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Spirometry in Primary Care. Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2010. Spirometry - Introduction. Spirometry is the gold standard for COPD diagnosis Underuse leads to inaccurate COPD diagnosis Widespread uptake has been limited by:

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spirometry in primary care

Spirometry in Primary Care

Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2010

spirometry introduction
Spirometry - Introduction
  • Spirometry is the gold standard for COPD diagnosis
  • Underuse leads to inaccurate COPD diagnosis
  • Widespread uptake has been limited by:
    • Concerns over technical performance of operators
    • Difficulty with interpretation of results
    • Lack of approved local training courses
    • Lack of evidence showing clear benefit when spirometry is incorporated into management
what is spirometry
What is Spirometry?

Spirometry is a method of assessing lung function by measuring the total volume of air the patient can expel from the lungs after a maximal inhalation.

why perform spirometry
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
  • Assessprognosis (FEV1) in COPD
  • Perform pre-operative assessment
spirometry additional uses
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
types of spirometers
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

standard spirometric indicies
Standard Spirometric Indicies
  • FEV1 - 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

  • FEV1/FVC ratio:

The fraction of air exhaled in the first second relative to the total volume exhaled

additional spirometric indicies
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

  • FEV6 – 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

lung volume terminology
Lung Volume Terminology

Inspiratory reserve

volume

Inspiratory

capacity

Total

lung

capacity

Tidal volume

Expiratory reserve

volume

Vital

capacity

Residual volume

spirogram patterns
Spirogram Patterns
  • Normal
  • Obstructive
  • Restrictive
  • Mixed Obstructive and Restrictive
predicted normal values
Predicted Normal Values
  • Age
  • Height
  • Sex
  • Ethnic Origin

Affected by:

criteria for normal post bronchodilator spirometry
Criteria for Normal Post-bronchodilator Spirometry
  • FEV1: % predicted > 80%
  • FVC: % predicted > 80%
  • FEV1/FVC: > 0.7 - 0.8, depending on age
normal trace showing fev 1 and fvc
Normal Trace Showing FEV1 and FVC

FVC

5

4

FEV1 = 4L

FVC = 5L

FEV1/FVC = 0.8

Volume, liters

3

2

1

1

2

3

4

5

6

1

Time, sec

slide19

SPIROMETRY

OBSTRUCTIVE DISEASE

spirometry obstructive disease
Spirometry: Obstructive Disease

Normal

5

4

3

Volume, liters

FEV1 = 1.8L

FVC = 3.2L

FEV1/FVC = 0.56

2

Obstructive

1

1

2

3

4

5

6

Time, seconds

spirometric diagnosis of copd
Spirometric Diagnosis of COPD
  • COPD is confirmed by post–bronchodilator FEV1/FVC < 0.7
  • Post-bronchodilator FEV1/FVC measured 15 minutes after 400µg salbutamol or equivalent
bronchodilator reversibility testing
Bronchodilator Reversibility Testing
  • Provides the best achievable FEV1(and FVC)
  • Helps to differentiate COPD from asthma

Must be interpreted with clinical history - neither asthma nor COPD are diagnosed on spirometry alone

bronchodilator reversibility testing23
Bronchodilator Reversibility Testing
  • Can be done on first visit if no diagnosis has been made
  • Best done as a planned procedure: pre- and post-bronchodilator tests require a minimum of 15 minutes
  • Post-bronchodilator only saves time but does not help confirm if asthma is present
  • Short-acting bronchodilators need to be withheld for at least 4 hours prior to test
bronchodilator reversibility testing24
Bronchodilator Reversibility Testing

* Some guidelines suggest nebulised bronchodilators can be given but the doses are not standardised. “There is no consensus on the drug, dose or mode of administering a bronchodilator in the laboratory.” Ref: ATS/ERS Task Force : Interpretive strategies for Lung Function Tests ERJ 2005;26:948

**Usually 8 puffs of 20 µg

slide26

Figure 5.1-6. Bronchodilator Reversibility Testing in COPD

  • Preparation
  • Tests should be performed when patients are clinically stable and free from respiratory infection
  • Patients should not have taken:
    • inhaled short-acting bronchodilators in the previous six hours
    • long-acting bronchodilator in the previous 12 hours
    • sustained-release theophylline in the previous 24 hours
slide27

Figure 5.1-6. Bronchodilator Reversibility Testing in COPD

  • Spirometry
  • FEV1 should be measured (minimum twice, within 5% or 150mls) before a bronchodilator is given
  • The bronchodilator should be given by metered dose inhaler through a spacer device or by nebulizer to be certain it has been inhaled
  • The bronchodilator dose should be selected to be high on the dose/response curve
  • (…..continued)
slide28

Figure 5.1-6. Bronchodilator Reversibility Testing in COPD

  • Spirometry (continued)
  • Possible dosage protocols:
  • 400 µg β2-agonist, or
  • 80-160 µg anticholinergic, or
  • the two combined
  • FEV1 should be measured again:
  • 15 minutes after a short-acting bronchodilator
  • 45 minutes after the combination
slide29

Figure 5.1-6. Bronchodilator Reversibility Testing in COPD

  • Results
  • An increase in FEV1 that is both greater than 200 ml and 12% above the pre-bronchodilator FEV1 (baseline value) is considered significant
  • It is usually helpful to report the absolute change (in ml) as well as the % change from baseline to set the improvement in a clinical context
slide30

SPIROMETRY

RESTRICTIVE DISEASE

criteria restrictive disease
Criteria: Restrictive Disease
  • FEV1:normal or mildly reduced
  • FVC: < 80% predicted
  • FEV1/FVC: > 0.7
slide32

Spirometry: Restrictive Disease

Normal

5

4

3

Volume, liters

Restrictive

FEV1 = 1.9L

FVC = 2.0L

FEV1/FVC = 0.95

2

1

1

2

3

4

5

6

Time, seconds

mixed obstructive restrictive
Mixed Obstructive/Restrictive
  • FEV1: < 80% predicted
  • FVC: < 80% predicted
  • FEV1 /FVC: < 0.7
mixed obstructive and restrictive
Mixed Obstructive and Restrictive

Normal

Volume, liters

FEV1 = 0.5L

FVC = 1.5L

FEV1/FVC = 0.30

Obstructive - Restrictive

Time, seconds

Restrictive and mixed obstructive-restrictive are difficult to diagnose by spirometry alone; full respiratory function tests are usually required

(e.g., bodyplethysmography, etc)

slide35

SPIROMETRY

Flow Volume

flow volume curve
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 mildairflow obstruction
flow volume curve37
Flow Volume Curve

Maximum expiratory flow (PEF)

Expiratory flow rate

L/sec

FVC

RV

TLC

Inspiratory flow rate

L/sec

Volume (L)

flow volume curve patterns obstructive and restrictive
Flow Volume Curve Patterns Obstructive and Restrictive

Obstructive

Severe obstructive

Restrictive

Expiratory flow rate

Expiratory flow rate

Expiratory flow rate

Volume (L)

Volume (L)

Volume (L)

Reduced peak flow, scooped out mid-curve

Steeple pattern, reduced peak flow, rapid fall off

Normal shape, normal peak flow, reduced volume

spirometry abnormal patterns
Spirometry: Abnormal Patterns

Obstructive

Restrictive

Mixed

Volume

Volume

Volume

Time

Time

Time

Fast rise to plateau at reduced maximum volume

Slow rise to reduced maximum volume; measure static lung volumes and full PFT’s to confirm

Slow rise, reduced volume expired; prolonged time to full expiration

practical session

PRACTICAL SESSION

Performing Spirometry

spirometry training
Spirometry Training
  • Training is essential for operators to learn correct performance and interpretation of results
  • Training for competent performance of spirometry requires a minimum of 3 hours
  • Acquiring good spirometry performance and interpretation skills requires practice, evaluation, and review
  • Spirometry performance (who, when and where) should be adapted to local needs and resources
  • Training for spirometry should be evaluated
obtaining predicted values
Obtaining Predicted Values
  • Independent of the type of spirometer
  • Choose values that best represent the

tested population

  • Check for appropriateness if built into

the spirometer

Optimally, subjects should rest 10 minutes

before performing spirometry

withholding medications
Withholding Medications

Before performing spirometry, withhold:

  • Short acting β2-agonists for 6 hours
  • Long acting β2-agonists for 12 hours
  • Ipratropium for 6 hours
  • Tiotropium for 24 hours

Optimally, subjects should avoid caffeine and cigarette smoking for 30 minutesbefore performing spirometry

performing spirometry preparation
Performing Spirometry - Preparation
  • Explain the purpose of the test and demonstrate the procedure
  • Record the patient’s age, height and gender and enter on the spirometer
  • Note when bronchodilator was last used
  • Have the patient sitting comfortably
  • Loosen any tight clothing
  • Empty the bladder beforehand if needed
performing spirometry
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
slide46

Performing Spirometry

  • 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 100ml or 5% of each other are obtained
slide47

Reproducibility - Quality of Results

Volume, liters

Time, seconds

Three times FVC within 5% or 0.15 litre (150ml)

spirometry possible side effects
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

spirometry quality control
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
spirometry common problems
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
equipment maintenance
Equipment Maintenance
  • Most spirometers need regular calibration to check accuracy
  • Calibration is normally performed with a 3 litre syringe
  • Some electronic spirometers do not require daily/weekly calibration
  • Good equipment cleanliness and anti-infection control are important; check instruction manual
  • Spirometers should be regularly serviced; check manufacturer’s recommendations
troubleshooting

Troubleshooting

Examples - Unacceptable Traces

unacceptable trace poor effort
Unacceptable Trace - Poor Effort

Normal

Volume, liters

Variable expiratory effort

Inadequate sustaining of effort

May be accompanied by a slow start

Time, seconds

unacceptable trace stop early
Unacceptable Trace – Stop Early

Normal

Volume, liters

Time, seconds

unacceptable trace slow start
Unacceptable Trace – Slow Start

Normal

Volume, liters

Time, seconds

slide56

Unacceptable Trace - Coughing

Normal

Volume, liters

Time, seconds

slide57

Unacceptable Trace – Extra Breath

Normal

Volume, liters

Time, seconds

some spirometry resources
Some Spirometry Resources
  • Global Initiative for Chronic Obstructive Lung Disease (GOLD) - www.goldcopd.org
  • Spirometry in Practice - www.brit-thoracic.org.uk
  • ATS-ERS Taskforce: Standardization of Spirometry. ERJ 2005;29:319-338

www.thoracic.org/sections/publications/statements

  • National Asthma Council: Spirometry Handbook

www.nationalasthma.org.au