Let's talk about the advantages, and disadvantages of using Airway Pressure Release Ventilation (APRV) mode on patients in mechanical ventilators who are suffering from COVID19 Pneumonia, and developed ARDS, also known as Acute Respiratory Distress Syndrome, Based on the studies, 30% of these patients have obesity as a pre-existing condition, followed by hypertension with 26% of the patients, then diabetes at 21%, 12% heart failure (for example, congested heart failure), that’s a total of 89%. The rest or runner-ups, are COPD, dementia, liver DZ, and active Cancer. Interestingly, respiratory issues are not the top pre-existing condition that puts patients in hospitals. This tells us, that when a patient gets intubated and is placed on a breathing machine, also called mechanical ventilation, is because their case is already so severe, that their pulmonary function had been compromised. The term ARDS refers to the condition in which the patient’s lungs are unable to expand normally. It is stiffer. We call that less compliant, or it has low compliance. This happens because of non-cardiogenic pulmonary edema. This is the fluid that goes in the interstitial space, the space between your alveoli (the smallest and end part of your airways). This is where the gas exchange happens when we breathe. Unfortunately, the fluid is not something that a diuretic can eliminate. Therefore, it prevents proper oxygenation, and the patient suffers from hypoxemia. So, our patients require supplementary oxygen, flow, and pressure to help them maintain normal oxygenation that their blood can carry to the rest of their body, and organs. This includes the heart, brain, kidneys, liver, etc. If the body does not get enough oxygen, the patient can die in a matter of minutes. Most COVID patients in Intensive Care Units simply need a High Flow device. The most common one is with a nasal cannula. When the patient’s condition deteriorates, and they are in respiratory failure, then they are intubated to allow better oxygenation, ventilation, and decreased WOB. Both High flow devices and Mechanical Ventilators have their advantages and disadvantages When the patient is still not oxygenating well, even on the highest high flow settings, that means their condition is getting worst. Remember, that the point of HF is to prevent the patient from being placed on a vent, but when it fails, this puts them in respiratory failure, which indicates that the patient needs to be intubated and be placed on a mechanical ventilator. APRV Advantages Alveolar Recruitment Better Oxygenation Less Sedation needed More Spontaneous Breathing APRV Disadvantages Volutrauma Increase Work of Breathing due to Spontaneous Breathing

1. By: Anrey Bartoszynski - M.Ed., BSRT, RRT-ACCS, RCP
Using APRV on COVID19,
Mechanically Vented
Patients, in the first
48-hours of ARDS
Illustrations Credit to: Anrey Bartoszynski 2019

2. Pre-existing
conditions that
increases risk
of COVID19
hospitalization
● 30% obesity,
● 26% to hypertension,
● 21% to diabetes,
● 12% to heart failure
● COPD
● Dementia
● Other: Europe and North America:
○ liver cirrhosis and active
cancer

3. Terminologies:
● HHFNC
○ Heated High
Flow Nasal
Cannula
● ARDS
○ Acute
Respiratory
Distress
Syndrome.
● APRV
○ Airway Pressure
Release
Ventilation
(APRV)
○ Other names
■ BiPhasic
■ DuoPAP
■ BiLevel
■ Bi-Vent
● LTV
○ Low Tidal
Volume
■ Lung
protective
ventilation
● AARC
○ American
Association for
Respiratory
Care.
● VAE
○ Ventialtor
Associated
Events or
● VAP
○ Ventilator
Acquired
Pneumonia

4. Pathophysiology of
ARDS caused by
COVID-19
pneumonia Illustration Credit to: Cristiano Antonino
● The disease process that leads to ARDS (Acute Respiratory Distress Syndrome)
○ Lungs are harder to inflate
■ Decreased compliance (stiffer)
○ Refractory Hypoxemia
■ Supplemental Oxygen is not effective
○ Lungs need pressure to keep the alveoli open and allow gas exchange
■ Alveoli without gas exchange, but has blood perfusion in capillaries = Shunting
■ The pressure allows more time for oxygen exchange by keeping the alveoli open
■ Better oxygenation improves organ functions

5. High Flow for COVID vs Mechanical Ventilation
High Flow
Pros:
● Less invasive.
● Prevents patient from getting intubated
Cons:
● Requires spontaneous breathing
● Leak around the interface
● Limited flow
Mechanical Ventilation
Pros:
● Better airway management
● Decreased WOB (Work of Breathing)
Cons:
● Increased VAE/VAP

6. APRV From AARC
Illustration Credit to:
https://journals.sagepub.com/doi/pdf/10.1177/1179548420903297
APRV used mainly as Rescue Therapy
● <48 hours upon ARDS diagnosis
APRV VIDEO

7. How APRV mode can
be used in severe
COVID-19 ARDS/
pneumonia patients?
● P/F ratio
○ <200
● IRV
○ Alveoli Recruitment
■ 2 levels of CPAP
Slides credit to AARC.org

8. Illustration graph credit to: https://link.springer.com/article/10.1007/s00134-017-4912-z/figures/3

9. Summary:
● APRV Advantages
○ Alveolar Recruitment
○ Better Oxygenation
○ Less Sedation needed
○ More Spontaneous Breathing
● APRV Disadvantages
○ Volutrauma
○ Increase Work of Breathing due to
Spontaneous Breathing
What’s next?
● Further studies on APRV and its effects on
mortality rate

10. Questions?
Feedbacks?

11. References:
Mahmoud, O., Patadia, D., & Salonia, J.
(2021). Utilization of Airway Pressure
Release Ventilation as a Rescue
Strategy in COVID-19 Patients: A
Retrospective Analysis. Journal of
intensive care medicine, 36(10),
1194–1200.
https:/
/doi.org/10.1177/088506662
11030899
Zhou, Y., Jin, X., Lv, Y., Wang, P., Yang,
Y., Liang, G., Wang, B., & Kang, Y.
(2017). Early application of airway
pressure release ventilation may
reduce the duration of mechanical
ventilation in acute respiratory
distress syndrome. Intensive care
medicine, 43(11), 1648–1659.
https:/
/doi.org/10.1007/s00134-017
-4912-z
Mahmoud, O., Patadia, D., &
Salonia, J. (2021). Utilization of
Airway Pressure Release
Ventilation as a Rescue Strategy in
COVID-19 Patients: A
Retrospective Analysis. Journal of
intensive care medicine, 36(10),
1194–1200.
https:/
/doi.org/10.1177/0885066
6211030899
Nishimura M. (2016). High-Flow
Nasal Cannula Oxygen Therapy in
Adults: Physiological Benefits,
Indication, Clinical Benefits, and
Adverse Effects. Respiratory care,
61(4), 529–541.
https:/
/doi.org/10.4187/respcar
e.04577
Coid.gov (2021) . Most COVID-19
hospitalizations due to four
conditions.
https:/
/www.nih.gov/news-events/
nih-research-matters/most-covid-19
-hospitalizations-due-four-conditions
Treskova-Schwarzbach, M., Haas, L.,
Reda, S., Pilic, A., Borodova, A., Karimi,
K., Koch, J., Nygren, T., Scholz, S.,
Schönfeld, V., Vygen-Bonnet, S.,
Wichmann, O., & Harder, T. (2021).
Pre-existing health conditions and
severe COVID-19 outcomes: an
umbrella review approach and
meta-analysis of global evidence.
BMC medicine, 19(1), 212.
https:/
/doi.org/10.1186/s12916-021-
02058-6