GOLD Spirometry 2010 CorxFeb11(22)

8/11/2019 GOLD Spirometry 2010 CorxFeb11(22)

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Spirometry in Primary Care

Global Initiative for Chronic ObstructiveLung Disease (GOLD) 2010


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Spirometry - Introduction

Spirometry is the gold standard for COPDdiagnosis

Underuse leads to inaccurate COPD diagnosis

Widespread uptake has been limited by:

Concerns over technical performance ofoperators

Difficulty with interpretation of results

Lack of approved local training courses

Lack of evidence showing clear benefit when

spirometry is incorporated into management


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What is Spirometry?

Spirometryis a method of

assessing lung function bymeasuring the total volume ofair the patient can expel from

the lungs after a maximalinhalation.


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Why Perform Spirometry?

Measure airflow obstruction to help make adefinitive diagnosis of COPD

Confirm presenceof 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


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SpirometryAdditional Uses

Make a diagnosis and assess severity in arange of other respiratory conditions

Distinguish between obstruction and

restrictionas causes of breathlessness

Screen workforces in occupationalenvironments

Assess fitness to dive

Performpre-employment screening in certainprofessions


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Types of Spirometers

Bellows spirometers:

Measure volume; mainly in lungfunction 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


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Flow Measuring Spirometer


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Desktop Electronic Spirometers


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Standard Spirometric Indicies

FEV1- Forced expiratory volume in one second:

The volume of air expired in the first second ofthe blow

FVC- Forced vital capacity:

The total volume of air that can be forciblyexhaled in one breath

FEV1/FVC ratio:

The fraction of air exhaled in the first secondrelative to the total volume exhaled


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Additional Spirometric Indicies

VC - Vital capacity:A volume of a full breath exhaled in the patientsown time and not forced. Often slightly greaterthan the FVC, particularly in COPD

FEV6Forced expired volume in six seconds:Often approximates the FVC. Easier to performin 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


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Criteria for NormalPost-bronchodilator Spirometry

FEV1: % predicted > 80%

FVC: % predicted > 80%

FEV1/FVC: > 0.7 - 0.8, dependingon age


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SPIROMETRY

OBSTRUCTIVE

DISEASE


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Spirometric Diagnosis of COPD

COPD is confirmed by postbronchodilator FEV1/FVC < 0.7

Post-bronchodilator FEV1/FVC

measured 15 minutes after 400gsalbutamol or equivalent


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Bronchodilator Reversibility Testing

Provides the best achievable FEV1(and FVC)

Helps to differentiate COPD fromasthma

Must be interpreted with clinicalhistory - neither asthma nor COPDare diagnosed on spirometry alone


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Figure 5.1-6.

BronchodilatorReversibilityTesting in COPD

GOLDReport (2009)


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Figure 5.1-6. BronchodilatorReversibility Testing in COPD

Preparation

Tests should be performed when patients areclinically stable and free from respiratory infection

Patients should not have taken:

inhaled short-acting bronchodilators in theprevious six hours

long-acting bronchodilator in the previous 12hours

sustained-release theophylline in the previous

24 hours


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Spirometry (continued)

Possible dosage protocols: 400 g 2-agonist, or 80-160 g anticholinergic, or the two combined

FEV1 should be measured again:15 minutes after a short-acting bronchodilator45 minutes after the combination


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Results

An increase in FEV1that is bothgreaterthan 200 ml and 12% above the pre-

bronchodilator FEV1(baseline value) isconsidered significant

It is usually helpful to report the absolutechange (in ml) as well as the % changefrom baseline to set the improvement in a

clinical context


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Criteria: Restrictive Disease

FEV1: normal or mildly reduced

FVC: < 80% predicted

FEV1/FVC: > 0.7


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Volume,

liters

Time, seconds

FEV1= 1.9L

FVC = 2.0L

FEV1/FVC = 0.95

1 2 3 4 5 6

5

4

3

2

1

Spirometry: Restrictive Disease

Normal

Restrictive


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Mixed Obstructive/Restrictive

FEV1: < 80% predicted

FVC:< 80% predicted

FEV1/FVC: < 0.7


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SPIROMETRY

Flow Volume


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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 mildairflowobstruction


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Flow Volume Curve

Expiratoryflow rateL/sec

Volume (L)

FVC

Maximumexpiratory flow(PEF)

Inspiratoryflow rate

L/sec

RVTLC

Flow Volume Curve Patterns


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Flow Volume Curve PatternsObstructive and Restrictive

Obstructive Severe obstructive Restrictive

Volume (L)

Ex

piratoryflowr

ate

E

xpiratoryflow

rate

E

xpiratoryflow

rate

Volume (L) Volume (L)

Steeple pattern,reduced peak flow,

rapid fall off

Normal shape,normal peak flow,

reduced volume

Reduced peak flow,scooped out mid-

curve


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PRACTICAL SESSION

Performing Spirometry


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Spirometry Training

Training is essential for operators to learn correctperformance 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


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Performing Spirometry - Preparation

1. Explain the purpose of the test anddemonstrate the procedure

2. Record the patients age, height and

gender and enter on the spirometer

3. Note when bronchodilator was last used

4. Have the patient sitting comfortably

5. Loosen any tight clothing

6. Empty the bladder beforehand if needed


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f


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Watchthe patient during the blow toassure the lips are sealed around themouthpiece

Check to determine if an adequatetrace has been achieved

Repeat the procedure at least twicemore until ideally 3 readings within 100ml or 5% of each other are obtained

Performing Spirometry


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

Reproducibility - Quality of Results

Vo

lume,

liters

Time, seconds


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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


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Spirometry - Quality Control

Most common cause of inconsistentreadings is poor patient technique

Sub-optimal inspiration

Sub-maximal expiratory effortDelay in forced expiration

Shortened expiratory time

Air leak around the mouthpiece

Subjects must be observed and encouragedthroughout the procedure


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SpirometryCommon 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 postureleaning forwards


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Equipment Maintenance

Most spirometers need regular calibration tocheck accuracy

Calibration is normally performed with a 3 litre

syringe Some electronic spirometers do not require

daily/weekly calibration

Good equipment cleanliness and anti-infectioncontrol are important; check instruction manual

Spirometers should be regularly serviced; check

manufacturers recommendations


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Troubleshooting

Examples - Unacceptable Traces


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bl S l


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Vo

lume,

liters

Time, seconds

Unacceptable TraceStop Early

Normal


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U bl T C hi


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Vo

lume

,liters

Time, seconds

Unacceptable Trace - Coughing

Normal

U t bl T E t B th


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Vo

lume,l

iters

Time, seconds

Unacceptable TraceExtra Breath

Normal


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Some Spirometry Resources

Global Initiative for Chronic Obstructive LungDisease (GOLD) - www.goldcopd.org

Spirometry in Practice - www.brit-thoracic.org.uk

ATS-ERS Taskforce: Standardization ofSpirometry. ERJ2005;29:319-338www.thoracic.org/sections/publications/statements

National Asthma Council: Spirometry Handbookwww.nationalasthma.org.au


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GOLD Spirometry 2010 CorxFeb11(22)

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