Bilevel Titrations: Who, What, Why, and When Gary Hamilton, BS, RRT Clinical Specialist ResMed 110162/1 07 04

Disclosures Employed by ResMed Own stock options of ResMed

Course Objectives By the end of this session, you should be able to: Identify when a CPAP may not be the device of choice Recognize different uses of bilevel and the different disease states it is applicable to Describe what tools are available to: Increase tolerance and compliance Treat the disease and/or disorder Understand how to impact patient outcomes by proper utilization of bilevel and its settings So what exactly is Complex sleep apnea? How prevalent is it? How big of a market/ opportunity is it for you? How are these patients been treated? How does the VPAP Adapt SV stack up against those methods? Is Complex Sleep Apnea is new diagnosis? How does a patient with this condition qualify for treatment? And lastly, once we know this, where are the opportunities? Who should I be talking to about Complex Sleep Apnea?

CPAP Intolerance- next step Bilevel Why patients fail CPAP: CPAP is uncomfortable Patient may feel CPAP is uncomfortable at higher pressures despite pressure relief features COPD patients have trapped air/pressure in their lungs, which may increase their work of breathing Patient may need higher levels of ventilatory support CPAP cannot provide COPD- RCS, remember that this topic will be covered in detail in another program, so keep this very basic CPAP does not provide ventilatory support, it just splints the airway

Comfort vs Ventilation Why make the switch from CPAP to Bilevel? Patient Comfort: Cannot tolerate CPAP On a high CPAP pressure and cannot tolerate it Ventilation: Obstructive disease Restrictive disease Neuromuscular disease What is non tolerance of CPAP What is a “High” CPAP pressure? Is it a number, like 14 or 15, or is it a patient who cannot tolerate any pressure they’re on? Obstructive-COPD or Asthma (needs improved ventilation, lower CO2, Morbid Obesity) Restrictive- (Scoliosis, Neuromuscular Disease, Paralysis, Pulmonary Fibrosis)

Bilevel- Can I get it paid for OSA?

Difference between Cpap and Bilevel Comfort/compliance features Cpap Lower pressure Ramp Pressure relief (Cflex or EPR) Waveform (sine vs square) Bilevel Pressure relief (Ipap and Epap) Waveform Rise time Trigger sensitivity Cycle sensitivity Ti control (controlling the time in inspiration or expiration) Pressure support ( muscle unloading)

Bilevel Breath Cycle Values That Tools Can Impact Inhalation Cycle Trigger Patient Flow Exhalation Delivered Pressure IPAP Pressure support ( P) * Be sure to mention that ResMed VPAP is the only device in which Trigger and Cycle sensitivities can be changed (next slide). What is the labs definition of high pressure?   ASM guidelines say chg to bilevel at 15 cm.  As well as saying to keep 4 cm difference between pressures.  Above 4 cm difference you begin to ventilate. The patient’s inspiratory effort triggers the VPAP airflow The air pressure increases to the set inspiratory pressure (IPAP) IPAP ends and EPAP starts when the VPAP detects that the patient’s inspiratory flow has dropped to a specific value. IPAP Maintains or augments ventilation (stabilizes O2 and decreases PCO2 especially during sleep) Decreases work of breathing and rests accessory muscles EPAP Splints the upper airway (same as CPAP) Promotes alveolar recruitment, enhancing oxygen exchange (same as PEEP) When properly set, EPAP overcomes PEEPi in COPD EPAP

What If It Is Not Just an Airway Problem? OSA Airway problem CompSA Airway and Ventilation problem Cheyne-Stokes Ventilation problem COPD Ventilation problem Neuromuscular Ventilation problem

Can I get Bilevel paid for when it not OSA?

CompSA or Cheyne-Stokes Tools Available in Bilevel for Specific Diseases

Tools for CompSA and/or Cheynes Stokes ST device Is back-up rate machine (E0471) Fixed rate – time controlled Not very comfortable- little synchrony Square wave- ventilates Servo ventilator Should be more comfortable- tries to sync with pt Sine wave- not trying to ventilate Very automatic (servo)

CompSA and the Apneic Threshold CompSA patient on Servo CompSA patient not treated Central apneas occur As discussed earlier, CompSA patients’ CO2 levels have downward swings into the apneic threshold and central apneas occur. This cycle continues when untreated. However, when the CompSA patient is treated with VPAP Adapt SV, its algorithm will begin to resolve the CO2 swings until the CO2 level stabilizes and remain in normal range. Central events are then eliminated. The goal of the ASV algorithm is to correct the CO2 swings and stabillize the breathing pattern. The CO2 levels will then remain in normal range and central apneas are eliminated. The theory behind these methodologies, (using a non-vented FFM, bleed-in of supplemental CO2, or the addition of deadspace) is nothing more than having the patient re-breathe their CO2. When this is done, they then raise their CO2 level above their “Apneic threshold”.   To further explain this…..a person’s normal PCO2 is in the range of 35-45. What causes the centrals to occur in the CompSA patient is that with the introduction of PAP therapy (PAP or bi-level), their CO2 level is driven downward. And at some point, they hit their apneic threshold……and when this happens…..central apneas begin to occur. So by re-breathing their CO2 in their own exhaled air or by entraining supplemental CO2, we are raising (or maintaining) their CO2 level to where the central apneas no longer occur. CHF patients with CSA ASV vs. additional Deadspace Both improved CSA (reduced AHI) Both stabilized ventilation But Deadspace also: Decreased total sleep time Increased total arousal index Increased sleep fragmentation Increase in respiratory effort Increased sympathetic activation? Szollosi,D et al 2006 European Sleep Research Society

Gives Support Only When Needed The ASV algorithm automatically adjusts the magnitude of pressure support breath by breath to: Provide minimal, comfortable support during the over- breathing phase (hyperpnea) or during normal breathing Increase support during the under-breathing phase (hypopnea or apnea) VPAP Adapt SV Once again, we are highlighting the ASVs ability to adjust PS up or down in order to maintain its target minute ventilation. This therapy not appropriate for patients who: 1. have chronic and profound hypoventilation 2. moderate to severe COPD 3. restrictive thoracic or neuromuscular disease Comfort through Synchronization: It also looks at the instantaneous direction, magnitude and rate of change of the patient’s airflow Delivered ventilation is matched to patient respiration via a series of set points identified in each breath Patient Flow

Tools Available in Bilevel for Specific Diseases COPD Tools Available in Bilevel for Specific Diseases

Tools For COPD- What are the problems? Lung tissue destroyed Elasticity of lungs disappearing Poor functioning diaphragm Reliance on accessory muscles Air trapping

Desaturations During REM in COPD Patient This patient’s histogram reflects saturation levels for an Overlap patient on room air. Notice the O2 sat is <90% at the start of the study. The patient’s supine position undoubtedly causes the O2 sat to further decrease. The saturation decreases even more when the patient falls asleep and there is a slight relaxation of the respiratory muscles. In REM the saturation falls significantly due to loss of use of the accessory muscles and increased incidence of obstructive apneas.

Tools for COPD- Problems on Bilevel May have difficulty exhaling on CPAP Extends their inspiratory time Asynchrony Increases their work of breathing Cycling problems (getting into exhalation) Auto-PEEP Missed triggers Work of breathing Delayed cycling = Decrease in Decreased expiratory time = Increase in Expiratory time Lung emptying You might be wondering why COPD patients need the cycle sensitivity set so high? Well– remember we talked about how the COPD patient’s airways can be filled with mucus– which increases the resistance? We also talked about how the COPD patient’s airways can be inflamed– which also increases resistance. That increased resistance causes the inspiratory flow to be slower than usual. If the cycle sensitivity is set too low– it will be a LONG time before the ventilator cycles from inspiration to expiration. You can see that delayed cycling results in a decreased expiratory time, and therefore decreased emptying of the lung. Not enough exhalation time leads to air-trapping or intrinsic peep– which leads to missed triggers and increased work of breathing. Now– you might be curious– why does auto-peep cause missed triggers? If the patient’s lungs are trapping a lot of gas, the patient will require added effort to inspire through that auto PEEP to reach the triggering threshold. Let’s try that together now. Take a big breath in and hold it, now- without exhaling– take another breath in. Do you see how it is harder to get that second breath? That is what happens to the COPD patinet.

Bilevel Tools- Sensitivity Adjustments Adjustable Trigger Sensitivity Adjustable Cycle Sensitivity Patient Flow Patient Flow EPAP EPAP Very High Quick to trigger 2.4 L/min High More sensitive 4 L/min Med Default 6 L/min Low Less sensitive 10 L/min Very Low Slow to trigger 15 L/min Very High Quick to cycle 50% of peak flow High More sensitive 35% Med Default 25% Low Less sensitive 15% Very Low Slow to cycle 8% *ResMed’s VPAP’s are the only bilevel with adjustable sensitivities for Trigger and Cycle. Cycle- when flow disintegrates to % of peak flow then cycle occurs. Trigger – how much volume is “pulled” before it triggers the breath. (2.4L of volume for Very setting)

Bilevel Tools - Time cycle inspiration S Mode: IPAP 10 EPAP 6, rise time 150ms, TiMax 2.0, TiMin 0.3, trigger cycle med S Mode: IPAP 10 EPAP 6, rise time 150ms, TiMax decreased to 1.0, TiMin 0.3, cycle sensitivity changed to higher Problem: Patient requires longer expiratory time (i.e. COPD) Solution: Best option – Shorten Ti Max time Additional options – Select higher cycle sensitivity, Select faster rise time

Bilevel Tools – Ti Control Rise Time For comfort Will affect how pressure “feels” to pt

Bilevel Tools- Sine Wave Easy-Breathe Square Wave *The reason for the mask pressure drop at the 1:00 to 1:10 minute section – while breathing on the VPAP device when you change modes in real time it takes the machine a few second to switch from Smode to Vauto. What you are seeing is a pressure drop as a result of this.  Only occurs during real time pressure change while patient continues to breathe.  Section 1 Spontaneous Mode (0:45 – 1:00) : IPAP 10, EPAP 6, (TiControl default settings) rise time 150ms, TiMax 2.0, TiMin 0.3, Trigger/Cycle sensitivities medium VAuto Mode: Max IPAP 10, Min EPAP 6, PS 4, TiMax 2.0, TiMin 0.3, Trigger/Cycle sensitivities medium

Neuromuscular and Obesity Hypoventilation Restrictive Patients Tools Available in Bilevel for Specific Diseases

Bilevel Tools- Asynchrony in Restrictive Patients Premature cycling creates asynchrony Occurs in restrictive patients Lungs physically restricted Paralysis or muscles deteriorated “However, premature cycling may also have detrimental effects on patient-ventilator synchrony. Premature cycling is simply when the ventilator terminates the breath while the patient requires a long inspiratory period.” This slide shows another recent paper from Mike Gentile. (CLICK) Note that this paper is talking about how premature cycling can have a detrimental effect on patient-ventilator synchrony. He then goes on to explain that premature cycling is when the ventialtor stops the breath while the patient needs a longer inspiration. Gentile. Respir Care 2011

Bilevel Tools- Restrictive Diseases An early fall in the absolute flow rates may trigger the transition to EPAP prematurely. Certain devices provide a minimum IPAP time to ensure that IPAP lasts long enough to allow delivery of an adequate tidal volume. ) 4.8.4 Minimum IPAP duration (if available) may be increased if the device cycles from IPAP to EPAP prematurely (eg, in restrictive chest wall disorders). Level A – Consensus In 2010 a group of some of the most respected key opinion leaders in sleep and ventilation wrote a consensus statement in the Journal of Clinical Sleep Medicine. They recognized that premature cycling is an issue in providing NIV to restrictive patients and recommended that IPAP Duration or TiMin be increased to ensure adequate breath time. Berry. J Clin Sleep Med 2010

Bilevel Tools- Increasing the Inspiratory Time Problem: Patient’s inspiratory effort is weak (i.e. restrictive disease)/can’t sustain adequate inspiration Solution: Best option – Increase/prolong Ti Min Second option – Select lower cycle sensitivity

Bilevel Tools- When You Need to Ventilate PS 5 PS 10 PS 15 PS 20

Bilevel Tools for Ventilation-VAPS iVAPS – (ResMed) Intelligent Volume Assured Pressure Support AVAPS (Philips) Average Volume Assured Pressure Support Can assure Tidal Volume while the patient is sleeping Is Servo Controlled

The iVAPS Algorithm: Example Alveolar ventilation drops patient moves into REM sleep iVAPS rapidly increases PS until target Va is reached REM Onset Ventilation [– AV –MV –TargetAV ] Pt. Flow PS If ventilation falls, pressure support is increased until the target is reached...this ensures the patient is not under-ventilated SpO2

Conclusion CPAP may not be the device of choice for specific patients Diagnoses will be a big determinant of what PAP machine will be appropriate for the patient Goals of therapy will tell you what machine you should use Stabilize airway Hypoventilate the patient Ventilate the patient Bilevel offers a greater amount of tools to: Increase comfort of patient Increase compliance of patient Increase the chances of the therapy goals being met Tools available Wave forms Time cycling Sensitivity adjustments Servo algorithms