Download - APRV
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