title: Patient-Specific Relationship Between Hydraulic Permeability of Microvasculature and the Extent of Burden of Excess Fluid in Hemodialysis Patients.
abstract: We have reported a significant correlation between hydraulic permeability of microvasculature adjusted with ultrafiltration rate (AdjLpst) and excess fluid divided by dry weight (ExF/DW) in a cross-sectional study of hemodialysis patients. We aimed to study longitudinally whether a similar relationship between them exists in each patient. Twelve hemodialysis (HD) patients in whom AdjLpst and ExF/DW had been measured more than four times (total of 85 measurements) were enrolled. AdjLpst was calculated by monitoring blood volume during HD. ExF was calculated from the fluid volume measured via bioimpedance spectroscopy. The borders of overhydration were 1.66 mL/mm Hg per min for AdjLpst and a positive value for ExF/DW. There was a significant correlation between AdjLpst and ExF/DW (r = 0.517). When the 85 measurements were classified into four quadrants according to ExF/DW and AdjLpst, the evaluations of fluid status agreed in 66 measurements. In six patients, significant positive correlations were found. In nine patients, equal to or more than 80.0% of evaluations by AdjLpst and those by ExF/DW agreed. In only one patient was there neither significant correlation nor agreement. AdjLpst of two patients suffering from chronic heart failure and microscopic polyangiitis was reduced compared with that of others loaded with the same extent of excess fluid. We concluded that there was a significant correlation between AdjLpst and ExF/DW and high agreement between evaluation by AdjLpst and evaluation by ExF/DW in the majority of patients. However, the relationship between them was patient-specific to some extent.
authors.affiliation: Division of Medical Engineering, Faculty of Medical Care Sciences, Himeji Dokkyo University, Hyogo, Japan. yashiro@pearl.ocn.ne.jp.
authors.forename: Masatomo
authors.initials: M
authors.lastname: Yashiro
authors.affiliation: Division of Nephrology, Kyoto City Hospital, Kyoto, Japan.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Ochiai
authors.affiliation: Division of Nephrology, Kyoto City Hospital, Kyoto, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yanai
authors.affiliation: Division of Medical Engineering, Faculty of Medical Care Sciences, Himeji Dokkyo University, Hyogo, Japan.
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Kotera
authors.affiliation: Division of Nephrology, Kyoto City Hospital, Kyoto, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Iehara
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001810:Blood Volume / Q000502:physiology*; D003430:Cross-Sectional Studies; D058266:Dielectric Spectroscopy / Q000379:methods; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D055806:Microvessels / Q000502:physiology*; D008875:Middle Aged; D010539:Permeability; D006435:Renal Dialysis / Q000379:methods*; D012189:Retrospective Studies; D014462:Ultrafiltration
keywords: Bioimpedance; Dry weight; Excess fluid; Hemodialysis; Hydraulic permeability