ARDS Flashcards
What are the Hallmarks of ARDS
Rapid onset of acute hypoxemic RF, decreased pulmonary compliance, bilateral pulmonary infiltrates, absence of left sided heart failure
What is happening on the cellular level in ARDS
Damage to type One alveolar cells and type 2 pneumocyte cells.
Describe the exudative phase of ARDS
First 7 days of illness or after exposure to risk factor.
Alveolar epithelium and vascular epithelium damage
Leakage of water, protein, inflammatory, and RBCs into interstitum and alveolar lumen
Irreversible damage to type one cells. Replacement of proteins, fibrin, and cellular deposits producing a hyaline membrane.
Type two cells are damaged decreasing surfactant leading to alveolar collapse
Describe the proliferative phase of ARDS
Occurs 7-21 days after exposure to risk factor
Type II cells proliferate, retreating epithelium, fibroblasts reaction, and remolding
Most patient recovers and are liberated from the vent
Lung injury recovery in 3-4wekks
What is the fibrotic stage of ARDS
Collagen deposition and development of microcysts
Changes to lung architecture
What are the risk factors for ARDS
Sepsis, prolonged hypotension or shock, acid aspiration, near drowning, blood product transfusions, pacreatitis, DIC, cardiopulmonary bypass, burn, age
What are some direct pulmonary causes of ARDS
Pneumonia, acid aspiration, inhalation lung injury, lung contusion, chest trauma, near drowning
What are extrapulmonary causes of ARDS
Sepsis, shock, pancreatitis, trauma, blood transfusions, burns, ICP
S/s of ARDS
Dyspnea, tachypnea, accessory muscle use, increased WOB
HALLMARK: refractory hypoxemia, increased shunt fraction, decreased pulmonary compliance, increased VD ventilation, bilateral pulmonary infiltrates with a normal cardiac silhouette
Define mild, moderate, and severe ARDS
Mild: PaO2/FIO2 ratio 200-300mmhg
Moderate: PaO2/FIO2 ratio 100-200mmhg
Severe: PaO2/FIO2 ratio <100mmhg
What is the treatment plan for ARDS
Ventilator, weaning protocol, HD maintenance, conservative fluid management, pressors, ionotropes, stress ulcer prophylaxis, DVT prevention, control glucose, VAP prevention, avoid oversedation, avoid MODS, no steroid use
What happens when you use high volumes in vented ARDS patients
Alveolar over distention and lung injury
What is volutrauma
Bruising from alveolar over distention
What is atelectotrauma
Lung injury with repetitive recruitment-decruitment
What is barotrauma
Alveolar rupture causing pneumothorax, pneumomediastinem, pneumoperitoneum, subq emphysema
