Investigation of the immediate pre-operative physical capacity of patients scheduled for elective abdominal surgery using the 6-minute walk test.

ABSTRACT

OBJECTIVES: To evaluate the effects of repetition of the 6-minute walk test in patients scheduled to undergo abdominal surgery within the next 48 hours, and to verify the physical capacity of these subjects before surgery. DESIGN: Cross-sectional study. SETTING: University teaching hospital. PARTICIPANTS: Forty-two patients scheduled for elective abdominal surgery within the next 48 hours. OUTCOME MEASURES: Distance walked in the 6-minute walk test, heart rate, peripheral oxygen saturation, dyspnoea and leg fatigue. RESULTS: Thirty-one patients (74%) were able to walk for a longer distance when the test was repeated. In these subjects, the mean increase in distance walked was 35.4 [standard deviation (SD) 19.9]m. Heart rate, dyspnoea and leg fatigue increased significantly over time on both tests (P<0.05). The mean heart rate at the end of the sixth minute was significantly higher on the second test (P=0.022). Peripheral oxygen saturation remained above 90% in both tests. The furthest distance walked was, on average, 461.3 (SD 89.7)m. This value was significantly lower than that predicted for the sample (P<0.001). CONCLUSION: Patients scheduled to undergo abdominal surgery were able to walk further when they performed a second 6-minute walk test. Moreover, they showed reduced physical ability before surgery. These findings suggest that repetition of the 6-minute walk test may increase the accuracy of the distance walked, which is useful for studies assessing the physical capacity of patients undergoing abdominal surgery.