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Spirometry in Primary Care Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2008.

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Presentation on theme: "Spirometry in Primary Care Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2008."— Presentation transcript:

1 Spirometry in Primary Care Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2008

2 What is Spirometry? Spirometry is a method of assessing lung function by measuring the volume of air the patient can expel (expiration) from the lungs after a maximal inspiration.

3 Why Perform Spirometry? Measure airflow obstruction to help make a definitive diagnosis of COPD Confirm presence of airway obstruction Assess severity of airflow obstruction in COPD Detect airflow obstruction in smokers who may have few or no symptoms Monitor disease progression in COPD Assess one aspect of response to therapy Assess prognosis (FEV 1 ) in COPD Perform pre-operative assessment

4 Spirometry – Additional Uses Make a diagnosis and assess severity in a range of other respiratory conditions Distinguish between obstruction and restriction as causes of breathlessness Screen workforces in occupational environments Assess fitness to dive Perform pre-employment screening in certain professions

5 Types of Spirometers Bellows spirometers: Measure volume; mainly in lung function units Electronic desk top spirometers: Measure flow and volume with real time display Small hand-held spirometers: Inexpensive and quick to use but no print out

6 Volume Measuring Spirometer

7 Flow Measuring Spirometer

8 Desktop Electronic Spirometers

9 Small Hand-held Spirometers

10 How to Perform Spirometry

11 Withholding Medications Before performing spirometry, withhold: Short acting β 2 -agonists for 6 hours Long acting β 2 -agonists for 12 hours Ipratropium for 6 hours Tiotropium for 24 hours Optimally, subjects should avoid caffeine and cigarette smoking for 30 minutes before performing spirometry

12 Performing Spirometry - Preparation 1.Record the patient’s age, height and gender and enter on the spirometer 2.Note when bronchodilator was last used 3.Have the patient sitting comfortably 4.Loosen any tight clothing 5.Empty the bladder beforehand if needed 6.Explain the purpose of the test and demonstrate the procedure

13 Performing Spirometry Breath in until the lungs are full Hold the breath and seal the lips tightly around a clean mouthpiece Blast the air out as forcibly and fast as possible. Provide lots of encouragement! Continue blowing until the lungs feel empty

14 Watch the patient during the blow to assure the lips are sealed around the mouthpiece Check to determine if an adequate trace has been achieved Repeat the procedure at least twice more until ideally 3 readings within 100 ml or 5% of each other are obtained Performing Spirometry

15 Three times FVC within 5% or 0.1 litre (100 ml) Reproducibility - Quality of Results Volume, liters Time, seconds

16 Spirometry - Possible Side Effects Feeling light-headed Headache Getting red in the face Fainting: reduced venous return or vasovagal attack (reflex) Transient urinary incontinence Spirometry should be avoided after recent heart attack or stroke

17 Spirometry - Quality Control Most common cause of inconsistent readings is poor patient technique Sub-optimal inspiration Sub-maximal expiratory effort Delay in forced expiration Shortened expiratory time Air leak around the mouthpiece Subjects must be observed and encouraged throughout the procedure

18 Spirometry – Common Problems Inadequate or incomplete blow Lack of blast effort during exhalation Slow start to maximal effort Lips not sealed around mouthpiece Coughing during the blow Extra breath during the blow Glottic closure or obstruction of mouthpiece by tongue or teeth Poor posture – leaning forwards

19 Standard Spirometric Indicies FEV 1 - Forced expiratory volume in one second: The volume of air expired in the first second of the blow FVC - Forced vital capacity: The total volume of air that can be forcibly exhaled in one breath FEV 1 /FVC ratio: The fraction of air exhaled in the first second relative to the total volume exhaled

20 Additional Spirometric Indicies VC - Vital capacity: A volume of a full breath exhaled in the patient’s own time and not forced. Often slightly greater than the FVC, particularly in COPD FEV 6 – Forced expired volume in six seconds: Often approximates the FVC. Easier to perform in older and COPD patients but role in COPD diagnosis remains under investigation MEFR – Mid-expiratory flow rates: Derived from the mid portion of the flow volume curve but is not useful for COPD diagnosis

21 Total lung capacity Tidal volume Inspiratory reserve volume Expiratory reserve volume Residual volume Inspiratory capacity Vital capacity Lung Volume Terminology

22

23 Spirogram Patterns Normal Obstructive Restrictive Mixed Obstructive and Restrictive

24 Spirometry Predicted Normal Values

25 Predicted Normal Values Age Height Sex Ethnic Origin Affected by:

26 Criteria for Normal Post-bronchodilator Spirometry FEV 1 : % predicted > 80% FVC: % predicted > 80% FEV 1 /FVC: > 0.7

27 Normal Trace Showing FEV 1 and FVC Volume, liters Time, seconds FVC 5 1 FEV 1 = 4L FVC = 5L FEV 1 /FVC = 0.8

28 SPIROMETRY OBSTRUCTIVE DISEASE

29 Obstructive Lung Disease The Flow rates are reduced due to obstruction in – the airways but the lung volumes are generally OK.

30 Spirometry: Obstructive Disease Volume, liters Time, seconds FEV 1 = 1.8L FVC = 3.2L FEV 1 /FVC = 0.56 Normal Obstructive

31 Diseases Associated With Airflow Obstruction COPD Asthma Bronchiectasis Cystic Fibrosis Post-tuberculosis Lung cancer (greater risk in COPD) Obliterative Bronchiolitis

32 Spirometric Diagnosis of COPD COPD is confirmed by post– bronchodilator FEV 1 /FVC < 0.7 Post-bronchodilator FEV 1 /FVC measured 15 minutes after 400µg salbutamol or equivalent

33 SPIROMETRY RESTRICTIVE DISEASE

34 Restrictive Lung Diseases With restrictive lung diseases there is a reduction In lung volumes due to decreases in lung compliance.

35 Criteria: Restrictive Disease FEV 1: % predicted < 80% FVC: % predicted < 80% FEV 1 /FVC: > 0.7

36 Volume, liters Time, seconds FEV 1 = 1.9L FVC = 2.0L FEV 1 /FVC = Spirometry: Restrictive Disease Normal Restrictive

37 Diseases Associated with a Restrictive Defect Pulmonary Fibrosing lung diseases Pneumoconioses Pulmonary edema Parenchymal lung tumors Lobectomy or pneumonectomy Extrapulmonary Thoracic cage deformity Obesity Pregnancy Neuromuscular disorders Fibrothorax

38 Mixed Obstructive/Restrictive FEV 1 : % predicted < 80% FVC: % predicted < 80% FEV 1 /FVC: < 0.7

39 Mixed Obstructive and Restrictive Volume, liters Time, seconds Restrictive and mixed obstructive-restrictive are difficult to diagnose by spirometry alone; full respiratory function tests are usually required (e.g., body plethysmography, etc) FEV 1 = 0.5L FVC = 1.5L FEV 1 /FVC = 0.30 Normal Obstructive - Restrictive

40 SPIROMETRY Flow Volume

41 Flow Volume Curve Standard on most desk-top spirometers Adds more information than volume time curve Less understood but not too difficult to interpret Better at demonstrating mild airflow obstruction

42 Flow Volume Curve Expiratory flow rate L/sec Volume (L) FVC Maximum expiratory flow (PEF) Inspiratory flow rate L/sec RV TLC

43 Flow Volume Curve Patterns Obstructive and Restrictive ObstructiveSevere obstructiveRestrictive Volume (L) Expiratory flow rate Volume (L) Steeple pattern, reduced peak flow, rapid fall off Normal shape, normal peak flow, reduced volume Reduced peak flow, scooped out mid- curve Predicted versus actual

44 ObstructiveRestrictiveMixed Time Volume Spirometry: Abnormal Patterns Slow rise, reduced volume expired; prolonged time to full expiration Fast rise to plateau at reduced maximum volume Slow rise to reduced maximum volume; measure static lung volumes and full PFT’s to confirm

45 Some Spirometry Resources Global Initiative for Chronic Obstructive Lung Disease (GOLD) - Spirometry in Practice - ATS-ERS Taskforce: Standardization of Spirometry. ERJ 2005;29: National Asthma Council: Spirometry Handbook


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