Dialysate calcium profiling during hemodialysis: use and clinical implications.

BACKGROUND: Low dialysate calcium (LdCa) concentration is used to prevent or treat hemodialysis (HD)-induced hypercalcemia, but its use has been complicated by intradialytic hypotension in some patients. Our goal was to explore the possibility that dialysis calcium profiling (dCaP) can ameliorate intradialytic hypotension in HD patients who need to have dialysis performed with LdCa. METHODS: In a randomized crossover design, eighteen HD patients underwent one four-hour HD session with LdCa of 1.25 mmol/L (LdCa group) and one four-hour HD session with LdCa of 1.25 mmol/L during the first two hours and high dCa of 1.75 mmol/L during the remaining two hours (dCaP group). After that, they underwent another four-hour HD session with medium dCa of 1.5 mmol/L (MdCa group). Before HD and at four 60-minute intervals during the HD sessions, blood pressure (BP), heart rate (HR) and noninvasive measurements of cardiac index (CI), using bioelectrical impedance, were obtained. Ionized serum calcium (iCa) also was measured before HD and at 120 and 240 minutes into the HD session. In a separate study, eight HD patients were treated for three weeks with 1.25 mmol/L dCa and three weeks with the dCaP technique described above, in random order. A three-week treatment with MdCa followed. BP and symptoms were recorded during each HD session. RESULTS: During the LdCa treatment the iCa values remained unchanged, whereas mean arterial pressure (MAP) and CI decreased by 16.5 +/- 8.3% and 14.2 +/- 14.6%, respectively, at the end of HD. During the first half of the dCaP treatment, iCa, MAP and CI decreased by 2.2 +/- 4.1%, 12.6 +/- 12.3%, and 9.6 +/- 13.4%, respectively, whereas during the second half of the same treatment, iCa, MAP and CI values increased by 10.2 +/- 3.3%, 7.8 +/- 7.2% and 10.8 +/- 9.1%, respectively, from the middle HD values. ANOVA showed that the time x treatment effect was significant for iCa, MAP and CI. Total peripheral resistance and HR changes were insignificant and similar among treatments. Hemodynamic effects were comparable between LdCa and MdCa treatments. Intradialytic events were reduced (P < 0.05) only with the dCaP treatment. CONCLUSIONS: The drop in BP observed during the last two hours of HD in both the LdCa and MdCa groups was abolished in the dCaP group. The latter was accomplished via an increase in cardiac output, due to an iCa-induced increase in myocardial contractility. Therefore, dCaP, by individualizing the dCa concentrations used and timing the switching between them, may improve intradialytic BP instability and simultaneously minimize the risk for HD patients to develop hypercalcemia.     

Effects of high sodium dialysate during maintenance hemodialysis

The effects of high sodium 144 mmol/l (mEq/l) dialysate were studied in normotensive, hypertensive and anephric chronic hemodialysis patients. Comparisons of blood pressures, weights and side effects associated with the hemodialysis procedure were made between two 6-month periods using dialysate sodium concentration of 133 mmol/l (mEq/l), followed by a high dialysate sodium of 144 mmol/l (mEq/l), each patient acting as his own control. No difference was found in the frequency of cramps or 'disequilibrium' side effects (nausea, vomiting, headache, restlessness). High sodium dialysate is beneficial for normotensive and anephric patients in reducing dialysis-induced hypotension and was not associated with any deleterious effects on long-term blood pressure control. In hypertensive patients, the benefit is less clear, and hypertension may increase.     

Comparison of parenteral iron sucrose and ferric chloride during erythropoietin therapy of haemodialysis patients

Aim:   To compare the effects of i.v. iron sucrose and Fe chloride on the iron indices of haemodialysis patients with anaemia.
Methods:   One hundred and eight haemodialysis patients receiving recombinant human erythropoiesis-stimulating agent (ESA) (mean age 59.37 years) were enrolled and randomly assigned to an iron sucrose or an Fe chloride group. Iron supplements were administered at 100 mg/week during the first 4 weeks (loading dose). Ferritin and transferrin saturation (TSAT) were then measured and dose adjusted. Ninety-eight subjects completed treatment; 51 in the iron sucrose group and 47 in the Fe chloride group. Ferritin, TSAT, haematocrit (Hct), reticulocyte count, serum albumin, fractional clearance of urea (Kt/V) and intact parathyroid hormone (iPTH) were measured.
Results:   There was no significant difference in baseline characteristics between the groups. Significant differences between the groups were observed in both iron indices and ESA dosage. Hct at week 24 (31.1% vs 29.7%, P  = 0.006) and ferritin at week 20 (731.3 vs 631.7 ng/mL, P  = 0.006) in the iron sucrose group were significantly higher than in the Fe chloride group. ESA dosage used in the iron sucrose group at week 8 was significantly lower than in the Fe chloride group (244.9 vs 322.6 U/kg per month, P  = 0.003), and iron sucrose group received significantly lower iron dose than the Fe chloride group at week 8 ( P  = 0.005).
Conclusion:   Although the differences in ESA dosage, ferritin and iron dosage between two groups were found during the study period while similar results were shown at the end of 24 week study. Thus, iron sucrose and Fe chloride are safe and work equally well for haemodialysis patients.     

Studies on dialysate mixing in the Genius single-pass batch system for hemodialysis therapy

BACKGROUND: The Genius single-pass batch system for hemodialysis contains a closed reservoir and dialysate circuit of 75 L dialysate. The unused dialysate is withdrawn at the top of the reservoir and the spent fluid is reintroduced into the container at the bottom. Although it has been claimed that both fractions remain unmixed during the dialysis session, no direct proof of this assumption has yet been provided. In the present study, we investigated whether contamination of the unused dialysate with uremic solutes occurred and at which time point it began. Two different dialysate temperatures were compared. METHODS: Ten chronic hemodialysis patients were dialyzed twice with the Genius system, with dialysate prepared at 37 degrees C and 38.5 degrees C, respectively. The sessions lasted 270 minutes with blood/dialysate flow set at 300 mL/min. Dialysate was sampled at 5, 60, 180, 210, 225, 230, 235, 240, 255, and 270 minutes both from the inlet and outlet dialysate line and blood was sampled from the arterial line predialysis, after 4 hours, and postdialysis. All samples were tested for osmolality, urea, creatinine, p-cresol, hippuric acid, and indoxyl sulfate. RESULTS: Uremic solutes appeared in the inlet dialysate line between 3 hours 50 minutes and 4 hours 10 minutes after the start of dialysis, corresponding to 68.6 and 74.7 L spent dialysate, respectively (37 degrees C vs. 38.5 degrees C; P = NS). No difference in the amount of removed solutes and in the serum levels was observed between 37 degrees C and 38.5 degrees C. A Kt/V of 1.17 +/- 0.20 and 1.18 +/- 0.26, respectively, was reached with the 37 degrees C and 38.5 degrees C dialysate temperature (P = NS). CONCLUSION: Contamination with uremic solutes occurred at the dialysate inlet only near the end of the session when small quantities of fresh dialysate were left in the container. Differences in dialysate temperature did not result in a different separation between used and unused dialysate, or in differences in removal of toxins or Kt/V.     

The effect of dialysate calcium levels on blood pressure during hemodialysis

A controlled double-blind prospective study was undertaken of the effect of dialysate calcium levels on BP during hemodialysis. Twenty patients and 240 dialyses were studied using a protocol in which patients underwent alternate hemodialyses with dialysate calcium of 2.5 and 3.5 mEq/L. Dialysate composition was otherwise the same. Mean BPs during dialysis were significantly lower at 1.5, 2.5, and 3.5 hours of dialysis when the lower dialysate calcium was used (P = .007 to .02). However, the difference in BP between the high and low dialysate calcium treatments was clinically minor, with a maximum mean difference (at 1.5 hours) of 4.6 mm Hg. Subgroups of patients with frequent hypotension and low or normal serum calcium did not appear more sensitive to the hypotensive effect of low calcium dialysate. Dialysate calcium levels of 2.5 and 3.5 mEq/L thus differ in their effect on intradialytic BP in a statistically significant, but clinically minor, way. Low calcium dialysate thus may prove useful in the management of patients in whom large amounts of enteric calcium absorption are indicated or unavoidable.     

Sodium ferric gluconate complex in sucrose: safer intravenous iron therapy than iron dextrans.

Use of recombinant human erythropoietin in patients with end-stage renal disease has highlighted iron deficiency as the major cause of resistant anemia. The current mainstay of intravenous (i.v.) iron replacement therapy, iron dextran, has been shown in prior studies to have a risk of serious life-threatening anaphylaxis of just under 1 per 100 patients exposed. The current study assessed the safety profile of an alternative i.v. iron, sodium ferric gluconate complex in sucrose (Ferrlecit), as compared with iron dextrans. Sodium ferric gluconate complex in sucrose, a unique chemical preparation, has been in use since 1959, principally in Europe, at a rate of approximately 2.7 million i.v. doses per year (1992 to 1996) in Germany and Italy alone. For iron dextran, usage in the United States was comparable--principally renal hemodialysis--and estimated from market sources at 3.0 million doses per year (1995). From 1976 to 1996, there were 74 allergic adverse events reported for sodium ferric gluconate complex in sucrose to the World Health Organization (WHO), German Health Bureau, and the manufacturer (all combined). For the years 1992 to 1996, sodium ferric gluconate complex in sucrose had an allergy event reporting rate of 3.3 allergy episodes per million doses per year compared with a similar rate of 8.7 reported allergy events per million doses per year for iron dextran in the United States in 1995. Case fatalities for sodium ferric gluconate complex in sucrose and iron dextran within these reports were then compared. For sodium ferric gluconate complex in sucrose, there were no reports of deaths over the entire period (1976 to 1996). However, for iron dextrans, there were 31 fatalities among 196 allergy/anaphylaxis cases reported in the United States between 1976 and 1996, yielding a case-fatality rate of 15.8%. These data show that sodium ferric gluconate complex in sucrose, when compared with iron dextrans in comparably sized patient usage populations with similar total rates of reporting of allergic events, has a significantly lower reported mortality rate (P < 0.001). Thus, the data justify usage of sodium ferric gluconate complex in sucrose as the safer iron replacement therapeutic agent.     

不同钙离子浓度透析液对单次血液透析钙平衡的影响

目的观察三种不同钙离子浓度透析液对维持性血液透析患者单次透析过程中血钙的影响,为透析液钙离子浓度的个体化选择提供理论参考。方法选择2014年1月在哈尔滨医科大学附属第一医院血液净化中心接受维持性血液透析治疗的患者80例为研究对象,随机分为3组,根据使用不同钙离子浓度分别为1.25 mmol/L(DCa 1.25组)、1.5 mmol/L(DCa 1.50组)和1.75 mmol/L(DCa 1.75组)的透析液进行单次血液透析治疗,每次透析4 h,3组所用透析液除钙离子浓度不同外,其他透析液主要成分组间无差别。分别检测每组透析前、后及下一次透析前的血肌酐(SCr)、尿素氮(BUN)、血白蛋白(albumin,Alb)、血钙、血磷等生化指标,同时监测单次透析前后患者的血压变化。结果对患者透析前基线数据初步分析结果表明,透析前iPTH水平为(458.7±408.2)ng/L、血钙(2.2±0.2)mmol/L、血磷(2.1±0.6)mmol/L、钙磷乘积(57.4±18.9)。iPTH、血钙、血磷达标率分别为53.8%、46.3%,25.0%;透析患者普遍伴有低钙血症(占48.8%)、高磷血症(占71.3%)和高甲状旁腺素血症(占23.8%)。单次透析治疗结束后的血钙水平分别为DCa 1.25组(2.27±0.20)mmol/L、DCa 1.50组(2.53±0.21)mmol/L、DCa 1.75组(2.51±0.20)mmol/L,组间比较差异有统计学意义(F=12.52,P0.01)。与透析前相比较,3组透析后血钙浓度较透析前均有所增加;协方差分析结果表明,在扣除透析前血钙浓度的影响因素后,DCa 1.25组血钙平均增加量最小。单次透析结束后血钙达标率分别为65.4%(DCa 1.25组)、48.1%(DCa 1.50组)、58.8%(DCa1.75组);透析结束后高钙血症的发生率DCa 1.75组(占41.2%)与DCa 1.50组(占51.9%)明显高于DCa 1.25组(占19.2%)。三种透析液对透析患者的血磷、血压影响差异均无统计学意义(P0.05)。结论单次使用钙离子浓度为1.25 mmol/L的透析液治疗,对透析后血钙浓度的影响最小、血钙达标率最高、高钙血症的发生率最低;与钙离子浓度分别为1.50 mmol/L和1.75 mmol/L透析液比较,钙离子浓度1.25 mmol/L更接近人体生理离子钙浓度。     

The role of dialysate in the stimulation of interleukin-1 production during clinical hemodialysis

To evaluate the role of the dialysate in the stimulation of interleukin-1 (IL-1) production during clinical hemodialysis (HD), we studied maintenance HD patients in two experiments. Cellulosic hollow-fiber dialyzers were obtained after 20 minutes of HD using either nonsterile standard dialysate (n = 6) or sterile pyrogen free 0.9% saline as dialysate (n = 6). After rinsing the blood compartment with normal saline, dialyzers were incubated at 37 degrees C for six hours. Aliquots from the blood compartment were analyzed for the presence of IL-1 by (1) rabbit pyrogenic response after intravenous injection or (2) thymocyte co-proliferation assay. The in vivo assay showed a significantly greater febrile response when standard dialysate was used than in the sterile saline group (P less than .001), and this response could be abolished by heat inactivation of aliquots (P less than .001). The in vitro assay confirmed the presence of significantly greater amounts of IL-1 (P less than .05). Studies were repeated using filter sterilized standard dialysate (n = 6) v standard dialysate (n = 6) for 240 minutes of clinical HD. The in vitro assay revealed significantly lower IL-1 levels in the filtered sterilized dialysate group (P less than .05), however, a blank control assay showed yet significantly lower levels (P less than .05). We conclude that IL-1 is produced during clinical HD and that endotoxin or its fragments play a role in the stimulation of IL-1 production, probably through monocytes adhering to the dialysis membrane. In addition to this dialysate factor, IL-1 production appears also to be stimulated by a blood-membrane interaction.     

Non-transferrin-bound iron in the serum of hemodialysis patients who receive ferric saccharate: no correlation to peroxide generation

Intravenous iron (iv.Fe) is used to optimize response to recombinant human erythropoietin (r-HuEPO) in ESRD, but no consensus exists with respect to the best regimen to avoid transferrin "oversaturation," oxidative stress, and the occurrence of non-transferrin-bound iron (NTBI). Iv.Fe was stopped for 1 wk in 35 hemodialysis (HD) patients who were routinely receiving iv.Fe and r-HuEPO. The iv.Fe group received 100 mg of ferric saccharate (Venofer) at the end of the first HD session, whereas the time-control group was treated under the same conditions but received no iv.Fe. Serum samples were taken before the first HD session, immediately and 60 min after iv.Fe administration, and before the next HD session. Sera were analyzed for NTBI and peroxides; transferrin saturation was analyzed by urea-PAGE and Western blot. In an in vitro model system with HepG2 cells, the effects of ESRD serum on the labile iron pool (LIP) were assayed using the fluorescence calcein assay. NTBI significantly increased after iv.Fe-administration and returned to baseline values before the next HD-session. There was a shift from apo- to monoferric transferrin, but no "oversaturation" of transferrin after iv.Fe-treatment. Peroxides increased in both groups after HD. Hemodialysis decreased bioavailable iron for the LIP in HepG2-cells, whereas serum of iv.Fe-treated HD patients highly increased the LIP in these cells. A total of 100 mg of iv.Fe led to NTBI generation but not to an oversaturation of transferrin. Peroxide concentrations significantly increased during HD but were not correlated to iv.Fe administration and seemed to result from other sources of oxidative stress related to HD. NTBI can enter liver cells and increase the potentially harmful LIP.     

Intravenous iron therapy in pediatric hemodialysis patients: a meta-analysis

Dialysis guidelines recommend aggressive management of anemia, including the use of intravenous iron (IVFe) when indicated. However, few published data are available to guide the use of IVFe in children, and studies are difficult to compare. In this meta-analysis we sought to combine evidence by pooling clinical trial data to determine if IVFe therapy helped increase hematocrit, serum levels of hemoglobin, ferritin, and transferrin saturation (TSAT), and reduce erythropoietin use. We searched MEDLINE and other databases, publications, and other sources to identify as many published and unpublished trials as possible. Of 379 possible studies, nine met the criteria for inclusion and analysis. Across all nine studies, 141 patients were studied, for durations of 2 weeks to 12 months. Pooled results identified an increase in hemoglobin, hematocrit, ferritin, and TSAT levels, and reduced use of erythropoietin, with effect sizes (in standardized weighted mean differences) ranging from 0.62 (95% confidence interval 0.11–1.13) to 1.86 (1.58–2.15) standard deviation improvements. Current practice is based largely on extrapolation from adult data and a few small pediatric trials. The pooled pediatric data suggest that IVFe is effective and produces moderate to large effects on the reported outcomes. Prospective, multi-center trials are needed to determine the optimal utilization of IVFe in children.     

Sodium ferric gluconate complex in hemodialysis patients: adverse reactions compared to placebo and iron dextran

BACKGROUND: Parenteral iron is often required by hemodialysis patients to maintain adequate iron stores. Until recently, the only available form of intravenous iron was iron dextran, which is associated with significant adverse reactions, including anaphylaxis and death. Sodium ferric gluconate complex (SFGC) was recently approved for use in the U.S. under FDA's priority drug review. This Phase IV study was designed to evaluate the safety of a single dose of intravenous SFGC as compared to placebo and a historical iron dextran control. METHODS: This multicenter, crossover, randomized, double blind, placebo-controlled prospective comparative study was performed in hemodialysis patients requiring at least 125 mg of elemental iron. The historical control was obtained from a meta-analysis of four publications examining outcomes in patients exposed to iron dextran. SFGC na?ve patients were administered SFGC without a test dose, undiluted, at a rate of 125 mg over 10 minutes, and compared to placebo comprising bacteriostatic saline. RESULTS: A total of 2534 patients were enrolled. The incidence of drug intolerance (an adverse event precluding re-exposure) was significantly less [0.44%, confidence interval (CI) 0.21 to 0.71%] after SFGC as compared to the iron dextran control (2.47%, CI 1.87 to 3.07%, P < 0.0001), but higher than after placebo (0.1%, P = 0.02). There was no difference found between SFGC and placebo in serious adverse events. A single life-threatening event occurred after SFGC (0.04%, CI 0.00 to 0.22%), which was significantly less than following iron dextran (0.61%, CI 0.36 to 0.86%), P = 0.0001. CONCLUSION: SFGC is well tolerated when given by intravenous push without a test dose. SFGC has a significantly lower incidence of drug intolerance and life-threatening events as compared to previous studies using iron dextran. The routine use of iron dextran in hemodialysis patients should be discontinued.     

Enhanced clearance of highly protein-bound drugs by albumin-supplemented dialysate during modeled continuous hemodialysis

Background. In 2006, there were 16 796 toxic exposures attributedto valproic acid (VPA), carbamazepine (CBZ) and phenytoin (PHT)reported to the US Toxic Exposure Surveillance System. Of these,30% (5046) were treated in a health care facility with 12 casesresulting in death. These drugs are highly protein bound andpoorly dialyzable; however, it has been suggested that albumin-supplementeddialysate may enhance dialytic clearance. We investigated whetherthe addition of albumin to dialysate affects dialytic clearanceof VPA, CBZ and PHT. Methods. VPA, CBZ and PHT were added to a bovine blood-basedin vitro continuous hemodialysis circuit, which included a polysulfoneor an AN69 hemodialyzer. VPA, CBZ and PHT clearances were calculatedfrom spent dialysate and pre-dialyzer plasma concentrations.VPA, CBZ and PHT clearances with control (albumin-free) dialysatewere compared to clearances achieved with 2.5% or 5% human albumin-containingdialysate. The influences of blood flow (180 and 270 mL/min)and dialysate flow (1, 2 and 4 L/h) on dialysis clearance werealso assessed. Results. The addition of 2.5% albumin to dialysate significantlyenhanced dialytic clearance of VPA and CBZ, but not PHT. Useof 5% albumin dialysate further increased VPA and CBZ clearance.Overall, drug clearance was related directly to dialysate flowbut independent of blood flow. Conclusion. Continuous hemodialysis with albumin-supplementeddialysate significantly enhanced VPA and CBZ, but not PHT, clearancecompared to control dialysate. Continuous hemodialysis withalbumin-supplemented dialysate may be a promising therapy toenhance dialytic clearance of selected highly protein-bounddrugs.     

Prolonged infusion therapy via the major vessels]

Some aspects of continuous infusion therapy by means of catheterization of large vessels are discussed. The authors share their experience of 215 punctures and catheterizations of the subclavian vein for persistent parenteral feeding after various thoracoabdominal operative interventions in patients with diseases of the gastrointestinal tract, lung, mediastinum and other lesions. The puncturing resulted in 13 complications, making 5.2%.     

不同钙离子浓度透析液对血液透析患者钙平衡及甲状旁腺素的影响

目的研究不同钙离子浓度透析液对维持性血液透析(MHD)患者透析过程中钙平衡及全段甲状旁腺激素(iPTH)的影响,为透析患者个体化选择透析液钙离子浓度提供理论依据.方法 12例血钙正常的稳定的MHD患者分别使用钙离子浓度为1.25 mmol/L(DCa1.25)、1.5mmol/L(DCa1.5)和1.75 mmol/L(DCa1.75)的透析液进行血液透析(透析液其他成分不变),每次透析4 h.检测透析前后血清总钙(tCa)、离子钙(iCa)、iPTH及透析废液的iCa和磷(P),并对血压进行监测.结果使用DCa1.25时,患者体内丢失的钙平均为5.03mmol,但透后血iCa和tCa浓度与透前相比无明显变化,iPTH透后较透前显著升高(P＜0.05).使用DCa1.5时,患者体内钙的蓄积平均为1.4 mmol,透后血iCa和tCa浓度与透前相比明显升高(P＜0.01),其中25%的患者发生透后高血钙,iPTH较透前无明显变化;使用DCa1.75时,患者体内钙的蓄积平均为3.3 mmol,透后血iCa和tCa浓度比透前明显升高(P＜0.01),其中83.3%的患者发生透后高血钙,iPTH较透前明显降低(P＜0.01).3种透析液对血磷的清除无明显差异(P＞0.05).结论对于透前血钙水平正常的患者,DCa1.75的透析液明显增加了患者的钙负荷,增加了透后高钙血症的发生.DCa1.25的透析液能够明显减轻钙负荷,但长期使用应注意监测iPTH水平.对于透前轻度低血钙或在正常值低限的患者,DCa1.5的透析液是适用的,如果发生透后高钙血症,则应改用DCa1.25的透析液.     

The role of glucose in hemodialysis: the effects of glucose-free dialysate

Glucose-free dialysate has been traditionally used in patients on chronic hemodialysis, reportedly without any side effects. Although hypoglycemia is not produced, several other metabolic changes must occur to maintain the euglycemic state. We studied ten patients on chronic hemodialysis using both a glucose-free bath and a glucose bath. Without glucose, a drop in osmolality of 20 mosm/kg H2O occurred, whereas a change of only 10 mosm/kg H2O was observed using a glucose bath. Abnormal EEG changes were observed after dialysis without glucose that were not present or were minimal with a glucose bath.     

Optimization of epoetin therapy with intravenous iron therapy in hemodialysis patients

Iron deficiency limits the efficacy of recombinant human erythropoietin (rhEPO) therapy in end-stage renal disease (ESRD) patients. Functional iron deficiency occurs with serum ferritin >500 ng/ml and/or transferrin saturation (TSAT) of 20 to 30%. This study examines the effects of a maintenance intravenous iron dextran (ivID) protocol that increased TSAT in ESRD hemodialysis patients from conventional levels of 20 to 30% (control group) to those of 30 to 50% (study group) for a period of 6 mo. Forty-two patients receiving chronic hemodialysis completed a 16- to 20-wk run-in period, during which maintenance ivID and rhEPO were administered in amounts to achieve average TSAT of 20 to 30% and baseline levels of hemoglobin of 9.5 to 12.0 g/dl. After the run-in period, 19 patients randomized to the control group received ivID doses of 25 to 150 mg/wk for 6 mo. Twenty-three patients randomized to the study group received four to six loading doses of ivID, 100 mg each, over a 2-wk period to achieve a TSAT >30% followed by 25 to 150 mg weekly to maintain TSAT between 30 and 50% for 6 mo. Both regimens were effective in maintaining targeted hemoglobin levels. Fifteen patients in the control group and 17 patients in the study group finished the study in which the primary outcome parameter by intention to treat analysis was the rhEPO dose needed to maintain prestudy hemoglobin levels. Maintenance ivID requirements in the study group increased from 176 to 501 mg/mo and were associated with a progressive increase in serum ferritin to 658 ng/ml. Epoetin dose requirements for the study group decreased by the third month and remained 40% lower than for the control group, resulting in an overall cost savings in managing the anemia. Secondary indicators of iron-deficient erythropoiesis were also assessed. Zinc protoporphyrin did not change in either group. Reticulocyte hemoglobin content increased only in the study group from 28.5 to 30.1 pg. It is concluded that maintenance of TSAT between 30 and 50% reduces rhEPO requirements significantly over a 6-mo period.     

Hypersensitivity reactions during hemodialysis related to the use of acetate dialysate. A case report.

A patient developed a hypersensitivity reaction two weeks after being put on hemodialysis with acetate dialysate. The reactions appeared exclusively during hemodialysis and were relieved immediately after its termination. These allergic manifestations disappeared with substitution of bicarbonate for acetate dialysate and reappeared upon rechallenge with acetate dialysate. The rest of the dialysis materials were excluded as possible causes of allergy by scheduled dialysis sessions with varying materials. Acetate dialysate is implicated as the cause of allergy reaction in this case.     

Dialysate partitioning in the Genius batch hemodialysis system: effect of temperature and solute concentration

BACKGROUND: The Genius batch system contains a 75-L closed reservoir from which fresh dialysate is extracted at the top, and to which spent dialysate is returned at the bottom. In vivo studies have demonstrated that almost the entire amount of dialysate can be used before contamination of fresh with spent dialysate occurs. The question is raised whether density differences cause this separation, and what the relative contributions of temperature and solute content are. METHODS: As patient substitute, a container filled with dialysate was loaded with various amounts of urea. Temperature differences between spent and fresh dialysate were imposed by not heating the dialysate at the outlet line from the dialyzer (A), heating the outlet to obtain continuously equal temperatures at inlet and outlet (B), or to temperatures as in vivo (C). With a dialysate flow set at 300 mL/min, urea is not expected at the inlet before 250 minutes. RESULTS: With a urea concentration of 33 mg/dL, urea contamination at the dialysate inlet line occurred after 185 +/- 20 (A), 122 +/- 11 (B), and 175 +/- 12 minutes (C) of dialysis, whereas with 67 mg/dL, this happened at 219 +/- 5 (A), 162 +/- 11 (B), and 202 +/- 8 minutes (C). With 100 and 150 mg/dL, urea contamination appeared at 224 +/- 2 (A) and 204 +/- 14 minutes (B), and 227 +/- 5 (A) and 232 +/- 3 minutes (B), respectively. CONCLUSION: Both temperature differences between spent and fresh dialysate and solute content of spent dialysate contribute to dialysate partitioning in the Genius dialysis system.