flowrate , the patient is “sucking in” attempting to get more air. This causes a drop in pressure. A main disadvantage of constant flow modes (e.g. Volume Control), is that it may not meet the patient’s inspiratory demands.

Asynchrony (out of sync) “Dip”

Flow Starvation Ventilator detects inadequate flow

Some ventilators have an adaptive flow system that will automatically increase flow to try and meet the patient’s demand. Notice that on the next breath, the flowrate has been increased.

Asynchrony (out of sync)

F/V Loop

P/V Loop

Any “dips” or irregular shaped loops are an indication of asynchrony.

Air-Trapping (auto-PEEP) Causes: • Insufficient expiratory time

• Early collapse of unstable alveoli/airways during exhalation

How to Identify it on the graphics: • Pressure waveform: While performing an expiratory hold, the waveform rises above baseline.

• Flow waveform: The expiratory flow wave doesn’t return to baseline before the next breath begins. • Volume waveform: The expiratory portion doesn’t return to baseline. • Flow/Volume Flow/Volume Loop: Lo op: The loop doesn’t return completely to baseline • Pressure/Volume Pressure/Volume Loop: The loop doesn’t return completely to baseline

How to Fix: • Give a bronchodilator treatment, adjust I-time, increase flow, adjust PEEP.

Airway Resistance Changes Causes: • • • • • •

Bronchospasm ETT problems (too small, kinked, obstructed) High flow rate Secretion build-up Damp or blocked expiratory valve/filter Water in the HME

How to identify it on the graphics: Pressure waveform: PIP increases, but the plateau stays the same Flow waveform: It takes longer for the exp side to reach baseline Volume waveform: It takes longer for the exp curve to reach the baseline Pressure/Volume Pressure/Volume loop: The loop will be wider. Increased insp. resistance will cause it to bulge to the right. Increased exp resistance will cause it to bulge to the left. • Flow/Volume Flow/Volume loop: loop : decreased exp flow, scooping on the exp curve

• • • •

How to fix: • Give a bronchodilator treatment, suction patient, drain water, change HME, change ETT, add a bite block, reduce flowrate, change exp filter .

Compliance Changes Decreased compliance Causes • • • • • • • • •

ARDS Atelectasis Abdominal distension CHF Consolidation Fibrosis Overdistention Pneumothorax Pleural effusion

How to identify it on the graphics: • Pressure wave: PIP and plateau both increase • Pressure/Volume loop: lays more horizontal

Increased compliance Causes • Emphysema • Surfactant Therapy

How to identify it on the graphics: • Pressure wave: PIP and plateau both decrease • Pressure/Volume loop: Stands more vertical (upright)

Leaks Causes: • Expiratory leak: ETT cuff leak , chest tube leak, BP fistula, NG tube in trachea • Inspiratory leak: Loose connections, ventilator malfunction, faulty flow sensor

How to identify it on the graphics: • Volume waveform: Expiratory side of wave doesn’t return to baseline • Flow waveform: PEF decreased • Pressure/Volume loop: Exp side doesn’t return to the baseline

• Flow/Volume loop: Exp side doesn’t return to baseline

How to fix it: • Check possible causes listed above • Do a leak test and make sure all connections are tight

Asynchrony Causes: (Flow, Rate, or Triggering) • • •

Air hunger (flow starvation) Neurological Injury Improperly set sensitivity

How to identify it on the graphics: • • • •

Pressure waveform: waveform: Patient tries to inhale/exhale in the middle of the waveform, causing a dip in the pressure Flow waveform: Patient tries to inhale/exhale in the middle of the waveform, causing erratic flows/dips in the waveform Pressure/Volume loop: loop: Patient makes effort to breath causing dips on either inspiratory or expiratory side. Flow/Volume loop: Patient makes effort to breath causing dips in loop on either inspiratory or expiratory side.

How to fix it: • • • •

Try Try increasing the flow rate, rate, decreasing the I-time, or increasing the set rate to “capture the patient” to better meet meet the patient’s patient’s needs. Change the mode - sometimes changing from partial to full support will solve the problem. If neurological, may need paralytic or sedative. Adjust sensitivity

The pressure waveform does have a plateau, plateau, but it’s from an insp. hold or set insp. pause.

square

Is this a Volume or Pressure mode?


Adjusting Rise time & Insp. Cycle Off %

Rise Time

Rise Time

The inspiratory inspiratory rise time is the time it takes to reach full inspiratory flow, or pressure, at the start of each breath. The rise time can be expressed as a percentage percentage of the breath cycle time (%) or in seconds (s).

Rise Time The Bart Simpson “spike”

Rise time “overshoots” “overshoots” desired pressure

Too fast

If rise time is set too fast, you can get an overshoot in the pressure wave, creating a pressure “spike”. If this occurs, you need to increase the rise time. This makes the flow valve open more slowly.

Rise Time

1. Here we can see the “spike” on our graphics.

2. The rise time is set at .05 seconds

Rise Time

t ime, thus 3. When we increase the rise time,

4. …the waveform will return to

making it slower…

normal.

Rise Time

Too slow

If rise time is too slow, the pressure waveform will become more slanted, when it should look more square. This may affect Vt delivery and may not meet the patient’s inspiratory demands. If this occurs, you will need to decrease the rise time to open the valve faster.

Inspiratory Cycle off % (Flow – Cycling)

In flow-cycled modes, like Pressure Support & Volume Support, the inspiratory cycle off % determines when the ventilator cycles from inspiration to expiration. Also know as: •Inspiratory Inspiratory cycle threshold •Inspiratory flow termination, •Expiratory flow sensitivity, •Inspiratory Inspiratory flow cycle %, %, •E-cycle, etc…


pressure

Inspiration ends

flow

The inspiration ends when inspiratory flow has dropped to a specific flow value.


Peak Inspiratory Flow (PIF) 100% 75%

Flow

50% 25%

30%

In the above example, the ventilator is set to stop inspiration and begin expiration, at 30% of the patient’s peak inspiratory flow (PIF).


The ventilator will cycle off inspiration at this point…

…and then begin expiration


Exhalation “spike”

100%

100%

60% 10%

The cycle off percentage is too high (60%), cycling inspiration off too soon.

The cycle off percentage is too low (10%), This makes the breath too long.

This makes the breath too small. (not enough Vt.)

This forces the patient to actively exhale against the breath, creating a pressure “spike”. “spike”. (increases (inc reases WOB),

Rise Time Question: What does this waveform waveform show?

Answer: Rise time is too slow


Question: This pressure support breath is set to insp. cycle off at 80%, 50%, 30%, or 10%? 100% 75%

w o l F

50% 25%

Answer: 30%

Sources:

Ventilator Waveforms, • Rapid Interpretation of Ventilator Waugh, Harwood, and Deshpande

• Ventilator Waveform Analysis, • Anatomy of Servo-i Graphics, Maquet, inc. Ventilation, • Golden Moments in Mechanical Ventilation, Pearson

Maquet, inc.


Me using the flow waveform to adjust I-time

Thank You!

Ventilator Graphics

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