Spirometry Overview
Transcript of Spirometry Overview
![Page 1: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/1.jpg)
Spirometry OverviewSpirometry Overview
Thomas B Casale, MDProfessor and Chief, Allergy/Immunology
Creighton UniversityOmaha, NE
USA
![Page 2: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/2.jpg)
Faculty Disclosure
• I have no financial interests/arrangements that would be considered a conflict of interest.
![Page 3: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/3.jpg)
Course Objectives
• To define what constitutes accurate and adequate spirometric assessment
• To discuss how spirometry performance and interpretation differ depending on age
• To review how pulmonary function assessment compares with other outcome measures in asthma
![Page 4: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/4.jpg)
Course Outline
![Page 5: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/5.jpg)
ATS/ERS TASK FORCE: STANDARDISATION OF LUNG FUNCTION TESTING
M.R. Miller, J. Hankinson, V. Brusasco, F. Burgos, et al. Standardisation of spirometry. Eur Respir J 2005; 26: 319–338
R. Pellegrino, G. Viegi, V. Brusasco, R.O. Crapo, et al. Interpretative strategies for lung function tests. Eur Respir J 2005; 26: 948–968.
![Page 6: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/6.jpg)
Indications For Spirometry
![Page 7: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/7.jpg)
Equipment Quality Control
![Page 8: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/8.jpg)
Closed Circuit Maneuver
![Page 9: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/9.jpg)
Spirometry Values
• FVC: Forced vital capacity: the volume of air that can be maximally forcefully exhaled.– FEV6 can be used as a measurement of FVC in adults
• FEV1: Forced expiratory volume in one second (best meas ure of assessing airway obstruction)
• FEV1/FVC: ratio expressed as a percentage (low values c /w obstructive lung disease)
• FEF25-75: The average forced expiratory flow during the mid (25 - 75%) portion of the FVC
• PEF: (FEFmax) Peak expiratory flow (liters/second) rate during expiration ( peak flow meter measurements are in L/min)
![Page 10: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/10.jpg)
Rep
rodu
cibi
lity
Crit
eria
![Page 11: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/11.jpg)
Application Of
Reproducibility And
AcceptabilityCriteria
![Page 12: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/12.jpg)
Percent Predicted Variables
• Gender: Males > Females• Age: Its downhill after 20-25• Height: The taller the Larger• Ethnicity Matters:
– Caucasians > Blacks and Indians > Chinese > Polynesians
![Page 13: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/13.jpg)
FEV1Plateau of lung function between the ages of 20 and 30then FEV1 falls approximately 20-30 mL per year.• Smokers lose about 60 mL per year
Men Women
![Page 14: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/14.jpg)
Spirometry
• Flow/volume curve
• Spirogram: Vol / time
![Page 15: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/15.jpg)
Spirogram
The normal volume time curve has a rapid upslope and approaches a plateau soon after exhalation. volume (FEV1).
Normally the volume exhaled in one second is approximately 80% of the total volume, while the volume after 3 seconds is equal to the FVC
![Page 16: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/16.jpg)
Flow Volume Loops
Flow is plotted against volume to display a continuous loop from inspiration to expiration.
The overall shape of the flow volume loop is important in interpreting spirometric results.
![Page 17: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/17.jpg)
Flow Volume loop
Effort Dependent
Effort Independent
![Page 18: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/18.jpg)
The Value Of FEV1 For Obstructive Lung Disease: Severity Classification
GOLD:
COPD
NIH: Asthma
![Page 19: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/19.jpg)
ATS/ERS Severity: FEV1
![Page 20: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/20.jpg)
Forced Vital Capacity (FVC)
• Full inspiration to TLC• Rapid, forceful maximum
expiration to RV• Effort dependent• Differs from Slow Vital Capacity
– Slow VC may be greater with obstruction
• Normal > 80%• Generally = FEV6
FVCFl
ow
Volume (liters)
![Page 21: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/21.jpg)
Younger Older
Normal Patterns: Age Matters
![Page 22: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/22.jpg)
FEV1/FVC
Sears M at al, N Engl J Med 2003;349:1414-22.
![Page 23: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/23.jpg)
FEV1/FVC
> 70 y/o healthy nonsmokers
Hardie JA at al, Eur Respir J 2002; 20: 1117–1122
![Page 24: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/24.jpg)
FEV1/FVC
NIH asthma guidelines 2007
![Page 25: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/25.jpg)
FEF 25-75%
• Mean forced expiratory flow rate between 25% and 75% of the expired vital capacity
• Rate of air flow during the middle of the test– “midflows” MMEF (maximum midexpiratory flow)
• Reflects air flow in the peripheral or small airway s– Less sensitive and specific– Largely effort independent
• Normal > 50%
![Page 26: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/26.jpg)
FEF 25-75
Abnormalities are “not specific for small airway disease and, though suggestive, should not be used to diagnose small airway disease in individual patients.”
Am Rev Respir Dis 1991; 144:1202-1218
![Page 27: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/27.jpg)
PEF
• Peak expiratory flow (L/sec)– Or FEFmax
• Measurement of FLOW not volume
• Effort dependent• Measured in L/sec• Handheld peak flow meter
measured in L/min: PEFR
Peak Expiratory Flow
Flow
Volume (liters)
![Page 28: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/28.jpg)
Spirometry should be interpreted using the flow volume and volume time curves as well as the absolute values for flows and volumes.
Interpretation
![Page 29: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/29.jpg)
Normal
Flow Volume Loop Normal Patterns
Normal Varient“knee”
![Page 30: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/30.jpg)
Obstructive pattern
![Page 31: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/31.jpg)
Shape of flow volume loop is relatively unaffected in restrictive disease:
• overall size of the curve will appear smaller when compared to normals.
• rapid upslope on the volume time curve, but such patients will reach a smaller vital capacity.
Restrictive lung disease cannot be diagnosed by spirometry alone.
Restrictive Disease
![Page 32: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/32.jpg)
Obstructive RestrictiveFVC normal FEV1
FEV1/FVC %FEF 25-75 normalFRC normalRV normalTLC normal
Obstructive vs Restrictive
![Page 33: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/33.jpg)
Reversibility: ATS/ERS Task Force
• Four separate doses of 100 mcg should be used when given by MDI using a spacer. Tests should be repeat ed after a 15-min delay
• An increase in FEV1 and/or FVC ≥ 12% of control and ≥200 mL constitutes “+” bronchodilator response
• Increments of <8% (or <150 mL) are likely to be wit hin measurement variability
![Page 34: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/34.jpg)
Unacceptable Patterns/ Maneuvers
Slow start
Did not exert maximal effort
May be lack of effort but may be normal if reproducible in young females
Called “rainbow curve”
![Page 35: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/35.jpg)
Unacceptable Patterns / Maneuvers
Effort ended earlyFalsely decreases FVCFalsely increases FEF 25-75
Stopped exhaling momentarily
![Page 36: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/36.jpg)
Flow Volume Loop Patterns
Coughing
“Sawtooth” patternUpper airway muscle
weakness, Classic for OSA
![Page 37: Spirometry Overview](https://reader034.fdocuments.in/reader034/viewer/2022051319/588729821a28ab11338c3992/html5/thumbnails/37.jpg)
Office spirometry
“When office spirometry shows severe abnormalities, or if questions arise regarding test accuracy or interpretation, further assessment should be performed in a specialized pulmonary function laboratory.”