1. Dr. Taj

2. What is Spirometry ? It is a measurement of the breathing capacity of the lungs. It is the most basic and frequently performed test of pulmonary (lung) function.

3. Why “Dynamic” ? It measures the rate at which the lung changes volume during forced breathing maneuvers.

4. How is it performed ? Requirements Vitalograph. Mouthpiece (disposable). Nose clip.

5. Procedure Make a tight seal around the mouthpiece. Ask subject to inhale deeply. Then ask the subject to exhale as strong and as fast as possible.

6. Two types of curves can be obtained: Flow-volume curve (Loops). Forced expiratory volume curve (FEV).

7. Forced Expiratory Volume Curve

8. Flow Volume Curve

9. Normally: Forced expiratory curve Measures:  FEV1=the volume of air exhaled in the 1 st second.  FVC=the total volume of exhaled air.  FEV1/FVC ratio= normally ≈ 80%

10. What is the importance of Spirometry? Helps in the diagnosis of pulmonary diseases. Follow disease progression. Determine strength and function of the chest.

11. Respiratory Diseases Restrictive Pulmonary Diseases Obstructive Pulmonary Diseases ↑ airway resistance ↓ Lung compliance

12. Obstructive pulmonary diseases  FEV1 ↓↓↓↓  FVC ↓ or ↔  FEV1/FVC ↓ Eg: Bronchial Asthma COPD (Emphysema)

13. Restrictive pulmonary disease  FEV1 ↓↓  FVC ↓↓  FEV1/ FVC ↔ or ↑ Eg: Pulmonary fibrosis Pneumoconiosis

14. EXAMPLE Dynamic Spirometry was done on 3 patients, the results were the following: A. FEV1= 4L, FVC=5L FEV1/FVC=80% B. FEV1=1.2L, FVC=3L FEV1/FVC=40% C. FEV1= 2.7 L, FVC=3L FEV1/FVC= 90%

15. Thank you