Pulmonology Coding Alert

Question: What is the "six-minute walk test"? Our pulmonologist is interested in using this tool. From what I understand, oxygen saturations are recorded before a patient walks for six minutes at his own pace, on an unobstructed track, and then oxygen saturations are again recorded. How should I bill for this? Nevada Subscriber Answer: According to Empire Medicare's LMRP, simple pulmonary stress testing (94620) allows quantification of workload and heart rate activity, while measuring oxygen desaturation. A physician performs this test to measure the degrees of hypoxemia or desaturation that occurs with exertion. Exercise with pulse oximetry to document desaturation or to determine oxygen flow to prevent desaturation is reported with 94761 (Noninvasive ear or pulse oximetry for oxygen saturation; multiple determinations [e.g., during exercise]).

The key to determining the code is in the definition of 94620: Pulmonary stress testing; simple (e.g., prolonged exercise test for bronchospasm with pre- and post-spirometry). Stress testing measures lung function in addition to O2 saturation. If you are only doing pulse oximetry readings, you should report 94761. However, most carriers consider pulse oximetry as incidental and will not pay for this service separately from any other reimbursable service.

Documentation is key here. Audits are common for simple pulmonary stress testing. The American College of Chest Physicians lists on its Web site (www.chestnet.org/about/advocacy/general/stress.php) several guidelines for documentation. Be sure the report contains the patient's name, ordering physician, date of test, diagnosis, comments, an interpretation, recommendations, name of interpreting physician, and date of interpretation. Also, you should include the following:

1. While at rest: amount of oxygen used, oxygen saturation, heart rate, degree of perceived dyspnea, and blood pressure
2. While exercising: measurements above, time of collection of data, speed, and amount of work or distance
3. During recovery: measurements above, time of collection of data
4. Total time and distance or MET. It is also helpful to include the height, weight and age of the patient, along with the method of administration of oxygen if it is needed.