Bilevel Titrations:Who, What, Why, and When

Gary Hamilton, BS, RRTClinical Specialist

ResMed

Employed by ResMed Own stock options of ResMed

Disclosures

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 patientoutcomes by proper utilization of bilevel and its settings

Course Objectives

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

CPAP Intolerance- next step Bilevel

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

Comfort vs Ventilation

Bilevel- Can I get it paid for OSA?

Comfort/compliance features◦ Cpap

Lower pressure Ramp Pressure relief (Cflex or EPR) Waveform (sine vs square)

◦ Bilevel Ramp 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)

Difference between Cpap and Bilevel

Bilevel Breath Cycle Values That Tools Can Impact

Patient Flow

Delivered Pressure IPAP

EPAP

Exhalation

Trigger

Cycle

Inhalation

Pressure support ( P)

OSA Airway problem

CompSA Airway and Ventilation problem

Cheyne-Stokes Ventilation problem

COPD Ventilation problem

Neuromuscular Ventilation problem

What If It Is Not Just an Airway Problem?

Can I get Bilevel paid for when it not OSA?

CompSA or Cheyne-Stokes

Tools Available in Bilevel for Specific Diseases

ST device◦ Is back-up rate machine (E0471)◦ Fixed rate – time controlled◦ Not very comfortable- little synchrony◦ Square wave- ventilates

Servo ventilator◦ Is back-up rate machine (E0471)◦ Should be more comfortable- tries to sync with pt◦ Sine wave- not trying to ventilate◦ Very automatic (servo)

Tools for CompSA and/or Cheynes Stokes

CompSA and the Apneic Threshold

Central apneas occur

CompSA patient not treated

CompSA patient on Servo

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)

Gives Support Only When Needed

VPAP Adapt SV

Patient Flow

COPD

Tools Available in Bilevel for Specific Diseases

Lung tissue destroyed Elasticity of lungs

disappearing Poor functioning

diaphragm Reliance on accessory

muscles Air trapping

Tools For COPD- What are the problems?

Desaturations During REMin COPD Patient

Tools for COPD- Problems on Bilevel

• Auto-PEEP• Missed

triggers• Work of

breathing

• Expiratory time

• Lung emptying

Decreased expiratory time =Increase in

Delayed cycling = Decrease in

• May have difficulty exhaling on CPAP• Extends their inspiratory time• Asynchrony• Increases their work of breathing • Cycling problems (getting into exhalation)

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

Bilevel Tools- Sensitivity Adjustments

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%

Adjustable Trigger Sensitivity

Patient Flow

EPAP

Adjustable Cycle Sensitivity

Patient Flow

EPAP

Bilevel Tools - Time cycle inspiration

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

Rise Time◦ For comfort◦ Will affect how pressure “feels” to pt

Bilevel Tools – Ti Control

Bilevel Tools- Sine Wave

Square Wave Easy-Breathe

Neuromuscular and Obesity HypoventilationRestrictive Patients

Tools Available in Bilevel for Specific Diseases

Bilevel Tools- Asynchrony in Restrictive Patients

Premature cycling creates asynchrony• Lungs physically restricted

• Paralysis or muscles deteriorated

Occurs in restrictive patients

“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.”

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

Berry. J Clin Sleep Med 2010

Bilevel Tools- Increasing the Inspiratory Time

Bilevel Tools- When You Need to Ventilate

PS 5 PS 10 PS 15 PS 20

iVAPS – (ResMed) Intelligent Volume Assured Pressure Support

Bilevel Tools for Ventilation-VAPS

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

Pt. Flow

PS

Ventilation [– AV –MV –TargetAV ]

SpO2

REM Onset

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

Conclusion