Spirometry By: Dr - PowerPoint Presentation

1. Spirometry By: Dr Saraei

2. ContentIndication Indications in occupational medicineContraindications Confounding factorsComplicationsType of spirometer Lung volumes & Lung capacitiesSpirometric values Hygiene & infection controlSpirometry steps Reference valuesInterpretation

3. Definition of spirometryA physiological test for measuring volumes inhaled or exhaled by an individual as a function of time

4. Indication Not a screening test for general populationDiagnostic MonitoringImpairment evaluationPublic health

5. Indication (diagnostic)Evaluation of symptoms and signsMeasuring the effect of dis. on pulmonary functionScreening individuals at risk for pulmonary dis.Assess preoperative risk

6. Indication (monitoring)Assess therapeutic interventionMonitor people exposed to injurious agents

7. Indications in occupational medicinePrimary prevention (Pre-employment) Physical demands of a job require a certain level of cardiopulmonary fitness, eg, heavy manual labor or firefightingRespirator use can impose a significant burden on the cardiopulmonary systems, eg, use of a self-contained breathing apparatus, or prolonged use of certain negative-pressure masks under conditions of heavy physical exertion and/or heat stress Research (Respiratory hazards)

8. Secondary prevention Medical surveillance programs & periodic evaluation OSHA : asbestos, cadmium, coke oven emissions, or cotton dust respirator-wearers exposed to benzene, formaldehyde methylene chloride Silicosis Spirometry detect large changes over a short time or smaller changes cumulated over a longer observation period, it is not sensitive to small, short-term changes Tertiary preventionFollow-up spirometryWorkers’ compensation setting

9. ContraindicationsActive hemoptysisPneumothoraxUnstable Cardiovascular status (6 w)Cerebral/Thoracic/Abdominal aneurysmRecent eye surgeryAcute disorder that may interfere with performance (e.g, vomiting) Thoracic or abdominal surgery( 3 w)Recent CVA or pulmonary emboliRespiratory distress

10. Confounding factorsCommon cold (3 days ago)Severe respiratory infection (3w)Smoking( 1hr)Heavy food (1hr)Bronchodilator use

11. ComplicationsChest painSyncope, dizzinessIncreased ICPParoxysmal coughingNosocomial infectionBronchospasm

12. Spirometry standardsATS (American Thoracic Society)ERS (European Respiratory Society)

13. Lung volumesTV :The volume of air inhaled & exhaled at each breath during normal quiet breathing IRV: The maximum amount of air that can be inhaled after a normal inhalationERV: The volume of air that can be forcefully expired following a normal quiet expirationRV: The volume of air remaining in the lungs after a forceful expiration

14. Lung capacitiesTLC: The total volume of the lungs VC:The maximum amount of air that can be exhaled after the fullest inspiration possibleIC :The maximum of air that can be inhale after end tidal positionFRC: The amount of air remaining in the lungs after a normal quiet expiration

15. Lung Volumes4 Volumes4 CapacitiesSum of 2 or more lung volumesIRVTVERVRVICFRCVCTLCRV15

16. Tidal Volume (TV)Volume of air inspired and expired during normal quiet breathingIRVTVERVRVICFRCVCTLCRV16

17. Inspiratory Reserve Volume (IRV)The maximum amount of air that can be inhaled after a normal tidal volume inspirationIRVTVERVRVICFRCVCTLCRV17

18. Expiratory Reserve Volume (ERV)Maximum amount of air that can be exhaled from the resting expiratory levelIRVTVERVRVICFRCVCTLCRV18

19. Functional Residual Capacity (FRC)Volume of air remaining in the lungs at the end of a TV expiration The elastic force of the chest wall is exactly balanced by the elastic force of the lungsFRC = ERV + RVIRVTVERVRVICFRCVCTLCRV19

20. Total Lung Capacity (TLC)Volume of air in the lungs after a maximum inspirationTLC = IRV + TV + ERV + RVIRVTVERVRVICFRCVCTLCRV20

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22. Spirometric valuesFVC (forced vital capacity)FEV1 (forced expiratory volume in 1 s)FEV1/FVCFEF25-75 (maximum midexpiratory flow)PEF (peak expiratory flow)VT curveFV curve

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24. Normal values depends on:AgeHeightKyphoscoliosis → arm span (H=arm span/1.06)GenderRaceCaucasianATS recommended scaling factor of 0.88 to the Caucasian predicted FEV1 and FVC for African-American, Chinese, and Japanese subjects

25. Hygiene & infection controlHand washingGlovesDisposable mouth piece & nose clipDisinfection or sterilization of reusable mouth pieceExtra precautions for patient with known transmissible infection

26. Subject maneuversFVC maneuverClosed circuit Open circuit Well-fitting false teeth → yes or noSitting or standingNose clipProcedure 1. Inhale compete & rapid 2. Exhale: with minimal hesitation “blast” not just “blow” “keep going”

27. maneuver evaluationStart of test criteria - Extrapolation volume (EV < 5% of FVCor 150 ml) -Time-to-PEF < 0.120 s End of test criteria - the subject cannot or should not continue - exhalation at least 6s (in children <10 yrs: at least 3s) - volume-time curve show no change in volume (<0.025 lit) for at least 1s In obstruction or older subjects more than 6s exhalation (till 15s)

28. bc a

29. Acceptability Start of test criteria End of test criteria Cough especially during first second Valsalva maneuver (glottis closure) Leak from the mouth Obstruction of the mouthpiece Extra breath during the maneuver At the most eight tests should be performed

30. Acceptable spirogram

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32. “rainbow”G

33. abcdef

34. Reproducibility At least three acceptable maneuversMaximum difference between the largest and next largest FVC and FEV1 = 150ml or 5% (If FVC <1lit, this value is 100ml)

35. Reproducibility

36. Flow chart of criteria

37. Reference valuesKnudson (male/ female)NHANES III (race difference)ACOEM recommends that the NHANES III equations be considered for general use in the occupational setting ERSATS

38. LLNFEV1 and FVC = 80%FEV1/FVC = 70-75%FEF25-75 = 50-60%

39. Interpretation

40. A. Normal: both the FVC and the FEV1/VC ratio are normal.“Knee”

41. B.Obstructive : FEV1/FVC , FEV1 TLC & RV or NL

42. The severity of the abnormality is graded:- % Pred FEV1 > 100 = May be a physiological variant- % Pred FEV1 < 80 and > 70 = Mild- % Pred FEV1 < 70 and > 60 = Moderate- % Pred FEV1 < 60 and > 50 = Moderately severe- % Pred FEV1 < 50 and > 35 Severe- % Pred FEV1 < 34 = Very severe

43. C. Restrictive: FEV1/FVC or NL FVC & FEV1 , TLC & RV

44. The severity of the abnormality might be graded as follows:- % Pred FVC < LLN and > 70 = mild- % Pred FVC < 70 and > 60 = Moderate% Pred FVC < 60 and > 50 = Moderately severe% Pred FVC < 50 and > 34 = Severe- % Pred FVC < 34 = Very severe

45. D.Mixed pattern: FEV1, FVC, FEV1/FVC< LLN ORFEV1,FVC <LLN,FEV1/FVC:NL

46. VCRVObstructiveVCRVNormalVCRVRestrictive

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49. Key Notes1.Be conservative in suggesting a specific diagnosis based only on pulmonary function abnormalities.2. Interpret borderline normal values with caution.3. First step = to evaluate and comment on the quality of the tests.

50. Key Notes4. The number of test indices (e.g., FVC, FEV1, etc.) used in interpretation should be limited to avoid an excessive number of false positive results.5. The primary guides for spirometry interpretation should be VC (slow or forced), FEV1, and FEV1/VC.

51. Key Notes6. FEV1/VC should be the primary guide for distinguishing obstructive from nonobstructive patterns.7. If FEV1/VC is borderline, use Instantaneous and mid flows to confirm airway obstruction.8. Don’t use FEF25-75 and the instantaneous flows to diagnose small airway disease.

52. Key Notes9. The pattern of a low FEV1/VC and greater than average VC and FEV1 should be recognized as one that may occur in healthy individuals.Borderline obstruction may exist when a subject's FEV1/FVC percent of predicted is below its LLN but the FEV1 falls within the normal range.10. The severity of airway obstruction should be based on FEV1.

53. Key Notes11. When FEV1 and FEV1/VC are normal, don’t use FEF25-75 for grading the severity of obstruction. flow rates may be used to confirm the presence of airway obstruction in the presence of a borderline FEV1/VC 12. A reduced VC and normal FEV1/VC suggest but not diagnose the presence of restriction (50-60%)13. The severity of restriction should be based on TLC. If VC is used, severity may be based on VC.

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55. Early small airway obx FV curve :upward concavity FVC, FEV1, FEV1/FVC :NL FEF 25-75 ???ATS states that FEF25-75% should not be used to diagnose small airway disease or to assess respiratory impairment

56. Probably normal spirogram Only  FEF 25-75No small airway disease (ATS)If FEV1/FVC is borderline → airway obxOnly  FEV1/FVC FEV1> 100% Normal FVC>100%

57. Non-specific ventilatory patternFEV1/FVC → NLFEV1 < LLNFVC< LLNTLC , RV , DLCO → NLObesityNormal variantOccult asthmaEarly stage of parenchymal disease

58. Significant changes %Time FVCFEV1Within a dayNormal subjects≥ 5≥ 5COPD patients≥ 5≥ 13Week to weekNormal subjects≥ 11≥ 12COPD patients≥ 20≥ 20Year to year≥ 15≥ 15

59. Significant changes Gender FEV1FVC Male 30ml / yr25 ml / yrFemale 25 ml / yr25 ml / yr

60. Case 1 A 60 year old man with a 60 pack/year smoking history and dyspnea on exertion FVC = 73% FEV1 = 23% FEV1/FVC = 25% FEF25-75 = 6% TLC = 150% obstruction

61. Case 2 50 year old man with a 65 pack/year smoking history and a cough. His chest x-ray shows a diffuse reticulonodular pattern FVC = 62% FEV1 = 42% FEV1/FVC = 56% FEF25-75 = 11% TLC = 64% Mixed

62. Case 3 43 year old woman with progressive dyspnea on exertion. Chest x-ray shows bilateral reticular infiltrates, especially in the lung bases FVC = 51% FEV1 = 49% FEV1/FVC = 78% FEF25-75 = 35% TLC = 52% Restriction

63. Case 4 A 38 year-old male Height: 171, weight: 82 FVC = 4.53 (100%) FEV1 = 3.35 (89%) FEV1/FVC = 74% FEF25-75 = 2.85 (65%) Normal

64. Case 5 A 53 year-old male Height: 180, weight: 73 FVC = 4.51 (97%) FEV1 = 3.18 (86%) FEV1/FVC = 70.50% FEF25-75 = 2.26 (58%) Borderline obx

65. Case 6 A 41 year-old male Height: 171, weight: 65 FVC = 4.77 (115%) FEV1 = 3.50 (101%) FEV1/FVC = 73.40% FEF25-75 = 2.74 (66%) Normal

66. Case 7 A 52 year-old male Height: 181, weight: 95 FVC = 3.81 (81%) FEV1 = 2.38 (63%) FEV1/FVC = 62.5% FEF25-75 = 1.72 (41%) Moderate obx

67. Case 8 A 39 year-old male Height: 184, weight: 83 FVC = 5.82 (111%) FEV1 = 4.98 (116%) FEV1/FVC = 85.6% FEF25-75 = 5.25 (114%) Normal

68. Case 9 A 44 year-old male Height: 185, weight: 92 FVC = 3.93 (76%) FEV1 = 2.75 (66%) FEV1/FVC = 70% FEF25-75 = 1.91 (43%) Mixed or pure obx

69. Case 10 A 54 year-old male Height: 178, weight: 80 FVC = 4.56 (121%) FEV1 = 3.10 (102%) FEV1/FVC = 68% FEF25-75 = 1.83 (51%) Normal

70. Case 11 41 year-old Female Height: 168, weight:72 FVC = 2.43 (68%) FEV1 =2.2(76%) FEV1/FVC = 91% FEF25-75 = 3.3 (123%) TLC = 79% Restriction

71. Case 12 A 68 year-old male FVC = 2.63(56%) FEV1 = 2.64 (52%) FEV1/FVC = 66% FEF25-75 = .7 (26%) TLC = 63% Mixed

72. Case 13 A 54 year-old male Height: 178, weight: 80 FVC = 3.8 (115%) FEV1 = 2.3 (81%) FEV1/FVC = 69 % FEF25-75 = 3.9 (68%) Borderline obx

73. Case 14 A 44 year-old male Height: 185, weight: 92 FVC = 1.73(42%) FEV1 = .5 (15%) FEV1/FVC = 30% FEF25-75 = 1.91 (43%) TLC = 119% Obstruction

74. Case 15 A 30 yrs male Height :173 ,weight : 70 FVC:74% FEV1: 66% FEV1/ FVC :75.4% FEF25-75 :45% Restriction

75. Case 16 A 24 yrs male Height :170 ,weight :82 FVC:85% FEV1: 78% FEV1/ FVC :69% FEF25-75 :55% Obstruction

76. Case 17 A 33 yrs male Height :170 ,weight :85 FVC:83% FEV1: 68% FEV1/ FVC :66% FEF25-75 :43% Obstruction

77. Case 18A 29 yrs male Height :168 ,weight :76 FVC:96% FEV1: 81% FEV1/ FVC :71.1% FEF25-75 :51% Obstruction (border line)

78. Case 19 A 33 yrs male Height :170 ,weight :75 FVC:85% FEV1: 55% FEV1/ FVC :53% FEF25-75 :28% Obstruction

79. Case 20A 38 yrs male Height :180 ,weight :67 FVC:64% FEV1: 51% FEV1/ FVC :67.7% FEF25-75 :31% Mixed / severe obstruction