Cooling dialysate during in-center hemodialysis:Beneficial and deleterious effects

The use of cooled dialysate temperatures first came about in the early 1980s as a way to curb the incidence of intradialytic hypotension （IDH）. IDH was then, and it remains today, the most common complication affecting chronic hemodialysis patients. It decreases quality of life on dialysis and is an independent risk factor for mortality. Cooling dialysate was first employed as a technique to incite peripheral vasoconstriction on dialysis and in turn reduce the incidence of intradialytic hypotension. Although it has become a common practice amongst in-center hemodialysis units, cooled dialysate results in up to 70% of patients feeling cold while on dialysis and some even experience shivering. Over the years, various studies have been performed to evaluate the safety and effcacy of cooled dialysate in comparison to a standard, more thermoneutral dialysate temperature of 37℃. Although these studies are limited by small sample size, they are promising in many aspects. They demonstrated that cooled dialysis is safe and equally efficacious as thermoneutral dialysis. Although patients report feeling cold on dialysis, they also report increased energy and an improvement in their overall health following cooled dialysis. They established that cooling dialysate temperatures improves hemodynamic tolerability during and after hemodialysis, even in patients prone to IDH, and does so without adversely affecting dialysis adequacy. Cooled dialysis also reduces the incidence of IDH and has a protective effect over major organs including the heart and brain. Finally, it is an inexpensive measure that decreases economic burden by reducing necessary nursing intervention for issues that arise on hemodialysis such as IDH. Before cooled dialysate becomes standard of care for patients on chronic hemodialysis, larger studies with longer follow-up periods will need to take place to confrm the encouraging outcomes mentioned here.

Solute clearance effect of citrate anticoagulation hemodialysate for hemodialysis in patients with high risk of bleeding

Objective To study the solute clearance effect of the new concentrated anticoagulation hemodialysate of citrate for hemodialysis in patients with high risk of bleeding. Methods Forty-two kidney failure patients with high risk of bleeding were divided into two groups (Group A and Group B) according to their hemodialysis manners. Patients in Group A were hemodialyzed with bicarbonate hemodialysate with low-molecular-weight heparin (dalteparin) anticoagulation and those in Group B with the new citrate anticoagulation hemodialysate prepared in our hospital without any other anticoagulant. Blood urea nitrogen (BUN) and creatinine (Cr) concentrations were measured before and after dialysis, and Kt/V and urea reduction rate (URR) were calculated. In addition, activated clotting time (ACT) and ionized calcium (iCa2+) concentration were also measured at the arterial and venous ends. Results ACT was extended and iCa2+ concentration decreased significantly at the venous end compared with those at the arterial end in Group B (P<0.01). BUN and Cr concentrations were markedly decreased after dialysis compared with those before dialysis in both groups (P<0.01), and no significant difference in solute clearance effect, as indicated by Kt/V and URR, was observed between Group A and Group B (P>0.05). Conclusion The solute clearance effect of the new concentrated anticoagulation hemodialysate of citrate is excellent during hemodialysis in kidney failure patients with high risk of bleeding.

Exploration of a reasonable dialysate temperature setting in hemodialysis for patients with hypertension

Objective：This study aims to investigate the effect of 4 different dialysate temperatures on blood pressure during hemodialysis for patients with hypertension.Methods：Using a self-controlled method,the patients＇ body temperature was set as T.Accordingly,the dialysate temperature was set as 37 ℃,T＋0.5 ℃,T,and T-0.5 ℃.The changes in blood pressure,heart rate,mean arterial pressure and dialysis-induced adverse reactions at the 4 different dialysate temperatures were consistently monitored.Results：Patients who received hemodialysis with 37 ℃ and T＋0.5 ℃ dialysate demonstrated an unstable blood pressure and a higher incidence of adverse reactions,Patients who received hemodialysis with T and T-0.5 ℃ dialysate showed a relatively stable blood pressure,heart rate,and mean arterial pressure during dialysis.In particular,dialysate at T-0.5 ℃ resulted in the most stable blood pressure,the fewest adverse reactions and the best self-assessed comfort scores（P 〈 0.01）.Conclusions：The dialysate temperature during hemodialysis for patients with hypertension should be set to a temperature based on patients＇ preoperative body temperate T or 0.5 ℃ below T.This practice is suggested to enhance the stability of patients＇ blood pressure and heart rate during hemodialysis,reduce complications and improve patients＇ tolerance of hemodialysis.

Individualized Isonatremic and Hyponatremic Dialysate Improves Blood Pressure in Patients with Intradialytic Hypertension: A Prospective Cross-Over Study with 24-h Ambulatory Blood Pressure Monitoring

Background. Intradialytic hypertension, a paradoxical rise in systolic blood pressure from pre- to postdialysis, is a poorly understood and difficult-to-treat phenomenon. We examined the effects of individually adjusted isonatremic and hyponatremic dialysate on intradialytic and interdialytic blood pressure in patients with intradialytic hypertension. Methods. We enrolled 11 patients with intradialytic hypertension in a prospective randomized cross-over study, with 4 treatment periods of different dialysate sodium concentrations. Period 1 (run-in) and 3 (wash-out) were standardized at 140 mEq/L;period 2 and 4 with iso- or hyponatremic sodium dialysate. Blood pressure was recorded each dialysis session, and 24-hour ambulatory blood pressure monitoring was performed at the end of each treatment period. Results. Isonatremic and hyponatremic dialysate were associated with significantly lower pre- and post-dialysis blood pressure as compared to baseline 140 mEq/L dialysate (predialysis 148.3 ± 24.7/67.7 ± 12.0 and 144.4 ± 16.5/68.8 ± 13.3 vs. 158.0 ± 18.3/75.6 ± 11.4 mmHg, resp p = 0.04 and 0.007 for systolic and p = 0.004 and 0.04 for diastolic blood pressure;postdialysis 154.2 ± 25.5/76.6 ± 14.1 and 142.5 ± 20.7/73.0 ± 12.9 vs. 159.1 ± 21.6/80.3 ± 12.1 mmHg, resp NS and p = 0.01 for systolic and NS and p = 0.04 for diastolic blood pressure). Postdialysis and 24 h systolic blood pressure tended to be lower with hyponatremic compared to isonatremic dialysate. Conclusion. Individually tailoring dialysate sodium concentration, based on the sodium set-point of each patient, resulted in a lower pre- and post-dialysis blood pressure in patients with intradialytic hypertension. 24 h blood pressure values tended to be lower as well with hyponatremic dialysate.

A study of effects of using low dialysate calcium concentration (1.50 mmol/L) on blood pressure,serum concentrations of calcium,parathyroid hormone and aldosterone in chronic hemodialysis patients

Background: Dialysis centres around the world use different concentrations of calcium in dialysate solution,ranging from 1. 25 to 1. 75 mmol / L. However,a dialysate concentration of 1. 25 mmol / L is recommended. [1] Higher or lower dialysate calcium concentrations are indicated in patients,depending on their co-morbid factors. We explored the effects of using a calcium dialysate solution of 1. 50 mmol / L compared to a 1. 75 mmol / L calcium dialysate solution on the Blood Pressure (BP) ,serum concentrations of Calcium,Parathyroid Hormone (PTH) and Aldosterone in chronic hemodialysis (HD) patients. Method: 42 patients were enrolled in the study. First a 1. 50 mmol / L low calcium dialysate solution (LCDS) was used for 4 hour dialysis,and for the next session of HD,a 1. 75 mmol / L (NCDS) normal calcium dialysate solution was used. Blood pressure was measured at 5 intervals of time: pre HD,at 60,120,180 and 240 minutes into the HD session. Pre and post HD blood samples were taken for serum calcium,PTH and Aldosterone levels. Results: All 42 patients completed the study. With LCDS,the post HD serum calcium levels were (2. 51 ± 0. 14) mmol / L,compared to (2. 85 ± 0. 17) mmol / L for NCDS (P < 0. 01) . A post HD serum PTH level of (80. 6 ± 144. 93) pg / ml was observed when using LCDS,whereas a (52. 25 ± 115. 89) pg / ml serum PTH level was noted with NCDS (P < 0. 01) . As for aldosterone,a post HD value of (161. 77 ± 80. 42) ng / L was obtained with LCDS and (165. 50 ± 78. 84) ng / L with NCDS (P < 0. 01) . The mean post HD systolic blood pressure was (129. 17 ± 25. 42) mmHg with LCDS dialysis compared to (132. 50 ± 20. 32) mmHg for NCDS dialysis (P < 0. 01) and the diastolic BP values observed were (75. 10 ±10. 34) mmHg and (78. 26 ±11. 63) mm Hg(P <0. 01) ,respectively. Conclusion: LCDS can more effectively improve hypercalcemic status in dialysis patients than NCDS. Using LCDS stimulates the secretion of PTH more than when using NCDS. LCDS decreases aldosterone levels more than NCDS. Patients undergoing dialysis with LCDS have a lower post dialysis BP compared to those using NCDS. LCDS has a greater effect in decreasing both the post systolic and diastolic blood pressure than NCDS. Serum calcium,PTH and aldosterone levels have a greater decreasing effect on BP in LCDS than NCDS. Dialysate calcium profiling might be used as a means of therapy to control hypercalcemia, especially in patients who are hemodynamically stable.

Adsorption of urea,creatinine,and uric acid from three solution types using spherical activated carbon and its recyclability

In this paper,we propose that the urinary toxins from the wastewater be adsorbed on an adsorbent such as spherical activated carbon and the latter be regenerated by subjecting it to high temperatures to recycle activated carbon and also to recycle the water used in dialysis.We studied the adsorption of artificial waste dialysate,which is a mixed solution of urea,creatinine,and uric acid,and the separate solutions for each of these and found that their extents of adsorption onto the spherical activated carbon material were nearly identical.The amount of adsorption was approximately 1.4 mg·g^−1 for urea,18 mg·g^−1 for creatinine,and 20 mg·g^−1 for uric acid.The urea,creatinine,and uric acid adsorbed onto the spherical activated carbon decomposed on heat treatment at 500℃,and the adsorption capacity of the spherical activated carbon was regenerated.Our study successfully demonstrated that the spherical activated carbon can be recycled in the waste dialysate treatment process.

Effect of combining different calcium concentration dialysate on calcium balance in peritoneal dialysis patients

Background Calcium and phosphorus metabolic disturbance are common in dialysis patients and associated with increased morbidity and mortality. Therefore, maintaining the balance of calcium and phosphate metabolism and suitable intact parathyroid hormone （iPTH） level has become the focus of attention. We investigated the effects of different peritoneal dialysate calcium concentrations on calcium phosphate metabolism and iPTH in continuous ambulatory peritoneal dialysis （CAPD） patients. Methods Forty stable CAPD patients with normal serum calcium were followed for six months of treatment with 1.25 mmol/L calcium dialysate （DCa1.25, PD4, 22 patients） or a combination of 1.75 mmol/L calcium dialysate （DCa1.75, PD2） and PD4 （18 patients） twice a day respectively. Total serum calcium （after albumin correction）, serum phosphorus, iPTH, alkaline phosphatase （ALP） and blood pressure were recorded before and 1, 3 and 6 months after treatment commenced. Results No significant difference was found in baseline serum calcium, phosphorus between the two patient groups, but the levels of iPTH were significantly different. No significant changes were found in the dosage of calcium carbonate and active vitamin D during 6 months. In the PD4 group, serum calcium level at the 1st, 3rd, 6th months were significantly lower than the baseline （P 〈0.05）. There was no significant difference in serum phosphorus after 6 months treatment. iPTH was significantly higher （P 〈0.001） at the 1st, 3rd, and 6th months compared with the baseline. No differences were seen in ALP and blood pressure. In the PD4＋PD2 group, no significant changes in serum calcium, phosphorus, iPTH, ALP and BP during the 6-month follow-up period. Conclusions Treatment with 1.25 mmol/L calcium dialysate for six months can decrease serum calcium, increase iPTH, without change in serum phosphorus, ALP, and BP. The combining of PD4 and PD2 can stabilize the serum calcium and avoid fluctuations in iPTH levels.

Prospective study of the short-term effect of 1.75 mmol/L calcium concentration dialysate on hemodialysis patients

Objective:The purpose of the current study was to determine the influence of a 1.75 mmol/L calcium(Ca)concentration dialysate(DCa 1.75)during maintenance hemodialysis(MHD)therapy for patients with chronic kidney disease,mineral,and bone disorders(CKD-MBD)on biochemical indices and clinical prognosis.Methods:Four hundred eighty-three MHD patients from three hemodialysis centers were en-rolled.During 24 months of follow-up(January 2011 to December 2012),289 patients from Center 1 who used 1.50 mmol/L Ca concentration dialysate(Dca 1.50)between January and December 2011 and DCa 1.75 between January and December 2012 were included in the high Ca group.The remaining 194 patients from the other centers who used DCa 1.50 for hemodialysis between January 2011 and December 2012 were included in the ordinary Ca group.The following CKD-MBD biochemical indices were monitored:blood Ca;blood phosphorus(P);intact parathyroid hormone(iPTH);and bone-specific alkaline phosphatase(BAP).The metastatic calcification index included calcification of aortic arch scoring(AoACS),abdominal aorta calcification(AAC),and cardiac valve calcification(CVC).The study end points included all-cause mortality(ACM),car-diovascular and cerebrovascular diseases(CCVDs),fractures,and new metastatic calcifications.The changes between the two groups in the observed indices were compared.Results:Two hundred eighty-four patients in the high Ca group(98.3%)and 194 patients in the ordinary Ca group(100.0%)completed an average follow-up of 21.3±5.6 months.After DCa 1.75 was used,the blood Ca in the high Ca group increased[(2.39±0.22)mmol/L vs.(2.34±0.21)mmol/L,t=-2.910,P=0.004]compared to the previous year,and increased[(2.39±0.22)mmol/L vs.(2.30±0.16)mmol/L,t=5.187,P<0.001]compared to the ordinary Ca group in the same year.The blood P and iPTH decreased[(1.78±0.39)mmol/L vs.(1.89±0.42)mmol/L,t=2.909,P=0.004 and(306.5±298.6)pg/ml vs.(425.7±365.1)pg/ml,t=8.377,P<0.001,respectively]compared with the previous year,and decreased[(1.78±0.39)mmol/L vs(1.86±0.39)mmol/L,t=-2.016,P=0.044 and(306.5±298.6)pg/ml vs.(366.6±341.0)pg/ml,t=-2.113,P=0.035,respectively]compared with the ordinary Ca group in the same year.There was no difference in AoACS between the two groups before and after the change in DCa in the high Ca group(P>0.05).In 2011,there was 13 CCVDs,2 fractures,and 13 new metastatic calcifications in the ordinary Ca group compared to 8 CCVDs,3 fractures,and 16 new metastatic calcifications in the high Ca group;there were no statistically significant differences in the incidence of end point events between the two groups(χ^(2)=2.747,P=0.098).In 2012,the values for the ordinary Ca group were 13,2,and 15,respec-tively,while the values for the high Ca group were 8,1,and 19,respectively,which indicated a statistically significant difference in the incidence of end point events between the two groups(χ^(2)=4.391,P=0.036).Conclusion:Short-term use of DCa 1.75 significantly reduced the blood P and iPTH levels in MHD patients,significantly increased the blood Ca level,did not increase the proportion of new cardiovascular calcifications,and decreased the overall inci-dence of end point events.

Application of regional citrate anticoagulation in patients at high risk of bleeding during intermittent hemodialysis:a prospective multicenter randomized controlled trial

Objective:Safe and effective anticoagulation is essential for hemodialysis patients who are at high risk of bleeding.The purpose of this trial is to evaluate the effectiveness and safety of two-stage regional citrate anticoagulation(RCA)combined with sequential anticoagulation and standard calcium-containing dialysate in intermittent hemodialysis(IHD)treatment.Methods:Patients at high risk of bleeding who underwent IHD from September 2019 to May 2021 were prospectively enrolled in 13 blood purification centers of nephrology departments,and were randomly divided into RCA group and saline flushing group.In the RCA group,0.04 g/mL sodium citrate was infused from the start of the dialysis line during blood draining and at the venous expansion chamber.The sodium citrate was stopped after 3 h of dialysis,which was changed to sequential dialysis without anticoagulant.The hazard ratios for coagulation were according to baseline.Results:A total of 159 patients and 208 sessions were enrolled,including RCA group(80 patients,110 sessions)and saline flushing group(79 patients,98 sessions).The incidence of severe coagulation events of extracorporeal circulation in the RCA group was significantly lower than that in the saline flushing group(3.64%vs.20.41%,P<0.001).The survival time of the filter pipeline in the RCA group was significantly longer than that in the saline flushing group((238.34±9.33)min vs.(221.73±34.10)min,P<0.001).The urea clearance index(Kt/V)in the RCA group was similar to that in the saline flushing group with no statistically significant difference(1.12±0.34 vs.1.08±0.34,P=0.41).Conclusions:Compared with saline flushing,the two-stage RCA combined with a sequential anticoagulation strategy significantly reduced extracorporeal circulation clotting events and prolonged the dialysis time without serious adverse events.

Effects of mildly increasing dialysis sodium removal on renin and sympathetic system in hemodialysis patients

Background It has been argued that the benefits of reducing sodium loading may be offset by increased activation of the renin-angiotensin-aldosterone system （RAAS） and sympathetic nervous system. This study aimed to investigate the long-term effects of an increase in dialysis sodium removal on circulating RAAS and sympathetic system in hypertensive hemodialysis （HD） patients with ＂normal＂ post-HD volume status. Methods Thirty hypertensive HD patients were enrolled in this pilot trial. After one month period of dialysis with standard dialysate sodium of 138 mmol/L, the patients were followed up for a four months period with dialysate sodium set at 136 retool/L, without changes in instructions regarding dietary sodium control. During the period of study, the dry weight was adjusted monthly under the guidance of bioimpedance spectroscopy to maintain post-HD volume status in a steady state; 44-hour ambulatory blood pressure, plasma renin, angiotensin II （Ang II）, aldosterone, and norepinephrine （NE） were measured. Results After four months of HD with low dialysate sodium of 136 mmol/L, 44-hour systolic and diastolic blood pressures （BPs） were significantly lower （-10 and -6 mmHg）, in the absence of changes in antihypertensive medications. No significant changes were observed in plasma renin, Ang II, aldosterone, and NE concentrations. The post-HD volume parameters were kept constant. Conclusion Mildly increasing dialysis sodium removal over 4 months can significantly improve BP control and does not activate circulating RAAS and sympathetic nervous system in hypertensive HD patients. Chin Med J 2014;127 （14）： 2628-2631