AVAPS & AVAPS-AEAuto-titration Modes of Non-invasive Ventilation Preliminary Setting Guidelines Nicholas Dawson, RRT and Bill Moller, RPSGT, RST Philips Home Health
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)269-275 2Mokhlesi. 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
P search opt P therapy crit P search AVAPS-AE: Auto EPAP proactive analysis Theory of Operation Device Pressure Upper Airway Resistance Illustration courtesy of Krames Medical Illustration.
P opt P ther P therapy P therapy P therapy AVAPS-AE: Auto EPAP proactive analysis Popt– Optimal Pressure Search (High Pressure Search) Pressure Popt EPAP P P crit crit P opt P opt P opt Resistance Critical Pressure Searches (Low Pressure Search) P therapy P crit EPAP Pcrit P crit
Current PRI Auto EPAP/CPAP Comparison of Auto EPAP methods Flow AVAPS-AE Pressure Peak Flatness Shape Roundness Forced oscillation technique (FOT) at 5 Hz, 1 cm amplitude during EPAP
Benefits of FOT R R R Increase in EPAP by 1 cm H2O s R • 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 brea
FOT – Flow resulting from pressure FOT signal Resulting flow
FOT – Patent vs. obstructed airway • . Patent/Normal airway Resulting flow (low resistance) Obstructed airway Resulting flow (higher resistance)
PS max IPAP PS min EPAP Target Vt AVAPS-AEMaintaining tidal volume and airway patency EPAP max EPAP min Resistance
Auto Back-up rate Auto Backup Rate • Auto backup rate is near resting rate • Comfortable assistance when needed • No manual adjustments (auto-default setting) Auto backup rate combined with the tidal volume assurance of AVAPS provides a minimum level of ventilation
Auto Backup rate Targeted auto backup rate is 2 bpm below avg. spontaneous rate Bpm Calculated spontaneous rate Target auto backup rate Moving breath rate Minimum auto backup rate 10 Spontaneous breaths Time50 spontaneous breaths
Auto backup rate • The buffer is reduced by timed triggers • The patient will be guided back to the targeted backup rate The auto backup rate is buffered by spontaneous triggers to promote synchrony with the device Bpm Target auto backup rate Moving breath rate Auto backup rate buffer zone 10 Timed Breaths Spontaneous Breaths 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 * 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,ProfJean 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)