We review Acute Respiratory Distress Syndrome Hosts: Sadakat Chowdhury, MD Brian Gilberti, MD https://media.blubrry.com/coreem/content.blubrry.com/coreem/ARDS.mp3 Download Leave a Comment Tags: Critical Care, Pulmonary Show Notes * Definition of ARDS: * Non-cardiogenic pulmonary edema characterized by acute respiratory failure. * Berlin criteria for diagnosis include acute onset within 7 days, bilateral pulmonary infiltrates on imaging, not fully explained by cardiac failure or fluid overload, and impaired oxygenation with PaO2/FiO2 ratio 5 cm H2O. * Severity based on oxygenation (Berlin criteria): * Mild: PaO2/FiO2 200-300 mmHg * Moderate: PaO2/FiO2 100-200 mmHg * Severe: PaO2/FiO2 100 mmHg * Epidemiology: * Occurs in up to 23% of mechanically ventilated patients. * Mortality rate of 30-40%, primarily due to multiorgan failure. * Differentiation from Cardiogenic Pulmonary Edema: * Chest CT shows diffuse edema and pleural effusion in cardiogenic edema; patchy edema, dense consolidation in ARDS. * Ultrasound may show diffuse B lines in cardiogenic edema; patchy B lines and normal A lines in ARDS. * Pathophysiology: * Exudative phase: Immune-mediated alveolar damage, pulmonary edema, cytokine release. * Proliferative phase: Reabsorption of edema fluid. * Fibrotic phase: Potential for prolonged ventilation. * Etiology: * Direct lung injury (pneumonia, toxins, aspiration, trauma, drowning) and indirect causes (sepsis, pancreatitis, transfusion reactions, certain drugs). * Diagnostics: * Comprehensive workup including imaging (chest X-ray, CT), laboratory tests (complete blood count, basic metabolic panel, blood gases), and specialized tests depending on suspected etiology. * Management Strategies: * Steroids: Beneficial in certain etiologies of ARDS, with specifics on dosing and duration. * Fluid Management: Conservative fluid strategy, diuresis guided by patient condition. * Ventilation: Non-invasive ventilation (NIV) preferred in specific cases; mechanical ventilation strategies to ensure lung-protective ventilation. * Proning: Used in severe ARDS to improve oxygenation. * Inhaled Vasodilators: Used for refractory hypoxemia and specific complications like right heart failure. * Extracorporeal Membrane Oxygenation (ECMO): Considered for severe ARDS as salvage therapy. * Supportive Care: Includes monitoring and management of complications, nutrition, and physical therapy. * Ventilation Specifics: * Tidal volume and pressure settings aim for lung-protective strategies to prevent ventilator-induced lung injury. * Permissive hypercapnia, plateau pressure, PEEP,