The Influence of the Dialysate Flow Rate on Hollow Fiber Hemodialyzer Performance

1995 ◽  
Vol 19 (11) ◽  
pp. 1176-1180 ◽  
Author(s):  
Richard Allen ◽  
Thomas Herbert Frost ◽  
Nicholas Andrew Hoenich
Keyword(s):  
Flow Rate ◽  
Hollow Fiber ◽  
Dialysate Flow ◽  
Dialysate Flow Rate

Does the Blood Pump Flow Rate have an Impact on the Dialysis Dose During Low Dialysate Flow Rate Hemodialysis?

2018 ◽  
Vol 46 (4) ◽  
pp. 279-285 ◽  
Author(s):  
Maxime Leclerc ◽  
Clémence Bechade ◽  
Patrick Henri ◽  
Elie Zagdoun ◽  
Erick Cardineau ◽  
...  
Keyword(s):  
Flow Rate ◽  
Blood Pump ◽  
Bivariate Analysis ◽  
Dialysis Dose ◽  
Dialysate Flow ◽  
Pump Flow ◽  
Dialysate Flow Rate ◽  
Pump Flow Rate ◽  
A Prospective Study ◽  
The Impact

We conducted a prospective study to assess the impact of the blood pump flow rate (BFR) on the dialysis dose with a low dialysate flow rate. Seventeen patients were observed for 3 short hemodialysis sessions in which only the BFR was altered (300,350 and 450 mL/min). Kt/V urea increased from 0.54 ± 0.10 to 0.58 ± 0.08 and 0.61 ± 0.09 for BFR of 300, 400 and 450 mL/min. For the same BFR variations, the reduction ratio (RR) of β2microglobulin increased from 0.40 ± 0.07 to 0.45 ± 0.06 and 0.48 ± 0.06 and the RR phosphorus increased from 0.46 ± 0.1 to 0.48 ± 0.08 and 0.49 ± 0.07. In bivariate analysis accounting for repeated observations, an increasing BFR resulted in an increase in spKt/V (0.048 per 100 mL/min increment in BPR [p < 0.05, 95% CI (0.03–0.06)]) and an increase in the RR β2m (5% per 100 mL/min increment in BPR [p < 0.05, 95% CI (0.03–0.07)]). An increasing BFR with low dialysate improves the removal of urea and β2m but with a potentially limited clinical impact.

Myoglobin Clearance during Continuous Veno-Venous Hemofiltration with or without Dialysis

1998 ◽  
Vol 21 (4) ◽  
pp. 205-209 ◽  
Author(s):  
D. Nicolau ◽  
Y.S. Feng ◽  
A.H.B. Wu ◽  
S.P. Bernstein ◽  
C.H. Nightingale
Keyword(s):  
Renal Failure ◽  
Animal Model ◽  
Flow Rate ◽  
Major Complication ◽  
Viable Option ◽  
Effective Technique ◽  
Dialysate Flow ◽  
Continuous Arteriovenous Hemofiltration ◽  
Pump Rate ◽  
Dialysate Flow Rate

The management of acute myoglobinuric renal failure, the major complication of rhab-domyolysis, continues to be a treatment dilemma for the clinician as limited therapeutic options are available. Previously, we have demonstrated that continuous arteriovenous hemofiltration (CAVH) is an effective technique for removing myoglobin in an animal model. In the present study, swine were administered four grams of equine myoglobin intravenously and underwent the continuous veno-venous hemofiltration (CVVH) procedure for six hours each. Animals were studied in each of the following groups: CVVH at a pump rate 100 ml/minute, CVVH at a pump rate 200 ml/minute and CVVH at a pump rate 100 ml/minute plus dialysis at a dialysate flow rate of one Liter/h. Once the filtering process was initiated there was a rapid and sustained production of ultrafiltrate in all groups. The amount of myoglobin excreted in the ultrafiltrate over the six-hour filtering period was 688, 948 and 570 mg which corresponded to 17, 24 and 14 percent of the administered dose, respectively, for the three treatments. In comparison to previous CAVH experiments, CVVH removed more circulating myoglobin and the addition of the dialysis component did not appear to improve removal. Based on these findings, it appears that the CVVH hemofiltration system is a viable option for the removal of systemic myoglobin.

Quantitating Dialysis using two Dialysate Samples: A Simple, Practical and Accurate Approach for Evaluating Urea Kinetics

1997 ◽  
Vol 20 (8) ◽  
pp. 422-427 ◽  
Author(s):  
D.S.C. Raj ◽  
S. Tobe ◽  
C. Saiphoo ◽  
M.A. Manuel
Keyword(s):  
Kinetic Parameters ◽  
Flow Rate ◽  
Volume Of Distribution ◽  
Mean Difference ◽  
Recent Analysis ◽  
Altman Plot ◽  
Bland Altman Plot ◽  
Dialysate Flow ◽  
Dialysate Flow Rate ◽  
Urea Kinetics

Urea kinetics is now widely used to determine the adequacy of dialysis. Several simplified formulae are currently in use but only a few have been accepted into clinical practice because of their simplicity and ease of calculation. A recent analysis of these formulae showed that for the same set of blood urea values the calculated Kt/V can range from 1.0 to 1.5. We have developed a new dialysate-based method (2DSM) to estimate the urea kinetic parameters using dialysate and blood samples taken at the beginning and at the end of dialysis. The total urea removed (TUR) was calculated from the geometric mean of the two dialysate samples, dialysate flow rate and the duration of dialysis. The Watson formula was used to determine the volume of distribution of urea. A comparison of the 2DSM and the direct dialysate quantification (DDQ) method showed the following results (mean ± sd, n = 52): for total urea removal (TUR) 697 ± 32 vs 722 ± 37 mmol (p = 0.6, r2 = 0.928, y = 101 + 0.83 ×, mean difference 25 ± 76 mmol, see Bland-Altman plot), dialysate urea concentration (Durea) 5.55 ± 0.25 vs 5.75 ± 0.29 mmol/l (p = 0.6, r2 = 0.928, y = 0.8 + 0.82 x, mean difference 0.2 ± 0.6 mmol, see Bland-Altman plot), dialyser clearance (K) 232 ± 4.4 vs 235 ± 5.6 ml/min (p - 0.54), Kt/V 1.42 ± 0.04 vs 1.51 ± 0.04 (p = 0.21), volume of distribution of urea (Vd) 40.14 ± 1.04 vs 38.74 ± 1.2 L, (p = 0.38), and PCR 64.6 ± 2.6 vs 68.1 ± 3.1 g/day. We have developed a simple method of determining dialysate-based urea kinetics which requires two dialysate samples, one at the beginning and one at the end of dialysis and a blood sample at the midpoint of dialysis. TUR can be calculated using the dialysate flow rate and the dialysis duration and once this is known all the other kinetic parameters can be calculated.

How to Reach Optimal Creatinine Clearances in Automated Peritoneal Dialysis

1996 ◽  
Vol 16 (1_suppl) ◽  
pp. 167-171 ◽  
Author(s):  
Pierre Yves Durand ◽  
Philippe Freida ◽  
Belkacem Issad ◽  
Jacques Chanliau
Keyword(s):  
Peritoneal Dialysis ◽  
Creatinine Clearance ◽  
Flow Rate ◽  
Clinical Results ◽  
Automated Peritoneal Dialysis ◽  
Dialysate Flow ◽  
Dialysate Flow Rate ◽  
Peritoneal Permeability ◽  
Number Of Cycles ◽  
Tidal Peritoneal Dialysis

This paper summarizes the basis of prescription for automated peritoneal dialysis (APD) established during a French national conference on APD. Clinical results and literature data show that peritoneal clearances are closely determined by peritoneal permeability and hourly dialysate flow rate, independently of dwell time or number of cycles. With APD, peritoneal creatinine clearance increases according to the hourly dialysate flow rate to a maximum (plateau), then decreases because of the multiplication of the drain-fill times. The hourly dialysate flow giving the maximum peritoneal creatinine clearance is defined as the “maximal effective dialysate flow” (MEDF). MEDF is higher for high peritoneal permeabilities: MEDF is 1.8 and 4.2 L/hr with nocturnal tidal peritoneal dialysis (TPD) for a 4-hr creatinine dialysate-to-plasma ratio (DIP) of 0.50 and 0.80, respectively. With nightly intermittent peritoneal dialysis (NIPD), MEDF is 1.6 and 2.3 Llhr for a DIP of 0.50 and 0.78, respectively. Under these conditions, tidal modalities can only be considered as a way to increase the MEDF. Using the MEDF concept for an identical APD session duration, the maximal weekly normalized peritoneal creatinine clearance can vary by 340% when 4hr DIP varies from 0.41 to 0.78. APD is not recommended when 4-hr creatinine DIP is lower than 0.50. However, the limits of this technique may be reached at higher peritoneal permeabilities in anurics because of the duration of sessions andlor the additional exchanges required by these patients.

P1116IS DIALYSIS ADEQUACY AMELIORATED AFTER INCREASING DIALYSATE FLOW RATE IN CHRONIC HEMODIALYSIS? - ONE YEAR FOLLOW-UP

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Aggeliki Barbatsi ◽  
Eugenia Karakou ◽  
Theodoros Chiras ◽  
Jacob Skarakis ◽  
Nikolaos Trakas ◽  
...  
Keyword(s):  
Flow Rate ◽  
Reduction Rate ◽  
Flow Distribution ◽  
Chronic Hemodialysis ◽  
Serum Urea ◽  
Dialysis Adequacy ◽  
Dialysate Flow ◽  
Dialysate Flow Rate ◽  
One Year

Abstract Background and Aims Hemodialysis (HD) adequacy, as measured by single pool (sp) Kt/V and urea reduction rate (URR), has been reported to be ameliorated after increasing dialysate flow rate (DFR). However, this is a matter of controversy as no benefit has been observed with dialyzers incorporating features to enhance dialysate flow distribution. We investigated the effect of increasing DFR on dialysis adequacy and on various laboratory parameters. Method Twenty-three patients, M/F=20/3, aged 65(44-89) years, dialyzed thrice weekly for 50(6-274) months, using polysulfone low flux dialyzers, participated in an annual randomized cross-over study. Patients were dialyzed with DFR of 500 ml/min and 700 ml/min for 6 consecutive months respectively, according to their usual dialysis prescription and with ultrafiltration volumes according to clinical need. Blood was sampled before and at the end of midweek sessions at the beginning of the first, 7th and 13rd month for urea, creatinine, potassium, sodium, albumin, total Ca and phosphate (sP). URR, spKt/V, corrected for albumin Ca(sCa) and sCa x sP product (CaxP) values were calculated. Results Under both 500 and 700 ml/min DFRs used, the expected post-dialysis alterations were found: decreased values in serum urea (respectively 161,5±38,0 to 49,9±20.1-p&lt;0,001 and 140,3±30 to 56,0±20.4 mg/dl-p&lt;0,001), creatinine (respectively 10,2±2 to 3.9±1,2-p&lt;0,001 and 10,2±3,3 to 4,1±1,6 mg/dl-p&lt;0,001), potassium (respectively 5,2±0,7 to 3,7±0,3 mM-p&lt;0,001 and 5,3±0,6 to 3,9±0,3mM-p&lt;0,001) and phosphate (respectively 5,4±1,7 to 2,9±0,6-p&lt;0,001 and 5,7±1,6 to 2,6±0,6 mg/dl-p&lt;0,001); increased values in serum albumin (respectively 4,3±0,4 to 4,7±0,4 g/dl-p=0,001 and 4,2±0,3 to 4,7±0,4 g/dl-p&lt;0,001) and sCa (9,1±0,7 to 11,3±0,9 mg/dl-p&lt;0,001 and 8,7±0,6 to 9,9±0,7 mg/dl-p&lt;0,001). After increasing DFR from 500 to 700 ml/min we observed no reductions in pre-dialysis serum urea and creatinine levels or URR (68,6±8,1% to 69,9±7,9%-p=NS) and Kt/V (1,41±0,4 to 1,42±0,3-p=NS) values. However, under DFR of 700ml/min post-dialysis sCa, sP and sCa x sP product values were always lower compared with those under DFR of 500 ml/min (respectively 9,9±0.7 vs 10,8±0.8 mg/dl-p&lt;0,001, 2,6±0,6 vs 2,9±0,6 mg/dl-p=0,02 and 25,6±6,2 vs 30,9±6,7 mg2/dl2-p&lt;0,001). Conclusion DFR increase from 500 to 700 ml/min did not lead to favorable effects on dialysis adequacy but resulted in post-dialysis amelioration of serum calcium and phosphate levels and may be useful in cases of hypercalcemia, hyperphosphatemia and calcifications. DFR increase utility needs further investigation in patients with disorders of calcium-phosphate metabolism.

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