The six-minute walk test is an objective method, to measure the ability to perform daily living activities. It is more often performed, to evaluate the functional status, monitor therapy, or assess the prognosis in patients with cardiac and pulmonary diseases. In comparison to traditional pulmonary exercise test, 6MWT needs less technical support or equipment, making it a simple and inexpensive method to measure functional capacity. The validity and the reliability of 6MWT was studied in different conditions, including obstructive lung diseases, interstitial lung diseases, pulmonary hypertension, heart failure and peripheral arterial diseases.
At the time of the test, the patient's heart rate, blood pressure and oxygen saturation, were measured. The patient was asked to indicate his or her level of "effort to breath", by using a Borg scale, a 12 points scale from 0 to 10, with corresponding expression figures in escalating intensity, printed on easy readable card, where 0 is "nothing at all" and 10 is "very, very severe".
The 6MWT was performed according to the ATS guidelines and it was supervised by a trained respiratory technician throughout the test. Subjects were asked to walk at their own pace, along a 30 m long and straight hospital hallway marked at one meter intervals. Each patient was instructed to walk as much distance as possible, in 6 minutes. No encouragement was offered, but the patient was told standardized phrases, to indicate the time remaining. The patient was allowed to stop, if symptoms of significant distress occurred, like severe dyspnea, chest pain, dizziness, diaphoresis, or leg cramps. However, the patient was asked to resume walking as soon as possible, if he or she could. At the end of six minutes, the patient was asked to stop and a repeated measurement of blood pressure, heart rate, oxygen saturation by pulse oximeter and Borg score, were measured and the distance walked for 6 minutes was recorded. The patients were asked to be observed for a 10-15 minutes period after the test, to assess any possible complications. Patients who started to walk but did not complete the test, were included in the study.
