title: Evaluation of cerebral oxygenation in patients undergoing long-term hemodialysis.
abstract: OBJECTIVE
  Patients undergoing hemodialysis (HD) have higher occurrence rates of cerebral diseases, including uremic encephalopathy, cognitive impairment, dementia, and cerebrovascular disease, than the general population. During HD, ultrafiltration is performed to maintain an adequate fluid condition and is associated with subsequent blood volume (BV) reduction. We aimed to (1) monitor changes in cerebral oxygenation and BV reduction during HD, and (2) clarify the mechanism that influences cerebral oxygenation in HD patients.
  
  
  METHODS
  Eighteen HD patients and 12 healthy controls were recruited. Regional saturation of oxygen (rSO2) was continuously monitored in the frontal cortex using INVOS 5100C before, during, and after HD, and in healthy controls. Relative change in BV (%ΔBV) was simultaneously monitored during HD using a BV monitor.
  
  
  RESULTS
  Before HD, patients had significantly lower rSO2 values than controls (56.1 ± 1.4 vs. 70.4 ± 2.5%, p < 0.001). Although %ΔBV significantly decreased from 20 min to the end of HD (20 min: -3.3 ± 0.3%, p < 0.05; end of HD: -12.0 ± 1.0%, p < 0.01), changes in rSO2 values during HD were not significant. No relationship existed between rSO2 values and blood pressure levels, hemoglobin levels, oxygen pressure, HCO3(- ), oxygen saturation, and arterial O2 content before and after HD. Furthermore, changes in rSO2 were not correlated with changes in these parameters.
  
  
  CONCLUSIONS
  rSO2 values before HD were significantly lower in HD patients than in healthy controls. rSO2 values were maintained during HD and were not influenced by BV reduction.
authors: Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University, Saitama City, Japan.
authors: Taro
authors: T
authors: Hoshino
authors: Susumu
authors: S
authors: Ookawara
authors: Sawako
authors: S
authors: Goto
authors: Haruhisa
authors: H
authors: Miyazawa
authors: Kiyonori
authors: K
authors: Ito
authors: Yuichiro
authors: Y
authors: Ueda
authors: Yoshio
authors: Y
authors: Kaku
authors: Keiji
authors: K
authors: Hirai
authors: Aoi
authors: A
authors: Nabata
authors: Honami
authors: H
authors: Mori
authors: Izumi
authors: I
authors: Yoshida
authors: Kaoru
authors: K
authors: Tabei
mesh_terms: D000368:Aged; D001810:Blood Volume; D002560:Cerebrovascular Circulation; D054022:Cerebrum / Q000098:blood supply / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000503:physiopathology* / Q000628:therapy; D008134:Long-Term Care; D008297:Male; D010100:Oxygen / Q000097:blood*; D006435:Renal Dialysis
chemical_list: D010100:Oxygen