Vyaire Avea User manual

Avea™
critical care ventilation
ENHANCED PULMONARY MONITORING USER GUIDE

Avea ventilator maneuvers �������������������������������������1
MIP/P100 Maneuver screen����������������������������������2–3
Controls ��������������������������������������������������������������������������2–3
Maximum inspiratory pressure (MIP) ���������������������4
Respiratory drive (P100)�������������������������������������������� 5
Inflection Point (Pflex) screen�����������������������������6–9
Controls �������������������������������������������������������������������������� 7–9
AutoPEEPaw Maneuver screen ����������������������� 10–11
Controls ������������������������������������������������������������������������������� 11
Esophageal maneuver screen ������������������������12–16
Testing ��������������������������������������������������������������������������12–13
Placement ������������������������������������������������������������������14–15
Additional information������������������������������������������������� 16
Table of contents
Tracheal catheter���������������������������������������������17–18
Placement ������������������������������������������������������������������ 17–18
Advanced pressure monitoring
of the respiratory system���������������������������������������19
Advanced mechanics ������������������������������������ 20–33
Compliance�������������������������������������������������������������20–22
Resistance ����������������������������������������������������������������23–24
Flow�������������������������������������������������������������������������������������� 25
Pressure���������������������������������������������������������������������� 26–27
AutoPEEP�������������������������������������������������������������������28–29
Work of breathing�������������������������������������������������30–33
Avea ventilator screens����������������������������������������34
Notes�����������������������������������������������������������������35–37

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Avea ventilator maneuvers

2
MIP/P100 Maneuver screen
Controls
Duration: This control determines the maximum time the maneuver will last.
Normal ventilation suspends and resumes after the set time has elapsed.
Range: 5 to 30 sec
Default: 10 sec
Maximum Inspiratory Pressure (MIP):
The P100 maneuver measures the negative
deflection in the pressure tracing during the
patient’s active eort to demand a breath.
During the maneuver, the inspiratory flow
valve remains closed so no inspiratory
flow is delivered.

3
Controls (continued)
Sensitivity: This control allows the clinician to set the maneuver sensitivity appropriate to
patient ability. This setting establishes the level below PEEP that the airway pressure must
drop before a determination of the onset of a patient eort is determined. Once patient
eort is detected, the timer for the maneuver duration starts. Maneuver sensitivity does
not aect ventilator trigger sensitivity.
Range: 0.1 to 5 cmH2O
Default: 3 cmH2O
NOTE: An excessively high setting of the maneuver sensitivity can aect the accuracy
of timing for P100 determination.
Start/Stop: This maneuver begins when START is pressed. The maneuver immediately
terminates when STOP is pressed. When STOP is pressed, normal ventilation can resume.
NOTE: If Start is pressed during a mandatory inspiratory breath, the maneuver does
not begin until the ventilator cycles into exhalation and the minimum expiratory time
of 150 msec has elapsed.

4
Maximum inspiratory pressure (MIP)
MIP is the maximum negative airway pressure a patient achieves during an expiratory hold
maneuver. It can be a good indicator of inspiratory muscle strength, useful in the weaning
process and a means of determining the progression of neuromuscular disease.
Range: -60 to 120 cmH2O
Normal: -70 to -100 cmH2O (adults)
-20 to -100 cmH2O (pediatrics)
Readiness for extubation < -20 cmH2O
NOTE: Patient eort can vary based on many factors (e.g., disease process, level of
sedation, comprehension of instructions, motivation). MIP decreases in conditions
such as kyphoscoliosis, advanced age, chronic obstructive pulmonary disease
(COPD) and neuromuscular disease.

5
Respiratory drive (P100)
The P100 is the negative pressure that occurs 100 ms after an inspiratory eort has been
detected while the inspiratory valve is closed. Because it normally takes at least 300 ms
for the patient to become aware of the occluded airway, P100 is a good test of the
respiratory center output. Because no change in lung volume or airflow occurs during
this initial 300 ms, abnormalities in lung mechanics do not aect the measurement.
P100 = Pend 100 – PEEPaw
Range: 60 to 120 cmH2O
Normal: -1 to -4 cmH2O (adults)
-0.5 to -4 cmH2O (pediatrics)
A high value (more negative) result reflects patient drive and strength. However,
a value more negative than -5 cmH2O may also indicate a high respiratory drive that
increases work of breathing and subsequent fatigue. Therefore, it is important to
conduct a thorough patient assessment if this measurement is to be the patient’s
readiness to wean from ventilatory support.

6
The Pflex Maneuver is performed on patients
during mandatory ventilation. Once the maneuver
tidal volume is delivered, the ventilator cycles
into exhalation and returns to normal ventilation
at the current ventilator settings. The pressure/
volume (PAW/Vol) loop freezes with upper and lower
inflection points that are automatically calculated
and displayed on the inspiratory portion of the
PAW/Vol loop.
The lower inflection point indicates the point
that collapsed airways begin to reopen. This can
be aected by both airway closure and alveolar
collapse, causing the point to be farther to the
right because more pressure is required to open the
airways. Alveoli are continually recruited throughout
the steep portion of the PV curve. The upper
inflection point represents the point that further
applied pressure results in overdistention.
Inflection Point (Pflex) Maneuver screen

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Inflection Point (Pflex) Maneuver screen (continued)
The user can override the calculated Pflex values by moving the Pflex indicators to a new point
along the PV loop and pressing the appropriate key. The corresponding Pflex values and delta
Pflex volume change to represent values based on the current position of the indicators. The
ventilator can store up to four PV loops and their respective inflection points simultaneously.
NOTE: Once the values have been redefined by the operator, the original values
cannot be restored. Normal ventilation suspends for the duration of the maneuver.
The maneuver terminates if a patient eort is detected. The message bar provides
text stating that patient eort was detected.
Controls
Tidal volume (volume): This control
determines the volume of gas delivered
to the patient during the maneuver.
Range: 0.1 to 2.5 L (adults) Default: 0.25 L (adults)
25 to 500 mL (pediatrics) 25 mL (pediatrics)
NOTE: The tidal volume is not circuit-compliance compensated.

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Controls (continued)
Peak flow: This control sets the peak flow.
Range: 0.5 to 5 L/min Default: 1 L/min
NOTE: A square wave flow pattern is used.
Maneuver PEEP: This control determines the baseline pressure when the maneuver begins.
Range: 0 to 50 cmH2O Default: 0 cmH2O
NOTE: The maneuver PEEP can be set independently of the PEEP used during
normal ventilation.
PEEP equilibration time (PEEP Teq): This control allows for airway pressure equilibration
prior to the maneuver. When the maneuver begins, PEEP is set for the Equilibration Time.
Range: 0 to 30 sec Default: 1 sec
Sensitivity: Establishes the level below the peak airway pressure that the pressure
must drop to terminate the Pflex maneuver. Maneuver sensitivity has no eect on
ventilator trigger sensitivity.
Range: 0.1 to 5 cmH2O Default: 3 cmH2O
NOTE: The maneuver terminates if a patient eort is detected, and a message displays.

9
Controls (continued)
Start/Stop: This maneuver begins when Start is pressed and immediately terminates
when Stop is pressed, a patient eort is detected or the maneuver tidal volume has
been delivered. Once the maneuver terminates, normal ventilation resumes.
Normal: < 5 cmH2O (lower)
28 to 32 cmH2O (upper-adults)
20 to 26 cmH2O (upper-pediatrics)
After the maneuver completes, the operator
may reselect the upper and lower points using
the cursor. The tidal volume delivered between
the two points is represented by the delta
tidal volume.

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AutoPEEP occurs when insucient expiratory time
or dynamic flow limitation is present, which results
in gas trapping. This is common in asthma or severe
COPD.
AutoPEEPaw: This function measures airway
pressure at the end of exhalation before the
beginning of the next mandatory inspiration.
During this maneuver, the ventilator executes
an expiratory hold with both the inspiratory and
expiratory valves closed. The ventilator establishes
the AutoPEEPaw measurement when the system pressure reaches equilibration,
at the next mandatory breath interval or after six seconds—whichever comes first.
Range: 0 to 50 cmH2O
Default: 0 cmH2O above the applied PEEP
NOTE: This maneuver requires a passive patient and a cued endotracheal (ET) tube.
AutoPEEPaw Maneuver screen

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Controls
Sensitivity: This control establishes the level that the airway pressure must drop below
PEEP to terminate the AutoPEEPaw maneuver. Maneuver sensitivity has no eect on
ventilator trigger sensitivity.
Range: 0.1 to 5 cmH2O
Default: 3 cmH2O
Start/Stop: The maneuver begins when Start is pressed and the ventilator is in exhalation.
The maneuver stops immediately when Stop is pressed, the maneuver completes or a
patient eort is detected. Once the maneuver stops, normal
ventilation resumes.
NOTE: If a patient eort is detected, the maneuver terminates and the message bar
indicates patient eort was detected.
Delta AutoPEEPaw (dAutoPEEPaw): This tool calculates the dierence between airway
pressure at the end of an expiratory hold maneuver and the airway pressure at the start
of the next mandatory breath, after the expiratory hold maneuver.
Delta AutoPEEPaw = Intrinsic PEEP – Applied PEEP
Range: 0 to 50 cmH2O
NOTE: This measurement requires a passive patient and a cued ET tube.

12
Esophageal maneuver screen
Testing
1� A balloon test must be performed prior to
placing the esophageal balloon. Connect the
extension tubing and esophageal balloon to
the ventilator, and select Esophageal Maneuver
from the Maneuver Select menu.
2� Confirm the balloon is not yet placed in
the patient.

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Testing (continued)
3� Press the Balloon Test soft key. The balloon fills
and empties twice to confirm its integrity. Once
this process completes, a Balloon Test Passed
message appears in the message bar.
4� Insert the catheter.

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Placement
Once the balloon leak test is passed, the balloon is
ready for placement. Proper placement is imperative
for accurate measurements. An approximate level of
placement can be made by measuring the distance
from the tip of the nose to the bottom of the earlobe
and from the earlobe to the distal tip of the
xiphoid process.
WARNING: Esophageal balloon placement
should only be conducted under direction of
a physician who has assessed the patient for
contraindications to esophageal balloon use.
Illustration is provided for
educational purposes only�
Transpulmonary pressure (Ptp) Ptp
= Paw - Pes
4
Airway
Pressure (Paw)
Esophageal
Pressure (Pes)

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Placement (continued)
After the catheter is inserted, touch Pes O. The key
changes color and reads Pes On. The ventilator fills
the balloon to the appropriate level and begins
monitoring data.
Confirming proper placement: Once the balloon
is placed, the appropriate balloon location can be
confirmed by performing an occlusion technique.
This requires that the airway be occluded and
the esophageal and airway pressures be compared
for similarity.
The Baydur maneuver (Am Rev. Resp Dis, 1982, 126:788). During an expiratory hold
(i.e., inspiratory and expiratory circuit occlusion), a patient inspiratory eort is
initiated (allow). With proper placement of the esophageal balloon, simultaneous
negative deflections in airway and Pes should be observed.

16
Additional information
The waveform produced can further confirm
proper placement. Pes waveforms correlate
to airway pressure in that they become
positive during a positive pressure breath
and negative during a spontaneous breath.
Esophageal tracings may also show small
cardiac oscillations reflective of cardiac
activity.
A� Airway pressure
B� Pes
A
B
NOTE: Airway pressure and Pes waveforms both have a positive deflection,
indicating proper balloon placement.

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Tracheal catheter
Placement
Some advanced mechanics measurements on
the Avea ventilator require a tracheal catheter.
To ensure the accuracy of measurements and
minimize risk, place the tracheal catheter in the
ET tube, and should not extend beyond the tip
of the tube.
A� The length of the tracheal catheter should
not exceed the length of the ET tube plus
the adapter. A

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Placement (continued)
To ensure proper placement, measure the length of the ET tube and its associated
adapters. Insert the tracheal catheter into the ET tube, and ensure the catheter does not
extend beyond the tip of the tube. Next, assess the patient for signs of adverse response
indicating the catheter may have been advanced beyond the tip of the
ET tube. Final confirmation of placement should be obtained by assessment of a
chest x-ray.
WARNING: Inserting the tracheal catheter beyond the tip of the ET tube may irritate
and inflame the trachea and airways or produce vagal responses in some patients.