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Puritan Bennett™ 980 Ventilator System
Product Training Sample Practice Exercises
Breathe More
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Information and Best Practices for More Effective Training
About These Exercises
The Puritan Bennett™ 980 Ventilator
Series Product Training Sample
Practice Exercises provide examples
of the kinds of practice exercises that
hospital educators may find useful for
reinforcing basic-use principles
following product training.
Each sample exercise contains an
objective and overview of a feature, a
fictional patient profile and scenarios,
sample scenario and practice
questions, and an answer key.
The medical scenarios are presented
as teaching examples only. Please
always refer to the Operator’s Manual
for complete product instructions.
Parameters of care in actual use need
to be based on practitioners’ medical
judgement.
2
TABLE OF
CONTENTS
Table of Contents
Sample Puritan Bennett™ BiLevel 2.0 Software Practice Exercise............4
Objective.............................................................................................4
Overview of BiLevel Mode....................................................................4
Patient Profile......................................................................................5
Scenario and Scenario Questions..........................................................5
BiLevel Mode Practice Questions..........................................................8
Sample Puritan Bennett™ Leak Sync Software Practice Exercise............10
Objective...........................................................................................10
Overview of Leak Sync Software.........................................................10
Patient Profile....................................................................................12
Scenario and Scenario Questions........................................................12
Leak Sync Software Practice Questions...............................................14
Sample Puritan Bennett™ PAV™*+ Software Practice Exercise..............16
Objective...........................................................................................16
Overview of PAV™*+ Software...........................................................16
Patient Profile....................................................................................17
Scenario and Scenario Questions........................................................17
PAV™*+ Breath Type Practice Questions.............................................20
Sample Volume Control Plus (VC+) with an Adult Patient
Practice Exercise...............................................................................22
Objective...........................................................................................22
Overview of VC+................................................................................22
Patient Profile....................................................................................22
Scenario and Scenario Questions........................................................23
VC+ Adult Practice Questions.............................................................24
Answer Key............................................................................................26
3
BiLevel Mode
Sample Puritan Bennett™ BiLevel 2.0 Software Practice Exercise
Objective
This sample practice exercise illustrates use of the Puritan Bennett™ 980 ventilator’s BiLevel 2.0
software with two different approaches:
• a normal I:E ratio approach;
• an inverse I:E ratio approach with the breathing pattern assuming a distinctly different shape as TL
is shortened and the TH:TL ratio is extended beyond 4:1.
Overview of BiLevel Mode
The BiLevel option combines mandatory/assisted and spontaneous assisted breath types.
Breaths are delivered in a manner similar to SIMV mode with PC mandatory breath type and PEEP
except that the operator-set upper pressure is the target pressure above ambient rather than above
PEEP and it is called PHIGH (PH). The lower pressure level is called PLOW (PL) instead
of PEEP.
Timing for moving between pressures is set with the f (frequency) and the TH, TL, or ratio of
TH to TL (inspiratory time to expiratory time) settings. Three “padlock” icons that are located below the
breath timing graph allow the operator to select which variable will be held constant during frequency
changes: TH, TL or TH:TL.
The patient is free to breathe spontaneously at the high and low pressure levels. Spontaneous breaths
can be assisted with pressure support (PSUPP) or tube compensation (TC). Here is how pressure support
breaths work:
• Pressure support (PSUPP) can be used to assist spontaneous breaths during TH and TL. Target
pressure for all PSUPP breaths = PL + PSUPP.
• Spontaneous patient efforts at PH are only pressure supported if PSUPP > (PH - PL).
If there is a need to boost mean airway pressure while ventilating with BiLevel, it is possible to do so by
raising the PL or by lengthening the TH.
In some cases, the TH is set longer than the TL. In order to lengthen the TH setting past the 1:1 and 4:1
limits, you will need to touch the Continue button in the prompt area of the GUI. Setting an extended
time at PH and short release to PL can provide the breathing circuit pressure and flow pattern that
was patented by John Downs and defined as airway pressure release ventilation (APRV). During this
approach, the TL may be referred to as release time. Some clinicians suggest that a relatively short
release time may be used in order to cause auto-PEEP and prevent alveolar de-recruitment during the
exhalation phase.
4
BILEVEL MODE
PATIENT PROFILE
A 42-year-old female was seen in the Emergency
Department where she was diagnosed with influenza
and discharged with an expectorant/cough suppressant.
Three days later, the patient returned to the Emergency
Department with severe shortness of breath and
hypoxemia. The patient’s chest X-ray showed bilateral
interstitial infiltrates and her SpO2 was below 80% on
~100% oxygen mask.
Scenario and Scenario Questions
Scenario:
Morning, Day 1
The patient was intubated, admitted to the
ICU and ventilation with volume control plus
(VC+) was initiated. She had a high respiratory drive and appeared to be restless and in
distress.
Scenario Question 1:
What are the primary ventilation settings
used with VC+?
Hint:
VC+ is a mandatory pressure controlled
breath type that allows the operator to set
a frequency, target tidal volume, inspiratory
time and also limit the range of pressure
used for breath delivery (hPPEAK minus
3 cmH2O).
Figure 1: Adult VC+
Scenario Question 2:
Study the pressure and flow waveforms shown in Figure 1. Can you identify a reason why this
patient continues to feel distress in spite of being ventilated?
Hint:
Look at the pressure waveform. Can you see that over time the pressure control level is getting
lower and lower, finally landing with a PPEAK of approximately 4 cmH2O above PEEP? Can you
also see that the exhaled tidal volume is 528 mL but set tidal volume is 400 mL? (Note that appropriately set alarms would alert the user to this condition.)
5
BiLevel Mode
Scenario:
Afternoon, Day 1
The mode of ventilation was switched to
BiLevel in order to provide a more consistent
pressure delivery that will not decrease
when patient effort increases. In addition,
O2 was raised to 60%.
Scenario Question 3:
How would you set up the Puritan Bennett™
980 ventilator for BiLevel mode with an
upper pressure of 20 cmH2O, a lower
pressure of 8 cmH2O, a normal I:E ratio, and
a PSUPP of 15 cmH2O?
Hint:
Look at Figure 2.
Figure 2: Setup Vent Screen – Adult BiLevel
Scenario:
Morning, Day 2
In Figure 2 you can see that the mode is
being switched to BiLevel with PH set at
20 cmH2O and PL set at 8 cmH2O. The timing
bar shows that the TH is padlocked. That
means changes in frequency will impact TL
and TH:TL ratio but not TH.
Figure 3 shows that the upper pressure
level has been stabilized and the patient
seems to be breathing more comfortably.
Ventilation is adequate via blood-gas
analysis; however, the patient’s oxygen
saturation via pulse oximetry is reading
85% on 60% oxygen.
Figure 3: Adult BiLevel Normal I:E
Scenario Question 4:
Other than increasing the set O2%, what might you do to raise the patient’s oxygen saturation?
Hint:
Mean airway pressure has a known impact on oxygenation.2
6
Scenario:
Afternoon, Day 2
By adopting an APRV strategy and increasing
TH from 1.00 seconds to 4.20 seconds, you
will note (see Figures 4 and 5) that the PMEAN
has gone from 12 cmH2O to 18 cmH2O.
TL, which we may now call release time, is
at 0.8 seconds. The padlock has been
changed from locking the TH to locking the
TL. The TL will remain fixed at the set value
as other timing variables are changed.
This means that changes in frequency will
impact TH and TH:TL rather than TL. In place
of pressure support, tube compensation has
been added for helping to ease the work for
spontaneous efforts.
Figure 4: Setup Vent Screen – Adult BiLevel APRV Style
Figure 5: Adult BiLevel APRV Style
7
BiLevel Mode
Scenario:
After an hour the patient has begun to
Evening, Day 2 respond to this approach. Within 24 hours,
her oxygenation level has improved and
the O2% has been adjusted down to 40%
(see Figure 6). It is time to begin backing off
support. The literature mentions the Drop
and Stretch®* approach2 as a way to do this.
With the patient oxygenating acceptably
at 40% oxygen, it was decided to back off
the upper pressure level by 2 cmH2O and
extend TH in 0.5 – 2 second increments every
two hours as tolerated. Note that the mean
airway pressure has decreased to 14 cmH2O.
The patient is continually weaned and then
extubated within 24 hours.
Figure 6: Adult BiLevel APRV Style – Drop and Stretch®*
BiLevel Mode Practice Questions
1. Adjusting ventilator settings so that mean airway pressure is higher might improve
.
2. Why did the clinician switch from VC+ to BiLevel 2.0 mode in this case?
3. How will having a short “release time” (TL) affect the lungs/ventilation?
4. W
hen using BiLevel mode with a normal I:E ratio, pressure support was used
to support the patient’s spontaneous breaths. Assuming effective triggering and cycling
synchrony between the patient and ventilator, when the PSUPP level is
raised, the work required from the patient to breathe spontaneously is likely to go
.
5. N
ame the method that was described for weaning a patient off of APRV-style of
BiLevel ventilation.
8
9
Leak Sync Software
Sample Puritan Bennett™ Leak Sync Software Practice Exercise
Objective
This sample practice exercise illustrates the use of Leak Sync software on the Puritan Bennett™
980 ventilator.
Overview of Leak Sync Software
• Leaks that cause circuit pressure and flow to fluctuate during the expiratory phase of
breathing can cause auto-triggering and missed triggering asynchrony (Puritan Bennett™
980 Series Ventilator Operator’s Manual).
• Leak Sync software regulates the bias flow delivered through the circuit between breaths
while keeping the flow trigger linked with the level of bias flow. This helps to minimize a
leak’s impact on triggering. Leak Sync software adds up to 40 L/min bias flow for pediatric
patients and 65 L/min bias flow for adults.
• During the inspiratory phase of a positive pressure breath, leaks can impact the VTI
measurement because VTI includes all gas exiting the ventilator—the gas entering the
patient and the gas exiting the leak. Breath management decisions made from VTI will be
impacted by the leak.
• When Leak Sync software is enabled, VTL (inspiratory tidal volume minus the estimated
leak) is reported and used in breath management in place of VTI. The VTL value estimates
the quantity of gas entering the patient (Puritan Bennett™ 980 Series Ventilator Operator’s
Manual). This helps to minimize a leak’s impact on pressure support and volume support
breath cycling off. It also ensures that VC+ and VS breath types control pressure delivery
based patient volume with the leak volume subtracted.
10
LEAK SYNC
SOFTWARE
When Leak Sync software is enabled (see Figure 7):
• LS appears in the upper right corner of the Vent Setup
button.
• DSENS is displayed in units of L/min, rather than %.
• Leak Detected is displayed if the ventilator detects a leak
during a respiratory mechanics maneuver.
• VTL and VTE reflect estimated patient values (measured
value is modified to account for leak).
• Graphic displays of flow indicate estimated lung flows
(graph is modified to account for leak).
• Three additional parameters are available in the data
display:
– VLEAK
Figure 7: Leak Sync Software On
– %LEAK
– LEAK
• The operator selects inspiratory and expiratory sensitivity
settings as usual.
• A new leak or change in leak rate is typically quantified
and compensated for within three breaths. Monitored
patient data stabilizes within a few breaths.
• If the ventilator auto-triggers while Leak Sync software is
enabled, the issue may be resolved by increasing the flow
sensitivity (vSENS) setting.
11
Leak Sync Software
PATIENT PROFILE
A 72-year-old female was extubated in the ICU
while recovering from congestive heart failure.
During her spontaneous breathing trial (SBT),
her SpO2 readings were in the mid-90s on 40%
O2. One hour post extubation, her oxygenation is
compromised with SpO2 readings in the upper 80s
on 70% oxygen delivered by oxygen mask.
Scenario and Scenario Questions
Scenario:
Morning, Day 1
• E ven after receiving appropriate
medications, the patient looked like she
was working hard to breathe.
• In an effort to resolve her hypoxia and
prevent re-intubation, the decision was
made to use the Puritan Bennett™ 980
ventilator to ventilate her noninvasively
with pressure support.
• She was set up on pressure support
ventilation via non-vented mask with
12 cmH2O of pressure support and
7.5 cmH2O of PEEP. During setup of the
ventilator (see Figure 8), the clinician
forgot to select NIV instead of Invasive
ventilation type (note that when NIV
is selected it is shown on the Vent
Setup button).
Figure 8: SPONT PS (No NIV or Leak Sync)
Scenario Question 1:
The clinician realized that there is a significant leak from around the mask. Why might this
be a problem?
Hint:
The waveforms in Figure 8 indicate the presence of auto-triggering, late cycling off and missed
triggering asynchrony, plus large inspiratory tidal volumes (VTI).
12
Scenario:
Day 1 Afternoon
In an attempt to resolve the auto-triggering,
the VSENS setting was increased to 5 L/min. In
an attempt to resolve cycling off delay, ESENS
was increased. These adjustments provided
a temporary resolution to the problems but
when the patient moved, some of the same
asynchrony issues returned.
Scenario:
Day 1 Evening
The clinician changed Vent type to NIV which
automatically enabled Leak Sync. Then he
readjusted alarms, including the DSENS.
No other adjustments were made.
Leak Sync enables the ventilator to
compensate for leaks in the breathing
circuit while accurately detecting the
patient’s effort to trigger and cycle a breath.
Because Leak Sync allows the ventilator
to differentiate between flow due to leaks
and flow due to patient respiratory effort,
it provides dynamic compensation and
enhances patient-ventilator synchrony
(Puritan Bennett™ 980 Series Ventilator
Operator’s Manual).
Figure 9: Enable Leak Sync
Note: Leak Sync is automatically enabled when NIV ventilation type is selected. Had the clinician
selected NIV when setting up pressure support via mask, this issue would have been prevented
(both NIV and LS would have appeared on the Vent Setup button).
Scenario Question 2:
How do you enable Leak Sync?
Hint:
The Setup More Settings screen (see Figure 9) contains controls for Leak Sync, O2 Sensor,
Humidification Type, Humidification Volume and DSENS. Leak Sync is also enabled automatically when
the Vent Type is changed to NIV.
13
Leak Sync Software
Scenario:
As you can see in Figure 10, Leak Sync
Day 2 Morning has dramatically improved synchrony
and now oxygenation is much better with
93% saturation on 45 %O2. VSENS has been
turned back down to 3 L/min. ESENS has
been set to 35% and that setting provides
appropriate cycling off timing. As this patient
is monitored over the course of the next
few days, the configurable vital patient
data display at the top of the touch screen
allows the operator to keep track of the
effectiveness of the mask seal. This image
of the ventilator’s touchscreen shows that
%LEAK is 10%.
Figure 10: Leak Sync Enabled
Scenario
Question 3:
The %LEAK is 10%. Describe what might happen if the mask fit was too tight.
Hint:
Comfort and compliance with therapy are all impacted by mask fit.
Scenario:
Day 2
Afternoon
This patient’s leak proved to be positional
(see Figure 11), meaning that it changed
when she moved her head or was
repositioned in bed. Since Leak Sync is
activated, the clinician does not need to
make changes to VSENS or ESENS in order
to compensate for the leak. The leak
compensation is managed automatically.
This feature should relieve the bedside
clinician from extending bedside time in
order to make ventilator adjustments needed
to manage leaks.
Figure 11: NIV and Leak Sync Activated; %LEAK Changed
Leak Sync Software Practice Questions
1. How does Puritan Bennett™ Leak Sync software compensate for leaks?
ow long does it usually take for a new leak or change in leak rate to be quantified and
2. H
compensated for on the Puritan Bennett™ 980 ventilator?
14
15
PAV™*+ Software
Sample Puritan Bennett™ PAV™*+ Software Practice Exercise
Objective
This sample practice exercise illustrates the use of PAV™*+ software on the
Puritan Bennett™ 980 ventilator.
Overview of PAV™*+ Software
• Proportional Assist™* Ventilation (PAV™*+) is a spontaneous breath type that is available
when Invasive SPONT mode is selected.
• PAV™*+ software is designed to help clinicians to improve the work of breathing of a
spontaneously breathing patient with compromised pulmonary mechanics.
• PAV™*+ software acts as an inspiratory amplifier; the degree of amplification is set by
the % Support setting (%Supp). PAV™*+ software continuously monitors the patient’s
instantaneous inspiratory flow/lung volume and instantaneous airway pressure, which
are indicators of the patient’s inspiratory effort. These signals, together with ongoing estimates
of the patient’s resistance and compliance, allow the software to instantaneously compute the
necessary pressure at the patient wye to assist the patient’s inspiratory
muscles to the degree selected by the %Supp setting.
• Higher inspiratory demand yields greater support from the ventilator.
• The PAV™*+ software contains safeguards for reducing the risk of inadvertent entry
of incompatible settings, such as small predicted body weight (PBW) paired with
a large airway.
• Flow ceases upon the cessation of patient effort.
Setting Up PAV™*+ breath type
• At the ventilator setup screen, enter the patient’s predicted body weight (PBW at least 25 kg)
or gender and height.
• Touch Invasive vent type.
• Touch SPONT mode.
• Touch the PAV+ breath type.
• Touch the desired trigger type (P-TRIG or v-TRIG).
• Select tube type.
• Adjust the tube ID (6-10 mm ID) if different from the default value based on the
PBW entered at ventilator startup.
16
PATIENT PROFILE
A 64-year-old male with chronic lung disease
was admitted to the ICU after post-operative
complications.
PAV ™*+
SOFTWARE
Scenario and Scenario Questions
Scenario:
Morning, Day 1
The patient was initially placed on A/C
volume control but exhibited significant
flow and timing asynchrony regardless of
how the bedside clinician adjusted breath
delivery settings on the Puritan Bennett™
980 ventilator. Since the patient’s respiratory
drive was intact, the decision was made to
manage him on pressure support with a PSUPP
of 20 cmH2O and PEEP of 5 cmH2O. Upon
inspection of the patient and the graphic
waveforms (see Figure 12), it was noted that
some of this patient’s spontaneous efforts
were not triggering the ventilator.
Figure 12: SPONT PS with Trigger and Cycling
Off Asynchrony
Scenario Question 1:
Why might switching from pressure support
to PAV™*+ improve triggering and cycling
off synchrony?
Hint:
The waveforms shown in Figure 12 indicate signs of late cycling off and missed triggering. These
are issues that may be observed when using pressure support to ventilate people with obstructive
lung disease, especially when the pressure support is set at higher levels and ESENS is not set to
match the patient’s needs.3 Late cycling off can cause auto-PEEP and that can lead to missed
triggering. Switching to a breath type that coordinates breath delivery with instantaneous flow/
lung volume and airway pressure measurements may be helpful in resolving the asynchrony issue.
17
PAV™*+ Software
Scenario:
Afternoon, Day 1
The breath type was changed from pressure
support to PAV™*+ in order to provide
a better means for managing patientventilator synchrony and patient work. The
primary setting in PAV™*+ is the % Support
setting (% Supp). It determines how much
work the ventilator will do versus how much
work the patient will do. In this situation,
a common starting point of 70 % Supp has
been selected.
Scenario Question 2:
What ventilation parameters are selected
during use of the PAV™*+ breath type?
Figure 13: Setup Vent Screen – PAV™*+
Hint:
The Setup Vent screen identifies the
parameters available for adjustment with
each mode and breath type (see Figure 13).
Scenario Question 3:
In this example (Figure 13), the Puritan Bennett™ 980 ventilator % Supp has been set to 70%.
How will this impact the amount of work that the patient will do?
Hint:
Think of the total breathing workload as being 100%.
18
Scenario:
Night Day 1:
Figure 14 shows that PAV™*+ breath
delivery is matching patient efforts well.
The inspiratory time (outlined in green) is
more physiologic at 0.91 seconds than it
was while the patient was ventilated with
pressure support.
Figure 14: PAV™*+ Good Synchrony
There are no visible signs of missed trigger
asynchrony. Also, the patient’s work of
breathing (WOBPT) indicator is in the green
zone, which is one of the indicators that this
patient is on the correct settings.
Scenario:
Day 2:
It is important to monitor the patient’s work
of breathing and other clinical indicators of
improvement and adjust the % Supp setting
as the patient’s underlying post-operative
complication begins to resolve. Figure 15
shows that the WOBPT is now below the
normal level.
Figure 15: PAV™*+ with Low WOBPT
19
PAV™*+ Software
PAV™*+
Scenario:
Day 3:
To bring WOBPT back up into the green zone,
the % Supp was adjusted down to 50%.
As the day progressed, the patient continued
to do well. Figure 16 shows the WOBPT in the
green zone at only 30% Support; it is time
to start assessing the patient’s readiness for
extubation. It is important to use multiple
touch points for this assessment based on
hospital protocol.
Figure 16 shows that the patient’s minute
volume remains moderately high at 10.5 L/
min. However, because lung compliance
(CPAV) has improved, delivered pressure
is down to only 10 cmH2O. This could
be considered a reasonable endpoint
to weaning. Provided all other weaning
criteria is met, this patient may be ready for
extubation directly from PAV™*+.
Figure 16: PAV™*+ with 30 % Supp
PAV™*+ Breath Type Practice Questions
1. I f the ESENS is not adjusted properly, patients with elevated compliance and resistance
levels may be at a disadvantage with pressure support because the inspiration phase
might be extended longer than the brain wants to inhale.
Describe some of the potential consequences.
hat may occur if a patient is ventilated with a WOBPT that is below the normal level?
2. W
20
21
Volume Control Plus (VC+)
Sample Volume Control Plus (VC+) with an Adult Patient Practice Exercise
Objective
This sample practice exercise illustrates the use of volume control plus (VC+) on the
Puritan Bennett™ 980 ventilator to ventilate an adult patient.
Overview of VC+ Software
VC+ is a mandatory/assisted, pressure-controlled breath type that automatically adjusts
the inspiratory pressure target from breath to breath to achieve the desired tidal volume
despite changing lung conditions (Puritan Bennett™ 980 Series Ventilator Operator’s Manual).
The pressure target is not adjusted outside the limits of the settings (range PEEP – 3 cmH2O to
PPeak – 3 cmH2O) even if the volume target is not achieved. See previous overview for
more detail.
PATIENT PROFILE
A 65-year-old male was admitted for shortness of
breath. A CXR revealed patchy infiltrates. A diagnosis
of pneumonia was determined. Blood gas revealed:
pH 7.26, CO2 70, pO2 45, on 60% O2. The patient was
intubated and placed on the ventilator using volume
control (VC) in the A/C mode. The patient was
sedated to alleviate discomfort. See Figure 21.
Figure 21: VC
22
Scenario and Scenario Questions
Scenario: Day 1
Morning
Scenario: Day 1
Afternoon
While the patient was ventilated with AC
VC, the bedside clinician noticed that each
time sedation was lightened the patient was
uncomfortable. A quick look at waveforms
(see Figure 22) revealed that there was
significant flow asynchrony when the patient
was actively breathing.
Figure 22: VC Flow Too Low
Sedation was increased again while the
bedside clinicians conferred on how to
resolve the patient discomfort that was
caused by the flow asynchrony. The decision
was made to increase the set peak flow
(VMAX) to 80 L/min (see Figure 23).
Figure 23: VC Flow Increased
Scenario:
Day 1 Evening
Sedation was lowered to see how the patient
would respond to the change in ventilator
settings. Unfortunately, the patient was still
uncomfortable and agitated (see Figure 24).
The sedation level was increased again.
Scenario Question 1
Look at Figure 24. What is most likely
causing the patient’s distress?
Hint:
Flow and inspiratory time are linked during
volume control mandatory breath delivery.
Scenario Question 1
What are two common signs of doubletrigger asynchrony?
VOLUME
CONTROL PLUS
(VC+)
Hint:
Figure 24: VC with Double Triggering
If a patient receives two breaths in response
to one effort, the patient will not have a
chance to exhale in between the breaths.
23
Volume Control Plus (VC+)
Scenario:
Day 2 Morning
Scenario: Day 3
At rounds, the issue of muscle atrophy, its
link to over-sedation, and the potential for
prolonging ventilator days was discussed.
The decision was made to switch to volume
control plus (VC+) in place of VC (Figure
25) so that the patient could have control
over inspiratory flow during breath delivery
without shortening the breath to do so.
Figure 25: Setup Vent Screen - VC+
As the patient’s pneumonia improved he
continued to breathe with the ventilator.
In Figure 26, the flow-time and volumetime scalars show the patient’s ability to
control inspiratory flow and volume on
a breath-by-breath basis. The graphics
show no indication of flow asynchrony
or double triggering. As the patient’s
condition improved, less distending pressure
was applied by the ventilator. VC+ also
accommodated the changes in time constant
that this patient experienced pre-post
suctioning and pre-post bronchodilator
therapy.
VC+ Adult Practice Questions
1. What are some goals of ventilating with VC+?
2. How might VC+ respond to an increase in lung compliance?
24
Figure 26: Adult VC+
25
Answer Key
BiLevel Mode Scenario Questions/Answers
1. W
hat are the primary ventilation settings used with VC+?
Answer:
In VC+, f (frequency), V T, TI, PPEAK (maximum inspiratory pressure = PPEAK minus 3 cmH2O), PEEP, O2%,
V-SENS or P-SENS, and pressure rise % are controlled by the clinician.
2. Study this image of the patient’s pressure and flow waveforms. Can you identify a reason why this
patient continues to feel distress in spite of being ventilated? (See Figure 1)
Answer:
In VC+, the software manages the pressure control level
between PEEP + 3 cmH2O and PPEAK – 3 cmH2O. It raises
the pressure control level if monitored V TI (or V TL) does
not reach the operator-set V T is not attained and lowers
it if the V TI (or V TL) exceeds the operator-set V T by a
pre-programmed margin. The pressure waveform shows
that this patient’s high respiratory drive has caused the
software to decrease the level of support provided by
mandatory breaths. With VC+, higher patient demand
has the possibility of resulting in lower
ventilator support.
26
Figure 1: Adult VC+
3. How would you set up the Puritan Bennett™ 980 ventilator for BiLevel ventilation with an upper
pressure of 20 cmH2O, a lower pressure of 5 cmH2O, a normal I:E ratio, and a pressure support of
15 cmH2O?
Answer:
• At the Setup Vent screen, enter PBW or gender and height.
• Touch the BiLevel mode button. After BiLevel is selected, the ventilator uses the PC mandatory
breath type, which cannot be changed.
• Choose the spontaneous type PS and set PSUPP to 15 cmH2O.
• Choose trigger type (P-TRIG or V-TRIG).
• Select desired ventilator settings. The default settings for BiLevel mode appear.
• To change a setting, touch its button and turn the knob to set its value. PH must always be at least
5 cmH2O greater than PL .
• Touch Start.
• Set the Apnea and Alarm settings by touching their respective tabs at the side of the ventilator
settings screen and changing settings appropriately.
4. Other than increasing the set O2%, what might you do to raise the patient’s oxygen saturation?
(See Figure 3)
Figure 3: Adult BiLevel Normal I:E
27
ANSWER KEY
nswer:
A
There are several methods that may be
applied for boosting patient oxygenation. One
possibility is to increase mean airway pressure
by lengthening the TH so that airway pressure
remains at the PH level longer. In some cases,
this means setting the TH longer than the TL.
The TH:TL ratio may be greater than 1:1 or even
greater than 4:1. While extending the TH, you
must touch the Continue button in the prompt
area of the GUI to confirm that you intend to
keep increasing the TH setting after reaching the
1:1 and 4:1 limits. Using an extended TH with a
shorter TL may be referred to as Airway Pressure
Release Ventilation (APRV) and the TL may be
referred to as release time.1
Answer Key
BiLevel Mode Practice Questions/Answers
1. A
djusting ventilator settings so that mean airway pressure is higher might improve
.
Answer:
Oxygenation
2. Why did the clinician switch from VC+ to BiLevel 2.0 mode in this case?
Answer:
To stabilize the level of support on a patient who has a high ventilatory demand.
3. How will having a short “release time” (TL) affect the lungs/ventilation?
Answer:
It will cause auto-PEEP.
4. When using BiLevel mode with a normal I:E ratio, pressure support was used
to support the patient’s spontaneous breaths. Assuming effective triggering and cycling
synchrony between the patient and ventilator, when the PSUPP level is raised, the work required
from the patient to breathe spontaneously is likely to go.
Answer:
Down
5. N
ame the method that was described for weaning a patient off of APRV-style of
BiLevel ventilation.
Answer:
Drop and Stretch®* Lower PH (PHIGH) and lengthen TH (THIGH).2
28
Leak Sync Software Scenario Questions/Answers
1. Th
e clinician realizes there is a significant leak from around the mask. Why might this be
a problem?
Answer:
If Leak Sync software is not enabled, a leak may cause auto-triggering and late cycling off of
pressure support breaths. Leak-related auto-triggering may cause a need to re-assess/re-adjust
sensitivity often in order to maintain reliable triggering. Leak-related late cycling off may cause a
need to re-assess/re-adjust ESENS often in order to maintain reliable cycling off timing. If Leak Sync
software is enabled, the DSENS alarm provides indication of disconnect. Too large of a leak could
cause activation of the DSENS alarm unless that alarm setting is raised. Note that a higher DSENS
alarm setting may desensitize notification of patient disconnect.
2. How do you enable Leak Sync software?
Answer:
To enable Leak Sync software:
• E nable NIV or while in INV: at the Setup Vent screen, touch the More Settings tab.
– Touch the Enabled button in the Leak Sync area.
– Touch Accept ALL to enable Leak Sync software.
3. The %LEAK is 10%. Describe what might happen if the mask fit was too tight.
Answer:
A mask that fits too tightly might cause patient discomfort, facial soreness and facial sores, and
nasal obstruction. All of these may cause the patient to be unwilling to wear the mask.
29
Answer Key
Leak Sync Software Practice Questions/Answers
1. H
ow does Puritan Bennett™ Leak Sync software compensate for leaks?
Answer:
When Leak Sync software is enabled:
• L eak Sync software regulates the bias flow delivered through the circuit between
breaths while keeping the flow trigger linked with the level of bias flow. This helps to
minimize a leak’s impact on triggering. Leak Sync software adds up to 40 L/min bias
flow for pediatric patients and 65 L/min bias flow for adults. If the ventilator autotriggers in spite of enabling Leak Sync, the operator may manually increase the flow
sensitivity (VSENS) setting.
• V TL (inspiratory tidal volume minus the estimated leak) is reported and used in breath
management in place of V TI. The V TL value estimates the inspired gas volume delivered
to the patient (Puritan Bennett™ 980 Series Ventilator Operator’s Manual). This helps to
avoid leak-related late cycling off of pressure support breaths and leak-related reduction
in pressure control/pressure support for VC+/VS breaths.
• The Vent Setup button on the GUI screen indicates that Leak Sync software is enabled.
• DSENS is displayed in units of L/min, rather than %.
• If the ventilator detects a leak during a respiratory mechanics maneuver, the message
Leak Detected is displayed.
• The operator selects inspiratory and expiratory sensitivity settings as usual.
2. How long does it usually take for a new leak or change in leak rate to be quantified and
compensated on the Puritan Bennett™ 980 ventilator?
Answer:
A new leak or change in leak rate is typically quantified and compensated within three
breaths. Monitored patient data stabilizes within a few breaths.
30
PAV™*+ Breath Type Scenario Questions/Answers
1. W
hy might switching from pressure support to PAV™*+ breath type improve cycling
off synchrony?
Answer:
SPONT with PAV™*+ breath type coordinates breath delivery with the patient’s breathing. It can
provide better cycling off synchrony because it cycles off with the cessation of patient effort.
2. What ventilation parameters are selected during use of the PAV™*+ breath type?
(See Figure 13)
Answer:
Follow these steps to set up the PAV™*+
breath type:
• At the Setup Vent screen for a patient
ventilated with a 6-10 mm ID ET/trach tube,
enter the patient’s gender and height or
PBW (must be at least 25 kg).
• Touch Invasive vent type.
• Touch SPONT mode.
• Touch PAV+ to select Spontaneous type.
• T ouch the desired trigger type
(P-TRIG or V-TRIG).
Figure 13: Setup Vent Screen – PAV™*+
• Select tube type.
• Select the tube ID. Initially, a default value is shown based on the PBW entered at ventilator
startup. If this ID is not correct for the airway in use, turn the knob to adjust the ID setting.
• If Leak Sync software is currently enabled, it becomes disabled when the PAV™*+ breath type is
selected.
• Initially, other settings like rise % and ESENS may be left at default values.
3. In this example, the Puritan Bennett™ 980 ventilator % Supp has been set to of 70%. How will
this impact the amount of work that the patient will do?
Answer:
This means that the machine will do approximately 70% of the work and the patient will do about
30% of the work.
31
Answer Key
PAV™*+ Breath Type Practice Questions/Answers
1. I f the ESENS setting is not adjusted properly, patients with elevated compliance and
resistance levels may be at a disadvantage with pressure support because the inspiration
phase might be extended longer than the brain wants to inhale. Describe some of the
potential consequences.
Answer:
When the ventilator extends breath delivery beyond when the patient wants/needs to
exhale, the patient may attempt but fail to trigger another breath before the inspiration of
the previous breath has finished. Also, the prolonged breath may decrease time to exhale,
cause auto-PEEP and prevent the patient from being able to trigger the subsequent
breath. These are examples of trigger asynchrony.
2. What may occur if a patient is ventilated with a WOBPT that is below the normal level?
Answer:
When too much work is assumed by the ventilator and the patient’s work of breathing is
below the normal level, muscle weakness due to muscle atrophy may occur. A decrease in
the
% Support setting may be indicated if all other indicators like the physical assessment of
work
are in agreement.
32
VC+ Adult Scenario Questions/Answers
1. L
ook at Figure 24. What is most likely
causing the patient’s distress?
Answer:
This is most likely caused by a mismatch
between the ventilator settings and the
patient demands. When flow was increased
to meet the patient’s flow demands the
inspiratory time was shortened. This could
cause double trigger asynchrony.
2. What are two common signs of doubletrigger asynchrony? (See Figure 24)
Figure 24: VC with Double Triggering
Answer:
The first is a “0.0” display for V TE monitored data. The second is little to no exhaled flow
(deflection below zero baseline) between inflations on the flow time curve.
VC+ Adult Practice Questions/Answers
1. W
hat are some goals of ventilating with VC+?
Answer:
• Enable a patient-determined flow.
• Allow patient to access additional spontaneous volume.
• Reduce target distending pressure via auto feedback.
2. How might VC+ respond to an increase in lung compliance?
Answer:
If the patient’s compliance improves (increases) it will likely take less pressure to deliver
the set tidal volume so the pressure control level will be decreased.
33
References
1. Downs JB, Stock MC. Airway pressure release ventilation: a new concept in ventilatory support. Crit Care Med. 1987;15(5):459-61.
2. Habashi NM. Other approaches to open-lung ventilation: airway pressure release
ventilation. Crit Care Med. 2005;33(3 Suppl):S228-40.
3. Kacmarek RM. Proportional assist ventilation and neurally adjusted ventilatory
assist. Respir Care. 2011;56(2):140-148.
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registered trademarks of The University of Manitoba, Canada. Used under license. ™*
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