Prescribing Dialysate Bicarbonate Concentrations for Hemodialysis Patients

1988 ◽  
Vol 11 (1) ◽  
pp. 45-50 ◽  
Author(s):  
F.G. Heineken ◽  
M. Brady-Smith ◽  
J. Haynie ◽  
J.C. Van Stone
Keyword(s):  
Blood Flow ◽  
Blood Flow Rate ◽  
Baseline Period ◽  
Hemodialysis Patients ◽  
Chronic Hemodialysis ◽  
Bicarbonate Concentration ◽  
Acid Base ◽  
Ultrafiltration Rate ◽  
Plasma Bicarbonate ◽  
Normal Acid

A rearranged equation of Sargent and Gotch (1) was used to determine dialysate bicarbonate concentrations for hemodialysis patients. Parameters in this equation include an estimate of the acid generated by each patient between treatments, an estimate for the dialyzer dialysance for bicarbonate, ultrafiltration rate, blood flow rate and a targeted mid-dialysis plasma bicarbonate concentration of 25 mEq/L. Nine patients were studied over a 35 week period to verify this method of determining each patient's dialysate bicarbonate concentration. Prescribed dialysate bicarbonate concentrations for the nine patients varied from 29 to 38 mEq/L with five patients having a prescribed value of 35 mEq/L. After a baseline period of five weeks, five patients switched from a 37 mEq/L acetate dialysate to their prescribed dialysate bicarbonate concentration. Four patients who had already been on bicarbonate dialysis at a concentration of 35 mEq/L were dialyzed with their prescribed dialysate bicarbonate concentrations. Patients were then followed for a study period of 30 weeks. The prescribed dialysate bicarbonate concentration resulted in more normal acid/base chemistries for both groups of patients. The results also demonstrate that chronic hemodialysis patients require individualization of dialysate bicarbonate concentrations.

Simulation Analysis of the Influence of Hemodialysis Control Parameters on Exchange Processes during Therapy

1992 ◽  
Vol 15 (4) ◽  
pp. 213-221 ◽  
Author(s):  
O. Thews
Keyword(s):  
Blood Flow ◽  
Flow Rate ◽  
Water Distribution ◽  
Simulation Analysis ◽  
Blood Flow Rate ◽  
Sodium Concentration ◽  
Control Parameters ◽  
Acid Base ◽  
Ultrafiltration Rate ◽  
Exchange Processes

The effect of dialysis control parameters (dialysate composition, ultrafiltration rate, blood flow rate) on the patient's internal milieu were studied using a mathematical model for the description of the dynamic exchange processes during hemodialysis. This model simulates the electrolyte and water distribution, the acid-base and the oxygenation state as well as the ventilation. The dialysate sodium concentration affects mainly the intra-/ extracellular water and the potassium distribution. The dialysate bicarbonate and acetate concentrations control the acid-base state and the electrolyte distribution (sodium and potassium). In addition, the dialysate acetate concentration has a strong effect on arterial oxygenation and on ventilation. The ultrafiltration rate controls the water distribution between plasma and the interstitial space but also the sodium distribution and the arterial acid-base state. The blood flow rate through the dialyser influences the acid-base state and, by this, it affects the potassium and sodium distribution. The acid-base state is affected in opposite directions when acetate or bicarbonate is used as a buffer.

Factors Affecting Bicarbonate Transfer with Bicarbonate-Containing CAPD Solution

1995 ◽  
Vol 15 (4) ◽  
pp. 336-341 ◽  
Author(s):  
Mariano Feriani ◽  
Jutta Passlick-Deetjen ◽  
Giuseppe La Greca
Keyword(s):  
Dwell Time ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Bicarbonate Concentration ◽  
Acid Base ◽  
Ultrafiltration Rate ◽  
Factors Affecting ◽  
Plasma Bicarbonate ◽  
Dialysis Solution ◽  
Acid Base Status

Objective To evaluate bicarbonate fluxes across the peritoneal membrane and bicarbonate gain in patients treated with continuous ambulatory peritoneal dialysis (CAPD) using dialysis solutions with different bicarbonate concentrations. Patients and Design Ninety-seven exchanges, using different dwell times and glucose and bicarbonate concentrations were performed in 43 stable CAPD patients. Dialysate effluent bicarbonate concentration and volumes were measured at different dwell times. Net dialytic bicarbonate gain was calculated. Patients’ acid-base status was determined at the middle of the dwell. Results In prolonged dwells (6 –12 hours)thedialysate effluent bicarbonate concentration correlated with arterial plasma bicarbonate concentration (F = 129, p < 0.0001), but not with ultrafiltration rate or dialysis solution bicarbonate concentration. In 4-hour dwells, effluent bicarbonate concentration correlated with both plasma bicarbonate concentration and ultrafiltration rate (F = 32.52, p < 0.0001 and F = 4.4, p < 0.05, respectively). The effluent bicarbonate concentration may be predicted from the patient's plasma bicarbonate concentration and net ultrafiltration rate for either a 4-hour or prolonged (6 –12 hours) dwell time. Net bicarbonate gain by the patient correlated with ultrafiltration rate, plasma bicarbonate, and dialysis solution bicarbonate concentration (F = 100.56, p < 0.0001 at 4 hours and F = 108.08, p < 0.0001 at 6 12 hours), with the ultrafiltration rate being the predominant parameter. Conclusions The effluent bicarbonate concentration is related to plasma bicarbonate concentration, with ultrafiltration playing a marginal role only during short dwells. However, the ultrafiltration rate has a profound effect on net patient bicarbonate gain. Multiple linear regression analysis allows the prediction of the effect of acid-base status, ultrafiltration, dwell time, and dialysis solution bicarbonate content on net patient bicarbonate gain. It seems that bicarbonate content in the CAPD dialysis solution should be progressively increased with increasing solution osmolality.

scholarly journals Manual Individualization of the Dialysate flow according to blood flow: Effects on the Hemodialysis dose delivered and on Dialysate consumption

2020 ◽  
Author(s):  
FAYE Moustapha ◽  
Niakhaleen KEITA ◽  
Maria Faye ◽  
Yousseph BERDAI ◽  
Ahmed Tall LEMRABOTT ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Rate ◽  
Blood Flow Rate ◽  
Hemodialysis Patients ◽  
Chronic Hemodialysis ◽  
Dialysis Dose ◽  
Dialysate Flow ◽  
Dialysate Flow Rate ◽  
Flow Effects ◽  
The Impact

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.

scholarly journals A redefinition of normal acid-base equilibrium in man: Carbon dioxide tension as a key determinant of normal plasma bicarbonate concentration

1979 ◽  
Vol 16 (5) ◽  
pp. 612-618 ◽  
Author(s):  
Nicolaos E. Madias ◽  
Horacio J. Adrogué ◽  
Gary L. Horowitz ◽  
Jordan J. Cohen ◽  
William B. Schwartz
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Tension ◽  
Bicarbonate Concentration ◽  
Acid Base ◽  
Plasma Bicarbonate ◽  
Base Equilibrium ◽  
Normal Plasma ◽  
Acid Base Equilibrium ◽  
Normal Acid

Acid-Base Balance with Different Capd Solutions

1996 ◽  
Vol 16 (1_suppl) ◽  
pp. 126-129 ◽  
Author(s):  
Mariano Feriani ◽  
Claudio Ronco ◽  
Giuseppe La Greca
Keyword(s):  
Acid Production ◽  
Dwell Time ◽  
Lactate Concentration ◽  
The Body ◽  
Plasma Lactate ◽  
Acid Base Balance ◽  
Bicarbonate Concentration ◽  
Acid Base ◽  
Plasma Bicarbonate ◽  
Base Balance

Our objective is to investigate transperitoneal buffer fluxes with solution containing lactate and bicarbonate, and to compare the final effect on body base balance of the two solutions. One hundred and four exchanges, using different dwell times, were performed in 52 stable continuous ambulatory peritoneal dialysis (CAPD) patients. Dialysate effluent lactate and bicarbonate and volumes were measured. Net dialytic base gain was calculated. Patients’ acid-base status and plasma lactate were determined. In lactate-buffered CAPD solution, lactate concentration in dialysate effluent inversely correlated with length of dwell time, but did not correlate with plasma lactate concentration and net ultrafiltration. Bicarbonate concentration in dialysate effluent correlated with plasma bicarbonate and dwell time but not with ultrafiltration. The arithmetic sum of the lactate gain and bicarbonate loss yielded the net dialytic base gain. Ultrafiltration was the most important factor affecting net dialytic base gain. A previous study demonstrated that in patients using a bicarbonate-buffered solution the net bicarbonate gain is a function of dwell time, ultrafiltration, and plasma bicarbonate. By combining the predicted data of the dialytic base gain with the calculated metabolic acid production, an approximate body base balance could be obtained with both lactate and bicarbonate-buffered CAPD solutions. The body base balance in CAPD patients is self-regulated by the feedback between plasma bicarbonate concentration and dialytic base gain. The level of plasma bicarbonate is determined by the dialytic base gain and the metabolic acid production. This can explain the large interpatient variability in acid-base correction. Bicarbonate-buffered CAPD solution is equal to lactate solution in correcting acid-base disorders of CAPD patients.

Influence of plasma bicarbonate concentration and pH on citrate excretion

1964 ◽  
Vol 206 (4) ◽  
pp. 875-882 ◽  
Author(s):  
David P. Simpson
Keyword(s):  
Linear Relationship ◽  
Metabolic Alkalosis ◽  
High Plasma ◽  
Alkaline Ph ◽  
Acid Base Balance ◽  
Bicarbonate Concentration ◽  
Acid Base ◽  
Plasma Bicarbonate ◽  
Close Relationship ◽  
Base Balance

Citrate excretion has been studied in dogs under various conditions of acid-base balance in order to determine which factors are responsible for the increased citrate clearance present in metabolic alkalosis. A close relationship, significantly modified by systemic pH, was found between plasma bicarbonate concentration and citrate clearance. In the presence of an alkaline plasma pH, there was a linear relationship between changes in plasma bicarbonate concentration and changes in citrate clearance. Other experiments also demonstrated the influence of plasma bicarbonate concentration on citrate clearance at alkaline pH. Under acidotic conditions citrate clearances were low and changes in plasma bicarbonate concentration had little effect on citrate excretion. A change in plasma pH from an acidotic to an alkalotic state, with a constant plasma bicarbonate concentration, produced an increase in citrate clearance. Thus the coexistence in metabolic alkalosis of high plasma bicarbonate concentration and high plasma pH results in a markedly increased citrate clearance.

Predicting arterio-venous fistula failure by urea–method derived access blood flow in chronic hemodialysis patients

2020 ◽  
Vol 21 (6) ◽  
pp. 1011-1016
Author(s):  
Kumtorn Lelamali ◽  
Piyarek Papirachanat ◽  
Thitiya Puavilai
Keyword(s):  
Blood Flow ◽  
Characteristic Curve ◽  
Hemodialysis Patients ◽  
Chronic Hemodialysis ◽  
Interquartile Range ◽  
Dialysis Access ◽  
Ultrasound Dilution ◽  
Limb Edema ◽  
Venous Fistula ◽  
Urea Method

Background: Dialysis access is an essential part of hemodialysis. Determining the access blood flow (Qa) can help predict arterio-venous fistula thrombosis. Qa determination by the urea method, which was previously described in the past is simple and is available in most of the dialysis units but was not be able to predict arterio-venous fistula thrombosis. Aim: To compare the efficacy of Qa determination by the urea method and by ultrasound dilution methods in predicting arterio-venous fistula failure. Methods: Qa was measured by urea method and by ultrasound dilution simultaneously, every 3 months for a period of 1 year, in stable chronic hemodialysis patients with arterio-venous fistula. Arterio-venous fistula failure determined by clinical parameters and confirmed by Doppler ultrasound before sending the patient for interventional angioplasty. Results: This study enrolled a total of 16 patients, with 63% being male, 75% with lower-arm arterio-venous fistula and around 43% with previously done angioplasty. 59-Qa measurements were done, and 6 patients underwent angioplasty (one patient for severe upper limb edema, one for access thrombosis, and four for access dysfunction). Qa determination by the urea method had non-significantly lower Qa, (745 mL/min (interquartile range: 509–1143) and 779 mL/min (interquartile range: 530–1160), (p = 0.58)) and high correlation (r = 0.83, p < 0.001) to Qa by ultrasound dilution. The cut-off criteria with its sensitivity and specificity in predicting the access failure were 440 mL/min, 66.67%, and 96.15% for Qa determination by the urea and 400 mL/min, 66.67% and 90.38% for Qa by ultrasound dilution, respectively, with no difference in the area under the receiver operating characteristic curve. Conclusion: Measurement of Qa determination by the urea method is well correlated with Qa by ultrasound dilution and can be used to predict vascular access failure.

Practical Evaluation of Acid-Base Balance

1957 ◽  
Vol 3 (5) ◽  
pp. 631-637
Author(s):  
Herbert P Jacobi ◽  
Anthony J Barak ◽  
Meyer Beber
Keyword(s):  
Respiratory Acidosis ◽  
Respiratory Alkalosis ◽  
Acid Base Balance ◽  
Bicarbonate Concentration ◽  
Acid Base ◽  
Plasma Bicarbonate ◽  
Practical Evaluation ◽  
Base Balance

Abstract The Co2 combining power bears a variable relationship to the in vivo plasma bicarbonate concentration, depending upon the type and severity of acid-base distortion. In respiratory alkalosis and metabolic acidosis the Co2 combining power will usually be greater than the in vivo plasma bicarbonate concentration; whereas, in respiratory acidosis and metabolic alkalosis the Co2 combining power will usually be less. Co2 content, on the other hand, will always parallel the in vivo plasma bicarbonate concentration quite closely, being only slightly greater. These facts, together with other considerations which are discussed, recommend the abandonment of the determination of CO2 combining power.

Role of endothelin-1 in renal regulation of acid-base equilibrium in acidotic humans

2012 ◽  
Vol 303 (7) ◽  
pp. F991-F999 ◽  
Author(s):  
Alexandra Pallini ◽  
Henry N. Hulter ◽  
Jurgen Muser ◽  
Reto Krapf
Keyword(s):  
Metabolic Acidosis ◽  
Bicarbonate Concentration ◽  
Acid Base ◽  
Endothelin 1 ◽  
Plasma Bicarbonate ◽  
Human Volunteers ◽  
Acid Base Equilibrium ◽  
Normal Human ◽  
Mineralocorticoid Activity

Endothelin-1 inhibits collecting duct sodium reabsorption and stimulates proximal and distal tubule acidification in experimental animals both directly and indirectly via increased mineralocorticoid activity. Diet-induced acid loads have been shown to increase renal endothelin-1 activity, and it is hypothesized that increased dietary acid-induced endothelin-1 activity may be a causative progression factor in human renal insufficiency and that this might be reversed by provision of dietary alkali. We sought to clarify, in normal human volunteers, the role of endothelin-1 in renal acidification and to determine whether the effect is dependent on dietary sodium chloride. Acid-base equilibrium was studied in seven normal human volunteers with experimentally induced metabolic acidosis [NH4Cl 2.1 mmol·kg body weight (BW)−1·day−1] with and without inhibition of endogenous endothelin-1 activity by the endothelin A/B-receptor antagonist bosentan (125 BID p.o./day) both during dietary NaCl restriction (20 mmol/day) and NaCl repletion (2 mmol NaCl·kg BW−1·day−1). During NaCl restriction, but not in the NaCl replete state, bosentan significantly increased renal net acid excretion in association with stimulation of ammoniagenesis resulting in a significantly increased plasma bicarbonate concentration (19.0 ± 0.8 to 20.1 ± 0.9 mmol/l) despite a decrease in mineralocorticoid activity and an increase in endogenous acid production. In pre-existing human metabolic acidosis, endothelin-1 activity worsens acidosis by decreasing the set-point for renal regulation of plasma bicarbonate concentration, but only when dietary NaCl provision is restricted.

Blood Flow Rate and Access Recirculation in Hemodialysis

1992 ◽  
Vol 15 (8) ◽  
pp. 470-474 ◽  
Author(s):  
I.D. Daniels ◽  
G.M. Berlyne ◽  
R.H. Barth
Keyword(s):  
Blood Flow ◽  
Flow Rate ◽  
Blood Flow Rate ◽  
Hemodialysis Patients ◽  
Blood Pump ◽  
Concomitant Increase ◽  
Urea Clearance ◽  
Extracorporeal Blood

We studied the effect of extracorporeal blood flow rate (BFR) on access recirculation (recirc) in 19 hemodialysis patients. BUN was determined in simultaneous peripheral (P), arterial (A), and venous (V) blood obtained at BFRs of 200, 400 and 600 ml/min. Percent recirc was calculated for each BFR using the formula (P-A) / (P-V) X 100. Venous drip-chamber (VP) and pre-blood-pump (AP) pressures were measured at each BFR. Fistulograms were performed in 10 patients, and stenoses were identified in 5, all at the proximal (arterial) end of the access. Recirc increased with increasing BFR from 200 to 400 ml/min but increased little from 400 to 600 ml/min. At all BFRs recirc in the stenotic patients was higher than that of non-stenotic or unstudied patients. Urea clearance, corrected for recirc, rose with blood flow both in stenotic and non-stenotic patients. There were no differences in AP or in VP between stenotic and non-stenotic patients. At BFR ≥ 400 ml/min, a recirc threshold of 15% identified stenoses with sensitivity 100% and specificity 71%. We conclude (1) recirc increases with increasing BFR but not enough to outweight the concomitant increase in urea clearance; (2) significant access stenosis and recirc may be present even with low VP; (3) recirc was associated with arterial side stenoses; (4) at BFR ≥ 400 ml/min, access stenosis is associated with recirc > 15%.

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