Multiprobe devices for exercise transcutaneous oxymetry in patients complaining claudication: interest and limits of unusual probe positions.

BACKGROUND

Exercise transcutaneous oximetry (PtcO2) can argue for a vascular origin of exercise-related pain in atypical unusual localizations, such as lumbar, thigh or foot pain. We used five probes as a standard for treadmill PtcO2 tests. Recent commercially available devices now include up to eight probes. We aimed at analyzing the potential interest of positioning a 6th probe on the area of unusual localization during exercise PtcO2 tests.

METHODS

We retrospectively analyzed our data with a 6-probes device, using as a standard: one probe on the chest, one on each buttock and one on each calf. The sixth probe was positioned either: in the lumbar median position (N.=342), on the anterior lower part of the thigh (N.=391) or on the dorsum of the foot (N.=155) in patients complaining exercise-induced pain including the back, thigh or foot respectively. Results on the sixth probe at the limb were compared to result of the standard adjacent probe. A positive test (abnormal result) was defined as a minimal value of the DROP-index lower than minus 15 mmHg.

RESULTS

Prevalence of positive results on the 6th probe with negative results on the adjacent standard probe was 2.3% at the lumbar site, 3.8% at the thigh and 12.3% at the foot level.

CONCLUSIONS

Atypical localizations are rarely but sometimes associated to isolated positive exercise PtcO2 results and may justify the use of more than five probes in some patients, specifically for foot pain.