The Nuts and Bolts of CPAP Use - A-Flex (for Auto-CPAP) lowers pressure on exhalation, gradually increases the pressure on inhalation • Resmed –EPR (expiratory pressure relief)

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The Nuts and Bolts of CPAP Use:

Titration, Tracking, Optimization

Grace Pien, MD, MSCEDivision of Pulmonary and Critical Care

Department of MedicineJohns Hopkins School of Medicine

16 February 2018

Outline

• Optimizing CPAP delivery– PAP systems

– Masks

– Accessories

– Troubleshooting

• Understanding and using tracking data– PAP adherence tracking systems

– Residual AHI and event detection

– Mask leak

– Data transmission and review systems

– Barriers to using tracking systems in clinical practice

– How to use the data

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Introduction to CPAP: What to Tell the Patient

• Safer than taking a medication

• Not a breathing machine – s/he will not die if disconnected from the unit or therapy stopped

• Pneumatic splint to open the airway - it is not oxygen

• Machine much quieter than snoring - white noise

• Use during sleep only

• Consider a desensitization program

− Get used to it - watch TV with CPAP on

− Take pictures of yourself

CPAP Units 2018

ResMed AirSense 10

Philips Respironics DreamStation

Fisher & Paykel SleepStyle

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Travel CPAPs

HDM Z1

ResMed AirMini

Is This the Future of CPAP?

• “MicroCPAP” microblower fluidic pump

• About half of capital raised from crowdfunding

• Still in prototype form • NOT yet evaluated in 

clinical trials or by FDA

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Cost of CPAP

• CPAP machines range from $300 to $800• More expensive units have compliance/efficacy

capability, some have built-in auto-PAP capability

• Auto-CPAP: $500 - $900 (no code for Medicare reimbursement)

• Bi-level systems: $950 - $1700

• Circuit and mask $75 - $200+• New CPAP mask every 6 months should be covered

• Insurance companies (including BC/BS, US Health Care, Medicare, HMO's, Managed Medicaid, etc) provide coverage

CPAP Advancements• Ramp systems

• Useful at high CPAP settings

• Heated humidification*• Multiple heated humidification systems available• Reduces nasal drying - useful for mouth leaks

and patients with sinus problems• Cool passive humidifiers not as effective

• Humidifier and CPAP in one unit• Heating coils in tubing• Tubing insulators

*AASM practice parameters CPAP/Bilevel pressure. Sleep 29: 375-380, 2006.

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CPAP Advancements: Variable Expiratory Pressure

• Different manufacturers, different names, different algorithms for pressure reduction

• Philips Respironics– C-Flex and A-Flex– Relative drop – C-Flex lowers pressure on exhalation, ramps back up to

the prescribed pressure at inhalation– A-Flex (for Auto-CPAP) lowers pressure on exhalation,

gradually increases the pressure on inhalation• Resmed

– EPR (expiratory pressure relief)– 1, 2 or 3 cm drop during exhalation, increased back to

prescribed pressure at inhalation

• DeVilbiss– Smartflex– 1, 2 or 3 cm drop during exhalation, separate settings for adjustment during inhalation

• Useful in patients with difficulty with exhalation• Equally effective as CPAP• No long term effect on adherence• No difference in cost

• These units adjust the pressure throughout night rather than delivering one fixed pressure

• Optimal CPAP varies during night– Changes in body, head position

– Sleep state dependent changes

• REM v. NREM; effects of sleep deprivation

– Alcohol or sedative effects

– Effects of URIs, seasonal allergies

– Useful for bariatric surgery patients

– Becoming standard with widespred use of HSAT

Auto-CPAP

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Auto-CPAP

• Noninvasively detects variations of upper airway obstruction and airflow limitation• Hypopneas

• Apneas

• Snoring

• APAP devices automatically increase pressure until flow limitation resolved

• Followed by gradual reduction in pressure until flow limitation resumed

• Maximum therapeutic range: 4 to 20 cm H2O

Auto-CPAP: Uses and Limitations

• mean pressure across the night• eg nasal complaints, nosebleeds

• Automated titration: in lab or at home• Able to determine appropriate CPAP settings• Allows for fewer technologists if in lab

• Inability to recognize central apneas and hypoventilation (may be changing)

• More expensive than conventional CPAP• This is changing• No code for medicare reimbursement

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Comparison of CPAP with APAP

• Meta-analysis of 9 RCTS (282 patients) published between 1996 – 2003• No significant difference

• Reduction in AHI• Daytime sleepiness (Epworth Sleepiness Scale)

• Adherence

• Significant reduction in mean pressure (2.2 cm water) with APAP

• Conclusions: CPAP should remain the primary treatment option for patients with OSA

Ayas et al, Sleep 27; 249-253, 2004

Bilevel Positive Airway Pressure

• Several different commercially available bilevel systems• Independent regulation of inspiratory (IPAP) and expiratory

(EPAP) airway pressures– Lower expiratory pressures– May be useful for patients who have difficulty with

exhalation or chest pain with CPAP– Algorithms to adjust pressures are empiric

• Increase EPAP or IPAP or both?• Role of IPAP and EPAP in abolishing apneas needs to be

studied

• Auto-Bilevel PAP systems - how do they work?– The pressure differential between IPAP and EPAP is

fixed (lowest setting is generally 4 cm of water)

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Bilevel PAP Systems

• Similar in weight and size to CPAP units• More expensive than CPAP units• Louder than CPAP?• Studies have not demonstrated improved

adherence or efficacy compared to CPAPReeves-Hoche et al. AJRCCM 151:443-449, 1995

• Reserved for patients who do not tolerate CPAP, especially with• Difficulties with exhalation, mask leaks• Chest pain as a result of lung hyperinflation

CPAP Interfaces

• Lack of controlled trials demonstrating differences in efficacy between various CPAP interfaces

• Nasal interfaces− Nasal masks

− Nasal pillows/direct nasal interfaces

• Full face masks

• Hybrid masks

• Oral masks

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CPAP Interfaces

• Unique mask features• Some require specific headgear• Many are a cushion and frame combo• Quick release clips• Swivel• Location of tubing connector• Additional connection port for oxygen• Gel-like material

Nasal Pillow Interfaces

ResMed Swift LT

ResMed Swift FX

ResMed Swift FX For Her Bella

Respironics Nuance Gel

Innomed Nasal Aire II

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Nasal Masks

ResMed AirTouch F20

Respironics DreamWear ResMed Mirage Activa LT

ResMed AirFit N20

Devilbiss EasyFit

ResMed Swift FX Nano

Full Face Masks

Respironics Amara

ResMed AirFit F20

DeVilbiss Quest

Fisher Paykel Simplus

ResMed Quattro FX for Her

Respironics Amara View

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Hybrid Interfaces

Resmed Mirage Liberty Respironics Wisp

Other Mask Interfaces

Fisher Paykel Oracle oral interface

Sleepweaver

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CPAP Problems and Adherence

• Patient acceptability

• Patient acceptability

• Patient acceptability

• Adherence 50 ‐ 60%

• Average nightly use 4.8 hours ‐ not so bad!

• Approximately 35% of patients "love" CPAP, 50% struggle with CPAP but eventually tolerate it and about 15% "hate" CPAP and never use it

• We are able to track CPAP use

CPAP Nasal Gel Pads

Boomerang Gel Pad Propellaire Gel PadGecko Nasal Pad

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CPAP Interface “Tricks”

• CPAP Mask Fitting Program• History

• Dentures, Eyeglasses

• Claustrophobia, Mouth Breathing

• Physical Exam

• Multiple trials before finding correct mask• Close follow-up important

CPAP Interface “Tricks”

• Large masks leak more than snug ones• If in doubt, start with smaller size

• Dry skin can reduce mask seal• Stay away from petroleum-based moisturizers

• Prescribe heated humidification• Consider nasal steroids• Clean masks with warm, soapy water

• No antibacterial soaps

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Common Complaints with CPAP

• Nocturnal arousals– Change mask interface

• Rhinitis, nasal irritation and dryness– Treat with heated humidification ± nasal steroids

• Aerophagia– Change body position or mask type

• Mask and mouth leaks– Switch mask type/chin strap

• Sinusitis– Add heated humidification/?Oracle

Common Complaints with CPAP

• Chest and back pain (lung hyperinflation)– Consider expiratory pressure relief or bilevel device

• Claustrophobia– Switch from a nasal mask to nasal pillows

– Desensitization

• Difficulty with exhalation– Consider expiratory pressure relief or bilevel device

• Severe complications– Case reports: epistaxis, meningitis and

pneumocephalus (pituitary surgery)

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• Decrease humidification• Can be difficult in winter

• Add heated tubing• Not compatible with all PAP units

• Tube buddy or snugglehose to keep tubing warm to prevent condensation

How To Treat CPAP Tubing Rainout?

CPAP Tubing Insulators…or, what is a SnuggleHose?

• Fabric tubing covers for CPAP hoses • Decrease condensation from humidifiers• Available in lengths up to 10 feet• SnuggleHose, Tube Buddy, Tubing Wrap,

Tender Tubing

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PAP Follow-Up Program

• Data suggests that supportive intervention after initiating CPAP improves usage

• CBT prior to initiation with continuation after the start of therapy leads to largest increases in average machine usage

• Short-term educational intervention not uniformly beneficial

Smith I, et al. Cochrane Database Syst Rev. 2009

PAP Follow-Up Program• Effective support requires additional resources to

complement physician encounters

• For instance:

• MA or RT for mask fittings, downloads and ongoing education

• Can be hired or can “team-up” with DME companies who provide the service to majority of your patients

• Nurse practitioner or registered nurse• Complement RT from DME company for mask fitting

• Can be trained in CBT for insomnia as well as CPAP

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Optimization of Delivery of Positive Airway Pressure: Summary

• Start with CPAP plus heated humidification– Change the interface if problems with adherence

– Mask fitting program

• If patients are unable to tolerate CPAP consider C-Flex, auto-CPAP, bilevel PAP– Especially if difficulty exhaling or pressure-related side

effects

• Address nasal complaints– Nasal steroids and consider nasal surgery if nasal

obstruction remains problematic

• Supportive intervention/monitor adherence• Early and often

CPAP Adherence Tracking: How to Use the Data

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CPAP Adherence PatternsWeaver TE et al, Sleep 1997

• 53% consistent users• Mean use 6.21 ± 1.21 hrs

• 47% intermittent users• Mean use 3.45 ± 1.94 hrs

Longitudinal Patterns of PAP AdherenceBabbin et al, Multivariate Behav Res 2015

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Relationship Between Nightly Hours of CPAP Use and Normalization of Outcomes – Why We Care

About CPAP Adherence

Weaver et al. Sleep 2007;30: 711

ESS

FOSQ

MSLT

CPAP Adherence Tracking Systems

• CPAP adherence tracking systems are used by nearly all sleep physicians who take care of patients with OSA

• Requirement for Medicare CPAP coverage

• While CPAP adherence tracking systems have not been extensively tested, their use intuitively make sense 

• Possible that CPAP adherence monitoring is a nice “supplement” to clinical decision making but does not fundamentally change results

• Conflicting data regarding whether use of these tracking systems by patients/providers increases adherence

• Algorithms for mask leak and residual AHI have not been well validated

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CPAP Adherence Tracking Systems

• How do they work? Well, they are all different 

• Typically track adherence, leak and efficacy 

• Are the data reliable or reproducible? – for adherence but not robust for leak or efficacy

• What are the “best” CPAP tracking systems?

• Good question??? 

• Are there guidelines on how to use these systems? 

• An Official American Thoracic Society Clinical Statement: CPAP Adherence Tracking Systems: the Optimal Monitoring Strategies and Outcome Measures (Schwab et al, AJRCCM 188, 613‐620, 2013) 

An Official American Thoracic Society Clinical Statement:

CPAP Adherence Tracking Systems: the Optimal Monitoring Strategies

and Outcome Measures

Richard J. Schwab, Safwan M. Badr, Lawrence J. Epstein, Peter C. Gay, David Gozal, Malcolm Kohler, Patrick Lévy, Atul Malhotra, Barbara A. Phillips, Ilene M. Rosen, Kingman P. Strohl, Patrick J. Strollo, Edward M. 

Weaver, Terri E. Weaver

American Journal of Respiratory and Critical Care Medicine (AJRCCM): 188, 613-620, 2013

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CPAP Adherence Tracking Systems

• How do they work? Well, they are all different 

• Typically track adherence, leak and efficacy 

• Are the data reliable or reproducible? – for adherence but not robust for leak or efficacy

• What are the “best” CPAP tracking systems?

• Good question??? 

• Are there guidelines on how to use these systems? 

• An Official American Thoracic Society Clinical Statement: CPAP Adherence Tracking Systems: the Optimal Monitoring Strategies and Outcome Measures (Schwab et al, AJRCCM 188, 613‐620, 2013) 

CPAP Adherence Tracking Systems

• Philips Respironics and ResMed have been leaders in developing CPAP tracking systems• Fisher & Paykel, DeVilbiss, other manufacturers also have adherence tracking

• Date range of device usage • Total number of nights PAP was used, not used• Percentage of nights with PAP usage• Percentage of nights with PAP usage ≥4 h/night, <4 h/night • Average usage on nights when PAP was used• Average usage on all nights • Additional potential data

• Measures of heart rate, oxygen saturation• High definition flow signals

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Objective Tracking of CPAP Adherence is Important!

• Patient self-report of hours of use• Low correlation with actual hours of use• Routine overestimate of actual usage

• Hour meter on the CPAP device• Meter hours/number of days • Major limitation: does not provide true pattern

of use • Cannot detect if the mask was applied – just

whether the machine is on or off

ResMed AirView

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Respironics EncoreAnywhere

Respironics EncoreAnywhere

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RED < 4 hoursGreen > 4 hoursBlack - no breathing detected

RED < 4 hoursGreen > 4 hoursBlack - no breathing detected

Hours/blower hours

Philips R

espironics

What would you do with this report if it were faxed to you in black and white?

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Problems Tracking CPAP Adherence

• Patients may fail to insert “smart card” into CPAP unit 

• They may have a faulty or corrupted card 

• Some machines track CPAP use only for limited periods

– Confusion if data downloaded for a period that exceeds storage capacity of recording system 

• Card may be unable to provide individualized information if PAP device or card has been used by multiple patients

• Flow sensor can malfunction, resulting in erroneous adherence

• Should time with a “large leak” be counted as time at effective pressure? 

Residual AHI and Event Detection

• What level of residual AHI matters?

• How reliable or accurate is residual AHI?

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Event Detection from PAP Device v. PSG

• No accepted definition for appropriate cutoff for residual AHI (?AHI <5 events/hour); long term effects of residual AHI not known; AHI is the wrong terminology

• These devices all have different algorithms to determine apneas and hypopneas

• Apnea more robust than hypopnea?

• Mouth leak may be a problem

• Hypopnea on lab PSG is determined with EEG arousal or oxyhemoglobin desaturation

• Devices rely only on flow patterns (pneumotach) to estimate residual AHI

• Averaged data over many nights/months – examine data during past week 

CPAP Unit Respiratory Event Detection:Can We Trust Residual AHI?

• Emerging data• Devices seem to over-estimate PSG AHI at lower levels, under-

estimate PSG AHI at higher levels

• Apneas appear more reliable than hypopneas

• Device AHI <10 events/hour suggests good treatment efficacy

• Consider that AHI may be underestimated because CPAP session time rather than sleep time is the denominator

• Also remember that data is averaged• Examining recent night to night data can provide insight

• All auto-PAPs are not created equal

• Terminology for residual AHI assessment should be standardized, could be reported as residual AHIFlow

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What Metric of Mask Leak Should Be Used?

Leak Measures

Respironics

• Average max leak

• Average 90% percentile leak

• Average large leak (time)

• Average % night in large leak

ResMed

• Average median leak (L/min)

• Avg 95% percentile leak

• Average maximum leak

Most units measure liters/minute but the leak can also be reported as liters/second 

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Mask Leaks

• Data Management software displays Total Leak

(either l/min or l/sec)

• Total Leak = Intentional Leak + Unintentional Leak

• Unintentional Leak = Total Leak minus Intentional

Leak

• Intentional Leak can be estimated from the

pressure/flow curves related to a given exhalation

valve for specific CPAP levels

• May not be able to detect if the leak occurs when the

mask is not applied while machine is running! (i.e. going

to the bathroom during the night)

Leak depends on mask and pressure

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Mask Leaks - Respironics Units

• Respironics units: intentional leak is subtracted from the total flow for leak estimation

• Large leak is defined as a high leak condition where the leak levels exceeds a pre‐set “flow vs. pressure”curve (the averaged leak through all mask exhalation ports at various pressures)

• The device can typically tolerate about 2X times the nominal exhalation leak 

• So if intentional leak were 20 l/m, a leak less than 50 l/m would not be registered as a large leak

• > 1 hour leak a problem?

Mask Leaks - ResMed Units• ResMed units reported leak = unintentional leak (device flow ‐ intentional leak) + mouth leak

• ResMed (look at 95th percentile)

• < 24 liters/minute nasal interface is ok

• < 36 liters/minute full face interface is ok

• Threshold of 24 L/min as "acceptable" unintentional leak relatively arbitrary

• Driven by empirical experience on noise

• 95th percentile used instead of median as it gives a better approximation of periods of high leak

• This is leak level that was not surpassed for 95% of night

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Quantifying Mask Leak• What is a clinically significant mask leak?

• Respironics: large leak for > 1 hour?

• ResMed: > 24 liters/minute (95th percentile); > 36 L/minute for a full face mask (95th percentile)

• DeVilbiss unit a mask leak of > 95 liters/minute

• Fisher & Paykel a mask leak > 60 liters/minute

• There may be no leak threshold that is “clinically meaningful,” as even a small leak directed into a patient’s eyes can be problematic

• Averaged data over weeks/months

• May be due to leak around mask or through mouth (with a nasal mask)

CPAP Adherence Data Tracking Transmission and Review Systems

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Transmission of Tracking Data

• Issues– Availability– Cost– Data safety and privacy– Few studies examining data transmission

• Older technology– Machine reading– Chip cards (“smart” cards)

SD cardCellular 

modem

Wireless 

(Wifi)Bluetooth QR code USB Phone

Computer 

code entry

Philips Respironics x x x x

ResMed x x

DeVilbiss x x x x x

Fisher & Paykel x x x

Human Design Medical x

3B Medical x x x x x

Tracking of CPAP Adherence

• myAir // AirView– Compatible with ResMed devices

– Cloud-based care management software

– Daily upload from wireless modem

– Professional (airview.resmed.com) and patient (myair.resmed.com) web portals, patient device app (apple only)

• DreamMapper // EncoreAnywhere– Compatible with Philips Respironics devices

– Interactive web-based application or phone app allows patients to self-monitor use

– Data download via Bluetooth or modem, syncs to computer or app on patient’s phone

– Professional (encoreanywhere.com) and patient (mydreammapper.com) portals, patient app available for apple and android devices

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MyAir DreamMapper

• Patients can track• Hours of use• Residual AHI• Total leak

• Set goals

• Patients can track• Hours of use• Residual AHI• Mask Fit

• Dynamic messaging (reminders)• Within‐app education 

Barriers to Using CPAP Tracking Systems

• Data profiles are not standardized• Data not always easily accessible

• Faxed reports are cumbersome

• Connectivity to server databases is suboptimal (particularly when using multiple homecare providers and device companies)

• May not interface with electronic health record• Current care delivery systems may not be

configured for this type of data management• Can slow down patient flow in a busy practice

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Medical Legal Ramifications of CPAP Tracking Systems

• Medical legal ramifications - motor vehicle crash• For instance, commercial driver on CPAP

• These data could potentially be used in lawsuit

• CPAP use prior to a crash could be examined• How much CPAP use is enough?

• Residual AHI – what level matters?

• Is the physician also at risk? • If patient’s CPAP use not ideal, e.g. high residual

AHI or large leak - why were these data not acted upon? How often should the data be checked (data available every night)?

CPAP Tracking Systems - Take Home

• Use of CPAP adherence monitoring in real time for clinical decision making is not strongly supported by the literature – read ATS clinical statement

• However, data are growing and technology is evolving quickly

• Current clinical care systems are not configured for this technology. Increased costs/time?

• Questions about event detection accuracy need to be resolved

• Data safety and privacy issues

• Medical legal issues

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CPAP Tracking Systems - Take Home

• Adherence – data mostly reliable

• Events (residual apnea/hypopnea) – data not robust but ends of the spectrum may be useful, focus on apneas– What residual AI or AHI is important?

– Change terminology to AHIFlow

• Leak – what level matters?

• Patient self-tracking of use can improve adherence• Can tracking improve outcomes?

• Technology, not science, is driving clinical management