Analysis of prefrontal cerebral blood volume and flow changes in ESKD patients undergoing hemodialysis using functional near-infrared spectroscopy.

BACKGROUND

End-stage kidney disease (ESKD) patients undergoing hemodialysis experience diverse neurological complications. This study investigated prefrontal cerebral blood volume (CBV) and cerebral blood flow (CBF) during hemodialysis using functional near-infrared spectroscopy (fNIRS) to analyze cerebral hemodynamic changes.

METHODS

ESKD patients undergoing maintenance hemodialysis without a history of neurological disorders were enrolled prospectively. The fNIRS data were collected using a NIRSIT Lite device. The fNIRS values were recorded three times for each patient: before the start of hemodialysis (pre-HD), 1 h after the start of hemodialysis (mid-HD), and after the end of hemodialysis (post-HD). The average changes in oxy-hemoglobin (HbO), deoxy-hemoglobin (HbR), total hemoglobin (HbT, calculated as HbO + HbR) concentrations, and in hemoglobin concentration difference (HbD, calculated as HbO - HbR) were analyzed. We then compared the differences in changes in HbO, HbR, HbT, and HbD according to the hemodialysis period.

RESULTS

Thirty hemodialysis patients were analyzed. The change in HbO, HbT, and HbD levels showed significant differences according to the hemodialysis period. Between the pre-HD and post-HD periods, there were significant differences in changes in HbO (0.005 ± 0.001 µM vs. 0.015 ± 0.004 µM,  = .046) and HbT (0.006 ± 0.001 µM vs. 0.016 ± 0.008 µM,  = .029). Additionally, between pre-HD and post-HD periods, HbD tended to increase (0.005 ± 0.001 µM vs. 0.014 ± 0.004 µM,  = .094).

CONCLUSIONS

We demonstrated that during one hemodialysis session, the relative change in prefrontal CBV increased post-HD compared with pre-HD. These results are expected to help understanding the mechanisms underlying the effects of hemodialysis on brain function.