Is estimation of laser Doppler skin perfusion pressure appropriate during hemodialysis enforcement

The laser Doppler skin perfusion pressure (SPP) testing is expected to be beneficial for assessment of lower extremity peripheral artery disease (PAD) in patients on hemodialysis (HD). However, it is inconsistent at what timing SPP should be measured in relation to HD procedure. We measured each SPP value before, during, and after HD in 12 limbs of 6 patients without diabetes or PAD. There were not significant differences among mean SPP values, which were 90mmHg (SD=15), 83mmHg (SD=10), 89mmHg (SD=12), and 86mmHg (SD=16) at predialysis, 2-hr, 3-hr, and postdialysis, respectively. Results of this study suggest that compensatory responses to volume loss could contribute to maintain cutaneous perfusion during ultrafiltration of fluid. The laser Doppler SPP examination is likely to be useful even during or after HD. However, it seems that the SPP evaluation during or after HD requires carefulness.