Acute Respiratory Distress Syndrome Taylor Wofford, MD UNC Internal Medicine July 14, 2009

Over the years… Shock lung Wet lung DaNang lung Stiff lung Pump lung … Actut Respiratory Distress Syndrome

ARDS PaO2/FiO2 <200 Acute onset Bilateral infiltrates c/w pulmonary edema No clinical evidence for elevated LA pressure (1994 American-European Consensus Conference Committee)

Pathophysiology ARDS Normal lung

Causes of ARDS Sepsis Aspiration Pneumonia Severe trauma/burns Massive blood transfusion TRALI Relief of airway obstruction Lung and BMT Drug overdose Pancreatitis Near drowning Smoke inhalation Cardiopulmonary bypass Venous air embolism Neurogenic pulmonary edema

Evaluation of ARDS ABG CXR Consider bronchoscopy Infectious workup

Management of ARDS Mechanical ventilation Vt <6 mL/kg PIP goal <40 cmH20 Permissive hypercapnea High PEEP Pressure mode > volume mode FiO2 as low as possible ARDS Network Study

Notable options Airway Pressure Release Ventilation (APRV) = BiVent NO Prone positioning High Frequency Oscillation Recruitment maneuvers

Outcomes of ARDS 10-15% of ICU admissions 190,600 cases in US per year Approximately 41% mortality

Bibliography Evans TW. Respiratory Management in Critical Care. BMJ, 2004. Fishman, AP. Shock lung: A distinict nonentity. Circulation 1973;47;921-923. Green GB et al. The Washington Manual of Medical Therpeutics, 31st ed. Philadelphia: Lippincott Williams & Wilkins, 2004. Husain AN. Pulmonary Pathology. www.meddean.luc.edu. Siegel, MD. Acute respiratory distress syndrome: Pathophysiology; clinical manifestations; prognosis; and outcome. UpToDate.com, 2009.