Interpreting Spirometry: Patient or Data ?
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Transcript of Interpreting Spirometry: Patient or Data ?
Interpreting Spirometry:Patient or Data?
David Robiony-Rogers CRFS
Service Leader Respiratory MedicineCapital & Coast District Health Board
Spirometry
Spirometry is the timed measurement of dynamic lung volumes during forced expiration and inspiration, and is used to quantify how effectively and how quickly the lungs can be emptied.
Spirometry Interpretation
Acceptability
* minimum of 3 acceptable manoeuvres* good start and satisfactory effort* no artefacts induced by coughing or glottic
closure in 1st second, or equipment problems* minimum of 6 seconds exhalation and/or plateau
in the volume time curve* Maximal inspiration prior to blow
Artefacts
a) No artefactb) Cough within 1st second of forced exhalationc) Incomplete exhalation/early termination (glottic
closure)d) Slow start/submaximal forced effort at start of blowe) Hesitant start
Reproducibility
Reproducibility
* two largest FVC within 0.150 L (150ml) of each other
* two largest FEV1 within 0.150 L (150ml) of each other
* must meet criteria for acceptability
If the reproducibility criteria is not met after a total of 8 tests, stop testing.
Disease Patterns
Obstructive patternA disproportionate reduction of maximal airflow from the lung in relation to the maximal volume
Restrictive patternCharacterised by a normal FEV1/VC ratio and reduction in FVC below the 5th percentile of the predicted
Mixed patternCharacterised by the coexistence of obstruction and restriction, and is defined physiologically when both FEV1/FVC and FVC are below 5th percentiles of the predicted value
Spirometric overlap between Asthma and COPD
* COPD has been described as a disease characterized by fixed airflow obstruction because in many patients FEV1 values improve little after bronchodilator challenge.
* Current guidelines on diagnosis and management describe COPD as a condition that is partially reversible because some patients exhibit substantial improvements in FEV1 (despite an FEV1-FVC ratio that remains below 0.70) that compares in magnitude to what is observed in some asthma patients.
* Tashkin et al (2008) have shown that about 54% of a large COPD cohort (N = 5756) exhibited an improvement in FEV1 values > 12% and 200 mL, while about 65% of patients had FEV1 increases > 15%.
* This substantial overlap in FEV1 reversibility between asthma and COPD underscores an important limitation of using this measurement to distinguish between asthma and COPD.
Can Fam Physician. Oct 2011; 57(10): 1148–1152.
Disease Patterns
The presence and site of disease have various effects on the volume-time and maximal expiratory flow volume
curveVitalograph Ltd 1986 &2000
Normal Ventilatory Function
The pattern of the lung and spirogram show a pattern of normality
Vitalograph Ltd 1986 &2000
Age: 22, Gender: Female; Height: 166 cm, Weight: 69.3 kg;
BMI: 25.15
Spirometry measure
Best Reference Ref ± CI
FVC, L 3.63 3.95 3.2 – 4.7
FEV1, L 3.02 3.43 2.8 – 4.0
FEV1/FVC, % 83 76.3 – 95.9
Age: 23; Gender: Male; Height: 175 cm; Weight: 67.6 kg; BMI: 22.07
Spirometry measure
Best Reference Ref ± CI
FVC, L 5.49 5.39 4.5 – 6.3
FEV1, L 4.29 4.48 3.7 – 5.2
FEV1/FVC, % 78 73.6 – 93.0
Reversible Obstruction
The lungs and spirogram show a pattern of airway obstruction (black), with the spirogram showing a marked improvement after the administration of a
bronchodilator (red) Vitalograph Ltd 1986 &2000
Age: 75; Gender: Male; Height: 175 cm; Weight: 97.2 kg; BMI: 31.74
Spirometry measure
Best Reference Ref ± CI
FVC, L 3.28 4.09 3.2 – 5.0
FEV1, L 2.07 2.97 2.2 – 3.7
FEV1/FVC, % 63 63.1 – 82.5
Age: 29; Gender: Female; Height: 162 cm; Weight: 98.6 kg; BMI: 37.57
Spirometry measure
Pre bronchodilator
best
Post bronchodilator
best% improvement Reference Ref ± CI
FVC, L 2.22 3.51 58 3.75 3.1 – 4.4
FEV1, L 1.49 2.68 80 3.18 2.6 – 3.8
FEV1/FVC, % 67 76 74.9 – 94.4
Irreversible Obstruction
The lungs and spirogram show a pattern of airflow obstruction, with the spirogram showing little or no
improvement after the administration of a bronchodilatorVitalograph Ltd 1986 &2000
Age: 74; Gender: Female; Height: 161 cm; Weight: 70.9 kg; BMI: 27.35
Spirometry measure
Pre bronchodilator
best
Post bronchodilator
best% improvement Reference Ref ± CI
FVC, L 1.46 1.72 18 2.78 2.1 – 3.5
FEV1, L 0.57 0.53 -7 2.08 1.5 – 2.7
FEV1/FVC, % 39 31 65.3 – 84.9
FEV6, L 1.42 1.51 6 2.64 2.0 – 3.3
Restrictive Defect
The lung and spirogram show a pattern of volume restriction
Vitalograph Ltd 1986 &2000
Age: 74; Gender: Male; Height: 160 cm; Weight: 82.3 kg; BMI: 32.15
Spirometry measure
Best Reference Ref ± CI
FVC, L 2.01 3.15 2.4 – 3.9
FEV1, L 1.53 2.26 1.6 – 2.9
FEV1/FVC, % 76 63.1 – 82.5
Combined Pattern
The lungs and spirogram show a pattern of combined airflow obstruction and volume restriction
Vitalograph Ltd 1986 &2000
Spirometry measure
Best Reference Ref ± CI
FVC, L 2.83 4.02 3.2 – 4.9
FEV1, L 0.94 2.96 2.2 – 3.7
FEV1/FVC, % 33 64.1 – 83.5
Age: 69; Gender: Male; Height: 171 cm; Weight: 50.9 kg; BMI: 17.41
Age: 35; Gender: Male; Height: 168 cm; Weight: 90.6 kg; BMI: 32.10
Spirometry measure
Best Reference Ref ± CI
FVC, L 2.52 4.76 3.9 – 5.6
FEV1, L 1.69 3.87 3.2 – 4.6
FEV1/FVC, % 67 71.2 – 90.5
Response to ß2-agonist
ß2-agonist bronchodilator
* Dose: 4 puffs of ß2-agonist delivered through a spacer device
* Wait 15-20 minutes before repeating spirometry* Significant response defined as >12% and more
than 200mL increase in either the FEV1 or FVC.
Severity classification
Degree of severity FEV1 % predicted
Mild >70
Moderate 60-69
Moderately severe 50-59
Severe 35-49
Very severe <35
Severity of any spirometric abnormality based on the forced expiratory volume in one second (FEV1)
ATS/ERS Task Force: Standardisation of lung function testing. Interpretative strategies for lung function tests. Eur Respir J 2005; 26: 948
Spirometry interpretation algorithm: Primary Care Respiratory Alliance of Canada
Asthma vs COPD (history)
Consistent with asthma
Consistent with asthma
Refer to specialist
FEV1, 12% and 200mL
FEV1, 12% and 200mL
FEV1, 12% and 200mL
Restrictive disorder
Reduced < LLN Normal (not COPD) FVC ≥ 80% predicted FEV1 and FVC
ß2-agonist ß2-agonist
Reduced < LLN Normal > LLN
Pre ß2-agonist FEV1/FVC ratio
Modified from Primary Health Care Alliance of Canada spirometry interpretation
algorithm 2011
Age: 58; Gender: Female; Height: 156 cm; Weight: 61.1 kg; BMI: 25.11
Spirometry measure
Best Reference Ref ± CI
FVC, L 1.47 2.08 1.4 – 2.7
FEV1, L 0.99 1.52 1.0 – 2.1
FEV1/FVC, % 67 63.0 – 82.5
Age: 68; Gender: Female; Height: 170 cm; Weight: 70.0 kg; BMI: 24.22
Spirometry measure
Best Reference Ref ± CI
FVC, L 2.90 3.43 2.7 – 4.2
FEV1, L 2.04 2.61 2.0 – 3.3
FEV1/FVC, % 70 66.6 – 86.2
Age: 35; Gender: Male; Height: 168 cm; Weight: 90.6 kg; BMI: 32.10
Spirometry measure
Best Reference Ref ± CI
FVC, L 2.52 4.76 3.9 – 5.6
FEV1, L 1.69 3.87 3.2 – 4.6
FEV1/FVC, % 67 71.2 – 90.5
Age: 50; Gender: Female; Height: 164 cm; Weight: 109.2 kg; BMI: 40.60
Spirometry measure
Best Reference Ref ± CI
FVC, L 3.16 3.61 2.9 – 4.3
FEV1, L 2.35 2.86 2.3 – 3.5
FEV1/FVC, % 74 70.4 – 90.0
Age: 64; Gender: Male; Height: 162 cm; Weight: 60.5 kg; BMI: 23.05
Spirometry measure
Best Reference Ref ± CI
FVC, L 3.34 3.64 2.9 – 4.4
FEV1, L 2.58 2.72 2.1 – 3.4
FEV1/FVC, % 77 65.2 – 84.5
Age: 70; Gender: Female; Height: 153 cm; Weight: 127.9 kg; BMI: 54.64
Spirometry measure
Best Reference Ref ± CI
FVC, L 1.91 2.55 1.9 – 3.2
FEV1, L 1.59 1.92 1.4 – 2.4
FEV1/FVC, % 83 66.1 – 85.7
Age: 70; Gender: Female; Height: 144 cm; Weight: 81.8 kg; BMI: 39.45
Spirometry measure
Best Reference Ref ± CI
FVC, L 2.05 2.15 1.6 – 2.7
FEV1, L 1.75 1.61 1.2 – 2.1
FEV1/FVC, % 85 66.1 – 85.7
Age: 52; Gender: Female; Height: 161 cm; Weight: 50.8 kg; BMI: 19.60
Spirometry measure
Best Reference Ref ± CI
FVC, L 3.84 3.42 2.7 – 4.1
FEV1, L 2.72 2.70 2.1 – 3.3
FEV1/FVC, % 71 70.0 – 89.6
Age: 39; Gender: Female; Height: 157 cm; Weight: 100.1 kg; BMI: 40.61
Spirometry measure
Best Reference Ref ± CI
FVC, L 3.09 3.44 2.8 – 4.1
FEV1, L 1.75 2.83 2.3 – 3.4
FEV1/FVC, % 56 72.7 – 92.3
Age: 67; Gender: Female; Height: 157 cm; Weight: 67.7 kg; BMI: 27.47
Spirometry measure
Best Reference Ref ± CI
FVC, L 2.67 2.83 2.2 – 3.5
FEV1, L 1.80 2.15 1.6 – 2.7
FEV1/FVC, % 67 66.8 – 86.4
https://www.youtube.com/watch?v=yNDKD_xI684
Spirometry Education
Pulmonary Function Tests (PFT): Lesson 2 - SpirometryPublished on Feb 3, 2014A discussion of FEV1, FVC, FEV1/FVC ratio, and the flow volume loop, including how these are used in the diagnosis of various lung diseases, with a particular focus on the distinction between obstructive and restrictive lung disease. A summary of flow volume loop patterns in upper airway obstruction is covered as well.