Transcript Document
PART IX Diffuse Alveolar Disease Slide 1 Copyright © 2006 by Mosby, Inc. Chapter 27 Acute Respiratory Distress Syndrome Figure 27-1. Adult respiratory distress syndrome. Slide 2 Copyright © 2006 by Mosby, Inc. Anatomic Alterations of the Lungs Slide 3 Interstitial and intra-alveolar edema and hemorrhage Alveolar consolidation Intra-alveolar hyaline membrane Pulmonary surfactant deficiency or abnormality Atelectasis Copyright © 2006 by Mosby, Inc. Other Names Used to Identify ARDS Slide 4 Adult respiratory distress syndrome Adult hyaline membrane disease Capillary leak syndrome Congestion atelectasis Da Nang lung Hemorrhagic pulmonary edema Noncardiac pulmonary edema Oxygen pneumonitis Oxygen toxicity Copyright © 2006 by Mosby, Inc. Etiology: Multitude of Factors In alphabetical order, some of the better-known causes Slide 5 Aspiration Central nervous system disease Cardiopulmonary bypass Congestive heart failure Disseminated intravascular coagulation Drug overdose Fat or air emboli Infections Inhalation of toxins and irritants Copyright © 2006 by Mosby, Inc. Etiology: Multitude of Factors In alphabetical order, some of the better-known causes Inhalation of toxins and irritants Immunologic reaction Massive blood transfusions Nonthoracic trauma Oxygen toxicity Pulmonary ischemia Radiation-induced lung injury Shock (hypovolemia) Burns Thoracic trauma Slide 6 Copyright © 2006 by Mosby, Inc. Overview of the Cardiopulmonary Clinical Manifestations Associated with ACUTE RESPIRATORY DISTRESS SYNDROME The following clinical manifestations result from the pathophysiologic mechanisms caused (or activated) by Atelectasis (see Figure 9-7), Alveolar Consolidation (see Figure 9-8), and Increased Alveolar-Capillary Membrane Thickness (see Figure 9-9)—the major anatomic alterations of the lungs associated with ARDS (see Figure 27-1). Slide 7 Copyright © 2006 by Mosby, Inc. Figure 9-7. Atelectasis clinical scenario. Slide 8 Copyright © 2006 by Mosby, Inc. Figure 9-8. Alveolar consolidation clinical scenario. Slide 9 Copyright © 2006 by Mosby, Inc. Figure 9-9. Increased alveolar-capillary membrane thickness clinical scenario. Slide 10 Copyright © 2006 by Mosby, Inc. Clinical Data Obtained at the Patient’s Bedside Vital signs Slide 11 Increased respiratory rate Increased heart rate, cardiac output, blood pressure Copyright © 2006 by Mosby, Inc. Clinical Data Obtained at the Patient’s Bedside Slide 12 Substernal/intercostal retractions Cyanosis Chest assessment findings Dull percussion note Bronchial breath sounds Crackles Copyright © 2006 by Mosby, Inc. Figure 2-11. A short, dull, or flat percussion note is typically produced over areas of alveolar consolidation. Slide 13 Copyright © 2006 by Mosby, Inc. Figure 2-16. Auscultation of bronchial breath sounds over a consolidated lung unit. Slide 14 Copyright © 2006 by Mosby, Inc. Clinical Data Obtained from Laboratory Tests and Special Procedures Slide 15 Copyright © 2006 by Mosby, Inc. Pulmonary Function Study: Expiratory Maneuver Findings FVC FEVT N or FEF25%-75% N or FEF200-1200 N PEFR MVV FEF50% FEV1% N Slide 16 N or N N or Copyright © 2006 by Mosby, Inc. Pulmonary Function Study: Lung Volume and Capacity Findings VT Slide 17 RV FRC TLC N or VC IC ERV RV/TLC% N Copyright © 2006 by Mosby, Inc. Decreased Diffusion Capacity (DLCO) Slide 18 Copyright © 2006 by Mosby, Inc. Arterial Blood Gases Mild to Moderate ARDS Acute alveolar hyperventilation with hypoxemia pH Slide 19 PaCO2 HCO3 (Slightly) PaO2 Copyright © 2006 by Mosby, Inc. Time and Progression of Disease Disease Onset Alveolar Hyperventilation 100 90 PaO2 or PaCO2 80 Point at which PaO2 declines enough to stimulate peripheral oxygen receptors 70 60 PaO2 50 40 30 20 10 0 Figure 4-2. PaO2 and PaCO2 trends during acute alveolar hyperventilation. Slide 20 Copyright © 2006 by Mosby, Inc. Arterial Blood Gases Severe ARDS Acute chronic ventilatory failure with hypoxemia pH Slide 21 PaCO2 HCO3 (Slightly) PaO2 Copyright © 2006 by Mosby, Inc. Time and Progression of Disease Disease Onset Alveolar Hyperventilation Acute Ventilatory Failure 100 90 Pa02 or PaC02 80 70 Point at which PaO2 declines enough to stimulate peripheral oxygen receptors Point at which disease becomes severe and patient begins to become fatigued 60 50 40 30 20 10 0 Figure 4-7. PaO2 and PaCO2 trends during acute ventilatory failure. Slide 22 Copyright © 2006 by Mosby, Inc. Oxygenation Indices QS/QT DO2 VO2 Normal O2ER Slide 23 C(a-v)O2 Normal SvO2 Copyright © 2006 by Mosby, Inc. Hemodynamic Indices (Severe ARDS) Slide 24 CVP RAP PA PCWP CO SV SVI CI RVSWI LVSWI PVR SVR Copyright © 2006 by Mosby, Inc. Radiologic Findings Chest radiograph Slide 25 Increased density Ground-glass appearance Copyright © 2006 by Mosby, Inc. Figure 27-2. Chest X-ray of a patient with moderately severe ARDS. Slide 26 Copyright © 2006 by Mosby, Inc. General Management of ARDS Respiratory care treatment protocols Slide 27 Oxygen therapy protocol Hyperinflation therapy protocol Mechanical ventilation protocol Copyright © 2006 by Mosby, Inc. General Management of ARDS Common ARDS mechanical ventilation strategy: Slide 28 Low-tidal volumes and high respiratory rates 4 to 8 mL/kg Ventilatory rates as high as 35 breaths per minute PEEP and/or CPAP—to offset atelectasis Copyright © 2006 by Mosby, Inc. General Management of ARDS The therapeutic goals of low-tidal volume ventilation 1. Decrease high transpulmonary pressure 2. Reduce overdistention of the lungs 3. Decrease barotrauma Slide 29 Copyright © 2006 by Mosby, Inc. General Management of ARDS Medications and procedures commonly prescribed by the physician Slide 30 Antibiotics Diuretics Corticosteroids Copyright © 2006 by Mosby, Inc. Classroom Discussion Case Study: ARDS Slide 31 Copyright © 2006 by Mosby, Inc.