avaps & avaps-ae auto-titration modes of non-invasive ventilation preliminary setting guidelines

Philips Home Health , NIcholas Dawson

Nicholas Dawson, RRT and Bill Moller, RPSGT, RST

AVAPS & AVAPS-AEAuto-titration Modes of Non-invasive Ventilation Preliminary Setting Guidelines

Philips Home Health

Philips Home Health , NIcholas Dawson 2

Educational ObjectivesWhat we will cover today:

• What is AVAPS-AE?

• AVAPS mode; Why do we need it?

• AVAPS & AVAPS-AE Modes; Settings and Range

• AVAPS-AE Suggested settings guidelines in OHS and COPD-OSA

• Summary/Questions


AVAPS-AE

AVAPS-AE is a auto-titration mode of noninvasive ventilation designed to treat respiratory insufficiency patients (OHS, COPD and NMD) in the hospital and homecare environments

• Proven performance of AVAPS – Maintains targeted Tidal volume

• Auto EPAP – Maintains patent upper airway at comfortable pressure

• Auto backup rate – Applies an auto backup rate near a patient’s resting rate


AVAPS; What is it?Average Volume Assured Pressure Support

• As name implies, it is simply volume targeted pressure support.• Auto titrating mode that responds in Inspiratory pressures to changes in

thoracic dynamics to ensure stable tidal volume delivery.• Considered a “Hybrid” mode since it is both Pressure and Volume

oriented mode of ventilation• Also used as an ‘adjunct’ or added to other modes of ventilation such as

“S” mode, “S/T” mode or even PC (Pressure Control) mode• Allows clinician to set operating pressure limits for safety or diagnostic

purposes• Available in R.A.D. platform, but more fully developed in Trilogy

Ventilator• Also recently developed in new Omni-Lab Advanced titration device.


AVAPS: proven effective

• Automatically titrates pressure support– Changes in body position– Sleep stage– Changes in respiratory mechanics

• Delivers average tidal volume– Throughout course of the night– Long-term progression = protects/defends resting lung volume.

• AVAPS produces results comparable to sleep lab titration of PS1 – CO2 reduction

– Health-related quality of life– Sleep quality

1Murphy, PBThorax thoraxjnl-2011-201081: Published Online First: 1 March 2012 doi:10.1136/thoraxjnl-2011-201081


AVAPS-AE: Who it treats

• AVAPS-AE is used for patients with complex breathing disorders with or without OSA component who suffer from Minute ventilation instability. Etiology can stem from Hypoventilation syndromes to airflow limitation related to obstructive pulmonary disease. Patients with dynamic I:E ratios and chronic parenchymal disease with limited reserve lung volumes can benefit from the auto rate feature alone.

• Many of these patients primarily have COPD and some Hx of Chronic Respiratory Failure who may be underserved by traditional sleep therapy modes & methods.


Who can benefit from AVAPS-AE?

• Neuromuscular disease

• Restrictive thoracic disorders

• COPD with Chronic respiratory failure

• OHS with chronic hypercapnea

• Pulmonary patients that fail to respond to traditional RAD device

therapy


AVAPS-AE: Adds Auto EPAP option

• Auto EPAP provides airway patency– Designed for NIV use only– Patient benefit: lower, more comfortable EPAP pressure

• AVAPS-AE and patient overlap

– ?? ~ 30% of COPD patients have OSA1

– 90% of OHS patients have OSA2

• AVAPS-AE: 1st NIV therapy with Auto EPAP designed for respiratory insufficiency and respiratory failure patients

1Jelic International Journal of COPD 2008:3(2)269-2752Mokhlesi. Chest 2007:131;1624-1626


AVAPS-AE: How to use it

• Start with tidal volume selection:– 8ml/kg IDEAL bw Suggest a range +/- 150mls

• Assess need for EPAP: select a range to monitor or manually titrate

• Choose Pressure support range: (2 methods) new user/existing user– New user: set Pressure support levels lower e.g. 5/15– Existing user: take existing Rx IPAP…+10 & -10

• Set back up rate if desired: set to auto for all COPD

• Set comfort settings: Ramp- Rise time- AVAPSrate


AVAPS-AE: Auto EPAP proactive analysis

Theory of Operation

Upper Airway Resistance

Device Pressure

P search

crit

Ptherapy

P searchopt

Illustration courtesy of Krames Medical Illustration.


AVAPS-AE: Auto EPAP proactive analysis

Popt – Optimal Pressure Search

(High Pressure Search)

EP

AP

P opt

P opt

P therapy

P therapy

Critical Pressure Searches

(Low Pressure Search)

P crit

P crit

P therapy

EP

AP

P crit

P therapy

Popt

Pcrit

Pther

Popt

Pre

ssur

e

Resistance

Pcrit

P opt


Comparison of Auto EPAP methodsCurrent PRI Auto EPAP/CPAP

FlatnessRoundnessPeakShape

AVAPS-AE

Flo

wP

res

su

re

Forced oscillation technique (FOT) at 5 Hz, 1 cm amplitude during EPAP


Benefits of FOT

• FOT may improve detection of obstructed airways at higher pressure support levels

– Not affected by high levels of pressure support– FOT measurements taken at end exhalation (10 breaR R R R

Increase in EPAP by 1 cm H2O s


FOT – Flow resulting from pressure

FOT signal

Resulting flow


FOT – Patent vs. obstructed airway

• . Patent/Normal airway

Resulting flow (higher resistance)

Resulting flow (low resistance)

Obstructed airway


AVAPS-AEMaintaining tidal volume and airway patency

EPAP

Target Vt

IPAP PS min

PS max

EPAP min

EPAP max

Resistance


Auto Back-up rate

• Auto backup rate is near resting rate

• Comfortable assistance when needed

• No manual adjustments (auto-default setting)

Auto Backup Rate

Auto backup rate combined with the tidal volume assurance of AVAPS provides a minimum level of ventilation


Auto Backup rateM

ovi

ng

bre

ath

rat

e

Minimum autobackup rate

Spontaneous breaths

Time 50 spontaneous breaths

10

Calculated spontaneous

rate

Target auto backup rate

Targeted auto backup rate is 2 bpm below avg. spontaneous rate

Bp

m


Auto backup rate

Spontaneous Breaths

Timed Breaths

Target auto backup rate

10 Auto backup rate buffer zone

The auto backup rate is buffered by spontaneous triggers to promote synchrony

with the device

• The buffer is reduced by timed triggers• The patient will be guided back to the

targeted backup rate

Bp

m

Mo

vin

g b

reat

h r

ate

Time (Night time session)


Auto Backup rate: Patient comfort features

• Comfort feature intent: Minimizes patient/device asynchrony

– Rate will not exceed patient’s initial resting

spontaneous rate

– Machine breath delayed if patient is still exhaling

– AVAPS-AE allows patient to terminate a machine delivered breath


AVAPS-AE suggested settings

OHS* COPD – OSA*Vt Target 8 -10 ml/Kg of ideal

bodyweight8 ml/Kg of ideal

bodyweight

Max P 35 cmH2O 30 cmH20

PS Max 19- 35 cmH2O 30 cmH2O

PS Min 14 -19 cmH2O 12 cmH2O

EPAP Max 14 cmH20 14 cm H2O

EPAP Min 4 cmH2O 4 cm H2O

Breath Rate Auto Auto

AVAPS Rate 2 N/A

* AVAPS-AE protocol Dr. N. Hart, Dr. P. Murphy, Lane Fox Respiratory unit, St. Thomas’ Hospital London UK* AVAPS-AE Multi Center Trial protocol l,Prof Jean François MUIR, France


AVAPS-AE: Comfort Settings

• Ramp- Sets pressure support back to minimum level setting. Use if patient sensitive to initial pressures at time of sleep. Can be turned “OFF” if not desired

• Rise time: setting 1-6 default is 3..lower toward 1 for flow starved patients, raise toward 6 for NMD

• AVAPS rate: sets speed of response for pressure support changes while chasing tidal volume


AVAPS-AE: What to monitor…

• AVAPS-AE will titrate pressure support based upon the tidal volume target set and the patients dynamic lung compliance or ability to generate volumes at the given inspiratory pressure support level.

• EPAP can be monitored during ventilation • Inspiratory flowrates can be monitored for patients who have disease

states that may require variability in inspiratory flow rates.• Respiratory rate can be set fixed BPM and monitored for flow

challenges with changing I:E ratios or can be set to “auto” and nocturnal respiratory rate can be monitored and compared to minute ventilation stability.


AVAPS-AE

• Proven performance of AVAPS– Confidence that tidal volume targets are being met

• Auto EPAP– Auto adjusting EPAP to meet changing patient needs – Maintains a patent airway

• Auto backup rate– Maintains a breath rate designed for patient comfort (easy to use)

avaps & avaps-ae auto-titration modes of non-invasive ventilation preliminary setting guidelines

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