Indications for PFT

1. Indications for PFT RET 2414 Pulmonary Function Testing Module 1.0

2. Indications For PFT • Learning Objectives • Categorize PFTs according to specific purposes • Identify at least one indication for spirometry, lung volumes, and diffusing capacity • List one obstructive and one restrictive pulmonary disorder • Name at least two disease in which air trapping may occur • Relate pulmonary history to indications for performing pulmonary function tests

3. Pulmonary Function Testing • Purpose for PFT Identify and quantify pulmonary impairments

4. Pulmonary Function Testing • Tests can be divided into categories • Airway Function • Lung Volumes and Gas Distribution • Diffusing Capacity • Blood Gas and Exchange Tests • Cardiopulmonary Exercise Tests

5. Airway Function Tests • Spirometry (meaning the measuring of breath) is the most common of the Pulmonary Function Tests (PFTs). It measures lung function, specifically the direct measurement of the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled.

6. Airway Function Tests • Spirometry • Vital Capacity (VC)

7. Airway Function Tests • Spirometry • Forced Vital Capacity (FVC)

8. Airway Function Tests • Spirometry • Flow – Volume Loop (FVL) • AKA; MEFV Curve

9. Airway Function Tests • Spirometry • Flow – Volume Loop (FVL) • AKA; MEFV Curve

10. Airway Function Tests • FVC and/or FVL • Pre/Post Bronchodilator • Pre/Post Bronchochallenge • Methacholine • Histamine • Exercise

11. Airway Function Tests • Spirometry • Maximum Voluntary Ventilation (MVV)

12. Airway Function Tests • Maximal Inspiratory (MIP) • Expiratory Pressure (MEP) • Airway Resistance (Raw) • Compliance (CL)

13. Indications for Spirometry • Detect the presence of lung disease Spirometry is recommended as the “Gold Standard” for diagnosis of obstructive lung disease by: • National Lung Health Education Program (NLHEP) • National Heart, Lung and Blood Institute (NHLBI) • World Health Organization (WHO)

14. Indications for Spirometry BOX 1-2 • Diagnose the presence or absence of lung disease • Quantify the extent of known disease on lung function • Measure the effects of occupational or environmental exposure • Determine beneficial or negative effects of therapy

15. Indications for Spirometry BOX 1-2 • Assess risk for surgical procedures • Evaluate disability or impairment • Epidemiologic or clinical research involving lung health or disease

16. Lung Volumes • Determination of lung volume • Includes the VC (spirometry) and its subdivisions, along with the FRC (indirect spirometry) – from these TLC and other lung volumes can be determined

17. Lung Volumes • Functional Residual Capacity (FRC) • Nitrogen Washout • Helium Dilution • Thoracic Gas Volumes

18. Indications for Lung Volume Tests Box 1-3 • Diagnose or assess the severity of restrictive lung disease • Differentiate between obstructive and restrictive disease patterns • Assess the response to therapy • Make preoperative assessment of patients with compromised lung function

19. Indications for Lung Volume Tests Box 1-3 • Determine or evaluate disability • Assess gas trapping by comparison of plethysmographic lung volumes with gas dilution lung volumes • Standardize other lung functions (i.e., specific conductance)

20. Ventilation • Minute Ventilation • Alveolar Ventilation • Dead Space

21. Distribution of Ventilation • Multiple – Breath N2 • He Equilibration • Single – Breath Techniques

22. Diffusing Capacity (DLco)

23. Diffusing Capacity (DLco) • Single – Breath (Breath Hold) • Steady – State • Other Techniques

24. Indications for Diffusing CapacityBox 1-4 • Evaluate or follow the progress of parenchymal lung disease • Evaluate pulmonary involvement in systemic disease • Evaluate obstructive lung disease

25. Indications for Diffusing CapacityBox 1-4 • Evaluate cardiovascular diseases • Quantify disability associated with interstitial lung disease • Evaluate pulmonary hemorrhage, polycythemia, or left-to-right shunts

26. Blood Gases and Gas Exchange

27. Blood Gases and Gas Exchange • Blood Gas Analysis and Oximetry • Shunt Study

28. Blood Gases and Gas Exchange • Pulse Oximetry and Capnography

29. Indications for Blood Gas AnalysisBox 1-5 • Evaluate the adequacy of lung function • Determine the need for supplemental oxygen • Monitor ventilatory support

30. Indications for Blood Gas AnalysisBox 1-5 • Document the severity or progression of know pulmonary disease • Provide data to correct or corroborate other pulmonary function measurement

31. Cardiopulmonary Exercise Test

32. Indications for Exercise TestingBox 1-6 • Determine the level of cardiorespiratory fitness • Document or diagnose exercise limitations as a result of fatigue, dyspnea, or pain, • Cardiovascular / Pulmonary Disease

33. Indications for Exercise TestingBox 1-6 • Evaluate adequacy of arterial oxygenation oxyhemoglobin saturation • Assess preoperative risk • Lung resection or reduction

34. Indications for Exercise TestingBox 1-6 • Assess disability • Occupational lung disease • Evaluate therapeutic interventions such as heart or lung transplant

35. Patterns of Impaired Pulmonary Function Sometimes, patients display patterns during pulmonary function testing that are consistent with a specific diagnosis

36. Obstructive Airway Diseases Simple definition: “Airflow into and out of the lungs is reduced”

37. Obstructive Airway Diseases • Chronic Obstructive Pulmonary Disease (COPD) Long-standing airway obstruction caused by: • Cystic Fibrosis • Bronchitis • Asthma • Bronchiectasis • Emphysema “CBABE”

38. Obstructive Airway Diseases • COPD Characterized by: • Dyspnea at rest or with exertion • Productive cough

39. Obstructive Airway Diseases • Emphysema“air trapping” • Primarily caused by cigarette smoking! • Genetic defect; absence of α-antitrypsin • Chronic exposure to environmental pollutants

40. Obstructive Airway Diseases • Emphysema • Dyspnea at rest or with exertion • Productive cough • Under weight • Barrel-chested • Use of accessory muscles

41. Obstructive Airway Diseases • Emphysema • Purse-lip breathing • Breath sounds are distant or absent • Chest X-Ray • Flattened diaphragms • Increased air spaces

42. Obstructive Airway Diseases • Emphysema • Airway obstruction • Spirometry • FEV1 is reduced • Air trapping • Lung Volumes • Hyperinflation of FRC

43. Obstructive Airway Diseases • Emphysema (cont) • Gas exchange abnormalities • Diffusing Capacity (DLco) • Reduced • Blood Gases • Hypoxemia/Hypercapnia • Possible O2 Desaturation with Exertion • Exercise Testing

44. Obstructive Airway Diseases • Chronic Bronchitis “Excessive mucus production, with a productive cough on most days, for at least 3 months for 2 years or more.”

45. Obstructive Airway Diseases • Chronic Bronchitis • Primarily caused by cigarette smoking! • Chronic exposure to environmental pollutants

46. Obstructive Airway Diseases • Chronic Bronchitis • Chronic cough – “smoker’s cough” • Dyspnea, particularly with exertion • Chest X-Ray • Congested airways • Enlarged heart w/prominent pulmonary vessels • Diaphragms normal or flattened • Edema of lower extremities

47. Obstructive Airway Diseases • Chronic Bronchitis (cont) • Airway obstruction • Spirometry • FEV1 is reduced • Dlco • Usually reduced • May have a preserved (normal) Dlco, which is helpful to distinguish it from emphysema

48. Obstructive Airway Diseases • Chronic Bronchitis (cont) • Gas exchange abnormalities • Blood Gases • Hypoxemia, Hypercapnia in advanced cases • Polycythemia • Cyanosis

49. Obstructive Airway Diseases • Bronchiectasis Pathologic dilatation of the bronchi, resulting from destruction of the bronchial wall by severe, repeated infections.

50. Obstructive Airway Diseases • Bronchiectasis Common in Cystic Fibrosis (CF), as well as following bronchial obstruction by a tumor or foreign body. When entire bronchial tree is involved, it is assumed that the disease is inherited.