GUIDELINES FOR CREDENTIALING PHYSICIANS AND

PULMONARY FUNCTION LABORATORIES

Category IIB

Guidelines for Credentialing Physicians and Pulmonary Function Laboratories

Category IIB

FORCED EXPIRATORY SPIROGRAM, WITH AND WITHOUT BRONCHODILATORS, WITH MEASUREMENTS OF FEV1, FVC, FEV1/FVC, MMEFR, WITH PREDICTED VALUES AND PER CENT OF PREDICTED, AND INTERPRETATION OF RESULTS

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These tests may be performed by the physician or by an adequately trained individual. The physician responsible for the test should have special interest and experience in respiratory disease. The equipment and methods used must conform with the standards developed by the Diagnostic Accreditation Program, according to the attached guidelines for routine spirometry under Category IIB and Category III.

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STANDARDS

IPROCEDURE FOR SETTING UP A NEW LABORATORY OR NEW EQUIPMENT FOR PULMONARY FUNCTION TESTING:

  1. It is recommended that after the initial set up of the equipment, that tests be performed on a small number (10) of healthy, non-smoking control subjects, to ensure that results are within the range of accepted predicted results.
  1. The predicted values chosen should, when possible, be based on measurements on a large number of non-smoking subjects, made using similar methods. In the case of special measurements or special groups of individuals, it may be necessary for the laboratory to determine its own predicted values. In general, the spirometry predicted values are those of Knudson, 1983 and for those individuals < 18 years of age, Polgar & Wang, 1979 or Hibbert (BCCH recommends).

IISPIROMETRY MEASUREMENT:

  1. In spirometric measurement of pulmonary function, the volume range of the instrument should not be less than 10 litres (ATPS).
  1. The accuracy should be within the +3% of the reading or 50 ml, whichever is greater.
  1. The instrument should have low inertia and offer low resistance to air flow, (less than 1.5 cm H20/L/sec at 12.0/L/sec flow). Manufacturers’ specifications will normally be acceptable evidence of this performance.
  1. The apparatus must incorporate a graphic recording. The volume sensitivity must be at least 10mm/L of volume.
  1. In the case of Category III laboratories, the laboratory should check the reproducibility of determinations of spirometry, FRC, lung volumes, and diffusing capacity by doing multiple determination over at least five days on a minimum of three non-smoking healthy normal subjects. This information should be on file prior to the inspection Credentialing visit. Record results on Worksheet 1B (attached)
  1. For computerized equipment, all the computer calculations of every test or measurement MUST by checked by manual calculations on a few subjects to ensure that the computer calculations are correct. The laboratory must keep on file the equations used by the manufacturer for calculating results, the published references for the predicted values, and the actual equations used by the computer for calculating predicted values. Predicted results should also be derived manually in a few subjects to check that the computer derived values are correct.
  1. The apparatus should incorporate a temperature sensing device such that flows and volumes recorded can be corrected to body temperature, pressure, saturated with water vapour (BTPS).

IIIPERFORMANCE AND RECORD KEEPING OF TESTS:

  1. At least three satisfactory tracings of forced expiratory spirograms should be obtained prior to the use of bronchodilators. The operator should ascertain that the patient has reached full inspiration and that maximal effort is used during the subsequent forced expiration. The forced expiration should be continued for at least 6 seconds to ensure that maximal expiration has resulted. Ideally the FEV1 and FVC from the satisfactory traces should not vary by more than 3%.
  1. The maximum FEV1 and FVC will be recorded after examining the data from all acceptable curves, even if the two values do not come from the same curve.
  1. For testing after bronchodilators, (the bronchodilator may be administered by either metered dose inhaler or dry powder inhaler); adequate time (a minimum of 15 minutes) should be allowed to lapse before the tests are repeated and at least two satisfactory forced expiratory spirograms obtained. Records of the tracings should be kept in the patient's file in the laboratory.
  1. A copy of the results and interpretation should be included in the patient's file in the laboratory. Use appropriate Worksheet 1A or 1B to conduct and record monthly calibrations.

SPECIFIC GUIDELINES (Minimum of 3 FVC's)

FEV1 should vary less than 2 - 3%

FVC should vary less than 2 - 3%

PEFR should vary less than 3 - 5%

The above range of variability applies to co-operative, healthy subjects; somewhat greater variability may be encountered in patients.
WORKSHEET #1A

Category IIB Laboratories

Hospital/Clinic: / Year:
SPIROMETRY
Wk # / Date / FVC / FEV1 / FEV1/FVC% / MMEFR
FEF 25-75% / PEFR

To Conduct Tests to Record Information on Worksheet #1A:

  1. Usually the first day of the week.
  2. Study at approximately the same time of day.
  3. Perform full tests on “Laboratory Normal”.
  4. Chart final results on Worksheet.
  5. Retain all data and graphs. File chronologically.

Signature of Physician / Date
Signature of Technician/Nurse / Date

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