Acute Lung Injury and ARDS - Stellenbosch （急性肺损伤和ARDS Stellenbosch）.ppt

Acute Lung InjuryandARDS Andreas Crede Emergency Medicine Registrar Overview Introduction Definition Pathophysiology Treatment New Stuff References Introduction 1st described 1967 (Ashbaugh et al) Incidence 1.5 -7.5/ 100000 population 28 day mortality 25 – 30%1 Diagnosis clinical Definition Acute onset (7days) respiratory failure/distress Diffuse, bilateral infiltrates on CXR Absent left atrial hypertension (PAOP ≤18mmHg) Or absent clinical evidence of left atrial hypertension PaO2/ FiO2 300mmHg (ALI) PaO2/ FiO2 200mmHg (ARDS)2 Risk Factors Alcoholism Genetic predisposition Causes Direct Injury1 Pneumonia Aspiration Drowning Amniotic fluid and fat embolism Alveolar haemorrhage Smoke, toxic gas inhalation Reperfusion (incl rapid drainage pleural effusion) Unilateral lung re-implantation Causes Indirect Injury1 Severe Sepsis Massive transfusion Shock Pancreatitis Salicylate/ narcotic overdose Anaphylaxis Cardiopulmonary bypass Differential LVF Fluid overload Mitral stenosis Lymphangitis carcinomatosis Interstitial lung disease1 Respiratory Failure Histologically Exudative Phase3 Neutrophilic Infiltrate Alveolar Haemorrhage Proteinaceous Pulmonary Oedema Cytokines (TNF, IL1,8) ↑ Inflammation ↑ Oxidative Stress and Protease Activity ↓ Surfactant Activity Atelectasis Histologically Elastase- induced capillary and alveolar damage3 ↑ Alveolar flooding ↓ Fluid clearance Capillary thrombosis ↓ Anticoagulant proteins ↑ Procoagulant proteins (Tissue Factor) ↑ Anti- fibrinolytic Protein (Plasminogen Activator Inhibitor) Post Acute Phase Fibroproliferative Phase3 Variable time period Fibrosis Chronic Inflammation Neovascularisation Resolution3 Improvement of hypoxaemia Improved dead space and lung compliance Resolution radiographic abnormalities Can take up to 1 year Residual restrictive or obstructive picture Long Term Chronic Respiratory Disease Muscle Fatigue Muscle Wasting Weakness Treatment Ventilation Fluid Management Steroids Other Stuff Ventilation Tidal V