Copyright © 2006 by Mosby, Inc. Slide 1 PART IX Diffuse Alveolar Disease
Copyright © 2006 by Mosby, Inc. Slide 2 Chapter 27 Acute Respiratory Distress Syndrome Figure Adult respiratory distress syndrome.
Copyright © 2006 by Mosby, Inc. Slide 3 Anatomic Alterations of the Lungs Interstitial and intra-alveolar edema and hemorrhage Alveolar consolidation Intra-alveolar hyaline membrane Pulmonary surfactant deficiency or abnormality Atelectasis
Copyright © 2006 by Mosby, Inc. Slide 4 Other Names Used to Identify ARDS 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. Slide 5 Etiology: Multitude of Factors In alphabetical order, some of the better-known causes 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. Slide 6 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
Copyright © 2006 by Mosby, Inc. Slide 7 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).
Copyright © 2006 by Mosby, Inc. Slide 8 Figure 9-7. Atelectasis clinical scenario.
Copyright © 2006 by Mosby, Inc. Slide 9 Figure 9-8. Alveolar consolidation clinical scenario.
Copyright © 2006 by Mosby, Inc. Slide 10 Figure 9-9. Increased alveolar-capillary membrane thickness clinical scenario.
Copyright © 2006 by Mosby, Inc. Slide 11 Clinical Data Obtained at the Patient’s Bedside Clinical Data Obtained at the Patient’s Bedside Vital signs Vital signs Increased respiratory rate Increased heart rate, cardiac output, blood pressure
Copyright © 2006 by Mosby, Inc. Slide 12 Clinical Data Obtained at the Patient’s Bedside Clinical Data Obtained at the Patient’s Bedside Substernal/intercostal retractions Cyanosis Chest assessment findings Dull percussion note Bronchial breath sounds Crackles
Copyright © 2006 by Mosby, Inc. Slide 13 Figure A short, dull, or flat percussion note is typically produced over areas of alveolar consolidation.
Copyright © 2006 by Mosby, Inc. Slide 14 Figure Auscultation of bronchial breath sounds over a consolidated lung unit.
Copyright © 2006 by Mosby, Inc. Slide 15 Clinical Data Obtained from Laboratory Tests and Special Procedures
Copyright © 2006 by Mosby, Inc. Slide 16 Pulmonary Function Study: Expiratory Maneuver Findings FVC FEV T FEF 25%-75% FEF N or N or N PEFR MVV FEF 50% FEV 1% N N or N N or FVC FEV T FEF 25%-75% FEF N or N or N PEFR MVV FEF 50% FEV 1% N N or N N or
Copyright © 2006 by Mosby, Inc. Slide 17 Pulmonary Function Study: Lung Volume and Capacity Findings V T RV FRC TLC N or VC IC ERV RV/TLC% N V T RV FRC TLC N or VC IC ERV RV/TLC% N
Copyright © 2006 by Mosby, Inc. Slide 18 Decreased Diffusion Capacity (DL CO )
Copyright © 2006 by Mosby, Inc. Slide 19 Arterial Blood Gases Mild to Moderate ARDS Acute alveolar hyperventilation with hypoxemia pH PaCO 2 HCO 3 - PaO 2 (Slightly) pH PaCO 2 HCO 3 - PaO 2 (Slightly)
Copyright © 2006 by Mosby, Inc. Slide 20 Time and Progression of Disease Pa CO Alveolar Hyperventilation Point at which PaO 2 declines enough to stimulate peripheral oxygen receptors Pa O 2 Disease Onset Pa O 2 or Pa CO 2 Figure 4-2. Pa O 2 and Pa CO 2 trends during acute alveolar hyperventilation.
Copyright © 2006 by Mosby, Inc. Slide 21 Arterial Blood Gases Severe ARDS Acute chronic ventilatory failure with hypoxemia pH PaCO 2 HCO 3 - PaO 2 (Slightly) pH PaCO 2 HCO 3 - PaO 2 (Slightly)
Copyright © 2006 by Mosby, Inc. Slide 22 Time and Progression of Disease Pa O Alveolar Hyperventilation Point at which PaO 2 declines enough to stimulate peripheral oxygen receptors Pa CO 2 Acute Ventilatory Failure Disease Onset Point at which disease becomes severe and patient begins to become fatigued Pa 0 2 or Pa C0 2 Figure 4-7. PaO 2 and PaCO 2 trends during acute ventilatory failure.
Copyright © 2006 by Mosby, Inc. Slide 23 Oxygenation Indices Q S /Q T D O 2 V O 2 C(a-v) O 2 Normal Normal O 2 ER Sv O 2 Q S /Q T D O 2 V O 2 C(a-v) O 2 Normal Normal O 2 ER Sv O 2
Copyright © 2006 by Mosby, Inc. Slide 24 Hemodynamic Indices (Severe ARDS) CVP RAPPAPCWP COSVSVICI RVSWILVSWIPVRSVR
Copyright © 2006 by Mosby, Inc. Slide 25 Radiologic Findings Chest radiograph Increased density Ground-glass appearance
Copyright © 2006 by Mosby, Inc. Slide 26 Figure Chest X-ray of a patient with moderately severe ARDS.
Copyright © 2006 by Mosby, Inc. Slide 27 General Management of ARDS Respiratory care treatment protocols Oxygen therapy protocol Hyperinflation therapy protocol Mechanical ventilation protocol
Copyright © 2006 by Mosby, Inc. Slide 28 General Management of ARDS Common ARDS mechanical ventilation strategy: 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. Slide 29 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
Copyright © 2006 by Mosby, Inc. Slide 30 General Management of ARDS Medications and procedures commonly prescribed by the physician Antibiotics Diuretics Corticosteroids
Copyright © 2006 by Mosby, Inc. Slide 31 Classroom Discussion Case Study: ARDS