Measurement of Changes in Cerebral Blood Flow Velocity During Hemodialysis

Kee, Kwang Soo; Choi, Young Bin; Han, Si Ryung; Kim, Yeong In; Park, Jung Hee; Park, Joo Hyun; Yang, Chul Woo; Kim, Yong Soo; Bang, Byung Kee

Abstract

Hemodialysis is a safe and effective treatment for uremic patients but hemodynamic changes during hemodialysis is suggested to be the possible cause of encephalopathy. However, few studies have evaluated the cerebral circulation of and the effects of hemodialysis. Therefore, this study was performed to evaluate the cerebral blood flow by transcranial doppler. The study populations were 12 male patients who ranged in age from 28 to 58 years(mean:57) and were receiving maintenance hernodialysis for 3.8 years(0.5-11.5 years). Mean blood flow velocity(MFV), pulsatility index(PI) and resistance index(RI) were measured in carotid artery(CA), middle cerebral artery(MCA), anterior cerebral artery(ACA) and posterior cerebral artery(PCA) before, during and after hemodialysis. Simultaneously, we also checked variables(body weight, blood pressure, arterial blood gases, hematocrits, and other biochemical parameters) which might affect cerebral blood flow. MFV during(70.5+/-20.3 vs. 60.0+/-211cm/sec) and after(vs. 60.6+/-13.7cm/sec, p<0.01) hemodialysis in CA showed significant reduction as compared to the that of before hemodialysis, but other vessels(MCA, ACA and PCA) showed no significant changes. There were no significant changes in PI and RI before, during and after hemodialysis. Body weight, PaCO(2), blood urea nitrogen and hematocrit changed significantly during and after hemodialysis as compared to those of before hemodialysis, but correlation between changes of MFV and these variables was not observed. Hemodialysis and its associated physiologic changes are not associated with cerebral blood flow, and this result suggests the well-preservation of autoregulation of cerebral blood flow during and after hemodialysis.