SEARCH RESULTS FOR: Acute-Respiratory-Distress-Syndrome

急性呼吸窘迫综合征: 发病机制及临床表现

急性呼吸窘迫综合征: 发病机制及临床表现 直接性肺损伤 病因包括肺炎、肺源性脓毒血症(社区获得性、医院获得性、吸入性、病 毒)、溺水及吸入化学物质(如胃内容物或直接吸入性肺损伤)。 作者 : David Olmstead 审稿 : Midas (Kening) Kang, Usama Malik, Kevin Solverson* 译者:Xiumei Deng(邓秀梅) 翻译审稿人: Yonglin Mai (麦泳琳)，Zesheng Ye(叶泽生) • 出版时担任临床医生 间接性肺损伤 病因包括非肺源性的脓毒血症、创伤、严重烧伤、输血相关 性肺损伤以及胰腺炎。 Note: 急性呼吸窘迫综合征是一种以急性肺损伤为 主要表现的临床综合征，表现为严重低氧血症及 双侧肺泡损伤，不伴左心压力增高。 肺组织炎症 渗出期: 由于炎症性刺激，中性 粒细胞迁移聚集至肺泡 Note: 虽然ARDS的三个病理阶段相 继发生，但是肺组织的每一个区 域并非同时处于相同的病理阶段， 因此三个病理阶段常重叠存在。 增生期: 机体试图修复肺损伤， 若修复失败，则进入纤维化期 以中性粒细胞为主的炎性渗出液 破坏肺泡表面活性物质的功能 中性粒细胞浸润及促炎细 胞因子导致肺水肿、肺功 能障碍及继发肺上皮损伤 缩略词表: PaO2: Partial pressure of oxygen in arterial blood(动脉氧分压) SpO2: Peripheral oxygen saturation(外周 血氧饱和度). CXR: Chest radiograph(肺部影像学). 由于缺乏肺泡表面活性物 质，导致肺泡塌陷 肺上皮损伤，气体交换障碍 肺毛细血管不能 完全吸收渗出液 机体尝试修复肺损伤，肺 透明膜形成 通气/血流 比值失调 肺水肿 气体扩散障碍 ↓ PaO2, ↓SpO2 呼吸急促 心动过速 呼吸困难 CXR:双肺 浸润影 ↓ PaO2, ↓SpO2 ↑ PaCO2 ↑ PaO2, ↓PaCO2 呼吸恢复正常 ↓需O 量 吞噬细胞清除肺泡腔里细胞碎片 肺泡上皮细胞修复 疾病迁延导致机体功能损伤 成纤维细胞的作用导 致胶原蛋白沉积于肺 泡腔及肺毛细血管内 气体交换的有效 肺泡表面积↑ 肺泡上皮的修复，有 助于渗出液的重吸收 2 CXR:肺浸润影消散 抑郁, 焦虑,创 伤后应激障碍 咳嗽/呼吸困难 神经源性肌无力 杵状指 纤维化期: 肺修复能力不足导 致长期的肺损伤(少见) 肺纤维化 肺动脉高压 疲劳 慢性呼吸功能障碍 图注: 病理生理学 机制 体征/症状/实验室检查 并发症 2018年2月6日发布于 www.thecalgaryguide.com

Syndrome de détresse respiratoire aigu: Pathogenèse et trouvailles cliniques

سندرم-زجر-تنفسی-حاد-ards

سندرم-زجر-تنفسی-حاد-ards

Acute Respiratory Distress Syndrome

Acute Respiratory Distress Syndrome: Pathogenesis and clinical findings Acute respiratory distress syndrome (ARDS) is a clinical syndrome involving acute lung injury. It results in severe hypoxemia and bilateral Authors: David Olmstead Mao Ding Reviewers: Midas (Kening) Kang Usama Malik Kevin Solverson* * MD at time of publication ↓ PaO2 (Partial pressure of oxygen in arterial blood ↓SpO2 (Peripheral oxygen saturation) Tachypnea (↑ RR) Tachycardia (↑ HR) Dyspnea Bilateral Opacity on chest radiograph ↓ PaO2, ↓SpO2 ↑ PaCO 2 ↑ PaO2, ↓PaCO2 Eupnea (normal breathing) ↓ O2 Requirements Depression, Anxiety, PTSD Neuromuscular Weakness Chronic Respiratory Dysfunction airspace disease in the absence of elevated left-heart pressures. Direct Lung Injury Causes include pneumonia and pulmonary sepsis (community- acquired, hospital-acquired, aspiration, viral), drowning, and chemical pneumonitis from aspiration or direct inhalational injury Indirect Lung Injury Causes include sepsis with a non-pulmonary source, trauma, severe burns, transfusion- related acute lung injury (TRALI) and pancreatitis Lung Tissue Inflammation Exudative: Neutrophils migrate into the alveoli in response to inflammatory stimulus Note: While the three phases of ARDS take place in sequence, all areas of the lung may not be in the same phase at the same time. For this reason, the processes can be thought of as overlapping. Proliferative: Body attempts to heal damage. If it is not successful, the tissue transitions to the fibrotic phase Neutrophil-containing pulmonary exudate interferes with surfactant function Neutrophil infiltration and proinflammatory cytokines lead to tissue edema, dysfunction and subsequent destruction of pulmonary epithelium Residual debris in alveoli are cleared by phagocytic cells Restoration of alveolar epithelial cells. Alveoli collapse in absence of working surfactant Damaged epithelium impairs gas exchange Pulmonary capillaries do not adequately absorb fluid The body’s attempts to heal lung tissue result in deposition of hyaline membranes in the alveoli Ventilation- Perfusion Mismatch Pulmonary Edema Impaired Gas Diffusion Functional epithelium is able to absorb fluid back into circulation ↑ useful surface area for gas exchange Clearing of CXR Impaired Function After Prolonged Illness Pulmonary Hypertension Fibrotic: Inadequate healing results in long-term pulmonary damage (rare) Fibroblast activity leads to deposition of collagen in alveoli and alveolar capillaries Fatigue Pulmonary Fibrosis Nail Clubbing (nails appear wider & swollen) Cough/Dyspnea Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published Feb 6, 2018, updated Oct 10, 2023 on www.thecalgaryguide.com Acute Respiratory Distress Syndrome: Note: Acute respiratory distress syndrome is a clinical Authors: David Olmstead Reviewers: Midas (Kening) Kang Usama Malik Kevin Solverson* * MD at time of publication Pathogenesis and clinical findings Direct Lung Injury Causes include pneumonia and pulmonary sepsis (community-acquired, hospital-acquired, aspiration, viral), drowning, and chemical pneumonitis from aspiration or direct inhalational injury Indirect Lung Injury syndrome involving acute lung injury. It results in severe hypoxemia and bilateral airspace disease in the absence of elevated left-heart pressures. Causes include sepsis with a non-pulmonary source, trauma, severe burns, transfusion-related acute lung injury (TRALI) and pancreatitis Lung Tissue Inflammation Exudative: Neutrophils migrate into the alveoli in response to inflammatory stimulus Note: While the three phases of ARDS take place in sequence, all areas of the lung may not be in the same phase at the same time. For this reason, the processes can be thought of as overlapping. Proliferative: Body attempts to heal damage. If it is not successful, the tissue transitions to the fibrotic phase Neutrophil-containing pulmonary exudate interferes with surfactant function Neutrophil infiltration and proinflammatory cytokines lead to tissue edema, dysfunction and subsequent destruction of pulmonary epithelium Abbreviations: PaO2: Partial pressure of oxygen in arterial blood SpO2: Peripheral oxygen saturation. CXR: Chest radiograph. Residual debris in alveoli are cleared by phagocytic cells Restoration of alveolar epithelial cells. Alveoli collapse in absence of working surfactant Damaged epithelium impairs gas exchange Pulmonary capillaries do not adequately absorb fluid The body’s attempts to heal lung tissue result in deposition of hyaline membranes in the alveoli Ventilation- Perfusion Mismatch Pulmonary Edema Impaired Gas Diffusion ↓ PaO2, ↓SpO2 Tachypnea Tachycardia Dyspnea Bilateral Opacity on CXR ↓ PaO , ↓SpO 2 2 ↑ PaCO2 ↑ PaO2, ↓PaCO2 Eupnea ↓ O2 Requirements Clearing of CXR Depression, Anxiety, PTSD Neuromuscular Weakness Chronic Respiratory Dysfunction ↑ useful surface area for gas exchange Functional epithelium is able to absorb fluid back into circulation Impaired Function After Prolonged Illness Fibrotic: Inadequate healing results in long-term pulmonary damage (rare) Fibroblast activity leads to deposition of collagen in alveoli and alveolar capillaries Pulmonary Fibrosis Pulmonary Hypertension Cough/Dyspnea Nail Clubbing Fatigue Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published February 06, 2018 on www.thecalgaryguide.com

Acute Respiratory Distress Syndrome ARDS CXR findings

Acute Respiratory Distress Syndrome (ARDS): Chest X-Ray Findings Author: Iffat Naeem Direct or indirect lung injury causing acute respiratory distress syndrome (see Acute Respiratory Distress Syndrome slide for pathogenesis and clinical findings) Activation of dysregulated inflammatory cascade Absent pleural effusion Normal heart size Absent Kerly B lines No perihilar infiltrate pattern Bilateral infiltrate that can present in all regions of lung Air bronchograms Silhouette sign Reviewers: Victória Silva, Mao Ding Tara Lohmann* *MD at the time of publication Edema not due to a cardiogenic cause Damage to alveolar epithelium Necrosis of epithelial cells Erosion of alveolar basement membrane ↑ Alveolar epithelium permeability Damage to lung capillary endothelium Release of inflammatory cytokines Neutrophils migrate into alveoli Fluid-filled alveoli show as white/grey opacities Air-filled bronchi appear dark when surrounded by grey/white opacification of fluid-filled alveoli Increased opacification from fluid-filled alveoli results in lack of differentiation of heart borders Diffuse and widespread damage to alveoli and interstitium that show as white/grey opacities ↑ Capillary endothelium permeability Alveolar edema Degradation of alveolar- capillary barrier Proliferative phase Alveolar epithelium attempts to recover Chronic phase Can either resolve or progress to fibrotic thickening and scaring of alveoli ↑ Leakage of fluid from capillaries into alveoli and lung interstitium Pulmonary fibrosis (scarring) ‘White lung’ appearance Image credit: Radiopaedia Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published November 25, 2023 on www.thecalgaryguide.com Acute Respiratory Distress Syndrome (ARDS): Chest X-Ray Findings Direct or indirect lung injury causing acute Author: Iffat Naeem Reviewers: Victória Silva respiratory distress syndrome* Activation of dysregulated inflammatory cascade Bilateral infiltrate that show as white/grey can present in Damage to alveolar epithelium Necrosis of epithelial cells Erosion of alveolar basement membrane ↑ Alveolar epithelium permeability Damage to lung capillary endothelium Fluid-filled alveoli opacities Air-filled bronchi appear dark when surrounded by grey/white opacification of fluid-filled alveoli Increased opacification from fluid-filled alveoli results in lack of differentiation of heart borders Diffuse and all regions of lung Release of inflammatory cytokines Neutrophils migrate into alveoli Alveolar edema Air bronchograms ↑ Capillary endothelium permeability Degradation of alveolar-capillary barrier Proliferative phase Alveolar epithelium attempts to recover Chronic phase Can either resolve or progress to fibrotic thickening and scaring of alveoli ↑ Leakage of fluid from capillaries into alveoli and lung interstitium Silhouette Sign widespread Pulmonary damage to alveoli ‘White lung’ appearance fibrosis (scarring) and interstitium that show as white/grey opacities *See corresponding Calgary Guide slides for more details Image credit: Radiopaedia Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published X, 2023 on www.thecalgaryguide.com Acute Respiratory Distress Syndrome (ARDS): Chest X-Ray Findings Direct or indirect lung injury causing acute respiratory Author: Iffat Naeem Reviewers: Victória Silva distress syndrome* Activation of dysregulated inflammatory cascade Bilateral infiltrate that show as white/grey can present in Damage to alveolar epithelium Necrosis of epithelial cells Denudation of alveolar basement membrane ↑ epithelium permeability Degradation of alveolar-capillary barrier Alveolar epithelium attempts to recover through (proliferative phase) Damage to lung capillary endothelium Fluid-filled alveoli opacities Air-filled bronchi appear dark when surrounded by grey/white opacification of fluid-filled alveoli Increased opacification from fluid-filled alveoli results in lack of differentiation of heart borders Diffuse and all regions of lung Air bronchograms Release of proinflamm atory cytokines Neutrophil migration into airspace Alveolar Edema ↑ capillary endothelium permeability ↑ leakage of fluid from vasculature into airspace and lung interstitium Can either resolve or progress to fibrotic Silhouette Sign widespread Pulmonary damage to alveoli ‘White lung’ appearance thickening and scaring of Fibrosis alveoli (chronic phase) and interstitium that show as white/grey opacities Image credit: Radiopaedia *See corresponding Calgary Guide slides for more details Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published X, 2023 on www.thecalgaryguide.com Acute Respiratory Distress Syndrome (ARDS): Chest X-Ray Findings Absent pleural effusion Normal heart size Absent Kerly B lines No perihilar infiltrate pattern Author: Iffat Naeem Reviewers: Victória Silva Acute Lung Injury (see ‘ARDS: Pathogenesis and Clinical findings’ slide) causing impaired oxygenation Lung injury not due to cardiogenic cause (see ‘ARDS: Pathogenesis and Clinical findings’ slide) Alveolar endothelium damage promotes inflammatory marker release Exudative phase (1-6 days): neutrophils adhere to damaged endothelium and release pro- inflammatory mediators Accumulation of intra-alveolar fluid that is rich in neutrophils, macrophages, and red blood cells Proliferative phase (7-14 days): proliferation of alveolar epithelial Fibroblasts deposit collagen tissue in alveolar walls and spaces Can either resolve or progress to fibrotic thickening and scaring Alveolar Edema Fluid-filled alveoli show as white/grey opacities Air-filled bronchi appear dark when surrounded by grey/white opacification of fluid-filled alveoli Increased opacification from fluid-filled alveoli Bilateral infiltrate present in all regions Air bronchograms results in lack of Silhouette Sign differentiation of heart borders Diffuse alveolar damage ‘White lung’ appearance Image credit: Radiopaedia *See corresponding Calgary Guide slides for more details Legend: (chronic phase) Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published X, 2023 on www.thecalgaryguide.com Lung injury not due to a cardiogenic cause Absent pleural effusion Normal heart size Absent Kerly B lines No perihilar infiltrate pattern Acute Respiratory Distress Syndrome (ARDS): Chest X-Ray Findings