Cerebral hemodynamics in peritoneal dialysis versus intermittent hemodialysis: A transcranial Doppler pilot study

Abstract

This study evaluated intradialytic cerebral hemodynamics measured by transcranial Doppler (TCD) in intermittent hemodialysis (iHD) versus nightly peritoneal dialysis (NIPD). Intradialytic TCD was serially performed in chronic dialysis patients receiving iHD ( n = 10) and NIPD ( n = 10). A linear mixed model was used to model mean flow velocity (MFV), pulsatility index (PI), and mean arterial pressure (MAP) as functions of time and treatment group. Intradialytic cerebral volatility (IDCV) was calculated using the coefficient of variation (CV) and mean absolute value of change (AVC) of each patient’s MFV, PI, and MAP values over time. Mixed model analyses found no significant difference between MFV, PI, and MAP treatment groups in change over time, though volatility differed significantly. Mean CV values for MFV, PI, and MAP were higher in iHD than NIPD (MFV 0.22 vs. 0.10, p = 0.005; PI 0.14 vs. 0.08, p = 0.003; MAP 0.057 vs. 0.032, p = 0.009). AVC values were similarly higher in iHD compared to NIPD (MFV 8.26 vs. 4.43, p = 0.04; PI 0.17 vs. 0.084, p < 0.001; MAP 6.05 vs. 2.9, p = 0.003). PI, MFV, and MAP were more stable in NIPD than iHD, as measured by intradialytic TCD monitoring. This study identifies IDCV as a unique TCD metric for intradialytic cerebral hemodynamics.

Cerebral blood flow pulsatility and cerebral artery stiffness acutely decrease during hemodialysis

“…These differences in findings may in part result from a higher calcium concentration (1.5 mmol/L) in the dialysis bath, acutely altering vascular tone and arterial stiffness (Mac-Way et al, 2011). In a more recent study, Ghoshal et al (2021) observed a slight increase in cerebral PI during hemodialysis that was not statistically significant. Small sample size, along with limited information regarding study populations and dialysis characteristics, however limit comparison between studies.…”

“…While cerebral blood flow and mean cerebral blood velocity have been measured during hemodialysis, very few studies have evaluated changes in pulsatile components of flow. Recently, Ghoshal et al ( 2021 ) reported an increase in middle cerebral artery blood velocity (MCAv) pulsatility index during hemodialysis, which could contribute to cerebral damage in the long term. However, the study did not provide mechanistic insight into the determinants of increased pulsatility.…”