Getting Spirometry Right It Matters! Performance, Quality Assessment, and Interpretation. Susan Blonshine RRT, RPFT, AE-C, FAARC

Transcription

1 Getting Spirometry Right It Matters! Performance, Quality Assessment, and Interpretation Susan Blonshine RRT, RPFT, AE-C, FAARC

2 Objectives Sample Title Recognize acceptable spirometry that meets the start of test and end of test criteria. Recognize an obstructive pattern consistent with COPD or asthma.

3 Sample Title Spirometry: a 3-Step Process 1. Pre-test 2. Test 3. Post-test a. Acceptability and Repeatability b. Report generation

4 Sample Title Spirometer Preparation (Equipment-dependent) Warm up spirometer before patient arrives Verify that the room is between 17º - 40º C (63º - 104º F) Record room s relative humidity and barometric pressure

5 Sample Title Equipment Function and Calibration Each day of patient testing, use a 3-liter syringe to verify proper equipment function Remember acceptable variance 105 ml Range: 2.90 to 3.10

6 Sample Title Never test patients on a system that cannot pass calibration checks

7 Patient Preparation

8 Sample Title Introductions and Information Introduce yourself to the patient Check patient identification Briefly explain the procedure Encourage questions, and answer them in easily understood terms Avoid using technical terms and acronyms

9 Sample Title Gathering Demographic and Patient Information Measure patient s height to the nearest centimeter or ½ inch Patient should be measured in stocking or bare feet

10 Patient Training

11 Sample Title Spirometry is effort-dependent The patient must: Understand testing needs Be cooperative during the testing process

12 Sample Title Spirometry is effort-dependent Good coaching can increase volume 10% to 15%

13 Sample Title Spirometry is effort-dependent Good technologist patient interaction is key to testing success

14 Testing Sample Position Title The patient should be sitting during testing (current ATS/ERS) Patient may be standing with a chair behind for occupational testing Both feet should be on the floor

15 Sample Title Tight clothing that may restrict breathing should be loosened

16 Open-circuit Sample TitleTesting 1. The patient breathes in as deeply as possible, to Total Lung Capacity 2. The patient inserts the mouthpiece between teeth and presses the lips together 3. The patient blows out as fast and hard as possible to Residual Volume

17 Closed-circuit Sample Title Testing 1. The patient positions the mouthpiece in his/her mouth and breathes normally through the mouthpiece 2. The patient inhales as deeply as possible to Total Lung Capacity 3. The patient blows out as fast and hard as possible, completely to Residual Volume

18 Sample Title Testing Position Instruct and demonstrate proper posture during testing Seated Looking forward Both feet on the floor

19 Sample Title Head Position The head should be slightly elevated The chin should be pointed forward

20 Sample Title Placement of the Mouthpiece The patient places the mouthpiece in his/her mouth The patient s tongue goes under the mouthpiece The patient s lips should wrap tightly around the mouthpiece The patient should not bite the mouthpiece

21 Sample Title Patients wearing dentures should remove them prior to testing

22 Sample Title Noseclips Explain how noseclips will be used during testing, to force all breathing through the mouthpiece

23 Go Sample Over Each Title Step 1. Place the mouthpiece in your mouth 2. Breathe in and out nice and easy 3. Breathe in as deep as possible 4. Blow out hard and fast 5. Keep squeezing all the air out for about six seconds or until you are told to breathe in deeply again 6. Take the mouthpiece out of your mouth and relax

24 Sample Title Testing Demonstration Always demonstrate the test procedure with animation and the same level of effort that is expected of the patient Most patients should be able to achieve an acceptable peak flow

25 Sample Title Instruct Patient to Sit up straight Place the mouthpiece in his/her mouth Breathe in as deeply as possible

26 Sample Title Observe the patient s effort and accessory muscles

27 Sample Title Instruct the patient to blow out hard and fast Watch the system s graphic displays as the patient blows out The patient should not hold his/her breath at Total Lung Capacity

28 Sample Title Instruct the patient to continue to squeeze all the air out for at least 6 seconds, or the volume-time curve shows a 1-second plateau

29 Sample Title When a flow-volume loop is being performed, tell the patient to breathe back in as rapidly as possible, to Total Lung Capacity

30 Sample Title Between Trials Instruct the patient to remove mouthpiece and rest between trials Use rest time between trials to reinstruct, as needed

31 Maneuver Performance Three acceptable maneuvers Practical upper limit of 8-clinical judgement

32 Satisfactory start of test Back extrapolated volume less than 5% or 150 ml Pause at TLC greater than 4-6 seconds decreases PEF and FEV 1

33 End of test criteria Obvious plateau of 1 second Minimum exhalation time Six seconds

34 Asthma Initiative of Michigan, Volume-Time Curve

35 Acceptability Criteria Was end of test criteria met? ( 1 second plateau) Was there a minimum exhalation time of 6 seconds? Was the start of test satisfactory? (Less than 5% back-extrapolation) Did the subject understand the instructions?

36 Acceptability Criteria Was inspiration performed with maximum effort? Was exhalation smooth and continuous? Was effort maximal on expiration? Are there at least 3 acceptable maneuvers? (all 7 criteria must be met)

37 Repeatability Is the variance less than.15 L between the largest and second largest FVC Is the variance less than.15 L between the largest and second largest FEV 1 Is there documentation for lack of repeatability?

38 Sample Title Deciding when Testing is Complete Have 3 acceptable tests been performed? Has repeatability criteria been met? Have 8 or more tests been performed? Can/should the patient continue testing? Are the inspiratory flow patterns repeatable with maximal effort?

39 Error Recognition and Correction A skilled technologist can recognize the following common errors and take necessary corrective measures

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48 Nonconsistent

49 Spirometry Flow Chart Miller MR, Hankinson J, Brusasco V, et al. Standardisation of spirometry. Eur Respir J. 2005;26:

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51 Reference Values Height must be accurate Match to patient population NHANESIII (8-80) Wang (<8) Use LLN 95% confidence interval

52 Reference Values Using.70 as a fixed lower limit for FEV1/FVC ratio increase false positive results Males >40 and females >50 Reference author should be noted on report Author s last name and date of publication

53 ATS/ERS Interpretation - Obstruction For identification of obstruction Use LLN for FEV1/VC NOT a fixed ratio of 0.70 (GOLD and ATS COPD recommendation) Roberts SD, et. al. FEV1/FVC Ratio of 70% Misclassifies Patients With Obstruction at the Extremes of Age. Chest 2006;130; *Also see Falling Ratio Working Group at:

54 ATS/ERS 2005

55 Barreiro and Perillo, National Asthma Council, 2005.

56 Normal

57 Obstruction

58 Restriction

59 Sarah, respiratory therapist Age: 52 years Her roommate has been complaining about Sarah s chronic cough and expectoration Patient has had a productive cough most mornings for >5 years and occasional sinus headaches Otherwise, she reports perfect health Does not exercise much Denies dyspnea

60 Finding Pre-Value (L) %Pred Postbronchodilator %Pred FVC FEV FEV 1 /FVC 48% 48% Petty and Enright, 2005.

61 Example 1 Pred Actual %Pred FVC % FEV % FEV 1 /FVC 79% 80% 101% A. Normal B. Obstruction C. Restriction

62 Example 2 Pred Actual %Pred FVC % FEV % FEV 1 /FVC 79% 100% 127% A. Normal B. Obstruction C. Restriction D. Unacceptable

63 Example 3 Pred Actual %Pred FVC % FEV % FEV 1 /FVC 79% 69% 87% A. Normal B. Obstruction C. Restriction D. Unacceptable (Cough)

64 Example 4 Pred Actual %Pred FVC % FEV % FEV 1 /FVC 79% 99% 125% A. Normal B. Obstruction C. Severe Restriction D. Unacceptable

65 SPIROMETRY INTERPRETATION 1. Check graph for maneuver ACCEPTABILITY and REPEATABILITY 2. Low FEV1/FVC ratio = obstruction 3. Low FVC, high FEV1/FVC = suggests restriction

66 Any Questions? Susan Blonshine BS, RRT, RPFT, FAARC, AE-C TechEd Consultants, Inc.