Clinical Application of
Pulmonary Function Tests
Gamal Rabie Agmy, MD, FCCP
Professor of Chest Diseases,Assiut University
...
Anatomy
 Lungs comprised of
 Airways
 Alveoli
http://www.aduk.org.uk/gfx/lungs.jpg
Weibel ER: Morphometry of the Human
Lung. Berlin and New York: Springer-
Verlag, 1963
The Airways
 Conducting zone: no
ga...
From Netter Atlas of Human Anatomy, 1989
How does gas exchange occur?
• Numerous capillaries are wrapped around
alveoli.
• Gas diffuses across this alveolar-capill...
Gas Exchange
From Netter
Atlas of
Human
Anatomy,
1989
The Alveoli
 Approximately 300
million alveoli
 1/3 mm diameter
 Total surface area if
they were complete
spheres 85 sq...
Mechanics of Breathing
 Inspiration
 Active process
 Expiration
 Quiet breathing: passive
 Can become active
Pulmonary Function Tests
 Airway function
 Simple spirometry
 Forced vital capacity
maneuver
 Maximal voluntary
ventil...
Pulmonary Function Tests
 Diffusing capacity
tests
 Blood gases and gas
exchange tests
 Blood gas analysis
 Pulse oxim...
Terminology
 Forced vital capacity
(FVC):
 Total volume of air that can
be exhaled forcefully from
TLC
 The majority of...
FVC
 Interpretation of % predicted:
 80-120% Normal
 70-79% Mild reduction
 50%-69% Moderate reduction
 <50% Severe r...
Terminology
 Forced expiratory volume
in 1 second: (FEV1)
 Volume of air forcefully
expired from full inflation
(TLC) in...
FEV1
 Interpretation of % predicted:
 > 80% Mild
 50-80% Moderate obstruction
 30-50% severe obstruction
 <30% Severe...
Terminology
 Forced expiratory flow 25-
75% (FEF25-75)
 Mean forced expiratory flow
during middle half of FVC
 Measured...
FEF25-75
 Interpretation of % predicted:
 >60% Normal
 40-60% Mild obstruction
 20-40% Moderate obstruction
 <20% Sev...
Acceptability Criteria
 Good start of test
 No coughing
 No variable flow
 No early termination
 Reproducibility
Acceptable and Unacceptable
Spirograms (from ATS, 1994)
Changes in Lung Volumes in
Various Disease States
RuppelGL. ManualofPulmonary Function Testing, 8th ed., Mosby 2003
TLC
 TLC < 80% of predicted value = restriction.
 TLC > 120% of predicted value =
hyperinflation.
1-First Step, Check quality of the
test
1- Start:
*Good start: Extrapolated volume (EV) <
5% of FVC or 0.15 L
*Poor start:...
2- Look at …………FEV1/FVC
< N(70%)
Obstructive or Mixed
≥ N(70%)
Restrictive or Normal
3- Look at FEV1 To detect degree
Mild...
4- Postbronchodilator FEV1/FVC
> 70%
asthma
< 70%
COPD
5- Reversibility test of FEV1
> 12%, 200 ml
Reversible (asthma)
< 12% ,200 ml
Ireversible (COPD)
6- Look at TLC
≥ 100% Pur...
2- Look at …………FEV1/FVC
< N(70%)
Obstructive or Mixed
≥ N(70%)
Restrictive or Normal
3- Look at FVC
≥ N(80%) < N(80%)
Norm...
Patterns of Abnormality
Restriction low FEV1 & FVC, high FEV1%FVC
Recorded Predicted SR %Pred
FEV 1 1.49 2.52 -2.0 59
FVC ...
Patterns of Abnormality
Upper AirwayObstruction low PEF relative to FEV1
Recorded Predicted SR %Pred
FEV 1 2.17 2.27 -0.3 ...
Common FVL Shapes
Volume
Flow
Normal Young or quitter Poor effort
Hesitation Knee Coughing
Asthma
0 1 2 3 4 5 6
0
2
4
6
8
10
12
FlowinL/s
Litres
concave FV curve
intrapulmonary airflow obstruction
Restrictive
0 1 2 3 4 5 6
-8
-6
-4
-2
0
2
4
6
8
10
12 F 19 yrs 1.64m
FVC 2.41 L -3.42 SR
FEV 2.41 L -2.62 SR
FEV% 100 +2.2...
COPD
0 1 2 3 4 5
-6
-4
-2
0
2
4
6
8
10
FlowinL/s
Litres
pressure dependent airways collapse
Poorly co-ordinated start
0 1 2 3 4 5 6
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
FlowinL/s
Litres
EV = large
Rise Time = 496 ms
Irr...
Upper Airway Obstruction
0 1 2 3 4 5 6
-6
-4
-2
0
2
4
6 Age 40 yrs
FVC 3.52 L 0.84 SR
FEV1
3.0 L 0.74 SR
PEF 4.57 L/s -2.1...
Upper Airway Obstruction
0 1 2 3 4 5 6
-6
-4
-2
0
2
4
6
8
10
12
FlowinL/s
Volume in Litres
Male aged 62 Height 1.68m
Recor...
Inspiration
-ve
-ve
Expiration
+ve
+ve
Extra-thoracic UAO
worse on insp.
Intra-thoracic UAO
worse on exp.
Variable UAO
Intra-thoracic UAO
0 1 2 3 4 5 6
-8
-6
-4
-2
0
2
4
6
8
10
12
FlowinL/s
Liters
Age 65 Female
FVC 2.97 L 1.3 SR
FEV1 2.26 L ...
Variable Extrathoracic Upper
Airway Obstruction
Fixed Upper Airway Obstruction
Upper Airway Obstruction
• Variable extrathoracic obstructions
1. vocal cord paralysis,
2. thyromegaly,
3. tracheomalacia,...
*If FIVC /FEVC >90, FIF50 <80% predicted and
FEF50/FIF50 <0.8 variable intrathoracic
large and upper airway obstruction.
...
Obstruction, Restriction, Mixed
True Restrictive Disorders
Intraparenchymal
Interstitial Infilterative Diffuse alveolar
Chest Wall
Pleural Skeletal
Reduce...
Pseudorestrictive Disorders
Normally: IC/ERV=2-3/1
True restrictive: IC/ERV=<2/1
Pseudorestrictive: IC/ERV=6/1
Pseudorestrictive Disorders
Obesity:
*Early airway closure (low ERV & high RV)
*FRC is more reduced than TLC&VC
*Low FEF50...
Pseudorestrictive Disorders
Neuromuscular Disease:
*FRC normal
*IC&ERV decreased
*Decreased TLC
*Increased RV
*A-aO2 gradi...
Pseudorestrictive Disorders
Asthma:
*FRC &TLC increased
*Improvement of FEV1&FVC with bronchodilators
*Positive bronchopro...
Pseudopseudorestrictive
Patients with obstructive diseases who do not
complete expiratory effort of FVC. This may
lead to ...
Where is the pathology ???????
in the areas with increased density
meaning there is ground glass
in the areas with decreas...
Pathology in black areas
Airtrapping: Airway Disease
Bronchiolitis obliterans (constrictive bronchiolitis)
idiopathic, con...
Airway Disease
what you see……
In inspiration
sharply demarcated areas of seemingly increased
density (normal) and decrease...
Bronchiolitis
obliterans
Early Sarcoidosis
Cystic Fibrosis
Chronic
Hypersensitivity pneumonitis
HRCT Morphology
chronic: fibrosis
Intra- / interlobular septal thickening
Irregular interface...
Pathology in white Areas
Alveolitis / Pneumonitis
Ground glass
desquamative intertitial pneumoinia (DIP)
nonspecific inter...
DIP
Cellular
NSIP
Mosaic Perfusion
Chronic pulmonary embolism
LOOK FOR
Pulmonary hypertension
idiopathic, cardiac disease, pulmonary
disease
CTEPH =
Chronic thrombembolic
pulmonary hypertension
Mixed Disorder
*Sarcoidosis
*Rhematoid
*Advanced IPF
*Bronchiectasis
*BOOP in smokers
PreoperativeAssessment
1- If FVC and FEV1>80% or 2L and DLco75%,
the patient can tolerate pneumonectomy.
2-If FVC,FEV1 an...
Split Lung Function Studies
• Unilateral ventilation is measured by
inhalation Xe133 and perfusion is measured
by IV Tc99m...
Split Lung Function Studies
• Postoperative FEV1= preoperative FEV1-
preoperative FEV1 x % of function of tumor-
containin...
Postoperative FEV1
• If radiospirometryis not done, then
Postoperative FEV1= preoperative FEV1-
preoperative FEV1 x 1/19x ...
PreoperativeAssessment
3- Exercise testing:Maximum o2
consumption>75% or 20 mL/kg/min-----
pneumonectomy.
Maximum o2 consu...
Clinical application of pulmonary function tests.pptm1
Clinical application of pulmonary function tests.pptm1
Clinical application of pulmonary function tests.pptm1
Clinical application of pulmonary function tests.pptm1
Clinical application of pulmonary function tests.pptm1
Clinical application of pulmonary function tests.pptm1
Clinical application of pulmonary function tests.pptm1
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Clinical application of pulmonary function tests.pptm1

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Clinical application of pulmonary function tests.pptm1

  1. 1. Clinical Application of Pulmonary Function Tests Gamal Rabie Agmy, MD, FCCP Professor of Chest Diseases,Assiut University ERS National Delegate of Egypt
  2. 2. Anatomy  Lungs comprised of  Airways  Alveoli http://www.aduk.org.uk/gfx/lungs.jpg
  3. 3. Weibel ER: Morphometry of the Human Lung. Berlin and New York: Springer- Verlag, 1963 The Airways  Conducting zone: no gas exchange occurs  Anatomic dead space  Transitional zone: alveoli appear, but are not great in number  Respiratory zone: contain the alveolar sacs
  4. 4. From Netter Atlas of Human Anatomy, 1989
  5. 5. How does gas exchange occur? • Numerous capillaries are wrapped around alveoli. • Gas diffuses across this alveolar-capillary barrier. • This barrier is as thin as 0.3 μm in some places and has a surface area of 50-100 square meters!
  6. 6. Gas Exchange From Netter Atlas of Human Anatomy, 1989
  7. 7. The Alveoli  Approximately 300 million alveoli  1/3 mm diameter  Total surface area if they were complete spheres 85 sq. meters (size of a tennis court) Murray & Nadel: Textbook of Respiratory Medicine, 3rd ed., Copyright © 2000 W. B. Saunders Company
  8. 8. Mechanics of Breathing  Inspiration  Active process  Expiration  Quiet breathing: passive  Can become active
  9. 9. Pulmonary Function Tests  Airway function  Simple spirometry  Forced vital capacity maneuver  Maximal voluntary ventilation  Maximal inspiratory/expiratory pressures  Airway resistance  Lung volumes and ventilation  Functional residual capacity  Total lung capacity, residual volume  Minute ventilation, alveolar ventilation, dead space  Distribution of ventilation
  10. 10. Pulmonary Function Tests  Diffusing capacity tests  Blood gases and gas exchange tests  Blood gas analysis  Pulse oximetry  Capnography  Cardiopulmonary exercise tests  Metabolic measurements  Resting energy expenditure  Substrate utilization  Chemical analysis of exhaled breath
  11. 11. Terminology  Forced vital capacity (FVC):  Total volume of air that can be exhaled forcefully from TLC  The majority of FVC can be exhaled in <3 seconds in normal people, but often is much more prolonged in obstructive diseases  Measured in liters (L)
  12. 12. FVC  Interpretation of % predicted:  80-120% Normal  70-79% Mild reduction  50%-69% Moderate reduction  <50% Severe reduction FVC
  13. 13. Terminology  Forced expiratory volume in 1 second: (FEV1)  Volume of air forcefully expired from full inflation (TLC) in the first second  Measured in liters (L)  Normal people can exhale more than 75-80% of their FVC in the first second; thus the FEV1/FVC can be utilized to characterize lung disease
  14. 14. FEV1  Interpretation of % predicted:  > 80% Mild  50-80% Moderate obstruction  30-50% severe obstruction  <30% Severe obstruction FEV1 FVC
  15. 15. Terminology  Forced expiratory flow 25- 75% (FEF25-75)  Mean forced expiratory flow during middle half of FVC  Measured in L/sec  May reflect effort independent expiration and the status of the small airways  Highly variable  Depends heavily on FVC
  16. 16. FEF25-75  Interpretation of % predicted:  >60% Normal  40-60% Mild obstruction  20-40% Moderate obstruction  <20% Severe obstruction
  17. 17. Acceptability Criteria  Good start of test  No coughing  No variable flow  No early termination  Reproducibility
  18. 18. Acceptable and Unacceptable Spirograms (from ATS, 1994)
  19. 19. Changes in Lung Volumes in Various Disease States RuppelGL. ManualofPulmonary Function Testing, 8th ed., Mosby 2003
  20. 20. TLC  TLC < 80% of predicted value = restriction.  TLC > 120% of predicted value = hyperinflation.
  21. 21. 1-First Step, Check quality of the test 1- Start: *Good start: Extrapolated volume (EV) < 5% of FVC or 0.15 L *Poor start: Extrapolated volume (EV) ≥5% of FVC or ≥ 0.15 L 2- Termination: *No early termination :Tex ≥ 6 s *Early termination : Tex < 6 s
  22. 22. 2- Look at …………FEV1/FVC < N(70%) Obstructive or Mixed ≥ N(70%) Restrictive or Normal 3- Look at FEV1 To detect degree Mild > 70% Mod 50-69 % Severe 35-49% Very severe < 35%
  23. 23. 4- Postbronchodilator FEV1/FVC > 70% asthma < 70% COPD
  24. 24. 5- Reversibility test of FEV1 > 12%, 200 ml Reversible (asthma) < 12% ,200 ml Ireversible (COPD) 6- Look at TLC ≥ 100% Pure obstruction < 100% Mixed
  25. 25. 2- Look at …………FEV1/FVC < N(70%) Obstructive or Mixed ≥ N(70%) Restrictive or Normal 3- Look at FVC ≥ N(80%) < N(80%) Normal or SAWD 4-Look at FEF25/75 > 50% Normal < 50% SAWD Restrictive
  26. 26. Patterns of Abnormality Restriction low FEV1 & FVC, high FEV1%FVC Recorded Predicted SR %Pred FEV 1 1.49 2.52 -2.0 59 FVC 1.97 3.32 -2.2 59 FEV 1 %FVC 76 74 0.3 103 PEF 8.42 7.19 1.0 117 Obstructive low FEV1 relative to FVC, low PEF, low FEV1%FVC Recorded Predicted SR %Pred FEV 1 0.56 3.25 -5.3 17 FVC 1.65 4.04 -3.9 41 FEV 1 %FVC 34 78 -6.1 44 PEF 2.5 8.28 -4.8 30 high PEF early ILD low PEF late ILD
  27. 27. Patterns of Abnormality Upper AirwayObstruction low PEF relative to FEV1 Recorded Predicted SR %Pred FEV 1 2.17 2.27 -0.3 96 FVC 2.68 2.70 0.0 99 FEV 1 %FVC 81 76 0.7 106 PEF 2.95 5.99 -3.4 49 FEV 1 /PEF 12.3 Discordant PEF and FEV1 High PEF versus FEV1 = early interstitial lung disease (ILD) Low PEF versus FEV1 = upper airway obstruction Concordant PEF and FEV1 Both low in airflow obstruction, myopathy, late ILD
  28. 28. Common FVL Shapes Volume Flow Normal Young or quitter Poor effort Hesitation Knee Coughing
  29. 29. Asthma 0 1 2 3 4 5 6 0 2 4 6 8 10 12 FlowinL/s Litres concave FV curve intrapulmonary airflow obstruction
  30. 30. Restrictive 0 1 2 3 4 5 6 -8 -6 -4 -2 0 2 4 6 8 10 12 F 19 yrs 1.64m FVC 2.41 L -3.42 SR FEV 2.41 L -2.62 SR FEV% 100 +2.23 SR PEF 5.55L/s -2.00 SR F/P 7.2 RT 116 ms FlowinL/s Litres
  31. 31. COPD 0 1 2 3 4 5 -6 -4 -2 0 2 4 6 8 10 FlowinL/s Litres pressure dependent airways collapse
  32. 32. Poorly co-ordinated start 0 1 2 3 4 5 6 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 FlowinL/s Litres EV = large Rise Time = 496 ms Irregular shape Poorly repeatable
  33. 33. Upper Airway Obstruction 0 1 2 3 4 5 6 -6 -4 -2 0 2 4 6 Age 40 yrs FVC 3.52 L 0.84 SR FEV1 3.0 L 0.74 SR PEF 4.57 L/s -2.18 SR FEV/PEF = 10.9 Inspiratory Expiratory FlowinL/s Volume in Litres FEV1 in mls PEF in L/min > 8
  34. 34. Upper Airway Obstruction 0 1 2 3 4 5 6 -6 -4 -2 0 2 4 6 8 10 12 FlowinL/s Volume in Litres Male aged 62 Height 1.68m Recorded Predicted Range SR FEV1 2.23 2.94 2.1 to 3.8 -1.4 FVC 3.40 3.71 2.7 to 4.7 -0.5 FEV1%FVC 66 76 64 to 88 -1.5 PEF 2.85 7.81 5.8 to 9.8 -4.1 FEV1/PEF 13.1
  35. 35. Inspiration -ve -ve Expiration +ve +ve Extra-thoracic UAO worse on insp. Intra-thoracic UAO worse on exp. Variable UAO
  36. 36. Intra-thoracic UAO 0 1 2 3 4 5 6 -8 -6 -4 -2 0 2 4 6 8 10 12 FlowinL/s Liters Age 65 Female FVC 2.97 L 1.3 SR FEV1 2.26 L 0.6 SR FEV1% 76% -0.1 SR PEF 3.4 L·s-1 -2.5 SR F/P 11.1 RT 455 ms
  37. 37. Variable Extrathoracic Upper Airway Obstruction
  38. 38. Fixed Upper Airway Obstruction
  39. 39. Upper Airway Obstruction • Variable extrathoracic obstructions 1. vocal cord paralysis, 2. thyromegaly, 3. tracheomalacia, or 4. Neoplasm • Large airways variable intrathoracic obstructions 1. tracheomalacia or 2. neoplasm • Fixed obstruction 1. tracheal stenosis, 2. foreign body, or 3. neoplasm.
  40. 40. *If FIVC /FEVC >90, FIF50 <80% predicted and FEF50/FIF50 <0.8 variable intrathoracic large and upper airway obstruction. *If FIVC /FEVC >90, FIF50 <80% predicted and FEF50/FIF50>1.2 Variable extrathoracic obstruction. *If FIVC /FEVC >90, FIF50 <80% predicted and FEF50/FIF50 = 0.8 – 1.2  Fixed upper airway obstruction.
  41. 41. Obstruction, Restriction, Mixed
  42. 42. True Restrictive Disorders Intraparenchymal Interstitial Infilterative Diffuse alveolar Chest Wall Pleural Skeletal Reduced TLC.FRC,RV,VC and normal to high FEV1/FVC In 50% DLco/VA>80% The other half had low DLco/VA
  43. 43. Pseudorestrictive Disorders Normally: IC/ERV=2-3/1 True restrictive: IC/ERV=<2/1 Pseudorestrictive: IC/ERV=6/1
  44. 44. Pseudorestrictive Disorders Obesity: *Early airway closure (low ERV & high RV) *FRC is more reduced than TLC&VC *Low FEF50% , FEF75%, FEF25-75%,
  45. 45. Pseudorestrictive Disorders Neuromuscular Disease: *FRC normal *IC&ERV decreased *Decreased TLC *Increased RV *A-aO2 gradient normal *MIP&MEP decreased
  46. 46. Pseudorestrictive Disorders Asthma: *FRC &TLC increased *Improvement of FEV1&FVC with bronchodilators *Positive bronchoprovacation test *Increased diffusing capacity and DLco/VA
  47. 47. Pseudopseudorestrictive Patients with obstructive diseases who do not complete expiratory effort of FVC. This may lead to a below normal FEV1 and FVC with pseudonormalization of ratio.
  48. 48. Where is the pathology ??????? in the areas with increased density meaning there is ground glass in the areas with decreased density meaning there is air trapping
  49. 49. Pathology in black areas Airtrapping: Airway Disease Bronchiolitis obliterans (constrictive bronchiolitis) idiopathic, connective tissue diseases, drug reaction, after transplantation, after infection Hypersensitivity pneumonitis granulomatous inflammation of bronchiolar wall Sarcoidosis granulomatous inflammation of bronchiolar wall Asthma / Bronchiectasis / Airway diseases
  50. 50. Airway Disease what you see…… In inspiration sharply demarcated areas of seemingly increased density (normal) and decreased density demarcation by interlobular septa In expiration ‘black’ areas remain in volume and density ‘white’ areas decrease in volume and increase in density INCREASE IN CONTRAST DIFFERENCES AIRTRAPPING
  51. 51. Bronchiolitis obliterans
  52. 52. Early Sarcoidosis
  53. 53. Cystic Fibrosis
  54. 54. Chronic
  55. 55. Hypersensitivity pneumonitis HRCT Morphology chronic: fibrosis Intra- / interlobular septal thickening Irregular interfaces Traction bronchiectasis acute - subacute acinar (centrilobular) unsharp densities ground glass (patchy - diffuse)
  56. 56. Pathology in white Areas Alveolitis / Pneumonitis Ground glass desquamative intertitial pneumoinia (DIP) nonspecific interstitial pneumonia (NSIP) organizing pneumonia In expiration both areas (white and black) decrease in volume and increase in density DECREASE IN CONTRAST DIFFERENCES
  57. 57. DIP
  58. 58. Cellular NSIP
  59. 59. Mosaic Perfusion Chronic pulmonary embolism LOOK FOR Pulmonary hypertension idiopathic, cardiac disease, pulmonary disease
  60. 60. CTEPH = Chronic thrombembolic pulmonary hypertension
  61. 61. Mixed Disorder *Sarcoidosis *Rhematoid *Advanced IPF *Bronchiectasis *BOOP in smokers
  62. 62. PreoperativeAssessment 1- If FVC and FEV1>80% or 2L and DLco75%, the patient can tolerate pneumonectomy. 2-If FVC,FEV1 and DLco< limits in step 1: Predicted postoperative values of FEV1 and DLco
  63. 63. Split Lung Function Studies • Unilateral ventilation is measured by inhalation Xe133 and perfusion is measured by IV Tc99m albumin macroaggregates.
  64. 64. Split Lung Function Studies • Postoperative FEV1= preoperative FEV1- preoperative FEV1 x % of function of tumor- containing lung X( no. of segments of resected lobe/ total no. of segments of the lung ) E.g. preoperative FEV1= 2.0L right lung function=40% RUL lobectomy will be done. Postoperative FEV1 = 2.0-2.0x40%x3/10=1.76L
  65. 65. Postoperative FEV1 • If radiospirometryis not done, then Postoperative FEV1= preoperative FEV1- preoperative FEV1 x 1/19x no. of resected segments E.g. preoperative FEV1= 2.0L RUL lobectomy will be done. Postoperative FEV1 = 2.0-2.0x1/19x3=1.684
  66. 66. PreoperativeAssessment 3- Exercise testing:Maximum o2 consumption>75% or 20 mL/kg/min----- pneumonectomy. Maximum o2 consumption <40% or 10 mL/kg/min- ----Inoperable

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