ATS Pulmonary Function Laboratory Manual

chapter  19

Pre-Test Preparation

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Step Action

5.

Determine exercise protocol: • Determine exercise device and protocol based on the history, physical exam, exercise limitations, type of available equipment, and patient age (9, 33, 34). • Treadmill 1. Maximal incremental protocols are based on the Bruce, Balke, and Naughton protocols (35–37). Modification of protocols may be necessary to meet the exercise limitations of the patient, though any modification should be documented. A linear treadmill ramp protocol can also be used (38). A complete set of protocols is available from the American College of Sports Medicine guide for exercise prescription and training (23). 2. Exercise protocols designed to determine ˙ V o 2 max as one end point typically last about 10 min- utes (39) (protocol may be modified with this total expected exercise time in mind). 3. Ramp protocols start the patient at a low speed, which is increased gradually until the patient has a good stride. The grade is increased progressively at fixed intervals (e.g., 10 to 60 seconds) or con- tinuously starting at 0% grade. The increase in grade is calculated so that the exercise is completed in 6 to 12 minutes (13). • Cycle ergometer 1. Standardized protocols: Jones (40), Astrand (41), James (42) 2. Maximal incremental protocol a. 3 minutes of unloaded pedaling b. Increase work rate in 10 to 25 Watt increments every minute until patient reaches volitional exhaustion, or test is terminated by the medical monitor. c. With computer-controlled cycle ergometers, it is possible to increase the work rate continu- ously, usually every 1 to 2 seconds in a ramp-like fashion (ramp protocol). However, the total increment per minute should be 5 to 25 W/minute (9). d. To determine an appropriate work rate increment to yield a test whose incremental exercise period is approximately 10 minutes in duration: • ( ˙ V o 2 max,predicted − ˙ V o 2 unloaded)/10 = estimated increments in power output (in Watts/minute) (where ˙ V o 2 is in ml/min) • Reduce the work rate increment for patients suspected of having reduced exercise tolerance. • Increase the work rate increment rate for very fit patients. If railings are used, the back of the hands can be used for balance or light touch. a. Avoid weight support which has an effect on ˙ V o 2 max and exercise time (22, 34). b. Use of upper extremities increases the muscle artifact in the ECG tracing. 3. Instruct the patient about walking on the belt. a. A brief trial walk may be appropriate to familiarize the patient with the equipment and to check the ECG signal for motion artifact. 4. For the safety of the patient, a spotter at the rear of the treadmill may be appropriate (20). • Cycle ergometer 1. Adjust handlebar and saddle height. a. When the pedal is at bottom center, knee flexion should be about 20°. 2. Instruct the patient on pedal speed (appropriate to ergometer); 60 rpm is the usual target. a. A brief trial with little or no power output is appropriate to familiarize the patient with the equipment and to check the ECG signal for motion artifact. Position patient on exercise device: • Treadmill 1. Hands at side 2.

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