1. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Chapter 27: Acute Respiratory Distress Syndrome

2. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Acute Lung Injury (ALI) Same symptoms as ARDS but less severe hypoxemia Etiology: same as ARDS Less severe version of ARDS –Direct injury –Indirect injury Acute Respiratory Distress Syndrome (ARDS) Hypoxemic respiratory failure (refractory to oxygen) Alveoli damaged and permeable to intravascular fluid Noncardiogenic pulmonary edema Bilateral infiltrates

3. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Acute Respiratory Distress (ARDS) StageAssessment Findings Diagnostic Findings Stage I - injury occurs to lungs Nonspecific symptomsRespiratory alkalosis Normal CXR Stage II - vascular congestion and inflammatory process Hypoxemia worsens; lung compliance decreases; fibrosis occurs Hypoxemia refractory to O2 Bilateral infiltrates Stage III - proliferationS/S of SIRS; hyperdynamic state Worsening hypoxemia Decreased lung capacity Organ damage Stage IV - lung remodeling Multiple organ involvements and complications Worsening hypoxemia Multiple organ damage complications

4. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Mechanical Ventilator Strategies for ARDS Used to Prevent Ventilator-Associated Lung Injury Low tidal volumes: <6 mL/Kg ideal body weight Low PEEP to avoid high FIO2 (10 to 15 cm H2O) Plateau pressure (30 cm H2O) Permissive hypercapnia (PaCO2 55 to 60 mm Hg with pH 7.25 to 7.35) Inverse ratio ventilation

5. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question Why is positive end-expiratory pressure (PEEP) used to treat a client with ARDS? A. It allows the alveoli to fully deflate and reinflate with ease. B. It keeps the alveoli partially inflated and participating in gas exchange. C. It protects the lungs from lung toxicity when high FiO2 levels are used. D. It improves cardiac output by increasing venous return.

6. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer B. It keeps the alveoli partially inflated and participating in gas exchange. Rationale: The positive pressure of PEEP is delivered at end- expiratory to keep the alveoli partially open so they will reinflate more easily the next time and so that they don’t collapse and are active in gas exchange. Thus, lower amounts of O2 are needed to reverse hypoxemia. PEEP causes positive intrathoracic pressure, which decreases venous return and decreases cardiac output.

7. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Symptoms of Pneumothorax Peak inspiratory pressure increases Sudden decrease in PaO2 and SaO2 Deviated trachea Absent breath sounds over affected lung Heart sounds become muffled Diaphoresis Increased restlessness

8. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Positioning the Patient With ARDS to Improve Oxygenation Prone positioning –Evaluate oxygenation and mentation when moved to this position –Protect all invasive lines and endotracheal tube Rotational therapy –Gradual side-to-side position changes –Evaluate oxygenation and mentation in all positions –Avoid position change that decreases SaO2 levels

9. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Nutritional Support of Patient with ARDS Mediators stimulate protein catabolism Calories needed: 35 to 45 Kcal/kg/day Avoid diet high in carbohydrates –Carbohydrates when metabolized release CO2 Decreased gut motility –Consider small bowel feeding

10. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question Why are carbohydrates avoided as the mainstay of the diet for a client with ARDS? A. The client needs increased protein to repair tissue. B. The client develops glucose intolerance because of the inflammatory process. C. Carbohydrates, when broken down in the body, release CO2, increasing the workload of the lungs. D. Carbohydrates are broken down to acids and strain the kidneys.

11. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer C. Carbohydrates, when broken down in the body, release CO2, increasing the workload of the lungs. Rationale: When carbohydrates are broken down in the body, CO2 is a byproduct, which the lungs must process. This would increase the workload of diseased lungs. Carbohydrates do not cause glucose intolerance. Glucose intolerance arises from insufficient insulin in the body. The client needs protein to repair damaged tissues, but that is not why carbohydrates are restricted in a client with ARDS. Proteins are broken down into acids, and the kidney buffers the acids.

12. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Institute for Healthcare Improvement: Key Aspects of Ventilator Bundle Head of bed at 30 degrees Provide breaks from continuous sedation every day Asses the patient’s readiness to be weaned from the ventilator daily Provide prophylaxis for peptic ulcer disease Provide prophylaxis for DVT

13. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins ARDS and Potential Complications Nosocomial infections –Discontinue invasive lines as soon as possible Muscle weakness –Use train-of-four monitoring with neuromuscular blockade Difficulty weaning from ventilator –Follow ventilator bundle

14. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins ARDS and Potential Complications (cont.) Renal failure –Monitor GFR, renal profile, fluid status closely Ileus –Assess bowel sounds DVT and pulmonary embolism –DVT prophylaxis

15. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question The older adult with ARDS is at risk for not receiving the same quality of treatment that a younger client would. A. True B. False

16. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer A. True Rationale: “Ageism” plays a tremendous role in the way health care professionals perceive older adults and how much investment they want to make when providing treatment. The age of the person should not play a role in the care he or she receives. Factors that should be considered when determining treatment options include comorbidities, gravity of the current situation, etc.