Specific slow tests are not mandatory in patients with extremely short standard (3.2 km/hr 10% slope) test durations during exercise oximetry

Abstract

Aim To compare the transcutaneous oxygen pressure results observed in patients with severe walking limitation during standard procedures (3.2 km/hr, 10% slope) versus during a test performed at a low speed (2 km/hr, 10% slope). Methods In 31 patients, the decrease from rest of oxygen pressure (DROP) index was measured on both buttocks, both thighs and both calves during two consecutive tests on treadmill. The maximal walking time (MWT) and the minimal DROP values (DROPmin) observed during the 2 tests were compared with t test. Correlation of DROPmin values during the slow and standard procedure was performed with linear regression. The −15 mmHg cut‐off value defined for standard test interpretation was used arbitrarily for the interpretation of slow test results. Results MWT was 80 ± 52 s versus 376 ± 269 s at standard and slow speed, respectively (p < .001). No difference on all recorded DROPmin values at a standard (−9.5 ± 6.9 mmHg) and slow (−10.5 ± 7.9 mmHg) speed was found; n = 186, p = .168. Coefficient of correlation between DROPmins found at the two tests was r = 0.820 (p < .01), with regression line close to the line of identity. With the identical −15 mmHg cut‐off, 166 (89.2%) of 186 the results were classified similarly after standard and slow procedures. Conclusion Specific slow treadmill procedures are not mandatory in patients with extremely short test durations when performing standard (3.2 km/hr 10% slope) exercise oximetry. In patients expected to be unable to walk at standard speed, the −15 mmHg normal limit seems to be valid for the interpretation of tests with a slow procedure (2.0 km/hr).

Lower Extremity Arterial Disease and Lumbar Spinal Stenosis: A Study of Exercise-Induced Arterial Ischemia in 5197 Patients Complaining of Claudication

“…DROPmin has been validated as a sensitive and specific indicator for exercise-induced ischemia for both proximal and distal arterial claudication. A previous study showed that the treadmill procedure had little influence on exercise-oximetry results in the patients that were candidates for a slow treadmill procedure [ 23 ].…”