Optimizing dialysis dose by increasing blood flow rate in patients with reduced vascular-access flow rate

Abstract Background: The objective of this work was to assess the impact of the decrease in dialysate flow rate on the dialysis dose delivered (spKt /V) to chronic hemodialysis patients and to estimate the resulting water saving. Methods: It was a prospective 4-week-period study that included chronic hemodialysis patients with clinical and hemodynamic stability. The patients successively underwent hemodialysis with a dialysate flow rate of 500 ml / min, at 1, 1.2 and 1.5 times the blood flow rate. Each dialysate flow rate was applied for one week. During these 4 weeks, the following parameters were kept constant: duration of dialysis, blood flow rate, anticoagulation, membrane nature and surface. Results: Forty-five chronic hemodialysis patients were included with a mean age of 48.4 ± 12.07 years. The weekly average spKt/V was statistically higher with a dialysate flow rate at 1.5 times the blood flow rate compared to the dialysate flow at 500 mL / min (p = 0.001). The proportion of patients achieving a standardized dialysis dose ≥ 1.4 was statistically higher with dialysate flow at 500 mL / min (64.4%) compared to dialysate flow at 1 or 1.2 times the blood flow rate which were 57.8% and 55.6%, respectively. It was statistically higher with a dialysate flow at 1.5 times the blood flow (93.3%) compared to the dialysate flow at 500 mL / min (p = 0.036). The dialysate volume used with a dialysate flow rate of 500 mL / min was higher compared to the other dialysate flow rates (p = 0.0001). Conclusions: An adequate dialysis dose could be achieved with a dialysate flow rate of 1.5 times the blood flow rate, thereby saving significant amount of water.

Download Full-text

Why Does Vascular Access Dysfunction Occur despite Brachial Artery Blood Flow Being Higher than Preset Blood Flow?

Kidney and Dialysis ◽

10.3390/kidneydial2010005 ◽

2022 ◽

Vol 2 (1) ◽

pp. 38-43

Author(s):

Jun-ichi Ono ◽

Takushi Oiwa ◽

Yasuo Ogasawara ◽

Seiichi Mochizuki

Keyword(s):

Blood Flow ◽

Flow Rate ◽

Vascular Access ◽

Brachial Artery ◽

Pure Water ◽

Blood Flow Rate ◽

Path Model ◽

Artery Blood Flow ◽

Recirculation Rate ◽

Model Fluid

Background: In recent years, many reports have investigated the usefulness of brachial artery blood flow (BAF) measured by ultrasonography as an evaluation index for the vascular access (VA) stenosis of hemodialysis patients. However, the mechanism of VA dysfunction, despite BAF being higher than the preset blood flow, has not been clarified to date. Methods: The relationship between actual blood-removal flow and recirculation rate with decreasing VA flow was examined using a VA flow path model and pure water as a model fluid. The blood-flow rate was set at 180 mL/min, and the set VA flow rate was lowered stepwise from 350 to 50 mL/min. VA flow rate, blood-removal flow rate, and flow waveform measured between two needle-puncture sites were recorded, and then the actual blood-removal flow rate and recirculation rate were calculated. Results: Recirculation was observed at a VA flow rate < 300 mL/min. The recirculation was due to the VA flow rate, which was transiently reduced to the level below the blood-removal flow rate, resulting in backflow. In contrast, no decrease in the actual blood-removal flow rate was observed. Conclusion: It is suggested that the mechanism of the VA dysfunction, despite the BAF being higher than the preset blood-flow rate, was due to the diastolic BAF being lower than the blood-removal flow rate.

Download Full-text

P1367THE RELATIONSHIP OF SERUM PHOSPHORUS LEVEL AND ARTERIOVENOUS FISTULA DYSFUNCTION IN MAINTENANCE HEMODIALYSIS

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfaa142.p1367 ◽

2020 ◽

Vol 35 (Supplement_3) ◽

Author(s):

Hyung-Jong Kim ◽

Mi Jung Lee

Keyword(s):

Blood Flow ◽

Risk Factor ◽

Arteriovenous Fistula ◽

Flow Rate ◽

Vascular Access ◽

Univariate Analysis ◽

Blood Flow Rate ◽

Dialysis Unit ◽

The Mean ◽

The Impact

Abstract Background and Aims It is known that maintenance of function of arteriovenous fistula (AVF) is very important in the management of hemodialysis (HD) patients. Therefore, identifying a risk factor for decreased vascular access flow has a clinical relevance in real world practice. Although hyperphosphatemia plays a crucial role in the pathogenesis of vascular calcification, there is lack of studies evaluating the effect of hyperphosphatemia on AVF. This study investigated the impact of serum phosphorous (P) on vascular access flow in HD patients. Method Sixty-two maintenance HD patients who visited dialysis unit of Bundang CHA Medical Center from November 2016 to December 2017 were included in this study. Serum P levels were determined every month and time-averaged serum P was calculated. All patients had left arm AVF (side to side anastomosis) and vascular access flow was assessed by Transonic HD 03. Decreased vascular access flow was defined as less than 600 mL/min. Results The mean age was 57.9 ± 12.1 years, 32 patients (51.6%) were men. The mean serum P levels were 5.1 ± 1.1 mg/dL and the vascular access flow was 1,071.4 ± 504.2 mL/min. Decreased vascular access flow was observed in 14 of 62 patients (22.6%). In univariate analysis, higher serum P was significantly associated with decreased vascular access flow (odds ratio [OR]=2.089, 95% confidence interval [CI]=1.159-3.766, P=0.014). But there was no significant association of dialysis blood flow rate, ejection fraction on echocardiography and serum calcium (Ca) levels with vascular access flow. Multivariable analysis indicated that higher serum P was independently associated with greater risk of decreased vascular access flow (OR=4.012, 95% CI=1.651-9.711, P=0.002). Old age, reduced EF, low dialysis blood flow rate and higher serum Ca was not associated with vascular access flow. Conclusion This study demonstrated that higher serum P was the independent risk factor for decreased vascular access flow in maintenance HD patients. Serial monitoring of serum P may be helpful to stratify the risk of vascular access dysfunction in these patients.

Download Full-text

Blood flow rate during orthostatic pressure changes in the pulp skin of the first toe

European Journal of Vascular and Endovascular Surgery ◽

10.1016/s1078-5884(97)80099-8 ◽

1997 ◽

Vol 13 (3) ◽

pp. 278-284 ◽

Cited By ~ 15

Author(s):

M. Midttun ◽

P. Sejrsen ◽

W.P. Paaske

Keyword(s):

Blood Flow ◽

Flow Rate ◽

Blood Flow Rate ◽

Pressure Changes

Download Full-text

The Effect of Furosemide on the Intrarenal Blood Flow Distribution in the Dog

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y72-113 ◽

1972 ◽

Vol 50 (8) ◽

pp. 774-783 ◽

Cited By ~ 4

Author(s):

Serge Carrière ◽

Michel Desrosiers ◽

Jacques Friborg ◽

Michèle Gagnan Brunette

Keyword(s):

Blood Flow ◽

Flow Rate ◽

Urine Volume ◽

Flow Distribution ◽

Blood Flow Rate ◽

Initial Distribution ◽

Blood Flow Distribution ◽

Intrarenal Blood Flow ◽

Femoral Blood ◽

Furosemide Administration

Furosemide (40 μg/min) was perfused directly into the renal artery of dogs in whom the femoral blood pressure was reduced (80 mm Hg) by aortic clamping above the renal arteries. This maneuver, which does not influence the intrarenal blood flow distribution, produced significant decreases of the urine volume, natriuresis, Ccreat, and CPAH, and prevented the marked diuresis normally produced by furosemide. Therefore the chances that systemic physiological changes occurred, secondary to large fluid movements, were minimized. In those conditions, however, furosemide produced a significant increase of the urine output and sodium excretion in the experimental kidney whereas Ccreat and CPAH were not affected. The outer cortical blood flow rate (ml/100 g-min) was modified neither by aortic constriction (562 ± 68 versus 569 ± 83) nor by the subsequent administration of furosemide (424 ± 70). The blood flow rate of the outer medulla in these three conditions remained unchanged (147 ± 52 versus 171 ± 44 versus 159 ± 54). The initial distribution of the radioactivity in each compartment remained comparable in the three conditions. In parallel with the results from the krypton-85 disappearance curves, the autoradiograms, silicone rubber casts, and EPAH did not suggest any change in the renal blood flow distribution secondary to furosemide administration.

Download Full-text

The Effect of Hematocrit on the Clearance of Small Molecules during Hemodialysis

The International Journal of Artificial Organs ◽

10.1177/039139888300600308 ◽

1983 ◽

Vol 6 (3) ◽

pp. 127-130 ◽

Cited By ~ 5

Author(s):

C. Woffindin ◽

N.A. Hoenich ◽

D.N.S. Kerr

Keyword(s):

Blood Flow ◽

Regression Analysis ◽

Small Molecules ◽

Flat Plate ◽

Flow Rate ◽

Distribution Curve ◽

Blood Flow Rate ◽

Hollow Fibre ◽

Urea Clearance ◽

Flow Rates

Data collected during the evaluation of a series of hemodialysers were analysed to see the effect of hematocrit on the clearance of urea and creatinine. All evaluations were performed on patients with a range of hematocrits with a mean close to 20%. The urea clearance of those in the upper half of the distribution curve (mean hematocrit 29.4%) was not significantly different from that of patients in the lower half of the distribution curve (mean hematocrit 16.9%) whether the clearance was studied at high or low blood flow rates and with hollow fibre or flat plate disposable hemodialysers. Likewise, there was no correlation between hematocrit and urea clearance by regression analysis. In contrast, the clearance of creatinine was affected by hematocrit being greater at lower hematocrit values. This difference was independent of blood flow rate and dialyser type and was confirmed by regression analysis.

Download Full-text