APRVBy Kellianne McCaffrey and

Rowena Eason

What is it?Airway Release Pressure Ventilation is a method of ventilation that provides two levels of continuous positive airway pressure (CPAP) and allows spontaneous breathing at both levels.

It is time triggered and time cycled

Ideally, promote higher MAP and improve oxygenation

Auto-PEEP and APRV

Release time does not allow the patient to expire entirely, intentionally causing an intrinsic PEEP air trapping to keep alveoli open

When is APRV used?

APRV is beneficial to patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS)

This is because these patients are difficult to oxygenate based on their inadequacy of gas exchange

How does it help?

APRV provides consistent lung recruitment, prolonged and improved oxygenation through the increased mean airway pressure

It does NOT increase PIP.

Set upWhat is set?

Time-hi (inspiratory)

Time-lo is the time that Low pressure is held (AW pressure release time to allow for CO2 release ie. expiratory)

Pressure-hi

Pressure-lo

FiO2

What does that mean?!?

Pressure-Hi is the high pressure given on inspiration

Pressure-Lo is the Low pressure given on expiration

Time-Hi is the amount of time the High pressure is held

Time-Lo is the time that the Low pressure is held

Basic Parameters

Low Pressure 0 cmH2O, High Pressure 20-30 cm H2O

Low Time 0.4-0.6 seconds, High Time 4-6 seconds

adjust accordingly to maintain Vt between 4-6 ml/kg

Oxygenation status

Different measures will be taken depending on whether or not the patient is oxygenating and ventilating well.

T-hi must be increased if patient remains severely hypoxemic after beginning APRV

If oxygenation is adequate, the patient may be ready to be weaned

WeaningCan be weaned to pressure support.

FiO2 is always weaned FIRST.

Inspiratory time is increased

Pres-lo is increased gradually to 8-10 cmH2O

Pres-hi is decreased, typically 2-3 cmH2O at a time

Weaning (cont’d)

Inspiratory time is increased while the high pressure is decreased in order to reduce the total number of release phases.

Ultimately the two pressures are set to match the MAP and allow the patient to breathe spontaneously on CPAP

Other names

Each ventilator has a different name for the same thing

Servo calls it BiVent

Puritan Bennet calls it BiLevel

Drager and Hamilton both call it APRV

APRV rocks!

Rowena’s favorite part about APRV is that it continuously recruits the lungs and really helps the ARDS patients.

Kellianne’s favorite part about APRV is the simplicity of the weaning process.

References

http://www.americannursetoday.com/airway-pressure-release-ventilation-a-boost-for-spontaneous-breathing/http://www.ncbi.nlm.nih.gov/pubmed/24093118

http://www.ccjm.org/content/78/2/101.long#abstract-2

www.respiratorytherapyfiles.net

Pilbeam’s Mechanical Ventilation 5th edition 2012

http://www.ncbi.nlm.nih.gov/pubmed/24093118

http://www.ccmtutorials.com/rs/mv/strategy/page14.htm