ATS Pulmonary Function Laboratory Manual

chapter  14

6. Recommendations for additional equipment and set-ups have been reported (48, 63). 6.1. Dry inspired air via a reservoir bag; connecting tubing, one-way valve or demand valve may be used to accentuate the response (48). This additional equipment can also be used if the water content of the room is more than 10 mg/L (20 to 23° C, 50% RH). 6.2. Cold dry air using a heat exchanger may be used to accentuate the response (18, 48). This device may be advantageous because it shortens the duration of the challenge portion of the test needed to induce bronchoconstriction in some studies. Procedure Several attempts have been made to standardize the exercise challenge testing procedure, but the methodology is still inconsistent (4–6, 36, 48, 54, 64, 65). Some of the difficulty of standardization can be attributed to the different populations being tested. Silverman and Anderson (4) and others have recommended exercise guidelines specific for children with asthma (54, 55). Others have recommended protocols that relate to a broad spectrum of adult populations (36, 53, 64, 65). Debate remains ongoing regarding the preferred type of exercise device. An early study demonstrated that treadmill exercise is more provocative than cycle testing. This same study reported a higher degree of response associated with free-running versus running on a treadmill, which could be possibly related to environmental factors or the level of exercise achieved (66). Currently, several authors recommend the use of cycle ergometers because it is easier to determine work rates and to monitor additional variables (53, 64). Selection of the exercise device and the type of exercise will likely be related to the availability of the equipment, staff preferences, and the clinical presentation and abilities of the patient. The test that has been extensively validated using a rapid ramp to 85% maximum HR and then a plateau phase at that work level for an additional 6 minutes. Safety concerns, especially in older adults, have led to a slower ramp up to the 85% target. 1. Pulmonary Function (PF) Test Evaluation Methodology PF tests are used to assess the airway function and responsiveness before and after exercise. 1.1. The type of measurement can be specific for the clinical presentation of the patient or the sophistica- tion of the laboratory, but spirometry is the standard mode of testing. 1.2. Spirometry is performed according to ATS/ERS recommendations prior to and after the exercise period (67). However, two acceptable spirometric test maneuvers (instead of the usual three) may be used for time considerations. 1.3. Peak expiratory flow rate (PEFR) using a peak flow meter can be used. However, while the instrumen- tation is less expensive than a spirometer, the PEFR measurement using a peak flow meter is more variable, more effort dependent, has poor quality control, and is less sensitive. 1.4. Airways resistance (Raw) can be a sensitive indicator of airway responsiveness (5, 68). 1.5. Static lung volume measurements can be performed to assess air trapping (6). 1.6. PF test equipment should be calibrated according to manufacturer’s and ATS/ERS recommendations (67).

2. Exercise Intensity 2.1.

Several authors recommend an exercise intensity based on the heart rate response (5, 6, 15, 48, 63, 69). Using the heart rate as an indicator of exercise intensity allows use of the treadmill or various ergom- eters and adjustment of the work rate based on the patient’s aerobic capacity.

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