ATS Pulmonary Function Laboratory Manual

chapter  19

Procedure Notes 1.

Several factors may influence the test results. 1.1. Patient effort 1.1.1.

Patient should be encouraged to give a maximal performance, unless early termination is warranted (40, 50). Variables to detect a maximal performance (30). 1. HR must be close to the maximal predicted: predicted HR = 210 − 0.65 × (age), (preferred), or 220 − age (3, 30, 50) 2. ˙ V e,max: between 60 and 80% of ventilatory capacity (3, 28) Ventilatory Capacity = MVV or FEV 1 × 35 to 40 3. Metabolic work: RER equal to or greater than 1.10 to 1.15; lactate equal to or greater than 7 mMol 4. Supervising clinician’s observation of apparent effort

1.1.2.

1.2. Medications 1. Beta-blockers, calcium channel blockers, and similar medications may affect the heart rate response. 2. Bronchodilators may affect the ventilatory response. 1.3. Exercise device selection and usage 1.3.1. Patient performance, coordination, and physical limitation with a particular exercise device can affect results: 1. Inability to walk on treadmill 2. Weight support on handrails 3. Inability to coordinate pedaling effort 4. Orthopedic constraints 1.3.2. Exercise device calibration 1. A poorly calibrated exercise device will affect reported work rate but not the overall ˙ V o 2 max. 1.3.3. In untrained patients without heart or lung disease, higher ˙ V o 2 max is usually obtained on a treadmill (20, 22). In trained patients, their usual form of exercise may produce the highest ˙ V o 2 max. 2. Clinical exercise testing using an arm ergometer (20, 23) 2.1. Useful alternative for diagnostic exercise testing in patients with lower extremity impairment 2.2. Performed for occupational evaluation in patients whose work primarily involves upper body activity 2.3. Arm ergometers can be either mechanically or electronically braked. 1. Calibration should be performed according to the manufacturer’s suggested guidelines (20). 2.4. Exercise protocols can be continuous, incremental, or discontinuous (23). 1. 10- to 25-Watt increments in 2-minute intervals are suggested (20, 23). 2.5. ˙ V o 2 max for arm exercise is generally equal to about 70% of that for leg exercise (58). 3. Cardiopulmonary exercise testing should be performed under the supervision of a physician appropriately trained to conduct clinical exercise tests and certified in advanced cardiac life support. The degree of super- vision will be determined by the clinical condition of the patient being tested. It is recommended that the physician be present when patients are tested.

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