109: U5: ARDS Flashcards
ARDS Definition
Acute Respiratory Distress Syndrome.
A form of acute respiratory failure characterized by hypoxemia, decreased pulmonary compliance, dyspnea, noncardiogenic bilateral pulmonary infiltrates.
ARDS Pathophys
Stimulation of inflammatory and immune systems after illness or injury.
Alveolar-capillary membrane is injured and permeable to proteins - fluid leaks. Decreased surfactant activity -> hyaline membrane lines alveoli (dead cells, protein, fibrin) alveoli unstable and collapse -> no longer involved in gas exchange -> interstitial edema -> lung volume decreases -> decreased complaince (elasticity) -> fluid, protein, and blood cells collect in interstitium and alveoli -> hypoxemia
ARDS Etiologies
Sepsis - most common Shock Trauma - massive severe Pancreatitis Fat and amniotic fluid emboli Pulmonary infections, Pneumonia Inhalation of toxic gases Pulmonary aspiration Drugs Hemolytic disorders, DIC Cardiopulmonary bypass Near drowning Multiple blood transfusions
ARDS S/S Early
Dyspnea
Increased RR
Cough
Restlessness
ARDS S/S
Respiratory alkalosis Crackles, rhonchi Tachypnea, grunting, increased WOB, retractions Cyanosis, pallor Diaphoresis Hypotension, tachycardia, dysrhythmias Decreased O2 sats PaO2/FiO2 ratio <200
ARDS Dx
ABG’s
CXR - White Out
ARDS Tx
Treat Cause! High flow O2 Intubation and mechanical ventilation PEEP (positive end expiratory pressure) Permissive hypercapnia (ventilate with smaller tidal volumes to avoid barotraumas) Continuous hemodynamic monitoring Sedation and Paralysis Positioning (Prone position, Continuous lateral rotation therapy) Nitric Oxide Extracoproreal Measures DVT prophylaxis Enteral nutrition or TPN Diuretics and mild fluid restriction Abx Inotropes, IVF Stress ulcer prevention Keep Hgb 9-10g/dL Weights and I&O
ARDS PEEP
Applies positive airway pressure during expiration to keep lungs partially expanded (increased FRC) and alveoli open, thereby improving oxygenation
ARDS Nitric Oxide
Still in clinical trials - when used in a gaseous form, NO can selectively vasodilate the vessels in the lungs
ARDS Extracorporeal Measures
ECMO: Extracorporeal Membrane Oxygenation and ECCO2R (Extracorporeal CO2 removal): blood removed with large bore catheters, passes a gas exchanging membrane outside the body, infused with O2 and CO2 is removed, returned back to patient.
ARDS PCs
Hypoxemia Barotrauma O2 toxicity ARF MI, dysrhythmias Anemia, thrombocytopenia, DIC Multi-organ failure Pneumonia Paralytic ileus Stress ulcers Death
