What exactly are PFTs?• The term encompasses a wide variety of objective  methods to assess lung function. (Remember that ...
Spirometry• Measurement of the pattern of air  movement into and out of the lungs during  controlled ventilatory maneuvers...
Importance• Patients and physicians have inaccurate  perceptions of severity of airflow  obstruction and/or severity of lu...
Silhouette of Hutchinson Performing Spirometry                       From                       Chest,                    ...
Indications• Detect disease• Evaluate extent and monitor course of  disease• Evaluate treatment• Measure effects of exposu...
contraindications• Chest or abdominal pain of any cause• Oral or facial pain exacerbated by  mouthpiece• Stress incontinen...
To be avoided•   Smoking- 1 hour•   Alcohol- 4 hour•   Vigorous exercise -30 minutes•   Large meal – 2 hour•   Wearing tig...
Preparation• Tests should be performed when patients are  clinically stable and free from respiratory infection•   Patient...
Volume Measuring Spirometer
Flow Measuring Spirometer
Desktop Electronic Spirometers
Small Hand-held Spirometers
The Airways                                       • Conducting zone: no                                         gas exchan...
FromNetterAtlas ofHumanAnatomy,1989
Lung Volumes                      • 4 Volumes                      • 4 CapacitiesIRV                     – Sum of 2 or    ...
Tidal Volume (TV)                        • Volume of air                          inspired and                          ex...
Inspiratory Reserve Volume (IRV)                               • The maximum                                 amount of air...
Expiratory Reserve Volume (ERV)                              • Maximum                                amount of air       ...
Residual Volume (RV)                          • Volume of air                            remaining in the                 ...
Vital Capacity (VC)                        • Volume of air that                          can be exhaled                   ...
Predicted Normal ValuesAffected by: Age Height Sex Ethnic Origin
Terminology    • Forced vital capacity      (FVC):      – Total volume of air that can        be exhaled forcefully from  ...
FVC• Interpretation of % predicted:  –   80-120%    Normal  –   70-79%     Mild reduction  –   50%-69%    Moderate reducti...
Terminology    • Forced expiratory volume      in 1 second: (FEV1)      – Volume of air forcefully        expired from ful...
FEV1• Interpretation of % predicted:  –   >75%       Normal  –   60%-75%    Mild obstruction  –   50-59%     Moderate obst...
Terminology   • Forced expiratory flow 25-     75% (FEF25-75)     – Mean forced expiratory flow       during middle half o...
FEF25-75• Interpretation of % predicted:  –   >60%     Normal  –   40-60%   Mild obstruction  –   20-40%   Moderate obstru...
Standard Spirometric Indicies• FEV1 - Forced expiratory volume in one second: The volume of air expired in the first secon...
Criteria for Normal  Post-bronchodilator Spirometry• FEV1: % predicted > 80%• FVC: % predicted > 80%• FEV1/FVC: > 0.7
Spirometry Interpretation:   Obstructive vs. Restrictive             Defect• Obstructive Disorders • Restrictive Disorders...
SPIROMETRYFlow Volume
Flow Volume Curve• Standard on most desk-top spirometers• Adds more information than volume  time curve• Less understood b...
Flow Volume Curve                     Maximum                     expiratory flow                     (PEF)Expiratoryflow ...
Flow-Volume Loop                                                       • Illustrates maximum                              ...
Normal Trace Showing FEV1 and                      FVC                 5                               FVCVolume, liters  ...
Reproducibility - Quality of Results  Volume, liters                   Time, secondsThree times FVC within 5% or 0.1 litre...
Spirogram Patterns• Normal• Obstructive• Restrictive• Mixed Obstructive and Restrictive
SPIROMETRYOBSTRUCTIVE  DISEASE
Spirometry: Obstructive Disease                 5                 4Volume, liters                                         ...
Flow Volume Curve Patterns                          Obstructive and Restrictive                       Obstructive         ...
Bronchodilator Reversibility Testing• Provides the best achievable FEV1  (and FVC)• Helps to differentiate COPD from  asth...
Bronchodilator Reversibility                  Testing in COPDSpirometry•FEV1 should be measured (minimum twice,within 5%) ...
Bronchodilator Reversibility Testing                   in COPD•An increase in FEV1 that is both greaterthan 200 ml and 12%...
Figure 5.1-6.                 Bronchodilator                  Reversibility                Testing in COPD    GOLDReport (...
SPIROMETRYRESTRICTIVE  DISEASE
Spirometry: Restrictive Disease                 5                    NormalVolume, liters                 4               ...
Flow Volume Curve Patterns                          Obstructive and Restrictive                       Obstructive         ...
Mixed Obstructive and Restrictive                                                   Normal       Volume, liters           ...
Spirometry - Quality Control• Most common cause of inconsistent  readings is poor patient technique    Sub-optimal inspir...
TroubleshootingExamples - Unacceptable Traces
Unacceptable Trace - Poor Effort Volume, liters                                     Normal                  Variable expir...
Unacceptable Trace – Stop Early                                  Normal Volume, liters                  Time, seconds
Unacceptable Trace – Slow Start                                  Normal Volume, liters                  Time, seconds
Unacceptable Trace - Coughing                                 NormalVolume, liters                 Time, seconds
Unacceptable Trace – Extra Breath                                  Normal Volume, liters                  Time, seconds
EXAMPLE 1TEST         PREDICTE         BROCHODILATOR    CHANGE             D                        BEFORE       AFTERFVC ...
EXAMPLE -2TEST         PREDICTE         BROCHODILATOR   CHANGE             D                        BEFORE       AFTERFVC ...
EXAMPLE 2 contTEST         PREDICTE         BROCHODILATOR   CHANGE             D                        BEFORE       AFTER...
EXAMPLE 3TEST         PREDICTE       BROCHODILATOR   CHANGE             D                         BEFORE    AFTERFVC      ...
EXAMPLE 4TEST         PREDICTE          BROCHODILATOR    CHANGE             D                         BEFORE       AFTERFV...
EXAMPLE 5TEST         PREDICTE       BROCHODILATOR   CHANGE             D                         BEFORE    AFTERFVC      ...
EXAMPLE 6TEST         PREDICTE         BROCHODILATOR     CHANGE             D                        BEFORE        AFTERFV...
EXAMPLE 7TEST         PREDICTE       BROCHODILATOR    CHANGE             D                         BEFORE    AFTERFVC     ...
EXAMPLE 8TEST         PREDICTE      BROCHODILATOR    CHANGE             D                        BEFORE    AFTERFVC       ...
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Pulmonary Function Test
Pulmonary Function Test
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Pulmonary Function Test

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Pulmonary Function Test

  1. 1. What exactly are PFTs?• The term encompasses a wide variety of objective methods to assess lung function. (Remember that the primary function is gas exchange).• Examples include: – Spirometry – Pulse oximetry – Blood gases – Lung volumes by helium dilution or body plethysmography – Exercise tests – Diffusing capacity – Bronchial challenge testing
  2. 2. Spirometry• Measurement of the pattern of air movement into and out of the lungs during controlled ventilatory maneuvers.• Often done as a maximal expiratory maneuver
  3. 3. Importance• Patients and physicians have inaccurate perceptions of severity of airflow obstruction and/or severity of lung disease by physical exam• Provides objective evidence in identifying patterns of disease
  4. 4. Silhouette of Hutchinson Performing Spirometry From Chest, 2002
  5. 5. Indications• Detect disease• Evaluate extent and monitor course of disease• Evaluate treatment• Measure effects of exposures• Assess risk for surgical procedures
  6. 6. contraindications• Chest or abdominal pain of any cause• Oral or facial pain exacerbated by mouthpiece• Stress incontinence• Dementia or confused state• Within one month of Myocardial Infarction
  7. 7. To be avoided• Smoking- 1 hour• Alcohol- 4 hour• Vigorous exercise -30 minutes• Large meal – 2 hour• Wearing tight clothes
  8. 8. Preparation• Tests should be performed when patients are clinically stable and free from respiratory infection• Patients should not have taken:  inhaled short-acting bronchodilators in the previous six hours  long-acting bronchodilator in the previous 12 hours  sustained-release theophylline in the previous 24 hours
  9. 9. Volume Measuring Spirometer
  10. 10. Flow Measuring Spirometer
  11. 11. Desktop Electronic Spirometers
  12. 12. Small Hand-held Spirometers
  13. 13. 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 sacsWeibel ER: Morphometry of the HumanLung. Berlin and New York: Springer-Verlag, 1963
  14. 14. FromNetterAtlas ofHumanAnatomy,1989
  15. 15. Lung Volumes • 4 Volumes • 4 CapacitiesIRV – Sum of 2 or IC more lung VCTV volumes TLCERV FRC RV RV
  16. 16. Tidal Volume (TV) • Volume of air inspired and expired during IRV normal quiet IC VC breathing TV TLC ERV FRC RV RV
  17. 17. Inspiratory Reserve Volume (IRV) • The maximum amount of air that can be IRV inhaled after a IC VC normal tidal TV TLC volume inspiration ERV FRC RV RV
  18. 18. Expiratory Reserve Volume (ERV) • Maximum amount of air that can be IRV exhaled from IC VC the resting TV TLC expiratory level ERV FRC RV RV
  19. 19. Residual Volume (RV) • Volume of air remaining in the lungs at the end IRV of maximum IC VC expiration TV TLC ERV FRC RV RV
  20. 20. Vital Capacity (VC) • Volume of air that can be exhaled from the lungs IRV after a maximum IC inspiration VC TV • FVC: when VC TLC exhaled forcefully ERV • SVC: when VC is FRC exhaled slowly RV RV • VC = IRV + TV + ERV
  21. 21. Predicted Normal ValuesAffected by: Age Height Sex Ethnic Origin
  22. 22. 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)
  23. 23. FVC• Interpretation of % predicted: – 80-120% Normal – 70-79% Mild reduction – 50%-69% Moderate reduction – <50% Severe reduction FVC
  24. 24. 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
  25. 25. FEV1• Interpretation of % predicted: – >75% Normal – 60%-75% Mild obstruction – 50-59% Moderate obstruction – <49% Severe obstruction FEV1 FVC
  26. 26. 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
  27. 27. FEF25-75• Interpretation of % predicted: – >60% Normal – 40-60% Mild obstruction – 20-40% Moderate obstruction – <10% Severe obstruction
  28. 28. Standard Spirometric Indicies• FEV1 - Forced expiratory volume in one second: The volume of air expired in the first second of the blow• FVC - Forced vital capacity: The total volume of air that can be forcibly exhaled in one breath• FEV1/FVC ratio: The fraction of air exhaled in the first second relative to the total volume exhaled
  29. 29. Criteria for Normal Post-bronchodilator Spirometry• FEV1: % predicted > 80%• FVC: % predicted > 80%• FEV1/FVC: > 0.7
  30. 30. Spirometry Interpretation: Obstructive vs. Restrictive Defect• Obstructive Disorders • Restrictive Disorders – FVC nl or↓ – FVC ↓ – FEV1 ↓ – FEV1 ↓ – FEF25-75% ↓ – FEF 25-75% nl to ↓ – FEV1/FVC ↓ – FEV1/FVC N↑ – TLC nl or ↑ – TLC ↓
  31. 31. SPIROMETRYFlow Volume
  32. 32. Flow Volume Curve• Standard on most desk-top spirometers• Adds more information than volume time curve• Less understood but not too difficult to interpret• Better at demonstrating mild airflow obstruction
  33. 33. Flow Volume Curve Maximum expiratory flow (PEF)Expiratoryflow rateL/sec FVC RV TLCInspiratory flow rate L/sec Volume (L)
  34. 34. Flow-Volume Loop • Illustrates maximum expiratory and inspiratory flow- volume curves • Useful to help characterize disease states (e.g. obstructive vs. restrictive)Ruppel GL. Manual of Pulmonary Function Testing, 8thed., Mosby 2003
  35. 35. Normal Trace Showing FEV1 and FVC 5 FVCVolume, liters 4 FEV1 = 4L 3 FVC = 5L 2 FEV1/FVC = 0.8 1 1 2 3 4 5 6 Time, seconds
  36. 36. Reproducibility - Quality of Results Volume, liters Time, secondsThree times FVC within 5% or 0.1 litre (100 ml)
  37. 37. Spirogram Patterns• Normal• Obstructive• Restrictive• Mixed Obstructive and Restrictive
  38. 38. SPIROMETRYOBSTRUCTIVE DISEASE
  39. 39. Spirometry: Obstructive Disease 5 4Volume, liters Normal 3 FEV1 = 1.8L 2 FVC = 3.2L Obstructive 1 FEV1/FVC = 0.56 1 2 3 4 5 6 Time, seconds
  40. 40. Flow Volume Curve Patterns Obstructive and Restrictive Obstructive Severe obstructive Restrictive Expiratory flow rate Expiratory flow rateExpiratory flow rate Volume (L) Volume (L) Volume (L) Reduced peak flow, Steeple pattern, Normal shape, scooped out mid- reduced peak flow, normal peak flow, curve rapid fall off reduced volume
  41. 41. Bronchodilator Reversibility Testing• Provides the best achievable FEV1 (and FVC)• Helps to differentiate COPD from asthma Must be interpreted with clinical history - neither asthma nor COPD are diagnosed on spirometry alone
  42. 42. Bronchodilator Reversibility Testing in COPDSpirometry•FEV1 should be measured (minimum twice,within 5%) before a bronchodilator is given•The bronchodilator should be given bymetered dose inhaler through a spacer deviceor by nebulizer to be certain it has beeninhaled•The bronchodilator dose should be selected tobe high on the dose/response curve
  43. 43. Bronchodilator Reversibility Testing in COPD•An increase in FEV1 that is both greaterthan 200 ml and 12% above the pre-bronchodilator FEV1 (baseline value) isconsidered significant•It is usually helpful to report the absolutechange (in ml) as well as the % change frombaseline to set the improvement in a clinicalcontext
  44. 44. Figure 5.1-6. Bronchodilator Reversibility Testing in COPD GOLDReport (2006)
  45. 45. SPIROMETRYRESTRICTIVE DISEASE
  46. 46. Spirometry: Restrictive Disease 5 NormalVolume, liters 4 3 Restrictive FEV1 = 1.9L 2 FVC = 2.0L 1 FEV1/FVC = 0.95 1 2 3 4 5 6 Time, seconds
  47. 47. Flow Volume Curve Patterns Obstructive and Restrictive Obstructive Severe obstructive Restrictive Expiratory flow rate Expiratory flow rateExpiratory flow rate Volume (L) Volume (L) Volume (L) Reduced peak flow, Steeple pattern, Normal shape, scooped out mid- reduced peak flow, normal peak flow, curve rapid fall off reduced volume
  48. 48. Mixed Obstructive and Restrictive Normal Volume, liters FEV1 = 0.5L Obstructive - Restrictive FVC = 1.5L FEV1/FVC = 0.30 Time, secondsRestrictive and mixed obstructive-restrictive are difficult to diagnose by spirometry alone; full respiratory function tests are usually required (e.g., body plethysmography, etc)
  49. 49. Spirometry - Quality Control• Most common cause of inconsistent readings is poor patient technique  Sub-optimal inspiration  Sub-maximal expiratory effort  Delay in forced expiration  Shortened expiratory time  Air leak around the mouthpiece• Subjects must be observed and encouraged throughout the procedure
  50. 50. TroubleshootingExamples - Unacceptable Traces
  51. 51. Unacceptable Trace - Poor Effort Volume, liters Normal Variable expiratory effort Inadequate sustaining of effort May be accompanied by a slow start Time, seconds
  52. 52. Unacceptable Trace – Stop Early Normal Volume, liters Time, seconds
  53. 53. Unacceptable Trace – Slow Start Normal Volume, liters Time, seconds
  54. 54. Unacceptable Trace - Coughing NormalVolume, liters Time, seconds
  55. 55. Unacceptable Trace – Extra Breath Normal Volume, liters Time, seconds
  56. 56. EXAMPLE 1TEST PREDICTE BROCHODILATOR CHANGE D BEFORE AFTERFVC 4.0 L 3.2 3.2FVC%(O/P) 80% 80%FEV1 3.7L 2.9 2.9 +0%- 0mlFEV1%(O/P) 78% 78%FEV1/FVC% 90% 90%PEF 3.51L/S 4.22L/S
  57. 57. EXAMPLE -2TEST PREDICTE BROCHODILATOR CHANGE D BEFORE AFTERFVC 2.8L 0.6FVC%(O/P) 22%FEV1 2.75L 0.5FEV1%(O/P) 18.18%FEV1/FVC% 84%PEF 5.3L/S 1.6
  58. 58. EXAMPLE 2 contTEST PREDICTE BROCHODILATOR CHANGE D BEFORE AFTERFVC 2.8L 0.6 1.6LFVC%(O/P) 22% 57%FEV1 2.75L 0.5 1.0L +100%-500mlFEV1%(O/P) 18.18% 36.3%FEV1/FVC% 84% 63%PEF 5.3L/S 1.6 4.8
  59. 59. EXAMPLE 3TEST PREDICTE BROCHODILATOR CHANGE D BEFORE AFTERFVC 2.60L 1.60 1.63FVC%(O/P) 62% 63%FEV1 2.17L 1.32 1.34 1.5%-20mlFEV1%(O/P) 61% 62%FEV1/FVC% 83% 82%PEF 5.85L/S 5.34 4.56
  60. 60. EXAMPLE 4TEST PREDICTE BROCHODILATOR CHANGE D BEFORE AFTERFVC 2.3L 1.8 1.8FVC%(O/P) 78% 78%FEV1 1.95L 0.75 0.75 +0-0mlFEV1%(O/P) 38% 38%FEV1/FVC% 41% 41%PEF 3.10L/s 1.30L/S 1.34L/S
  61. 61. EXAMPLE 5TEST PREDICTE BROCHODILATOR CHANGE D BEFORE AFTERFVC 3.22L 1.69 1.82FVC%(O/P) 52% 56%FEV1 2.50L 1.15 1.19 +3%FEV1%(O/P) 46% 48%FEV1/FVC% 68% 66%PEF 7.17L/S 4.48 4.41
  62. 62. EXAMPLE 6TEST PREDICTE BROCHODILATOR CHANGE D BEFORE AFTERFVC 2.75L 1.1 1.5FVC%(O/P) 40% 54%FEV1 2L 0.9 1.0 +11%-100mlFEV1%(O/P) 31% 46%FEV1/FVC% 81% 66%PEF 3.7L/s 1.00L/s 3.20L/s
  63. 63. EXAMPLE 7TEST PREDICTE BROCHODILATOR CHANGE D BEFORE AFTERFVC 3.2L 1.54 2.3FVC%(O/P) 48% 71%FEV1 2.75L 0.95 1.94 +104%- 990mlFEV1%(O/P) 34.5% 72%FEV1/FVC% 61% 69%PEF 4.50L/s 3L/s 3.70L/s
  64. 64. EXAMPLE 8TEST PREDICTE BROCHODILATOR CHANGE D BEFORE AFTERFVC 3.2 L 2.55 2.75FVC%(O/P) 79% 86%FEV1 2.75L 1.95 2.3 +18%- 350mlFEV1%(O/P) 70% 84%FEV1/FVC% 76% 83%PEF 4.5L/s 4.00L/s 4.40L/s
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