Acute Respiratory Distress Syndrome Flashcards
How is acute respiratory distress syndrome characterized?
- Clinical syndrome of a rapidly progressing state that occurs in critically ill patients (ICU)
- Three inclusion and one exclusion criteria
What are the risk factors of Acute Respiratory distress syndrome (ARDS)
- Sepsis
- Aspiration
- Lung contusion
- Toxic inhalation
- Near drowning
- Infection
- Multiple blood transfusions
How does the Berlin criteria describe ARDS
- Presentation within 1 week of clincial insult (I)
- New bilateral radiographic pulmonary opacities (I)
*not from HF, volume overload, effusion, atelectasis or nodules (E) - Ratio of partial pressure of arterial blood O2 to fractional concentration of inspired O2 is less than 300mmHg (I)
- Life threatening, acute, will eventually lead to failure
What is a normal health ratio of partial pressure of arterial blood O2 (Pao2) to fractional concentration of inspired O2 (Fio2)
> 400mmHg
What was the old term for Acute Respiratory distress syndrome
Adult respiratory distress syndrome
What is the etiology of ARDS
Systemic
*sepsis
Pulmonary
*aspiration of gastric contents
*Covid 19
What is the pathophysiology of ARDS
- Some event happens which leads to inappropriate host inflammatory response
*will be development of pulmonary edema, impaired gas exchange and possible fibrosis
What happens within the lung interstitial / alveoli during ARDS (activated neutrophils)
- Activated neutrophils leads to inflammatory cascade
*cytokines, pro coagulant molecules, oxidants, proteases, PAF, other toxic mediators
What happens within the lung interstitial / alveoli during ARDS (endothelia dysfunction)
- Endothelia dysfunction leads to tissue damage and the induction of pulmonary vasoconstriction, formation of micro vascular emboli, potential vascular remodeling, pulm HTN and eventually fibrosis
What happens to the alveolar space during ARDS
Fluid releasing from capillaries filling the alveolar space and preventing gas exchange
What is the acute stage of ARDS
Exudative stage (days 0-6)
1. Pulmonary edema with endothelial and epithelial damage
What is the subacute stage of ARDS
Fibroproliferative stage (days 7-14)
1. Edema improves
2. Epithelial repair with collagen and fibroblasts begins
What is the chronic stage of ARDS
Fibrotic stage (days 14 and later)
1. Cleared acute neutrophil infiltration but residual fibrosis remains
Will all patients with ARDS progress to the chronic stage
No
What are the S/sx of ARDS
Rapid onset of profound dyspnea (12-48 Hours) after insult
1. Labored breathing
2. Tachypnea
3. Intercostal retractions
4. Fever cough
5. Pink frothy sputum
6. Hypoxemia refractory to oxygen therapy