Practical utility of on-line clearance and blood temperature monitors as noninvasive techniques to measure hemodialysis blood access flow.
OBJECTIVE
Access blood flow (Qa) measurements are recommended by the current guidelines as one of the most important components in vascular access maintenance programs. This study evaluates the efficiency of Qa measurement with on-line conductivity (OLC-Qa) and blood temperature monitoring (BTM-Qa) in comparison with the gold standard saline dilution method (SDM-Qa).


METHODS
50 long-term hemodialysis patients (42 arteriovenous fistulas/8 arteriovenous grafts) were studied. Bland-Altman and Lin's coefficient (ρ(c)) were used to study accuracy and precision.


RESULTS
Mean values were 1,021.7 ± 502.4 ml/min SDM-Qa, 832.8 ± 574.3 ml/min OLC-Qa (p = 0.007) and 1,094.9 ± 491.9 ml/min with BTM-Qa (p = NS). Biases and ρ(c) obtained were -188.8 ml/min (ρ(c) 0.58) OLC-Qa and 73.2 ml/min (ρ(c) 0.89) BTM-Qa. The limits of agreement (bias ± 1.96 SD) obtained were from -1,119 to 741.3 ml/min (OLC-Qa) and -350.6 to 497.2 ml/min (BTM-Qa).


CONCLUSIONS
BTM-Qa and OLC-Qa are valid noninvasive and practical methods to estimate Qa, although BTM-Qa was more accurate and had better concordance than OLC-Qa compared with SDM-Qa.
Departments of Nephrology, Hospital Clinic, University of Barcelona, C/Villarroel No. 170, Barcelona, Spain. fontsere@clinic.ub.es
Néstor
N
Fontseré
Miquel
M
Blasco
Francisco
F
Maduell
Manel
M
Vera
Marta
M
Arias-Guillen
Sandra
S
Herranz
Teresa
T
Blanco
Marta
M
Barrufet
Marta
M
Burrel
Javier
J
Montaña
Maria Isabel
MI
Real
Gaspar
G
Mestres
Vicenç
V
Riambau
Josep M
JM
Campistol
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001831:Body Temperature; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow; D006435:Renal Dialysis / Q000295:instrumentation / Q000379:methods* / Q000592:standards