Effects of Inhaled Nitric Oxide In Children with AHRF一氧化氮吸入治疗小儿急性低氧性呼吸衰竭的影响.ppt

Pediatric ARDS: Understanding It and Managing It James D. Fortenberry, MD Medical Director, Pediatric and Adult ECMO Medical Director, Critical Care Medicine Children’s Healthcare of Atlanta at Egleston New and Improved Adult Respiratory Distress Syndrome Acute Respiratory Distress Syndrome ARDS: New Definition Criteria Acute onset Bilateral CXR infiltrates PA pressure 18 mm Hg Classification Acute lung injury - PaO2 : F1O2 300 Acute respiratory distress syndrome - PaO2 : F1O2 200 Clinical Disorders Associated with ARDS The Problem: Lung Injury ARDS - Pathogenesis Instigation Endothelial injury: increased permeability of alveolar - capillary barrier Epithelial injury : alveolar flood, loss of surfactant, barrier vs. infection Proinflammatory mechanisms ARDS Pathogenesis Resolution Equally important Alveolar edema - resolved by active sodium transport Alveolar type II cells - re-epithelialize Neutrophil clearance needed ARDS - Pathophysiology Decreased compliance Alveolar edema Heterogenous “Baby Lungs” ARDS:CT Scan View Phases of ARDS Acute - exudative, inflammatory (0 - 3 days) Subacute - proliferative (4 - 10 days) Chronic - fibrosing alveolitis ( 10 days) ARDS - Outcomes Most studies - mortality 40% to 60%; similar for children/adults Death is usually due to sepsis/MODS rather than primary respiratory Mortality may be decreasing 53/68 % 39/36 % ARDS - Principles of Therapy Provide adequate gas exchange Avoid secondary injury Therapies for ARDS The Dangers of Overdistention Repetitive shear stress Injury to normal alveoli inflammatory response air trapping Phasic volume swings: volutrauma The Dangers of Atelectasis compliance intrapulmonary shunt FiO2 WOB inflammatory response Lung Injury Zones ARDS: George Bush Therapy Lower Tidal Volumes for ARDS Is turning the ARDS patient “prone” to be helpful? Prone Positioning in ARDS Theory: let gravity improve matching perfusion to better ventilated areas Improvement im