Transcript Pandemic [H1N1] 2009 RT Education Module 1 Ventilation Outline • Indications for Ventilation • Standard Modes of Ventilation • Weaning – Controlled modes to support modes – Weaning.

Pandemic [H1N1] 2009
RT Education
Module 1
Ventilation
Outline
• Indications for Ventilation
• Standard Modes of Ventilation
• Weaning
– Controlled modes to support modes
– Weaning protocol (RAH)
– Factors Associated with Difficulty Weaning
– Plugging (to be added)
– Speaking valves (to be added)
• Non-Invasive Ventilation: An overview
• The VISIONS Ventilator (to be added)
• Ventilators and their Modes
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To Ventilate or not to Ventilate
• There are no rules, just guidelines:
– Acute Respiratory Failure
– Impending Respiratory Failure
– Apnea
– Hypoxic Respiratory Failure
– [post-op care]
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Standard Modes of Ventilation
Full Support
Partial Support
Spontaneous Breathing
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Which Mode to Choose?
• What is the indication?
• Does the patient have lung disease?
• Is the respiratory centre functioning?
• Lung Mechanics?
• Compliance vs. Resistance
• How much support does the patient need?
• Is the patient making spontaneous efforts?
• How hard is my patient working to maintain
ventilation?
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Full Support
Volume Cycled Breaths
versus
Pressure Limited Breaths
OR
A little of BOTH
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Volume Ventilation: VC – CMV - A/C
• Set Parameters:
– Tidal volume (Vt)
– Respiratory Rate (RR)
– Inspiratory time (Ti)
– PEEP
– FiO2
– If the patient wants
additional breaths, they
are delivered according to
set parameters.
• Variable Parameters:
– Peak inspiratory pressure
(PIP) will vary with
changes in resistance
and/or compliance (Cp).
• Resistance = PIP
• Cp = PIP
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Pressure Ventilation: PCV - PCV+Assist
• Set Parameters:
– Pressure (PC)
– RR
– Ti
– PEEP
– FiO2
– Patient is able to trigger
additional breaths that will
be delivered with the set
parameters.
• Variable Parameters:
– Vt will vary with changes in
lung mechanics.
– Resistance = Vt
– Cp = Vt
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Pressure Control with
Volume Guarantee: PRVC – CMV (autoflow) – VC+
• Set Parameters:
– Vt
– RR
– Ti
– PEEP
– FiO2
– If the patient wants
additional breaths, they
are delivered according to
set parameters.
• Variable Parameters:
– PIP will vary with changes
in resistance and/or
compliance.
– Ventilator automatically
adjust pressure needed to
ensure tidal volume is
delivered.
– Resistance/Cp = PIP
– Resistance/Cp = 
PIP
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Partial Support
Volume Cycled Breaths
Pressure Limited Breaths
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Synchronized Intermittent Mandatory Ventilation
(SIMV): SIMV (VC) + PSV - SIMV (PC) + PSV - SIMV (PRVC) + PSV
• Set Parameters:
– RR
– Vt or PC for mandatory
breaths
– Ti
– PEEP
– FiO2
– PSV for any spontaneous
breaths taken by the
patient.
• Trigger window is established
allowing patient to
spontaneously breath on PSV,
if no effort is made then a
mandatory breath is delivered.
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Pressure Support: PSV
• Set Parameters:
– PS level which provides an
inspiratory ‘boost’ to
augment the spontaneous
tidal volume.
– PEEP
– FiO2
• Variable Parameters:
– RR
– Vt will vary
• Changes in lung
mechanics
• Patient effort
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Proportional Assist Ventilation: PAV
• Currently only available on the PB 840.
• Patients must have an intact respiratory drive.
• Support from the ventilator is proportional to the
patients effort.
• Patient effort is amplified by % support (set by
operator).
• Synchrony is assured since machine assistance is
applied only when there is an effort from the patient.
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Proportional Assist Ventilation: PAV
• Set Parameters:
– % support
• Amount of pressure
that is used to
augmentation to a
patient effort.
• NO EFFORT = NO
BREATH DELIVERY
– FiO2
• Variable Parameters:
– RR
– Vt
– PIP
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SPONTANEOUS BREATHING
CPAP
Weaning
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Continuous Positive Airway Pressure:
CPAP
• Set Parameters:
– Pressure
• Variable Parameters:
– Everything else!
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Weaning
• Weaning must be tailored to fit the needs of each individual patient.
• Contributing Factors:
• Surgeries
• Complications
• Length of time on the ventilator
• Patient condition prior to intubation
• Age
• LOC [level of consciousness]
• Co-morbities
• Type of airway
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Weaning
• RAH Weaning Protocol:
• Purpose:
– To facilitate timely and eventual removal of ventilatory support
as part of patient discharge from the ICU.
• Special Considerations:
– The weaning protocol will be initiated on patients who have
been in AICU for at least 24 hours and/or have been assessed
by the attending physician/chief resident with the appropriate
order written.
– Assessment for weaning will be based on the defined criteria.
– Assessment during weaning will be based on the defined
criteria.
– Extubation will occur promptly following assessment of CXR.
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Assessment for Weaning
ASSESSMENT FOR WEANING TRIAL
• Hemoglobin > 70 mg/dl
• PaO2 ≥ 60
• FiO2 ≤ 45
• PEEP at :
– Measured autoPEEP OR
– PEEP of 5 cmH2O
• RSBI ≤ 140
• Adequate cough
• GCS ≥ 11
• No infusions of vasopressors or sedatives
• Endotracheal tube cuff leak present [Evaluate in A/C and assess if there is
a Ventilation Volume loss of 105 ml, with tidal volume being no less than
400ml NIF ≥ 20 cmH2O ( for patients ventilated greater than 48 hrs)]
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Failure to Wean
ASSESSMENT DURING WEANING TRIAL – FAILURE TO WEAN IS
DEFINED BY:
• SpO2 < 90% for 5 minutes
• RR > 35
• HR 25% change from baseline for 10 min
• BP < 90 mmHg or >200 mmHg
• Abnormal paradox
• Diaphoresis
• Anxiety unresponsive to anti-anxiety measures
• ↓ LOC
• Deterioration of Chest X-Ray
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Weaning Protocol
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Weaning
• CPAP Trials:
– Patient Population: Chrionic ventialted patients,
difficult to wean or those with poor respiratory muscle
strength.
– Patient breathes on CPAP for short periods of time,
progressively getting longer.
– Patient rested on full ventilatory support mode.
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Factors Associated with Difficulty Weaning
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Cardiovascular collapse.
Poor muscle strength or atrophy.
Increased work of breathing.
Excessive secretions.
Patient not psychologically or physiologically ready.
Primary illness not resolved.
Improper weaning procedure or patient cannot be weaned (terminal illness).
Pulmonary complications (e.g. atelectasis, pulmonary infection, bronchospasm).
Poor nutrition.
Continued use of sedatives or analgesics.
Acid-base imbalance.
Electrolyte imbalance.
Abdominal distension.
Anemia.
Fluid overload.
Renal failure.
Malfunction of equipment.
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VENTILATORS AND THEIR MODES
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SERVO 300
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VC
PCV
PRVC
SIMV(VC) + PSV
SIMV(PC) + PSV
VS
PS
CPAP
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SERVO-i
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VC
PC
PRVC
SIMV(VC) + PSV
SIMV(PC) + PSV
SIMV(PRVC) + PSV
VS
PS
CPAP
Bi-Vent
NIV
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PB 840
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AC
VC+
PCV
SIMV
PSV
PAV
CPAP
Bi-Level
NIV
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EVITA
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CMV
CMV (autoflow)
PCV
PCV +Assist
APRV
PSV
CPAP
NIV
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BiPAP Visions
• CPAP
• S/T (BiPAP)
• PAV
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Non-Invasive Ventilation
•
•
•
The application of positive pressure through a mask to the upper airway and lung
fields.
The pressure applied aids in stabilization of the upper airway to allow for adequate
movement of air into the lungs.
The mask can be applied to just the nose [nasal] or to both the nose and mouth [full
face].
– Mask used will depend on amount of assistance required.
•
Pressure applied can be on a constant basis [CPAP)] or in two phases [BiPAP] that
mimics inspiration and expiration.
– Method of pressure delivery will be determined by the type of
assistance required.
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Modes of Non-invasive Ventilation
CPAP
Continuous Positive Airway
Pressure

Splints airway open to allow for
movement of air into the lungs.
BiPAP
Bi-level Positive Airway
Pressure


The inspiratory pressure provides a
boost to inspiration which means a
bigger breath with less effort by the
individual.
The expiratory pressure is to keep
the airway open while exhaling.
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What is this ‘VISION’ you speak of?
• What the manual says:
“The VISION ventilator is a microprocessor-controlled
positive pressure ventilatory assist system.”
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What does that mean?
• The VISION ventilator provides positive airway pressure and
positive pressure ventilation in non-invasive situations.
• It is indicated for assisted ventilation and is intended to
augment a spontaneously breathing patient.
• The VISION ventilator has the ability to provide total
ventilatory support.
– NOTE! At the RAH we will not be providing total ventilatory
support with this machine!
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How does it work?
• Pressure regulation is achieved on the VISION
ventilator through a series of algorithms.
• By monitoring proximal airway pressure and adjusting
flows generated by the machine, the ventilator is able to
ensure that the proximal pressure is equal to the set
pressure.
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What can the VISION ventilator do for my
patients?
• Provides % oxygen-this is key!
• Provides 3 modes of NIMV:
– CPAP
– BIPAP (S/T)
– PAV/T (Proportional Assist Ventilation)
• Leak compensated
• Alarms for patient safety
• Set up for adequate humidification
• Circuit has a built in leak valve=CASTLE VALVE
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Initializing
•
Designated VISION’s circuit
– Pressure line adaptor
– Heated Wide bore hose
– Castle Valve
•
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•
Square Green Filter
Humidifier and sterile water bag
Calibrated O2 Analyzer and analyzer t-in
Rubber adaptor
•
•
Temperature probe
Mask
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Initializing
Specialty Bits and Pieces
• O2 module versus O2 t-in:
– Bayonet style
– RAH will be using the O2 module only
• Controls the concentration from 21%-100%
• A more stable and reliable method of oxygen delivery
– Displays a % of O2.
– Must use with an O2 analyzer.
– Accurate within +3% FiO2 or
– Accurate within +10% set FiO2
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Initializing
Specialty Bits and Pieces
• Castle Valve
– Clear plastic adjunct to the circuit
– Should never be removed from the circuit
• Continuous flow from the valve flushes exhaled gases from
the circuit.
• Occlusion of this port is potentially dangerous.
– Necessary for the Exhalation Port test
– Included in the disposable circuit package
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Initializing
• Performance Verification
– CLEAN IT!
– CIRCUIT IT!
– CHECK IT!
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Initializing
• Exhalation Port Test
– This must be done!!
– During the test the system learns the intentional leak,
stores it in its memory and uses it to perform leak
calculations and provide an accurate display of
patient leak, Vt and MV.
– In turn, accurate Vt and MV will ensure the alarms
are able to activate appropriately.
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The Meat and Potatoes
• Modes of Ventilation
– CPAP
– S/T (BIPAP)
– Proportional Assist Ventilation (PAV/T)
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CPAP
• Same old, same old
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CPAP
ACTIVE
EPAP (set)
%O2
ACTIVELY INACTIVE
Learn Base Flow
Back up rate
MEASURED
EPAP
Rate
Vtexh
MV
PIP
Leak
Ti/Ttot
INACTIVE
IPAP
Rise Time
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Those Crazy Alarms
APNEA
Interval
ALARMS
Hi Pressure Limit (Hi P)
Low Pressure Limit (Lo P)
Low Pressure Alarm Delay (Lo P
Delay)
Low Minute Ventilation (Lo
MinVent)
High Rate (Hi Rate)
Low Rate (Lo Rate)
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S/T
• “…the S/T mode of the VISION ventilator delivers
pressure support with PEEP”
– Fancy way of saying it provides IPAP and EPAP but
displays the difference in pressure as “PS”.
• Referenced as S/T=Spontaneously Timed
– This means that the machine is capable of delivering
timed breaths if the patient’s RR decreases to or
below a set limit.
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S/T
• This mode is set up exactly like the BIPAP we know and
love!
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What is a Timed Breath?
• A timed breath is a machine triggered, pressure-limited,
time-cycled, pressure controlled breath at the set IPAP
level. The Inspiratory Time control controls the length of
the breath.
• A machine controlled breath will be indicated on the
volume waveform by a tiny little ‘V’ right on the wave
form.
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S/T
ACTIVE
IPAP (set)
EPAP (set)
%O2 (set)
Rise Time (IPAP)
ACTIVELY INACTIVE
Learn Base Flow
MEASURED
IPAP
EPAP
Rate
Vtexh
MV
PIP
Leak
Ti/Ttot
%Patient-Triggered breaths
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Those Crazy Alarms
APNEA
Interval (set)
Rate (set)
ALARMS
Hi P
Lo P
Lo P Delay
Lo Rate
Lo MinVent
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Say What?
• PAV/T= Proportional Assist Ventilation/Timed
• “…combines patient triggered breaths that can deliver
pressure in proportion to effort (PAV) and a preset
backup rate that activates machine-triggered, pressure
limited, time-cycled breaths (Timed).”
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PAV/T
• Concept:
– The ventilator has the capability to respond to patient
effort and their needs to determine when to start and
stop the breath and the flow and pressure changes
required by the patient within that breath. As well as
the ability to trigger a timed breath if the patient fails
to initiate inspiration.
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PAV/T
ACTIVE
% Set (set)
Volume Assist (set)
Flow Assist (set)
EPAP (set)
%O2 (set)
MEASURED
Volume Assist
Flow Assist
EPAP
Rate
Vtexh
MV
PIP
Leak
Ti/Ttot
%Patient-Triggered breaths
ACTIVELY INACTIVE
IPAP (set)
Rise Time (IPAP)
Learn Base Flow
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Mode Particulars
• Language
– Volume Assist
– Flow Assist
– % set
– PAV Delivery Options
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Volume Assist (VA)
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Clinician adjustable control
Overcomes the elastance (compliance) of the lungs
Amplifies patient volume
Start at 5cmH2O/L
Increase or decrease by increments of 2
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Flow Assist (FA)
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Clinician adjustable control
Overcomes the resistance of the airways
Amplifies patient inspiratory flow rate
Start at 2cmH2O/L/sec
Increase or decrease in increments of 2
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% Set
• Clinician adjustable control
• Sets the % of work done by the ventilator to obtain Vt
and inspiratory flow rate in conjunction with the VA and
FA settings
• Adjustable from 0-100%
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% Set
• Directly affects VA and FA settings
– Example:
• % Set = 50%
• VA (set)=5cmH2O/L
• VA (delivered)=2.5cmH2O/L
• FA (set)=2cmH2O/L/sec
• FA (delivered)=1cmH2O/L/sec
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PAV/T
• A ‘HANDS-ON’ mode.
• Ultimately, it is the therapists job to determine how high
those demands and needs are and set the parameters
appropriately.
• I ask you…
– Is this any different from any other mode or anything
else we do?
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Where do I start?
• PAV/T Delivery Options
– obstructive
– restrictive
– mixed
– normal
– quick set up
– custom
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PAV/T
• Scenario:
– 75 year old male brought into ER by EMS in severe
respiratory distress. Bronchodilator treatments are
ineffective and it is determined that the patient
should be placed on the VISION ventilator. In
conjunction with the CO you decide that you are
going to try the patient on PAV. What initial set up do
you choose?
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Custom %
• Whereas the other delivery options provide the user
with preset, yet adjustable values, custom % gives you
the option to individually set the VA, FA and % Set.
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Belinda’s way…
On a patient in severe respiratory distress:
• % Set=80%
• VA=5cmH2O/L
• FA=2cmH2O/L/sec
• Leave the % set where it is and adjust the VA and FA so that you
know which ones are making the difference.
• Ensure that EPAP is set appropriately.
• Never take your eyes off the patient!
• Tweak the VA and FA and EPAP.
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Those Crazy Alarms
APNEA
Interval (set)
Rate (set)
ALARMS
Hi P
Lo P
Lo P Delay
Lo Rate
Lo MinVent
Max Pav Press
Max Pav Vt
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Auto-Trak Sensitivity
• Automatically adjusts to changing circuit conditions (i.e.
leaks)
• Ventilator is capable of ensuring optimum patient
ventilator synchrony despite changes in breathing
pattern and leaks
• NOT ADJUSTABLE!!
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Auto-Trak Sensitivity
Leak Tolerance
• Flow & Volume
– At end expiration the machine compares the total flow with the
originally established intentional leak (Port test).
– If the volume varies through the breath the VISION assumes
that this may be due to a leak in the system.
– Therefore:
• the machine will redefine the baseline so that the patient
does not have to and a smooth transition between EPAP to
IPAP continues.
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Auto-Trak Sensitivity
• The VISION ventilator tracks a patient’s breathing patterns and
automatically adjusts sensitivity via the use of algorithms.
– Shape signal
– 6cc inspired volume above baseline
– Spontaneous Expiratory Threshold
– 3.0sec maximum IPAP
– Flow reversal during IPAP (leak around the mask)
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Bronchodilators
•
•
•
•
What is the best way?
What are we doing?
What do I need to tell the RN’s?
References
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I never said it was perfect!
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•
Manual
Auto-Trak Sensitivity
Displays things that are not active
Low pressure alarm available but often is not activated
because the machine can compensate for such extreme
leaks
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