spirometry
DESCRIPTION
how to prepare, do, interpret spirometry testTRANSCRIPT
![Page 1: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/1.jpg)
1
Dr. Maha YousifDr. Maha Yousif
Assist. Lecturer of Chest Diseases Minufiya University, Egypt
E-mail: [email protected]
Oct. 2008
Basics of spirometryBasics of spirometry
![Page 2: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/2.jpg)
2
![Page 3: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/3.jpg)
3
Contraindications to spirometry
• No absolute contraindications.• FVC manoeuvre raise intra-cranial, intra-thoracic and intra-
abdominal pressures so, Relative contraindications may be:
◆ Recent eye, thoracic or abdominal surgery ◆ Recent myocardial infarction, uncontrolled hypertension or pulmonary
embolism ◆ Recent cerebrovascular haemorrhage or known cerebral or
abdominal aneurysm ◆ Pneumothorax ◆ Haemoptysis of unknown origin (FVC maneuver may aggravate
underlying condition.) ◆ Acute disorders affecting test performance (e.g. vomiting, nausea,
vertigo)
![Page 4: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/4.jpg)
4
Patient preparation
Before the test ◘ Avoid: • Acohol 4h • Large meal 2h• Smoking 1h• Vigorous exercise 30min
◘ Wear loose , comfortable clothing.
◘ relaxed, and have time to visit the toilet.
![Page 5: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/5.jpg)
5
• For bronchodilator reversibility testing withhold bronchodilators prior to the test:
◘ Short-acting inhaled β2 agonists for 2–4h.
◘ Short-acting inhaled anticholinergics for 4–6 h.
◘ Long-acting inhaled or oral β2 agonists for 12–24 h
◘ Long-acting inhaled anticholinergics for 24–36 h.
◘ Theophyllines for 12 h.
◘ Sustained release theophyllines for 24 h.
![Page 6: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/6.jpg)
6
Calibration
• To ensure accurate recording of the tested lung volumes.
• Daily routine.• A spirometer that is transported from one location to
another and exposed to changes in temperature should be re-calibration before use.
![Page 7: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/7.jpg)
7
Performing the test
• Explain the procedure.• Check any contraindications,complied instructions as
withholding bronchodilators, not smoking,……• Accurately measure height, standing (without shoes)• If patients are unable to stand, or have a severe spinal
deformity such as a scoliosis, height can be estimated by measuring arm span.
• Enter the patient data to the software.N.B: 1. False teeth, unless they are very ill-fitting and loose, should be left in.2. Record any deviations from the ideal so that subsequent tests can
be carried out under the same conditions
![Page 8: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/8.jpg)
8
Correct position of head and body
• Seating Position:(The standing position is not advised), The test position should be noted on the report.
• Upright position:
• Position of the head :upright or slightly leaned back. (If the neck is flexed forward the upper airways are narrowing.
• No leaning forward during the test.
![Page 9: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/9.jpg)
9
Slow expiratory vital capacity( SVC,EVC).
Should be tested before any forced maneuvres
SVC Maneuvre• 1) Breath normally (Facultative)• 2) Execute a maximal slow inspiration• 3) Execute a maximal slow expiration• 4) Breath at rest
Wait a minute or so before attempting another recording
![Page 10: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/10.jpg)
10
Slow Vital Capacity (SVC)
Main parameters measured are:• EVC: Slow expiratory vital capacity( SVC).• IVC : Inspiratory Vital cpacity• ERV: Expiratory reserve volume• IRV: Inspiratory reserve volumeOthers are: • VE: Expired Volume per minute• Vt : Tidal Volume• Rf: Respiratory Frequency• Ttot: Duration of a complete respiratory cycle• Ti/Ttot, Vt/Ti
![Page 11: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/11.jpg)
11
Forced Vital Capacity
FVC Manoeuvre• 1) Breath normally (Facultative)• 2) Execute a Forced Maximal inspiration• 3) Execute a Forced maximal expiration• 4) Execute a maximal inspiration (Facultative)• 5) Breath at restWait at least 1 minute before attempting another recordingN.BNormally, the SVC and FVC are nearly equal. But in airway
obstruction SVC > FVC.
![Page 12: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/12.jpg)
12
Forced Vital Capacity
The Main Measured Parameters are:• FVC Forced Expiratory Vital Capacity.• FEV1 Forced Expired Volume after one second.• FEV1/FVC% Percentage of FEV1 against the FVC.• PEF Expiratory Peak flow.• MEF 25-75% (FEF 25-75% )Mean Forced expiratory
flow.The representative graphs are:• The flow-volume curve (loop).• The volume-time curve.
![Page 13: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/13.jpg)
13
Flow / volume curve Volume / time curve
![Page 14: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/14.jpg)
14
The volume/time curve
• A normal volume/time curve has a typical shape. There is a rapid rise to the trace as three-quarters of the air is expired in the first second
• The trace plateaus between 4 and 6 seconds
![Page 15: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/15.jpg)
15
A normal flow/volume curve has a typical shape
◘ Rises almost vertically to PEF
◘ The trace merges smoothly with the horizontal axis of the graph at FVC
The flow/volume curve
![Page 16: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/16.jpg)
16
Mid-expiratory flow rates (MEF25, MEF50, MEF75)
• MEF25: ‘The maximum flow achievable when 75% of the FVC has been expired’ (when 25% of the FVC remains in the lungs).
MEF75: refers to the maximum flow achievable when 75% of the FVC remains in the lungs and the MEF50 is the maximum flow rate achievable when the lungs are half-empty
• a sign of early airflow obstruction (small airway disease).
• Some spirometers use the equivalent of MEF: the forced expiratory flow (FEF25, FEF50 and FEF75).
![Page 17: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/17.jpg)
17
• Peak expiratory flow: the highest flow achieved from a maximal forced expiratory manoeuvre started without hesitation from a position of maximal lung inflation’
• occurs very early in a forced expiration – within the first tenth of a second
• airflow from the larger airways
![Page 18: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/18.jpg)
18
Common errors
Coughing
![Page 19: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/19.jpg)
19
• Failure to expire to FVC: The volume/time trace will fail to plateau
The flow/volume trace will not merge with the horizontal axis and will ‘drop off’
![Page 20: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/20.jpg)
20
• Slow start to the forced expiratory manoeuvre:• Will give an ‘S’ shape to the start of the volume/time trace,
The flow/volume trace will have a sloping, rather than vertical start
![Page 21: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/21.jpg)
21
• Air leak:
The volume/time trace will ‘dip’ downwards, rather than rise steadily to a plateau
![Page 22: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/22.jpg)
22
![Page 23: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/23.jpg)
23
Technical acceptability
• Maximum effort for the forced manoeuvre• Immediate exhalation from the position of maximal
inspiration• No coughing• Complete exhalation.• Traces are smooth and free of irregularity• The volume/time trace should plateau for at least 1
second and there should not be an ‘S’ shape to the beginning of the trace
![Page 24: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/24.jpg)
24
• The flow/volume trace should rise almost vertically to a peak and the trace should merge smoothly with the horizontal axis at the end of the blow
• At least three technically acceptable manoeuvres should be obtained, ideally with less than 0.2 L (5%) variability for FEV1 (and FVC) between the highest and second highest result. Quote the largest value.
• If the difference is > 5% this means Sub-maximal effort. (repeat the test)
• Reductions in PEF and FEV1 have been shown when inspiration is slow and/or there is a 4–6 s pause at total lung capacity (TLC) before beginning exhalation
![Page 25: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/25.jpg)
25
![Page 26: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/26.jpg)
26
Spirometry interpretation
• Spirometry parameters are considered to be within the normal range if:
• The FEV1, FVC and VC are between 80% and 120% of the reference value for someone of that age, gender, height and ethnic group
• The FEV1/FVC is about 75% (0.75) or over 80% of the reference value for someone of that age, gender, height and ethnic group
![Page 27: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/27.jpg)
27
Obstructive abnormality
• Spirometry parameters compatible with airflow obstruction are:
◘ A reduced FEV1/FVC, or FEV1/VC. Values of less than 70% and/or less than 80% of the reference value
◘ An FEV1 of less than 80% of the reference valueN.B: When the slow vital capacity is higher than the FVC,
the FEV1/VC should be calculated◘ Once the diagnosis of obstructive abnormality is made,
comment on: Severity of obstruction. Reversibility of obstruction
![Page 28: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/28.jpg)
28
Severity of obstruction
• The severity of reductions in the FEV1% pred can be characterized by the following scheme:
![Page 29: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/29.jpg)
29
Reversibility test
• Response to β agonist is assessed after 10-15 min after inhalation of (100 mcg each, 400 mcg total dose) albuterol administered through a valved spacer device. When concern about tremor or heart rate exists, lower doses may be used. Response to an anticholinergic drug may be assessed 30 minutes after 4 inhalations (40 mcg each, 160 mcg total dose) of ipratropium bromide.
![Page 30: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/30.jpg)
30
Reversibility test
• FVC before and after bronchodilator
![Page 31: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/31.jpg)
31
Restrictive abnormality
• Spirometry parameters compatible with a restrictive abnormality are:
◘ An FEV1, FVC and VC reduced to less than 80% of their reference value
◘ A normal or high FEV1/FVC, or FEV1/VC (about 75%). The FEV1/FVC will be over 80% of the reference value
◘ The severity of restriction is based on the degree of reduction in FVC % Pred.the same classification as obstructive abnormality.
![Page 32: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/32.jpg)
32
Mixed abnormality
• Reduced FVC & a low FEV1/FVC% ratio.• Means: a combination of both obstruction and
restriction, or airflow obstruction with gas trapping. It is necessary to measure the patient's total lung capacity to distinguish between these two possibilities.
![Page 33: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/33.jpg)
33
![Page 34: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/34.jpg)
34
![Page 35: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/35.jpg)
35
![Page 36: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/36.jpg)
36
Examples of lesions of the major airway detected with the flow-volume loop
1. Variable extrathoracic lesions ◘ Vocal cord paralysis
◘ Subglottic stenosis ◘ Hypopharyngeal or tracheal tumour
◘ Goiter
2. Variable intrathoracic lesions ◘ Tumor of lower trachea (below sternal notch) ◘ Tracheomalacia ◘ Strictures ◘ Wegener's granulomatosis or relapsing polychondritis
3. Fixed lesions ◘ Fixed neoplasm in central airway (at any level) ◘ Vocal cord paralysis with fixed stenosis ◘ Fibrotic stricture
![Page 37: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/37.jpg)
37
Maximum Voluntary Ventilation (MVV)
• Normally, the MVV is approximately = FEV1×40. If the FEV1 is 3.0 L, the MVV should be approximately 120 L/min.
• MVV/(40×FEV1)< 0.80 indicates that the MVV is low relative to the FEV1, means:
◘ a major airway obstruction◘ neuromuscular diseases (amyotrophic lateral sclerosis,
myasthenia gravis, polymyositis).◘ Poor patient performance due to weakness, lack of
coordination,◘ the subject is massively obese? The MVV tends to
decrease before the FEV1 does.
![Page 38: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/38.jpg)
38
Maximum Voluntary Ventilation (MVV)
MVV Manoeuvre• Breath in and out deeply and rapidly for 12 second.
![Page 39: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/39.jpg)
39
Obstructive abnormality: very severe, Restrictive abnormality: moderate (mixed).
![Page 40: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/40.jpg)
40
Obstructive abnormality: very severe, Restrictive abnormality: severe (mixed).
![Page 41: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/41.jpg)
41
Obstructive abnormality: severe, Restrictive abnormality: mild (mixed).
![Page 42: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/42.jpg)
42Moderate restrictive abnormality
![Page 43: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/43.jpg)
43Normal spirometry
![Page 44: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/44.jpg)
44Mild restrictive abnormality
![Page 45: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/45.jpg)
45Restrictive abnormality: moderatey severe
![Page 46: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/46.jpg)
46Obstructive abnormality: moderately severe.
![Page 47: Spirometry](https://reader036.vdocuments.us/reader036/viewer/2022081413/547157c2b4af9f36648b4595/html5/thumbnails/47.jpg)
The EndThe End