The document discusses spirometry as a crucial tool for diagnosing and monitoring obstructive lung diseases, particularly COPD and asthma. It outlines the differences between the two conditions, detailing symptoms, diagnostic criteria, and the importance of spirometry in assessing lung function and guiding treatment. The document further explains the testing procedures, interpretations of results, and the significance of understanding various spirometric measurements.

1. Spirometry of ObstructiveLung Diseases

2. Pulmonary Disorders Effects onPulmonary Function
Obstructive:
Any process that interferes with air flow either into or out of the lungs.
Large or small airways.
Restrictive:
Any process that interferes with the bellows action of the lungs or chest wall.
Reduced lung volumes.

3. Differential Diagnosis: COPD and Asthma
COPD
Onset In mid-life
Symptoms slowly progressive
Long smoking history
Dyspnea during exercise
Largely Irreversible airflow limitation
Asthma
Onset early in life (often childhood)
Symptoms vary from day to day
Symptoms at nigh/early morning
Allergy, rhinitis, and/or eczema also present
Family history of asthma
Largely reversible airflow limitation

4. Inflammatory Cascade inCOPD & Asthma

5. Measures of Assessment andMonitoring of Asthma
Asthma diagnosis criteria:
Positive episodic symptoms of airflow obstruction.
Airflow obstruction partially reversible.
R/ O alternative dx.

6. Objective lung functionmeasurements in Asthma
Spirometry:
▫Forced Expiratory Maneuvers.
Exhaled Nitric Oxide.
Peak Flows.

7. EPR-3 Statements for Asthma
The Expert Panel recommends that office-based physicians who care for asthma patients should have access to spirometry, which is useful in both diagnosis and periodic monitoring .
Spirometryshould be performed using equipment and techniques that meet standards developed by the ATS (EPR-2 1997).

8. GOLD 2013: Diagnosis of COPD
SPIROMETRY REQUIREDTO DIAGNOSE COPD
Presence of a post-bronchodilator FEV1/FVC < 0.70 confirms the presence of persistent airflow limitation and thus of COPD.
Key Indicators to Consider COPD Diagnosis:
1
•SYMPTOMS
•Dyspnea-progressive (worsens over time and with exercise)
•Chronic cough
•Sputum
2
•HISTORY OF EXPOSURE TO RISK FACTORS
•Tobacco smoke
•Smoke from home cooking/heating fuels
•Occupational dusts and chemical
3
•FAMILY HISTORY OF COPD
Adapted from GOLD 2013

9. Spirometry
Spirometryshould be performed after the administration of an adequate dose of a short acting inhaled bronchodilator (e.g. 400 ᶙg salbutamol) to minimize variability.
A post-bronchodilator FEV 1/FVC <0.70 confirms the presence of airflow limitation that is not fully reversible.
Where possible, values should be compared to age-related normal values to avoid over- diagnosis of COPD In the elderly.

10. Why Do We Need Spirometryin COPD?
Spirometryis useful for:
Screen individuals at risk for pulmonary disease.
Confirmation of COPD diagnosis.
Assessing severity of pulmonary dysfunction.
Guiding selection of treatment.
Assessing the effects of therapeutic interventions.

11. Who Should Be Screened forCOPD?
Consider COPD, and perform spirometry, if any of these indicators are present in an individual over age 40.
▫Dyspnea that is progressive, usually worse with exercise, and persistent.
▫Chronic cough (may be intermittent and unproductive).
▫Chronic sputum.
▫History of tobacco smoke exposure.
▫Exposure to occupational dusts and chemicals.
▫Risk factors.
▫Exposure to smoke from home cooking and heating fuels.

12. SpirometryOrigin
Most basic of Pulmonary Function Tests
Clinical Tools Origin -Mid 1800' s
▫John Hutchinson.
▫Water-sealed spirometryto measure vital capacity (VC).

13. Reasons for PerformingSpirometry
Diagnostic Purposes.
Monitoring Lung Disease.
Assessing Disability.

14. Spirometry
Spirometrywith flow volume loops assesses the mechanical properties of the respiratory system by measuring expiratory volumes and flow rates.
▫Maximal inspiratory and expiratory effort.
▫At least 3 tests of acceptable effort are performed to ensure reproducibility.

15. 21st Century Spirometry
Measurements of:
Forced Vital Capacity (FVC).
Forced Expiratory Volume in one second (FEV1).
Forced Expiratory Volume in six seconds (FEV6).
Forced Expiratory Flow over various Intervals (FEFx).
Peak Expiratory Flow (PEF).

16. Definitions and Terms
FEV1 -forced expiratory volume 1 -the volume of air that is forcefully exhaled in one second.
FEV6 -forced expiratory volume 6 -the volume of air that Is forcefully exhaled in six seconds.
FVC-forced vital capacity-the volume of air that can be maximally forcefully exhaled.
FEV/FVC-ratio of FEV1 to FVC, expressed as a percentage.

17. Definitions and Terms
FEV/FVC-ratio of FEV6 to FVC, expressed as a percentage.
FEF25 -75 -forced expiratory flow -the average forced expiratory flow during the mid (25 -75%) portion of the FVC.
PEF-peak expiratory flow rate -the peak flow rate during expiration.

18. Spirometry
Flow volume loops provide a graphic illustration of a patient's spirometricefforts.
Flow is plotted against volume to display a continuous loop from inspiration to expiration.
The volume versus time curve is a an alternative way of plotting spirometricresults.
The overall shape of the flow volume loop is important in Interpreting spirometricresults.

19. Acceptability & Repeatability

20. Acceptability
At least three (3) acceptable maneuvers
Good start to the test.
No hesitation or coughing for the 1stsecond.
FVC lasts at least 6 seconds with a plateau of at least 1 second.
No valsalvamaneuver or obstruction of the mouthpiece.
FIVC shows apparent maximal effort.

21. Repeatability
Repeatability criteria act as guideline to determine need for additional efforts.
▫Largest and 2nd largest FVC must be within 150 mL.
▫Largest and 2nd largest FEV 1 must be 150 mL.
▫PEF values may be variable (within 15%).
If three acceptable reproducible maneuvers are not recorded, up to B attempts may be recorded.

22. SpirometryValue
Spirometryis typically reported in both absolute values and as a predicted percentage of normal.
Normal values vary and are dependent on:
▫Gender,
▫Race,
▫Age, and
▫Height.

23. Reporting Standards
Largest FVC obtained from all acceptable efforts should be reported.
Largest FEV1 obtained from all acceptable trials should be reported.
May or may not come from largest FVC effort.
All other flows, should come from the effort with the largest sum of FEV 1 & FVC.
PEF should be the largest value obtained from at least 3 acceptable maneuvers.

24. Results ReportingExample

25. Report Format
Report should also include:
▫Age on testing day.
▫Height (standing without shoes).
▫Weight (without shoes).
▫Gender.
▫Race or ethnic origin.
▫Technologist comment section.

26. FEV1 Results for Asthma

27. FEV 1 Severity Results for Asthma

28. At Risk for COPD
Spirometricclassification of airflow limitation (in patients with FEV1/FVC<0.70).
▫GOLD 1(Mild; FEV1 ≥80% predicted).
▫GOLD 2 (Moderate; 50% ≤FEV1 <80% predicted).
▫GOLD 3 (Severe; 30% ≤FEV1 <50% predicted).
▫GOLD 4 (Very severe; FEV1 <30% predicted).
Adapted from GOLD 2013

29. Pre & Post BronchodilatorStudies
B-Adrenergic aerosols are most common form for testing.
Standardize.
▫Drug.
▫Dosage.
▫Delivery Device.
Minimum of 15 minutes between pre and post tests.

30. Pre & Post Bronchodilator Studies: Withholding Medications

31. Pre & Post BronchodilatorStudies: Interpretations
Determined based on improvement of FEV1.
Commonly expressed as Percent Change.
% Change = Post FEV 1 -Pre FEV1 x 100
Pre FEV1

32. Reversibility
Reversibility of airways obstruction can be assessed with the use of bronchodilators.
> 12% increase in the FEV1 and 200 ml
improvement in FEV1
OR
> 12% increase in the FVC and 200 ml
improvement in FVC.

33. Spirometry

34. Asthma Challenge Testing
Spirometrycan be used to detect the bronchial hyperreactivitythat characterizes asthma.
Increasing concentrations of histamine or methacholine.
Patients with asthma will demonstrate symptoms and produce spirometricresults consistent with airways obstruction at much lower threshold concentration than normals.

35. Bronchial Provocation for Asthma

36. Other Diagnostic Tests
Sputum Induction
6-Minute Walks
Impulse Oscillometry
Exhaled Nitric Oxide
Exhaled Breath Condensate

37. References