SpirometrySpirometryStudy DayStudy Day

2323rdrd September 2010 September 2010

Robert DawRobert Daw

Clinical Lead Nurse for COPDClinical Lead Nurse for COPD

BACHSBACHS

‘….airflow obstruction is usually progressive, not fully reversible and

does not change markedly over several months. The disease is

predominantly caused by smoking.’

NICE 2004

‘….in susceptible individuals, inflammatory symptoms are usually

associated with widespread but variable airflow obstruction and an increase in airway response to a variety of stimuli. Obstruction is

often reversible, either spontaneously or with treatment.’

BTS and SIGN 2003

Spirometry is a method of assessing lung function by measuring the volume of air the patient is able to expel out from the lungs after maximal inspiration

Spirometry is a reliable method of identifying Obstructive illness i.e. chronic

obstructive pulmonary disease Reversible disease I.e. Asthma Restrictive disease i.e. Pulmonary fibrosis

It can be used to grade the severity of COPD

Diagnosing COPD

At the time of their initial diagnostic evaluation in addition to spirometry all patients should have:

CXR FBC BMI

Additional Investigations

CT ScanECGEchoPulse OximetrySputum CultureTransfer factor for carbon monoxide

(TLCO)Serial Domiciliary Peak FlowsAlpha-1-antitrypsin

FEV1 The volume of air that the patient is able to breathe out in the first second of forced expiration

FVC The total volume of air that the patient can exhale forcibly in one breathe

FEV1 / FVC The ratio is expressed as a percentageALSO

Peak Flow The volume of air that the patient is able to breathe out in the first 1000th of a second of forced expiration

Cooper B, 2005

Performing spirometry with no training were of poor standard when compared to labs

Machines not being compared cared for or calibrated

Minimum standards of acceptancePoor Interpretation

VerificationThis is to check that the spirometer

is reading correctly using a known standard.

CalibrationCalibration is the process in which

the signal from a spirometer is adjusted to produce a known output.

If equipment is not properly calibrated it can lead to false results – i.e. the patient may appear better or worse than they really are.

This depends on the equipment. Most pneumotach based equipment needs calibrating every day. Some equipment can only be calibrated by a trained engineer. In this case it is necessary to perform regular quality control / verification.

Syringe This can be performed using a 3 litre syringe or 1

litre syringe depending on spirometer model. Results should be within 3% of calibration syringeBiological Control The person performing the quality control should

have normal lung function. Results should not vary by more than 10% from

the last time. Equipment should be calibrated if this is not the

case.

Spirometers are a potential source of cross infection for patients.

As a minimum one way cardboard mouthpieces should be used.

Ideally (especially in high TB areas) bacterial filters are the mouthpiece of choice.

Ease of cleaning the equipment should be considered when purchasing

Always use manufacturer guidelines.

FLOW HEADS SHOULD BE CLEANED USING MANUFACTUROURS

GUIDELINES AFTER EVERY SESSION IF NOT USING BACTERIAL FILTERS

The patient, ideally, should – - Avoid alcohol for at least 4 hours- Avoid eating a substantial meal- Wear loose fitting clothing

If Reversibility is to be performed -- Avoid taking short acting bronchodilators for at least 4 hours prior to testing- Avoid smoking for 1 hour prior to testing-Be Well!!

Haemoptysis of unknown originPneumothorax (Need confirmation of

resolution)Unstable cardiovascular statusMyocardial Infarction (Last 3 months)Thoracic, abdominal or cerebral

aneurysms

Recent Eye surgery (3 months)Recent thoracic or abdominal

surgery (3 months)Pregnancy (1st Trimester

contraindicated but in 2nd and 3rd Trimester results may be effected by uterus size)

Gain verbal consent Check for contraindications and that the patient

has been properly prepared for the test Gain an accurate height Make note of Ethnic Origin and Age The room should be a comfortable temperature The patient should be sat in a hard backed chair

with their feet able to touch the floor The patient should sit upright with their legs

uncrossed A drink of water should be made available The technique and purpose of spirometry should be

explained in full prior to the test Spirometry should be performed in the patients

own time and they should not feel hurried

Reinforce and Reassure

Performed due to collapsing alveoli in some patients during Forced Vital Capacity technique

This technique would usually be performed before the Forced Vital Capacity readings

The reading is sometimes referred to as VC, EVC or RVC

Minimum of three readings takenTwo best results should be within 150mls

of each otherMaximum of 4 tests

Take as large a breath of air in as possible

Pinch your nose or attach a nose clip to prevent air leakage

Put the filter into your mouth ensuring that there are no leaks at the sides of your mouth

Breathe out for as long as possible. This breath should be in your own time and should not be forced

A minimum of three readings should be taken There should be less than 5% or 150mls

variance between the best two results The technique should be repeated until this is

achieved or the patient is exhausted and can no longer perform the technique

Time should be given to the patient to recover between readings

Take as large a breath of air in as possible

Put the filter into your mouth ensuring there are no leaks at the side of your mouth

Pinch your nose or attach a nose clip to prevent air leakage

‘Blast’ as quickly as possible and for as long as possible

Could we have a volunteer please ?

Volume Time The vertical scale

indicates total volume (l) the patient has blown out

The horizontal scale indicates the total time (s) the patient has been blowing out for

Note the initial part of the curve which is steep followed by a gradual flattening of the curve

Flow Volume Loop The vertical scale

indicates litres of air breathed out per second (L/s) at that moment in time

The horizontal scale indicates total volume expired (L)

Note the sharp peak at the beginning of the curve followed by an initially sharp trough that gradually flattens out

Cough

This curve suggests the patient has coughed during a FVC reading

Note the peaks and troughs that occur throughout the curve

This will effect the FVC reading

Poor Effort

This curve suggests the patient has not blown as hard as they can during the FVC technique

Note the rounded top to the peak at the beginning of the curve

This will effect the FEV1 reading

Slow Start

This curve suggests the patient has started off blowing slowly during a FVC technique

Note the peak in L/s comes in the middle of the curve rather than at the beginning

This will effect the FEV1 reading

Inspiration

This curve indicates the patient has breathed in at the beginning of the technique

This usually occurs when the patient puts the filter in their mouth before they have finished breathing in

Note the negative L/s reading at the beginning of the curve

This could effect all readings

Inspiration

This curve suggests the patient has breathed in at the end of the FVC technique

This usually occurs when the patient attempts to take an extra breath in to prolong expiration

Note the negative L/s at the end of the curve

This could effect the FVC reading

BTS Guidelines Only

Ethnic Origin Correction Factor

Caucasian 100%

Afro-Caribbean Reduce by 13% (87%)

Asian Reduce by 7% (93%)

SPIROMETRY IN PRACTICEA PRACTICAL GUIDE TO USING SPIROMETRY IN PRIMARY CARE 2ND EditionBTS 2005http://www.brit-thoracic.org.uk/Portals/0/Clinical%20Information/COPD/COPD

%20Consortium/spirometry_in_practice051.pdf

GENERAL CONSIDERATIONS FOR LUNG FUNCTION TESTINGATS/ERS TASK FORCE: STANDARDISATION OF LUNG FUNCTION TESTINGEuropean Respiratory Journal 2005http://erj.ersjournals.com/cgi/reprint/26/1/153.pdf

STANDARDISATION OF SPIROMETRYATS/ERS TASK FORCE: STANDARDISATION OF LUNG FUNCTION TESTINGEuropean Respiratory Journal 2005http://www.thoracic.org/sections/publications/statements/pages/pfet/pft2.html

Use Best Test (Less than 5% Variance from next best)

Best Test – FVC, FEV1 or FVC & FEV1 If spirometer selects best test,

CHECKMinimum number of tests <3 Is Interpretation correct?

Curve shape – effort, cough, extra breath etc

Relaxed Expiratory Vital Capacity (EVC) recorded and used when better than FVC

Accurate heightCorrection Factors

FEV1 The volume of air that the patient is able to breathe out in the first second of forced expiration

FVC The total volume of air that the patient can exhale forcibly in one breathe

FEV1 / FVC The ratio is expressed as a percentage

Peak Flow The volume of air that the patient is able to breathe out in the first 1000th of a second of forced expiration

VITAL CAPACITYVC, RVC, EVC

FORCED VITAL CAPACITYForced vital capacity describes the techniqueFVC

RATIORatio, FER, FEV1%, FEV1/VC, FEV1/FVC

Done in 70’s Need modernising Use age, height and sex to make prediction

of ability Need to use correction factors for different

ethnic origins Accurate height essential These can be reported as

Percentage of Predicted Ranges Standard Residuals

BTS Guidelines Only

Ethnic Origin Correction Factor

Caucasian 100%

Afro-Caribbean Reduce by 13% (87%)

Asian Reduce by 7% (93%)

Done in 70’s Need modernising Use age, height and sex to make prediction

of ability Need to use correction factors for different

ethnic origins Accurate height essential These can be reported as

Percentage of Predicted Ranges Standard Residuals

Most frequently referred to value within the community

Need to be aware that this gives an absolute value and clearly there is variability within normality

Measured x 100 = % PredictedPredicted

Ceri 55 years old 155 cm tall

FEV1 measured:1.64 l x 100

FEV1 predicted: 2.15 l

FEV1 % predicted: 76%

FEV1 > 80% predicted

FVC > 80% predicted

FEV1 < 80% predicted

FVC > 80% predicted

Ratio <70%

CautionIf ratio is low but FEV1 and FVC are normal there is still obstruction present

COPDAsthmaBronchiectasisTumourForeign Body

NICE 2010

Consider alternative diagnoses in:

Older people without typical symptoms of COPD where the FEV1/FVC is <0.7

Younger people with symptoms of COPD where the FEV1/FVC ration is ≥ 0.7

FEV1 <80% predicted

FVC < 80% predicted

Ratio >70%

KyphoscoliosisMuscular Dystrophy ProblemsArthritisPleural Problems Interstitial Lung DiseaseObesityDrugs

FEV1 <80% predicted

FVC <80% predicted Ratio <70%

Severe COPDMultiple Pathology e.g.

Kyphscoliosis and COPD Tumour and COPD

Based on % Predicted of FEV1Good predictor of PrognosisPoor Predictor of Disability and

Quality of LifeCategories;

▪ BTS (1997)▪ GOLD (2001)▪ NICE (2004)▪ NICE (2010)

NICE Guideline (2004)

ATS/ERS (2004)

GOLD (2008)

NICE Guideline (2010)

Post-Bronchodilator FEV1/FVC

FEV1 % Predicted

Severity of Airflow Obstruction

Post -Bronchodilator

Post -Bronchodilator

Post -Bronchodilator

<0.7 ≥ 80% Mild Stage 1-Mild Stage 1-Mild*

<0.7 50-79% Mild Moderate Stage 2-Moderate

Stage 2-Moderate

<0.7 30-49% Moderate Severe Stage 3-Severe

Stage 3-Severe

<0.7 < 30% Severe Very Severe Stage 4-Very Severe**

Stage 4-Very Severe**

*Symptoms should be present to diagnose COPD with mild airflow obstruction

**or FEV1 <50% with respiratory failure

MRC scoreBODEModified BODEAOD

Grade

Degree of breathlessness related to activities

11 Not troubled by breathlessness except on strenuous Not troubled by breathlessness except on strenuous exerciseexercise

22 Short of breath when hurrying or walking up a slight hillShort of breath when hurrying or walking up a slight hill

33Walks slower than contemporaries on the level because of Walks slower than contemporaries on the level because of breathlessness, or has to stop for breath when walking at breathlessness, or has to stop for breath when walking at

own paceown pace

44 Stops for breath after walking about 100m or after a few Stops for breath after walking about 100m or after a few minutes on the levelminutes on the level

55 Too breathless to leave the house, or breathless when Too breathless to leave the house, or breathless when dressing or undressingdressing or undressing

Used to detect sudden deterioration in lung function

Should precipitate action if deterioration marked.

Normal deterioration in FEV1 thought to be 50ml/annum in none smoking

individual

AsthmaOr

COPD ?

‘….airflow obstruction is usually progressive, not fully reversible and

does not change markedly over several months. The disease is

predominantly caused by smoking.’

NICE 2004

‘….in susceptible individuals, inflammatory symptoms are usually

associated with widespread but variable airflow obstruction and an increase in airway response to a variety of stimuli. Obstruction is

often reversible, either spontaneously or with treatment.’

BTS and SIGN 2003

QOF 12 (2009/10) states that a diagnosis of COPD should be confirmed by recording post bronchodilator spirometry

Bronchodilator should be taken 15 minutes prior to spirometry being performed i.e. 4 puffs Salbutamol 100 MDI with

AeroChamber Salbutamol 2.5mg nebuliser

Why?

Post Bronchodilator recommended by GOLD and used in new trials e.g. UPLIFT

Removes conflict with many guidelines Decrease work load in primary care Failure to use post bronchodilator over

estimates COPD by 25%DOH 2009

Why Not Reversibility?

Repeated FEV1 measurements can show small spontaneous fluctuations

The results of a reversibility test performed on different occasions can be inconsistent and not reproducible

Over-reliance on a single reversibility test may be misleading unless the change in FEV1 is greater than 400 ml

The definition of the magnitude of a significant change is purely arbitrary

Response to long-term therapy is not predicted by acute reversibility testing. NICE 2010

COPD Asthma

Smoker or ex-smoker Nearly all Possibly

Symptoms under the age 35 Rare Often

Chronic Productive Cough Common Uncommon

BreathlessnessPresent and progressive

Variable

Night time waking with breathlessness and or wheeze

Uncommon Common

Significant diurnal or day to day variability of symptoms Uncommon Common

Cigarettes per Day x Years Smoked = 1 pack Year 20

e.g. 1 Pack Year = 20 cigarettes/day for 1 year or;10 cigarettes/day for 2 years40 cigarettes a day for 6 months

50g/2oz tobacco = 100 cigarettesCigars – Café Crème = 3 cigarettes

Hamlet = 5 cigarettes Corona = 8+ cigarettes

20 pack years is considered a significant factor for developing COPD

COPD Asthma

Smoker or ex-smoker Nearly all Possibly

Symptoms under the age 35 Rare Often

Chronic Productive Cough Common Uncommon

BreathlessnessPresent and progressive

Variable

Night time waking with breathlessness and or wheeze

Uncommon Common

Significant diurnal or day to day variability of symptoms Uncommon Common

Useful if diagnosis is not clear

Either;Measure peak flows for 14 days

morning and evening. Diurnal variation of greater than 20% indicates asthma

Record pre and post bronchodilator spirometry

Repeat Spirometry following one of the following (Post);

1. Salbutamol 100mcg MDI 4 puffs via spacer

2. Salbutamol 2.5mg nebuliser

Repeat Spirometry after 15-30 minutes

An FEV1 that increases by < 400mls is likely to have COPD

An FEV1 that increases by > 400mls is likely to have asthma

However if; FEV1 < 80% Ratio < 70% Post > 400mls Obstruction is not fully reversible

Billy FEV1 2.34 l FEV1 56% of predicted Ratio 40%

Given Salbutamol 2.5mg nebuliser and spirometry repeated after 30 minutes

POST FEV1 3.09 l FEV1 91% of predicted Ratio 71%

47 years oldSmoked 30 cigarettes a day

since he was 15 years oldPainter and decoratorRepeated chest infections every

yearFinding it difficult to climb

ladders and walk up steep hillsChronic Productive Cough

SPIROMETRY IN PRACTICEA PRACTICAL GUIDE TO USING SPIROMETRY IN PRIMARY CARE 2ND EditionBTS 2005http://www.brit-thoracic.org.uk/Portals/0/Clinical%20Information/COPD/COPD

%20Consortium/spirometry_in_practice051.pdf

GENERAL CONSIDERATIONS FOR LUNG FUNCTION TESTINGATS/ERS TASK FORCE: STANDARDISATION OF LUNG FUNCTION TESTINGEuropean Respiratory Journal 2005http://erj.ersjournals.com/cgi/reprint/26/1/153.pdf

STANDARDISATION OF SPIROMETRYATS/ERS TASK FORCE: STANDARDISATION OF LUNG FUNCTION TESTINGEuropean Respiratory Journal 2005http://www.thoracic.org/sections/publications/statements/pages/pfet/pft2.html

69 years old Has smoked 10 a day since the age of 21 Retired cleaner Frequent chest infections Frequent hospital admissions Oxygen at home House bound 10 metre exercise tolerance None productive cough

56 years old Unemployed. Varied previous employment 3 recent admissions to hospital with breathlessness Normally walks to shops with no problems Breathing problems for the last 3 years Smoked 20 a day since the age of 18 Currently sleeping on the sofa as can’t make it up

stairs Hospital measured spirometry on her last

admission. Fev1 0.51 litres or 22% of predicted Normally none productive cough currently coughing

up green sputum

35 years oldTeacher20 pack year history of smokingBreathless in the last 6 monthsBreathless on exertion and has

to stop if walking fastNone productive cough

75 year old retired chef Never smoked 4 hospital admissions in the last year

with breathlessness Home oxygen and nebulisers Breathless since being a baby with

repeated infections Often walks to shops half a mile away,

but when unwell unable to leave flat No cough

50 years old30 pack year history of smokingNever workedRecent frequent chest infectionsOccasional productive coughNo exertional breathlessnessOnly breathless with chest

infections

85 years oldRetired office worker80 pack year history of smoking

but gave up 6 months agoRegular rambler but finds himself

increasingly breathless on hills2 chest infections since giving up

smokingNo cough unless he has a chest

infection

56 years old 25 pack year history of smoking Works in dusty warehouses Breathless for last 3 years 2 recent A&E admissions but discharged as panic

attacks Maximum inhaled bronchodilator therapy for COPD Breathless around the house Breathlessness starts when he is coughing but not

sure of trigger for coughing None productive cough Lots of stress at home at present During summer was playing 18 holes of golf

75 years old 50 pack year history of smoking and still

smokes 10 a day Retired office worker None productive cough Walks everywhere and plays bowls when

well Breathless at rest and unable to leave the

house when unwell Frequent exacerbations though can never

bring anything up Audible wheeze at rest when unwell

77 years old 35 pack year history of smoking but ex smoker for

10 years Retired shop worker Breathless for the last 30 years since an acute

episode of pulmonary Sarcoidosis (Inflammatory Lung Disease) which left lung scarring

Breathlessness has got progressively worse in the last 5 years

Long Term Oxygen and nebulisers Breathless at rest even when well Productive cough at all times

72 years old None smoker Worked in wool mills as spinner for 5

years then a teacher Breathless for last 15 years Chronic Productive Cough Frequent exacerbations No hospital admissions 5 metre exercise tolerance Long term Oxygen and nebulisers Plays cards 7 times a week and goes to

the gym on a Friday

62 years oldBreathless for last yearBreathless on exertionExercise tolerance 200 metresNone smokerWorks in a shopNo chest infectionsNone productive cough