Review of ARDS for ICU Nurses.

1. ACUTE RESPIRTAORY DISTRESS
SYNDROME

2. ACUTE RESPIRATORY DISTRESS
SYNDROME
• Define ARDS (Primary & Secondary)
• Stages of ARDS
• Lung Protective Ventilation
• Prone Position / ECMO

3. ACUTE RESPIRATORY DISTRESS
SYNDROME
Acute Respiratory Distress Syndrome (ARDS) is
defined as a:
“syndrome of acute and persistent lung
inflammation with increased vascular
permeability” (Hansen-Fletcher et al)

4. ACUTE RESPIRATORY DISTRESS
SYNDROME
Clinically, ARDS is
characterized by:
• acute onset (< 48 hours)
• bilateral infiltrates
• PaO2/FiO2 ratio
<300mmHg
• No evidence of cardiac
causes

5. ACUTE RESPIRATORY DISTRESS
SYNDROME
ARDS can be
caused by direct
injury to the
lungs (primary)
or indirect injury
(secondary)

6. ACUTE RESPIRATORY DISTRESS
SYNDROME
Pneumonia
Pulmonary Contusions
Aspiration
Inhalation Injuries

7. ACUTE RESPIRATORY DISTRESS
SYNDROME
Sepsis
Burns
Overdoses
Blood Transfusions
Fat Embolisms

8. ACUTE RESPIRATORY DISTRESS
SYNDROME
Lung injury creates an immune &
inflammatory response. The alveolus
fill with protein-rich edema, WBC,
RBC while the hyaline membrane
thickens.
This causes:
• ↓PaO2
• ↓Compliance
• ↑PaCO2
• Respiratory Failure

9. ACUTE RESPIRATORY DISTRESS
SYNDROME
ARDS
Mild
ARDS
Moderate
ARDS
Severe
ARDS

10. ACUTE RESPIRATORY DISTRESS
SYNDROME
Recovery
Stage
•Slow restoration of lung
function
Proliferative
Stage
•7—21 days
•Alteration of lung tissue
•Poor Compliance
•Decreased Edema
Exudative
Stage
•0-7 days
•Edema (peaks 048hrs)
•Inflammation
Furthermore, ARDS has three stages:

11. ACUTE RESPIRATORY DISTRESS
SYNDROME
Unfortunately, some patient can develop with pulmonary fibrosis.

12. ACUTE RESPIRATORY DISTRESS
SYNDROME
ARDS
Direct
ARDS
Indirect
ARDS
Mild
ARDS
Moderate
ARDS
Severe
ARDS
Lets review:
ARDS is classified by its
cause: direct or indirect
lung injury.
Its severity: mild, moderate
and severe.
Its stages: exudative,
proliferative and recovery.

13. ACUTE RESPIRATORY DISTRESS
SYNDROME
ARDS
Mechanical
Ventilation
Ventilator
Associated
Lung Injury
Immune &
Inflammatory
Response
Worsening
ARDS
Cycle of Injury:
Mechanical
ventilation can
worsen ARDS and
cause long-term
disability (ie:
pulmonary fibrosis)
ARDS patient
frequently require
mechanical
ventilation.
How can this be a
problem?

14. ACUTE RESPIRATORY DISTRESS
SYNDROME
How can mechanical ventilation worsen ARDS?
Barotrauma: too much
pressure (>35mmHg)
Atelectotrauma: collapse
and expansion of the alveoli
Volutrauma: too
much tidal volume

15. ACUTE RESPIRATORY DISTRESS
SYNDROME
Lung
Protective
Ventilation
Small Tidal
Volumes
(VT)
High
Respiratory
Rate
Minimize
Airway
Pressures
(PIP & PLT)
Adequate
PEEP
Lung protective ventilation attempts to prevent volutrauma,
barotrauma and atelectotrauma with:

16. ACUTE RESPIRATORY DISTRESS
SYNDROME
Small tidal
volume & high
respiratory rate
Adequate
PEEP
PEAK Pressure
<35-40

17. ACUTE RESPIRATORY DISTRESS
SYNDROME
PaO2<60mmHg PaCO2>80mmHgPH <7.1 Peak >45cmH20
What if lung protective ventilation fails?

18. ACUTE RESPIRATORY DISTRESS
SYNDROME
Lung
Protective
Ventilation
Prone
Position
ECMO
Rescue Therapy:
• Prone Position
• VV-ECMO

19. ACUTE RESPIRATORY DISTRESS
SYNDROME
The Prone Position:
• Improves perfusion to the lungs → Better V:Q matching
• The diaphragm drops and the heart shift forward → Improved compliance
• Improved lung recruitment
• Lung Protective
• Indicated:
• Moderate to Severe ARDS
• Early (<48hours)
• Duration: 12 – 16 hours

20. ACUTE RESPIRATORY DISTRESS
SYNDROME
VV-ECMO:
• Provides oxygenation and removal of CO2
• Allows the lung to rest (breaking the cycle of lung injury)
• Blood movement is facilitated by an external pump
• Indicated:
• Early (<7days)
• Severe ARDS

21. ACUTE RESPIRATORY DISTRESS SYNDROME
In review:
• The prone position may
be beneficial early
(<48hours) in moderate
to severe ARDS
• VV-ECMO may be
indicated in severe ARDS
when conventional
therapy has failed.

22. ACUTE RESPIRATORY DISTRESS
SYNDROME
(1) Hansen-Flaschen, J., Siegel, M. (2009). Acute respiratory
distress syndrome: definition; epidemiology; diagnosis; and
etiology. Up to Date
(2) NIH-NHLBI ARDS Network (www.ards.net)
(3) Fessler, H., Talmor, D. (2010). Should prone position be
routinely used for lung protective during mechanical
ventilation?. Respiratory Care. 55(1); 89-98
(4) Capital District Health Authority, Prone Positioning/Proning.
#CC45-075
(5) Guerin, C., Reignier, J., Richard, JC., Beuret, P., Gacouin, A.,
Boulain, T., Mercier, E., Badet, M., Mercat, A., Budin, O.,
Clavel, M., Chatellier, D., Jbar, S., Rosselli, S., Mancebo, J.,
Sirodot, M., Hilbert, G., Bengler, C., Richecoeur, J., Gainner,
M., Bayle, F., Boudin, G., Laery, V., Girard, R., Baboi, L., Ayzac,
L.(2016). Prone position in severe acute respiratory distress
syndrome. New England Journal of Medicine, 368, 2159-2168

23. Extras:
Acute Respiratory Distress Syndrome:
https://www.youtube.com/watch?v=cVCvYxVxSt4
Lung Protective Ventilation:
https://www.youtube.com/watch?v=5hdpBRMdZ9M