to perform optimal spirometric measurement

To Perform Optimal Spirometric To Perform Optimal Spirometric MeasurementMeasurement

Ass.Prof.Dr.Gaye UlubayAss.Prof.Dr.Gaye UlubayBaskent University School of Medicine Baskent University School of Medicine

Dept. of Pulmonary DiseasesDept. of Pulmonary Diseases

OverviewOverview

Definition History of spirometry Why needed standardisation? Equipment Acceptability Repeatability Test selection

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DescriptionDescription

Pulmonary function testings (PFTs) are maneuvers to measure airflow and lung volumes using standardized equipments

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History of SpirometryHistory of Spirometry

1846 Hutchinson water spirometer 1933 Hermannsen MVV 1948 Normal predicted values of MVV determined 1947 Tiffeneau and Pinelli FVC

1955 Leuallen and Fowler FEF 25-75 %

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1979 Standardization of PFTs by ATS 1987 Spirometry standards revised 1991 Reference values & interpretation 1993 ERS standards 1994 BTS standards 1994 ATS standards revised 2005 ATS/ERS Task Force: General Laboratory,

spirometry,diffusion capacity, lung volumes and interpretation

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Why do we need to standards?

to reduce the noise on the signal

to ensure data are universally comparable

The standards

should not limited obtaining data on an individual

should not over ride common sense

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European Respiratory Journal 2005; 26: 153-161

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European Respiratory Journal 2005; 26: 319-338

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StandardizationStandardization

Availability of equipment Calibration control Measurement Acceptability Repeatability Reference values Interpretation

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Patients should not be tested within 1 month of a myocardial infarction

ContraindicationsContraindications

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Conditions which test could be suboptimalConditions which test could be suboptimal

Abdominal or chest pain of any causes Oral or facial pain exacerbated by a mouthpiece Stress incontinence Dementia or confusial state

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LaboratoryLaboratory

Ambient temperature, pressure and time of day must be recorded

Test should not perform below 17 Cº

Same equipment for repeat testing Same technician, same time of day Technicians should be trained once for each 3-5

years

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EquipmentsEquipments

The spirometer must be capable of measuring volume for 15s

Measuring volumes of 8L with an accuracy of at least 3 % or 0.050 L

Total resistance to airflow at 14L/s must be <1.5cmH2O/L/s

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Cihazın kontrolüCihazın kontrolü

Test Minimum interval

Kontrol

Volume Daily3L’lik şırınga ile kalibrasyon

kontrolü

Leak Daily 1 dakika 3 cm H2O basınç vererek

Volume linearity QTüm volümlerde 1L’lik kalibrasyon

şırıngasıyla

Flow linearity Her hafta En az 3 akım hızında test

Time 3 ayda bir Mekanik rekorderin saatle kontrolü

Equipment ControlEquipment Control

Check of mechanic recorder with stopwatch

QuarterlyTime

Test at least three different flow ranges

WeeklyFlow linearity

1L calibration syringe for all volumes

QuarterlyVolume linearity

3 cm H2O pressure for 1 min.DailyLeak

Calibration check with a 3L syringeDailyVolume

ControlMinimum interval

Test

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Syringe should be stored and used in a same ambient conditions with the spirometer

Syringe should be checked for leak monthly

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Ambient temperature should be 17-40 oC during calibration and tests

Air leaks should be checked every day

Leaks should be checked by applying a constant pressure of 3cmH2O

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Predicted valuesPredicted values

Weight Age (year) Height Gender Subjects with a deformity of thoracic cage

Height = arm span distance/1.06

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Patient preperationPatient preperation

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Should not smoke within at least 1h of testing Should not consume alcohol within 4 h of testing Should not performe vigorous exercise within 30

min of testing Should not wear strict clothes Should not eat a large meal within 2 hours of testing Bronchodilator medications?

Before testBefore test

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Sitting or standing position Upright sitting Nose clip Army chair Wheelchair? Obesity? False teeth?

During testDuring test

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Should be rest 5-10 min. Should be relaxed Should be informed on tests

During testDuring test

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Recommended order of testsRecommended order of tests

Dynamic studies: spirometry, flow volume loop, PEF Static lung volumes Diffusing capacity Bronchodilator test

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In spirometry;

First step is maximum inspiration

Second step is maksimum forced expiration

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Acceptability criteriasAcceptability criteriasATS/ERS Task Force 2005ATS/ERS Task Force 2005

No artefacts on spirogram: Should not cough Should not close glottis within 1s of

exhalation Should not terminate test early Should not perform variable effort Should not leak from mouthpiece Should not close of openness by mouthpiece

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Extrapolation volume

Start of test must be rapidStart of test must be rapid

1

2

3

4

1 2 3 40

BACK EXTRAPOLATION

ZERO TIME (EV)

EXTRAPOLATED VOLUME

MAXIMAL INSPIRATORY

LEVEL

TIME, s

VO

LU

ME

, L

Ekstrapolation volume must be < 5% of FVC or 0.150 LA pause of < 1s at TLC after inspirium

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Exhalation:Exhalation: Exhalation time must be 6s and/or a plateau must be

seen in volume time curve The patient cannot continue further exhalation

No change in volume for 1 s at the end of exhalation

Time could be prolonged in patients with obstruction or older subjects

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End of test criteria End of test criteria

Quality control of test Quality control of test

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Volume –time display Flow- volume display

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Acceptable SpirogramAcceptable Spirogram

Volume-TimeVolume-Time Flow-VolumeFlow-Volume

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Cough in 1secondCough in 1second

Volume-Time Flow-Volume

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Glottic closureGlottic closure

Volume-Time Flow-Volume

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Variable effortVariable effortEarly terminationEarly termination

Volume-Time Flow-Volume

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Air leakAir leak

Volume-Time Flow-Volume

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Three acceptable spirograms The largest values of FVC must be < 0.150 L of each other The largest values of FEV1 must be < 0.150 L For those with an FVC of ≤ 1 L both these values are

0.100LIf both of these criteria do not meet

Continue testing until Both criteria are met with acceptable spirograms A total 8 tests have been performed The patient cannot continue

Spirometry Acceptability CriteriasSpirometry Acceptability CriteriasATS/ERS Task Force 2005ATS/ERS Task Force 2005

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Test selectionTest selection

Three tests with acceptable start of test and free from artefact are selected and saved

The largest FVC and the largest FEV1 should be recorded and FEV1 /FVC should be calculated

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Test appropriate for the repeatability criteriasTest appropriate for the repeatability criterias

Flow-VolumeVolume-Time

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TEKRARLANABİLİRLİK

Volume-Time Flow-Volume

Tekrarlanabilirlik Kriterine Uygun Olmayan TestTekrarlanabilirlik Kriterine Uygun Olmayan TestTest not appropriate for the repeatability criteriasTest not appropriate for the repeatability criterias

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StandardisationStandardisation

Interpret

FVC Maneuver

Met within acceptability criteria?

3 acceptability manoeuvers?

Met between repeatibilty criteria?

Determine the largest FVC and largest FEV1

Select maneouvre with largest FVC+ FEV1

Yes

Yes

Yes

No

No

No

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Equipment performance criteria

Equipment validation

Quality control

Perform maneuver

Measurement procedures

Acceptability

Repeatability

Reference value/ interpretation

Clinical assessment

Quality assessment Feedback to technician

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