Are You Optimizing Every Bilevel Breath?

Jim Eddins, RRT

Objectives• Discuss the basics of non-invasive

ventilation and the benefits of using NIV• Discuss features that improve bilevel

tolerance • Determine the most effective bilevel

settings based on disease state

Consider Using NIV When …

Use NIVUse NIVObstructive events

persist at 15 cm H2O

Respirations are characterized by CSA,

CSR or CompSA

Patient has a history of ventilatory insufficiency

Patient is not tolerating high pressure settings or

is complaining of inability to exhale, despite expiratory

pressure relief feature

Utilizing Pressures Effectively

Breath Cycle on Bilevel

Patient Flow

Delivered Pressure IPAP

EPAP

Exhalation

TriggerCycle

Inhalation

Pressure support ( P)

The Problem with Asynchrony

How Can Inspiratory Time Controls Help Increase Compliance?

IPAP

EPAP

Ti Max

Ti Min

Breath cycle

0

RiseTime

Rise Time

Problem: Patient describes “Pressure is too STRONG!”Solution: Increase rise time

Maximum Inspiratory Time

Problem: Patient requires longer expiratory time (i.e. COPD)

Solution: Best option – Shorten inspiratory time

Additional options – Select higher cycle sensitivity,Select faster rise time

Minimum 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

Trigger & Cycle Sensitivities

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%

Adjustable Trigger Sensitivity

Patient Flow

EPAP

Adjustable Cycle Sensitivity

Patient Flow

EPAP

Cycling for COPD PatientsIncreased inflammation and mucus

Slower inspiratory flow rates

Delayed cycling to expiration

Less time for exhalation

Increased air trapping (PEEPi)

Increased trigger delay and trigger workload

Increased missed triggers

Increased work of breathing

COPD

Synchrony Insight - Ti Min

Gentile, Respiratory Care, 2011

“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.”

Restrictive Disease

Clinical Parameters

Conclusion•There are multiple benefits to using NIV, particularly in patients with chronic hypoventilation

•There are additional features on some devices that modify pressure waveforms and work to improve bilevel tolerance