title: Thermodilution versus saline dilution method for vascular access blood flow measurement in high-flux and on-line hemodiafiltration.
abstract: OBJECTIVE
  Access blood flow (Qa) measurements are one of the most important components in vascular access monitoring programs, even though these indirect methods have only been validated with high-flux hemodialysis (HF; pump flow [Qb] 300 mL/min). This study was to assess the utility from thermodilution (BTM) with respect to the saline dilution method (SDM) in HF and on-line hemodiafiltration (OL-HDF) with routinely prescribed parameters in comparison with validation conditions.
  
  
  METHODS
  Three consecutive sessions were assessed in 31 hemodialysis patients (27AVF). The Bland-Altman method and Lin's concordance coefficient (ρc) were used to study accuracy and precision. We used the student t test for the analysis of Qa-value in the different subgroups.
  
  
  RESULTS
  In HF-hemodialysis 1 (Qb 300 mL/min), Qa was 1109 ± 541 mL/min SDM(a) and 1213 ± 639 mL/min BTM (P=.993(a); bias 103.7 mL/min and ρc 0.78). In HF-hemodialysis 2 (Qb 420 mL/min) Qa 1071 ± 578 mL/min SDM (P=1.0(a); -38.2 mL/min and 0.96) and 1216 ± 667 mL/min BTM (P=.992(a); 127.3 mL/min and 0.70). In OL-HDF hemodialysis 3 (Qb 420 mL/min) Qa 1071 ± 510 mL/min SDM (P=1.0(a); -48.4 mL/min and 0.96) and 1219 ± 580 mL/min BTM (P=.977(a); 99.2 mL/min and 0.75). Statistically significant differences were only obtained in patients aged ≥ 65 years old (P=.016) and peripheral vascular disease (P=.007).
  
  
  CONCLUSIONS
  Our results demonstrate how the saline dilution method was more accurate than thermodilution in the HF and OL-HDF modalities with routinely prescribed parameters. Finally, in this study, advanced age (>65 years old) and peripheral vascular disease were associated with a significantly lower Qa-value.
authors.affiliation: Department of Nephrology, Vascular Access Unit, Hospital Clinic, University of Barcelona, Spain. fontsere@clinic.ub.es
authors.forename: Néstor
authors.initials: N
authors.lastname: Fontseré
authors.forename: Francisco
authors.initials: F
authors.lastname: Maduell
authors.forename: Miquel
authors.initials: M
authors.lastname: Blasco
authors.forename: Manel
authors.initials: M
authors.lastname: Vera
authors.forename: Marta
authors.initials: M
authors.lastname: Arias
authors.forename: Gaspar
authors.initials: G
authors.lastname: Mestres
authors.forename: Patricia
authors.initials: P
authors.lastname: Bermudez
authors.forename: Josep M
authors.initials: JM
authors.lastname: Campistol
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001166:Arteriovenous Shunt, Surgical / Q000009:adverse effects; D001783:Blood Flow Velocity; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects; D003430:Cross-Sectional Studies; D005260:Female; D017583:Hemodiafiltration / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D007201:Indicator Dilution Techniques; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000503:physiopathology; D011237:Predictive Value of Tests; D012039:Regional Blood Flow; D015203:Reproducibility of Results; D012307:Risk Factors; D012965:Sodium Chloride; D013815:Thermodilution
chemical_list: D012965:Sodium Chloride