1. Copyright © 2006 by Mosby, Inc. Slide 1 PART IX Diffuse Alveolar Disease

2. Copyright © 2006 by Mosby, Inc. Slide 2 Chapter 27 Acute Respiratory Distress Syndrome Figure 27-1. Adult respiratory distress syndrome.

3. 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

4. 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

5. 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

6. 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

7. 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).

8. Copyright © 2006 by Mosby, Inc. Slide 8 Figure 9-7. Atelectasis clinical scenario.

9. Copyright © 2006 by Mosby, Inc. Slide 9 Figure 9-8. Alveolar consolidation clinical scenario.

10. Copyright © 2006 by Mosby, Inc. Slide 10 Figure 9-9. Increased alveolar-capillary membrane thickness clinical scenario.

11. 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

12. 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

13. Copyright © 2006 by Mosby, Inc. Slide 13 Figure 2-11. A short, dull, or flat percussion note is typically produced over areas of alveolar consolidation.

14. Copyright © 2006 by Mosby, Inc. Slide 14 Figure 2-16. Auscultation of bronchial breath sounds over a consolidated lung unit.

15. Copyright © 2006 by Mosby, Inc. Slide 15 Clinical Data Obtained from Laboratory Tests and Special Procedures

16. Copyright © 2006 by Mosby, Inc. Slide 16 Pulmonary Function Study: Expiratory Maneuver Findings FVC FEV T FEF 25%-75% FEF 200-1200  N or  N or  N PEFR MVV FEF 50% FEV 1% N N or  N N or  FVC FEV T FEF 25%-75% FEF 200-1200  N or  N or  N PEFR MVV FEF 50% FEV 1% N N or  N N or 

17. 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

18. Copyright © 2006 by Mosby, Inc. Slide 18 Decreased Diffusion Capacity (DL CO )

19. 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) 

20. Copyright © 2006 by Mosby, Inc. Slide 20 Time and Progression of Disease 100 50 30 80 0 0 Pa CO 2 10 20 40 Alveolar Hyperventilation 60 70 90 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.

21. 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) 

22. Copyright © 2006 by Mosby, Inc. Slide 22 Time and Progression of Disease 100 50 30 80 0 Pa O 2 10 20 40 Alveolar Hyperventilation 60 70 90 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.

23. 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  

24. Copyright © 2006 by Mosby, Inc. Slide 24 Hemodynamic Indices (Severe ARDS) CVP RAPPAPCWP   COSVSVICI         RVSWILVSWIPVRSVR    

25. Copyright © 2006 by Mosby, Inc. Slide 25 Radiologic Findings Chest radiograph  Increased density  Ground-glass appearance

26. Copyright © 2006 by Mosby, Inc. Slide 26 Figure 27-2. Chest X-ray of a patient with moderately severe ARDS.

27. Copyright © 2006 by Mosby, Inc. Slide 27 General Management of ARDS Respiratory care treatment protocols  Oxygen therapy protocol  Hyperinflation therapy protocol  Mechanical ventilation protocol

28. 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

29. 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

30. Copyright © 2006 by Mosby, Inc. Slide 30 General Management of ARDS Medications and procedures commonly prescribed by the physician  Antibiotics  Diuretics  Corticosteroids

31. Copyright © 2006 by Mosby, Inc. Slide 31 Classroom Discussion Case Study: ARDS