David Wolfe

Crouse Hospital

Upstate Medical University

Alphabet Soup

CPAP

BPAP

IPAP

PS

EPAP

APAP

ASV

AVAPS

iVAPS

OSA

RLS

PLMD

OHS

EDS

Making it Simpler

CPAP/BPAP – airway

A/i VAPS – lung (hypercapnic)

ASV – brain (normo/hypocapnic)

OHS Criteria

Chronic daytime hypercapnia (PaCO2 >

45 mm Hg)

in obese patients (BMI > 30 kg/m2)

after ruling out any other causes of

hypoventilation

OHS Signs and Symptoms

Hypoxemia

Dyspnea

EDS

Morning headache

Depression

As many as 90% of OHS patients also

have OSA.

OHS Indications

Headaches and somnolence after CPAP

treatment

Continuous O2 saturation < 90%

DOE

OHS Untreated

Pulmonary HTN

R heart failure

Polycythemia

Treatment of OHS

Weight loss

NIV

Bilevel PAP (BPAP)

EPAP

IPAP

PS – difference between EPAP and

IPAP

EPAP = 6, IPAP = 14

Rise Time

Time it takes to change from the

expiratory pressure setting to the

inspiratory pressure setting.

BPAP

iVAPS

intelligent Volume-Assured Pressure

Support

“Under-achievers”

Targets alveolar ventilation by adjusting

to patient’s RR and adjusting PS.

iVAPS - Alveolar Ventilation

Targets and maintains alveolar ventilation instead of ṼE or VT

Delivers required ventilation at the alveoli (gas exchange) ○ Compensates for the air that travels through the

conducting airways

Maintains VA with fluctuating RR ○ Normal anatomical deadspace ~1/3 (?) of VT

○ With respiratory disorders, as RR ↑, wasted deadspace volume ↑

○ Estimating anatomical deadspace maintains consistent ventilation at the alveolar level, even with RR fluctuations

iVAPS

Rate and alveolar ventilation targets are

set for the patient

Responding to the patient’s breathing

changes, it automatically adjusts

pressure support

Provides an intelligent back-up rate

Helps reduce the need for frequent f/u

iVAPS

COPD - hyperinflation

OHS

Neuromuscular Disorders

Restrictive Diseases

iVAPS

Set-up manually or “Learn Targets”

(learned during set-up) feature

Learned/Set Target Patient Rate =

Spontaneous Respiratory Rate

Learned/Set Target VA (height) =

Required VA

iVAPS constantly monitors & estimates

pt’s VA in relation to target VA ventilation.

Automatically adjusts PS to achieve &

maintain target VA, varying speed of

response as required.

If VA is far from target, PS adjusts

quickly.

As VA gets close to target, PS gently

levels off.

Maintains stable VA automatically during

changes in respiratory mechanics (i.e.

REM sleep transition, postural change).

Back-up rate = 2/3 of the patient’s

spontaneous breathing rate

Unable to trigger the device, back-up

rate provides breaths at the target

patient rate.

iVAPS

The PS and back-up rate work to

balance efficacy and pt. comfort.

BiPAP AVAPS

Average Volume Assured Pressure

Support

Increases pressure quickly to maintain

target VT, but slow enough to keep

patient asleep.

Averages VT and

changes PS

gradually (several

minutes).

AVAPS

Automatically adapts to changing patient

needs and disease progression

Maintains optimal patient comfort

Improves efficacy of ventilation

AVAPS

Digital Auto-Trak Sensitivity algorithm:

Allows clinicians to achieve optimum

patient/ventilator synchrony.

Recognizes & compensates for leaks

Automatically adjusts its variable trigger and

cycle thresholds

AVAPS Settings

Target VT set to ideal body

weight – 8 ml/kg

Set IPAP limits

Max: 25 cm H2O (depends on pt pathology)

Min: EPAP + 4 cm H2O

Set RR: 2-3 BPM < resting RR

Set Ti

Adjust rise time for pt comfort

AVAPS

As pt effort decreases, PS increases to

maintain target VT.

IPAP level will not rise above IPAP Max.

As pt effort increases, PS decreases.

IPAP will not fall below IPAP Min.

AVAPS

Trilogy

AVAPS AE

Forced oscillation technique

AVAPS rate

Dual prescriptions

Passive (AVAPS) or active exhalation

port

For OHS

BPAP and AVAPS improved:

Oxygenation

Sleep quality

QOL

AVAPS – greater improvement in

ventilation than BPAP.

Storre et al, Chest, 2006

OHS. Compared to BPAP . . .

Nocturnal ventilation with AVAPS,

lowered TcCO2 by 3 mmHg.

AVAPS:

Impaired sleep quantity and architecture.

Subjectively poorer sleep.

Janssens et al, Respir Med, 2009

Adaptive/Automatic Servo

Ventilation

“Over-achievers”

Treats: CSA

Complex SA

Mixed apnea

Periodic breathing

How: EPAP - keeps airways open

PS – increases VT

(IPAP = EPAP + PS)

AirCurve™ 10 (VPAP Adapt SV)

90% of recent ventilation.

Automatically adjusts PS.

Min PS and Max PS restrict PS range.

EPAP adjusted to eliminate OE’s.

Mandatory breaths delivered at pt’s

recent spontaneous breath rate:

timed backup rate automatically

calculated to match pt’s needs.

ASV

Add diagram . . .

ASV Auto

Automatically adjusts EPAP.

Analyzes the state of patient’s upper airway on a breath-by-breath basis.

Min and Max EPAP restricts EPAP range.

Delivers (titrates) EPAP within the allowed range according to obstruction degree.

EPAP changes based on:

○ Inspiratory flow limitation

○ Snoring

○ OA’s

ASV Auto

Breath Phase Mapping

PS

PS trigger points set automatically,

based on patient respiratory flow

measurement.

ResMed recommends Max PS to be ≥

15 cm H2O.

Backup Rate

Uses breath phase mapping.

Provides a timed backup rate

synchronized with pt’s breathing.

If deviation from the target ventilation:

First, adjusts PS.

Second, if necessary, adjusts backup rate

○ From a backup that matches the pt’s recent

rate,

○ Towards the built-in 15 BPM default backup.

Ramp

Set at 5 - 45 min

ASV

Start EPAP to set EPAP

Min PS to PS range (Min PS and Max PS)

ASVAuto

Start EPAP to Min EPAP (EPAP range)

Min PS to

PS range

BiPAP autoSV

Targets peak flow (over time period):

Flow = Volume/Time

Hypopnea/apnea, pt flow decreases . . .

device flow increases.

Increases flow first, then backup rate.

BiPAP autoSV Advanced

Auto EPAP

Automatically distinguishes between clear

airway and obstructed apneas.

Advanced backup rate

Timing of backup rate delivery calculated to

encourage spontaneous breathing at pt’s

own natural rate.

Synchronous with pt’s breathing.

BiPAP autoSV Advanced – cont’d

Servo Ventilation algorithm

Monitors peak flow & Δ’s PS “breath by

breath” to stabilize breathing pattern.

Establishes a target peak flow.

Rapidly normalizes unstable breathing

pattern.

BiPAP autoSV Advanced – cont’d

Bi-flex technology

Provides pressure relief:

○ During exhalation.

○ At critical transition points from

Exhalation to inhalation

Inhalation to exhalation.

BiPAP autoSV Advanced –

Suggested Titration Protocol

EPAPmin = 4 cm H2O

4 cm H2O (or pt comfort) – known CPAP < 10

6-8 cm H2O (or pt comfort) – known CPAP > 10

EPAPmax = 15 cm H2O

PSmin = 0 cm H2O

PSmax = 20 cm H2O

Max pressure = 25 cm H2O

Rate = auto

Bi-Flex = to pt comfort

Set It and Forget It?

Increase EPAPmin for obstructive events.

Adjust Bi-Flex and/or increase PSmin for

patient comfort.

Increase PSmax for central events

Inadequate breathing rate?

Set rate to minimum 8-10 bpm or 2 below

resting RR

Set I-time = 1.5 seconds

Wait 20 minutes after change.

ASV – through March 2015

CSA/CSB due to HF consistently

demonstrated that ASV decreases CA

frequency.1,2,3

ASV improved LVEF.1,4

ASV impact on mortality and QOL

uncertain (not been studied).

1. Pepperell et al, Am J Respir Crit Care Med, 2003

2. Oldenburg et al, Eur J Heart Fail, 2008

3. Fietze et al, Sleep Med, 2008

4. Sharma et al, Chest, 2012

May 2015 press release

Cautioned against ASV use in pt’s with

symptomatic chronic HF & LVEF ≤ 45%.

↑ risk appears to be in LVEF < 30%.

EPAP not adjusted much – not a lot of

obstruction.

EPAP was not auto.

No difference in exercise capacity or

QOL.

Confusing?

Present settings:

EPAP = 8 cm H2O

IPAPmin = 10 cm H2O

IPAPmax = 25 cm H2O

New settings to EQUAL present settings?

EPAPmin

EPAPmax

PSmin

PSmax

Max pressure

Confusing? No!

Present settings on ASV:

EPAP = 8 cm H2O

IPAPmin = 10 cm H2O

IPAPmax = 25 cm H2O

New settings to EQUAL present settings?

EPAPmin = 8 cm H2O

EPAPmax = 8 cm H2O

PSmin = 2 cm H2O

PSmax = 17 cm H2O

Max pressure = 25 cm H2O

Quick Takeaways

AVAPS targets TV

iVAPS targets VA

AVAPS AE has auto-EPAP

i/AVAPS - underachievers

ASV – overachievers

ASV Auto – tracks (minute) ventilation

BiPAP AutoSV – tracks peak flow

End of Quiz . . . No Bonus Questions

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