Hemodialysis Machine Research Articles

Can Advances in Hemodialysis Machine Technology Prevent Intradialytic Hypotension?

Intradialytic hypotension remains a frequent problem in routine outpatient hemodialysis. Although hypotension can be reduced by more frequent dialysis sessions and longer session duration, these options are not available for many patients. Advances in hemodialysis machine technology have led to the development of relative blood volume monitoring. However, multicenter trials seeking to document a reduction in the frequency of intradialytic hypotension have been disappointing. Further technological advances using "fuzzy" logic systems have been introduced; they track the fall in relative blood volume and then adjust either or both the ultrafiltration rate and dialyzate sodium concentration to maintain a preprogrammed fall in relative blood volume that is likely to be hemodynamically uneventful. Although these systems have been reported to reduce the frequency of serious intradialytic hypotensive episodes, they have not been successful in preventing them probably due to underlying issues with the use of relative blood volume monitoring. More attention needs to be focused on reducing ultrafiltration rates by reducing interdialytic weight gains. Successfully improving patient motivation and education, emphasizing dietary sodium restriction, lowering dialyzate sodium concentrations will all go a long way toward this goal. Technology has much to offer but will not solve this persistent problem.

Technical Advances in Home Dialysis

Recently, multiple initiatives to produce dedicated and simplified hemodialysis machines for home hemodialysis (HHD) have begun. Most have been designed for short daily hemodialysis 6 times per week. Only 1 machine currently has Food and Drug Administration clearance for HHD, but others are in clinical trial or are soon to be. There has been a trend toward using sorbent technology to allow online regeneration of dialysate to facilitate portability and to reduce machine size and reduce water consumption. Many of the machines are intended to be a stepping stone to a wearable artificial kidney (WAK). A WAK using peritoneal dialysis rather than hemodialysis is also in the development stage.

Why nephrologists should perform therapeutic plasma exchange

Why nephrologists should perform therapeutic plasma exchange

Life can change on a dime

Life can change on a dime. I learned that lesson the hard way. It was 1961 and I was 17 years old and had just enrolled at Purdue University to study engineering. America was on a mission to reach the moon. I hoped to be a part of the efforts. But as I mentioned, life can change. I applied to be a participant in the Reserve Officers Training Program (ROTC) at Purdue. To enlist, I had to take a physical exam. That's when I first heard the word proteinuria. Further tests would show I had glomerulonephritis. The doctors told me the disease was progressive, but I would be fine for many years if I stuck to a low-salt diet. I developed hypertension in 1963 and had to be placed on high blood pressure medication. With my kidney function continuing to decrease, I was no longer eligible for ROTC. I managed to get through the first semester of my senior year but had to go home soon after for medical treatment. Here I was 20 years old in a Rochester, N.Y., hospital being given continuous peritoneal dialysis (PD) treatment, and I was still very sick. Doctors placed an external arteriovenous shunt in my forearm to provide a connection to the hemodialysis machine. Those were the days when patients dialyzed for 12 hours a day, every other day. I can't even imagine doing that now. I was placed on a flatbed (Kiil) machine that utilized my heart as its pump. Doctors knew this couldn't be a long-term solution. My parents and I were referred to Peter Bent Brigham Hospital in Boston for a possible transplant. Fortunately, my father was a compatible match, and he could donate one of his kidneys to me. In March 1965, Dr. Joseph Murray, who later would receive the Nobel Prize for Transplantation, transplanted my father's kidney into me. This was before Medicare coverage, so donations from the hospital and some insurance money covered the costs. But as life sometimes does, I was thrown a curve ball when doctors discovered a malignant melanoma and advised me to stop taking my immunosuppressant medicines. That meant I was going to reject my kidney transplant. In 1984 I began dialysis at Holy Name Hospital in New Jersey. During this time, two new drugs came onto the market, cyclosporine and Epogen. Each was very important to me. Epogen eliminated my need for transfusions, which were still risky (because of hepatitis C and AIDS), and cyclosporine allowed me to be considered for a second transplant. I was fortunate to be accepted in the EPO Trial Program under the direction of Drs. Eli Friedman and Peter Lundin in Brooklyn, N.Y. Being on the transplant waiting list was nerve-racking. I wore a beeper 24 hours a day, every day. For months I heard nothing. And the one day it did beep, it was the wrong number. When it did beep again and was the right number, I couldn't take the kidney because I had a respiratory infection. My luck started to change in May 1988. There was a severe thunderstorm. I was having dinner and dialyzing at home when the power went out. As we struggled in the dark to return my blood and disconnect me from the machine, my daughter picked up the ringing phone. I told her to tell whomever it was that we were busy. She then said, “Dad, they have a kidney for you.” My wife and I immediately went to Columbia Presbyterian Medical Center in New York City to receive the transplant. The kidney came from an 11-year-old girl in San Francisco. Many years later, my younger daughter would need a kidney. My daughter Barbara was diagnosed with focal segmental glomerulosclerosis at age 13. She's 36 now. Fortunately, my wife, Dottie, was able to donate a kidney to her 6 years ago, and they are both very healthy today. I am living a full and fortunate life. I am grateful to my parents and the family of the 11-year-old girl who donated a kidney to me. I've tried to repay their gift by giving back to the kidney community. Over the years, I've worked with a number of kidney organizations, including the American Association of Kidney Patients (AAKP), serving as its president for six years. I've seen a lot of great changes over the years in the kidney community, and change only comes when patients and healthcare professionals demand it. Encourage your patients to get involved in their healthcare. Tell them to ask you questions and write their congressional leaders. Urge them to take the time to learn about their disease.

Microbiological contamination of a hemodialysis center water distribution system

The microbiological monitoring of the water used for hemodialysis is extremely important, especially because of the debilitated immune system of patients suffering from chronic renal insufficiency. To investigate the occurrence and species diversity of bacteria in waters, water samples were collected monthly from a hemodialysis center in upstate São Paulo and tap water samples at the terminal sites of the distribution system was sampled repeatedly (22 times) at each of five points in the distribution system; a further 36 samples were taken from cannulae in 19 hemodialysis machines that were ready for the next patient, four samples from the reuse system and 13 from the water storage system. To identify bacteria, samples were filtered through 0.22 microm-pore membranes; for mycobacteria, 0.45 microm pores were used. Conventional microbiological and molecular methods were used in the analysis. Bacteria were isolated from the distribution system (128 isolates), kidney machine water (43) and reuse system (3). Among these isolates, 32 were Gram-positive rods, 120 Gram-negative rods, 20 Gram-positive cocci and 11 mycobacteria. We propose the continual monitoring of the water supplies in hemodialysis centers and the adoption of effective prophylactic measures that minimize the exposure of these immunodeficient patients to contaminated sources of water.

Immobilization of soybean ( Glycine max) urease on alginate and chitosan beads showing improved stability: Analytical applications

The soybean ( Glycine max) urease was immobilized on alginate and chitosan beads and various parameters were optimized and compared. The best immobilization obtained were 77% and 54% for chitosan and alginate, respectively. A 2% chitosan solution (w/v) was used to form beads in 1N KOH. The beads were activated with 1% glutaraldehyde and 0.5 mg protein was immobilized per ml of chitosan gel for optimum results. The activation and coupling time were 6 h and 12 h, respectively. Further, alginate and soluble urease were mixed to form beads and final concentrations of alginate and protein in beads were 3.5% (w/v) and 0.5 mg/5 ml gel. From steady-state kinetics, the optimum temperature for urease was 65 °C (soluble), 75 °C (chitosan) and 80 °C (alginate). The activation energies were found to be 3.68 kcal mol −1, 5.02 kcal mol −1, 6.45 kcal mol −1 for the soluble, chitosan- and alginate-immobilized ureases, respectively. With time-dependent thermal inactivation studies, the immobilized urease showed improved stability at 75 °C and the t 1/2 of decay in urease activity was 12 min, 43 min and 58 min for soluble, alginate and chitosan, respectively. The optimum pH of urease was 7, 6.2 and 7.9 for soluble, alginate and chitosan, respectively. A significant change in K m value was noticed for alginate-immobilized urease (5.88 mM), almost twice that of soluble urease (2.70 mM), while chitosan showed little change (3.92 mM). The values of V max for alginate-, chitosan-immobilized ureases and soluble urease were 2.82 × 10 2 μmol NH 3 min −1 mg −1 protein, 2.65 × 10 2 μmol NH 3 min −1 mg −1 protein and 2.85 × 10 2 μmol NH 3 min −1 mg −1 protein, respectively. By contrast, reusability studies showed that chitosan–urease beads can be used almost 14 times with only 20% loss in original activity while alginate–urease beads lost 45% of activity after same number of uses. Immobilized urease showed improved stability when stored at 4 °C and t 1/2 of urease was found to be 19 days, 80 days and 121 days, respectively for soluble, alginate and chitosan ureases. The immobilized urease was used to estimate the blood urea in clinical samples. The results obtained with the immobilized urease were quite similar to those obtained with the autoanalyzer ®. The immobilization studies have a potential role in haemodialysis machines.

Renal Replacement Therapy in Support of Operation Iraqi Freedom: A Tri-Service Perspective

Experience with delivery of renal replacement therapy (RRT) in support of combat operations by the U.S. military has not been reported since the 1970s. We describe the tri-service military medical experience with RRT in support of Operation Iraqi Freedom. Through December 31, 2006, RRT was provided to 12 individuals inside the theater of operations. Navy medical personnel provided RRT to three patients (two U.S. active duty service members and one host nation individual) aboard the USNS Comfort, a mobile level 4 hospital. Dialysis was performed using conventional single-pass hemodialysis machines equipped with portable reverse osmosis systems. Army and Air Force medical personnel provided RRT to nine patients in theater (eight host nation patients and one U.S. active duty service member), using peritoneal dialysis and continuous renal replacement therapy (CRRT), not requiring trained renal nurses or technicians. Originally, U.S. military personnel with acute kidney injury (AKI) who were evacuated from theater to Landstuhl Regional Medical Center (LRMC), or those who developed AKI at LRMC were transferred to the German civilian medical system, if RRT was required. After creation of a rapid-response dialysis team and, later, positioning of a full-time active duty reserve nephrologist at LRMC, 16 patients received RRT at LRMC. None had required RRT in theater. Renal failure requiring RRT during combat operations remains an unusual but serious event, calling for flexibility in the provision of care. Notably, the Operation Iraqi Freedom experience has highlighted the needs of injured host nation patients with AKI and future military medical planning will need to account for their intratheater renal care.

Prevalence and Incidence of Hepatitis C Virus in Hemodialysis Patients in British Columbia: Follow‐up after a Possible Breach in Hemodialysis Machines

A possible breach of the transducer protector in specific dialysis machines was reported in June 2004 in British Columbia (BC), which led to testing of hemodialysis patients for hepatitis C virus (HCV), hepatitis B virus (HBV) and HIV. This testing provided an opportunity to examine HCV incidence, prevalence and coinfection with HBV and HIV, and to compare anti-HCV and HCV polymerase chain reaction (PCR). The results of hemodialysis patients who were dialyzed on the implicated machines (65% of BC dialysis patients), and tested for HCV, HBV and HIV, between June 1, 2004, and December 31, 2004, were reviewed and compared with available previous results. Of 1286 hemodialysis patients with anti-HCV and/or HCV-PCR testing, 69 (5.4%) tested positive. Two HCV genotype 4 seroconversions were identified. HCV incidence rate on dialysis was 78.8 cases per 100,000 person-years. Younger age, history of renal transplant and past HBV infection were associated with HCV infection. No occult infection was identified using HCV-PCR. Hemodialysis patients had three times the HCV prevalence rate of the general BC population, and more than 20 times the incident rate of the general Canadian population. One of the two seroconversions occurred before the testing campaign; the patient was likely infected during hemodialysis in South Asia. The other was plausibly a late seroconversion following renal transplant in South Asia. Nosocomial transmission cannot be ruled out because both patients were dialyzed in the same centre. Baseline and annual anti-HCV testing is recommended. HCV-PCR should be considered at baseline for persons with HCV risk factors, and for returning travellers who received dialysis in HCV-endemic countries to identify HCV infection occurring outside the hemodialysis unit.

A comparison of methods for determining urea distribution volume for routine use in on-line monitoring of haemodialysis adequacy

The availability of haemodialysis machines equipped with on-line clearance monitoring (OCM) allows frequent assessment of dialysis efficiency and adequacy without the need for blood samples. Accurate estimation of the urea distribution volume 'V' is required for Kt/V calculated from OCM to be consistent with conventional blood sample-based methods. Ten stable HD patients were monitored monthly for 6 months. Time-averaged OCM clearance (K(OCM)) and pre- and post-dialysis blood samples were collected at each monitored session. The second generation Daugirdas formula was used to calculate the single-pool variable volume Kt/V, (Kt/V)(D). Values of V to allow comparison between OCM and blood-based Kt/V were determined from Watson's formula (V(Watson)), bioimpedance spectroscopy (V(BIS)), classical urea kinetic modelling (V(UKM_C)) and a simple computation of V (V(UKM_S)) from the blood-based Kt/V and K(OCM)t. Comparison of K(OCM)t/V with (Kt/V)(D) shows that using V(Watson) leads to significant systematic underestimation of dialysis dose. K(OCM)t/V(BIS) agrees with (Kt/V)(D) to within +/- 10%. K(OCM)t/V(UKM_S) is, by definition, identical to (Kt/V)(D) when initially calculated. However, if a historical value of V is used, agreement between K(OCM)t/V and (Kt/V)(D) over 6 months varies by 5% for V(BIS) and 10% for V(UKM_S). When investigating the effect of different treatment strategies on dialysis efficiency, any estimate of V can be used provided it is constant, as K is the relevant parameter. When frequent supervision of actual dialysis dose is required, the greatest consistency between K(OCM)t/V and the reference, Kt/V(D), over time is achieved with V(BIS).

Comparison of a Pulsatile Blood Pump and a Peristaltic Roller Pump During Hemoperfusion Treatment in a Canine Model of Paraquat Poisoning

This study examined the treatment efficacy and the damage to the blood during hemoperfusion for treating paraquat poisoning using two blood pump mechanisms. Paraquat-poisoned animal models were prepared. A conventional hemodialysis machine, AK90, with a peristaltic roller pump and a cardiopulmonary support system, T-PLS, with a pulsatile blood pump were used during the animal experiments. A total of 12 dogs were treated with hemoperfusion using a charcoal column. Six dogs were treated with hemoperfusion and T-PLS, and the other six were treated with AK90. A paraquat dose of 30 mg/kg was administrated by an intravenous injection. Both pumps maintained blood flow rates of 125 mL/min measured by an ultrasonic flowmeter. For anticoagulation, heparin was administrated by an initial bolus (250 IU/kg) and a continuous injection (100 IU/kg/h). During the experiments, T-PLS and AK90 showed a similar toxin removal efficacy. Both devices decreased the plasma paraquat concentration to 10% of the initial dose within 4-h hemoperfusion. The two pumps showed similar hemolysis properties with acceptable levels. Although T-PLS was developed as a cardiopulmonary bypass system, it can also be used as a hemoperfusion treatment device.

The ideal home hemodialysis machine

Daily home hemodialysis (HD) patients have a much superior survival rate than patients on regular, 3 times a week in-center HD or on peritoneal dialysis. Present-day HD machines are unsuitable for use at home by patients. We present our concept of the ideal home HD machine that allows daily short and long HD, does all the work preparing for and cleaning up after dialysis, has an intravenous infusion system controlled by the patient, needs no systemic anticoagulation, and teaches and interacts with the patient during dialysis. To fulfill these functionalities, the dialyzer and blood tubing must be integrated with the machine and replaced less often than monthly, the machine must be capable of at least 200 L/week of hemodiafiltration, prepare all fluids necessary between and during dialyses, and all the components and fluids must be much beyond ultrapure.

CMS Finalizes Revisions to Conditions to Participation

CMS Finalizes Revisions to Conditions to Participation

Influence of the Ionic Dialysance Monitor on Kt Measurement in Hemodialysis

Ionic dialysance can provide accurate monitoring of dialysis dose during each hemodialysis session. Increasingly, hemodialysis machines incorporate devices that measure ionic dialysance, allowing the dialysis dose to be determined noninvasively in real time and in each session. Because Kt product was proposed as a measure of hemodialysis dose to avoid the reverse J-shaped curve between urea reduction ratio or Kt/V and mortality, we investigated whether ionic dialysance values and Kt measurements are affected by different ionic dialysance monitors (Diascan and online clearance monitoring [OCM]) and dialysis machines. Four-period crossover. 31 adult long-term hemodialysis patients using 2 different ionic dialysance monitors in 4 dialysis machines: Diascan in Hospal Integra and Gambro AK-200 machines and OCM in Fresenius 4008S and 5008 machines. Ionic dialysance monitor and machine used in 4 hemodialysis sessions for each participant. Kt and Kt/V measured by using ionic dialysance and serum urea nitrogen. Mean values for initial and final ionic dialysance were similar for Integra and AK-200 machines, both measured by using Diascan, and for the 4008S and 5008 machines, both measured by using OCM; however, OCM values tended to be greater in the 4008S and 5008 machines. Kt measured in the 4008S and 5008 machines was greater (59.6 +/- 12 and 58.6 +/- 11 L, respectively) than with the Integra and AK-200 machines (53.4 +/- 11 and 53.8 +/- 11 L). Mean urea reduction ratio and Kt/V were 78.0% +/- 8% and 1.89 +/- 0.43 for Diascan monitors and 79.6% +/- 8% and 1.99 +/- 0.44 for OCM monitors, respectively (P < 0.01). Differences between monitors in Kt determination were caused in part by a real difference in dialysis effectiveness (6%) and in part by an intermethod difference (4%). Kt adjusted by Kt/V differences was recalculated, and because of good correlation between Diascan and OCM, we were able to apply a formula (Kt(OCM) = 1.08 Kt(Diascan) - 2; r =0.95) that allowed both Kt quantification methods to be compared. Nonblinded nonrandomized small sample. Kt is a valid method for judging dialysis dose in real time by using ionic dialysance measurements. Adjustments to correct intermethod differences may be necessary to ensure generalizability among ionic dialysance monitors.

Reviews: Pathophysiology and Clinical Implications of Microbubbles during Hemodialysis

Microbubbles have been detected in the human circulation of end-stage renal disease patients who are treated by hemodialysis throughout the past decade as a result of advanced ultrasound and Doppler technology. These detection tools uncovered signals of microbubbles, which originate in extracorporeal lines and tubing of hemodialysis machine, circulate in the blood stream until lodging in the capillary bed of various organs, mainly the lungs. During its course within the capillary, a bubble abrades the glycocalyx layer lining the surface of the vessels and thereafter obstructs blood flow through the capillary. This causes tissue ischemia, inflammatory response, and complement activation. Aggregation of platelets and clot formation occurs as well, leading to further obstruction of the microcirculation and subsequent tissue damage. In this review, we describe the biological and clinical effects of microbubbles during hemodialysis and discuss management with regard to prevention and treatment.

Frequent hemodialysis with NxStage™ system in pediatric patients receiving maintenance hemodialysis

Recent evidence from adult hemodialysis (HD) patient studies reveal improved biochemical control and reported health-related quality of life after transition from conventional thrice weekly to daily home maintenance HD treatment. Published pediatric frequent dialysis experiences demonstrate similar improvement but all used conventional HD machines, which employ a treated municipal water supply, thereby frequently exposing patients to proinflammatory components. We report our pediatric experience with six-times-weekly HD using the NxStage system, which uses sterile dialysis fluid to provide dialysis in the home or center setting. Four patients (weight range 38-61.4 kg) completed the 16-week study. Patients exhibited progressive reductions in casual pretreatment systolic and diastolic blood pressures, discontinuation of antihypertensive medications, and decreased blood pressure load by ambulatory blood pressure monitoring. Mean serum phosphorus improved without change in phosphorus binder medication, and all three patients with a normalized protein catabolic rate <1 g/kg per day at the beginning of the study improved to a normalized protein catabolic rate (nPCR) of >1.1 g/kg per day. Patients reported no adverse effects. Variable changes in proinflammatory cytokine levels were observed. We suggest that frequent HD with the NxStage system be considered for children who would benefit from home-based maintenance dialysis.

Comparison of Middle-Molecule Clearance between Convective Control Double High-Flux Hemodiafiltration and On-Line Hemodiafiltration

Hemodiafiltration (HDF) is now a well-recognized treatment modality for end-stage renal disease (ESRD) patients. It provides superior characteristics over conventional hemodialysis in many respects. On-line HDF, however, which has been mainly used in clinical practice, requires a special machine. Interestingly, the recently innovated convective-control double high-flux hemodiafiltration (CC-DHF) machine can provide HDF treatment with an adjustable convection rate by using the conventional volume-controlled dialysate flow hemodialysis machine in a modified way. The present study was conducted to compare the efficacy of CC-DHF compared to on-line HDF in terms of middle and small solute clearances in 12 stable, chronic hemodialysis patients who underwent hemodialysis three times a week for at least 6 months. The results showed that the beta 2-microglobulin (beta 2M) removal represented by the beta 2M clearance in CC-DHF was comparable to that in on-line HDF (112.4+/-17.0 vs. 119.4+/-15.5 ml/min respectively, NS). Also, the beta 2M reduction ratio in the CC-DHF group did not differ from the on-line HDF group (85.5+/-4.2% vs. 86.1+/-6.7%, NS). With regard to small solute clearances, the values of single-pool Kt/V and phosphate clearance did not differ between CC-DHF and on-line HDF groups. In conclusion, CC-DHF provides removal of beta 2M and small molecule uremic toxins that is comparable to on-line HDF. An on-line HDF machine may not be available in all hemodialysis centers, whereas CC-DHF can be easily set up, with proper precautions regarding the fluid quality. Therefore, CC-DHF can provide the benefits of convective therapy to patients in situations where use of an on-line HDF machine is limited.

Acoustical Bubble Trapper Applied to Hemodialysis

Gaseous microemboli can arise in extracorporeal lines and devices such as dialysis machines. They are associated with severe pulmonary side effects in patients undergoing chronic hemodialysis sessions. The goal of this study was to develop a gaseous emboli trapper using ultrasound waves to remove any air bubble from the tubing system before they reach the patient. A homemade bubble trapper, developed in the laboratory, consists of a Perspex block containing a main channel connected to the tubing of a hemodialysis machine and a second subchannel positioned perpendicularly to the main one, used to trap the air microemboli. The microemboli flowing in the main channel were insonified through an acoustic window with an ultrasound wave, at a frequency of 500 kHz and with a maximal acoustic pressure of 500 kPa, generated by a single-element transducer positioned 3 cm away from the main flow. The radiation force induced by the ultrasound beam acts directly on the flowing air emboli, by pushing them into the subchannel. Two Doppler probes operating both at 2 MHz, connected to a DWL Doppler machine were placed before and after the bubble trapper to count sequentially the number of embolic events. The flow of the machine was varied between 200 mL/min and 500 mL/min. Depending on the flow velocity, the number of microembolic signals (MES) detected by the Doppler probes before and after the trapping system was identical and ranged from 5 to 150 MES/min in absence of the ultrasound irradiation. When the air bubble trapper was activated, a reduction of the number of MES, up to 70%, was achieved. Doppler recordings suggest that the circulating bubbles were either fragmented into smaller bubble fragments or directly got pushed into the second subchannel where they were collected. This simple approach using an ultrasound-based trapping system was shown to operate adequately with the current settings and can be used to filter air microemboli. (E-mail: palanchon@med.univ-tours.fr)

The D&amp;T Report

The D&amp;T Report

Assessment of management and treatment responses in haemodialysis patients from Tehran province, Iran

Chronic kidney disease (CKD) and end-stage renal disease (ESRD) are emerging as globally important public health problems, and will necessitate improvements in health-care policy. ESRD incidence/prevalence data are not available from large parts of the developing world. The main objective of this study is to describe and assess the current clinical practices for patients on maintenance haemodialysis (HD) living in the province of Tehran. In December 2005, an observational study was performed with 2630 patients (1505 males and 1125 females) from 56 different centres in the province of Tehran (the entire HD population), which has a population of 13.5 million inhabitants. The prevalence/incidence of HD was 194.8/77.3 p.m.p. The leading causes of ESRD were diabetes and hypertension. Population of 90.3 and 9% received three and two sessions per week, respectively, with a KT/V mean value of 0.97+/-0.25. All centres used synthetic membranes, and 68% of the sessions were performed using bicarbonate as a buffer. The type of vascular access was autogenous arteriovenous fistula in 91% of patients. Our findings indicated that compliance with the K/DOQI recommendations for calcium-phosphorus management is difficult to achieve. Only 1.8% of patients achieved all four target laboratory tests. For the management of anaemia, ferritin was the most commonly performed measure of iron status (76.7%). Iron deficiency was seen in <20% of patients (ferritin <or=200) and the mean value of haemoglobin (Hb) was 10.14+/-2.00 g/dl. The achieved standard of renal replacement therapy (RRT) in Tehran province, Iran is acceptable and in some aspects is comparable with European countries, but the number of ESRD patients is increasing in Tehran and worldwide. Increases in the number of HD centres, machines, shifts and kidney transplantations are taking place but cannot keep pace with the increasing number of patients. It is highly recommended that we try to increase peritoneal dialysis (PD) coverage and cadaveric transplantation, while keeping in mind that the prevalent population of individuals with CKD is estimated to be at least 20 times the number with ESRD. It is not too ambitious to consider CKD prevention, and we should place initial focus on strategies and treatments that slow disease progression, in order to postpone RRT.

Ultrapure Dialysate for Home Hemodialysis?

Use of ultrapure dialysate (bacteria < 0.1 CFU/mL and endotoxin < 0.03 EU/mL) is associated with a reduction in inflammation and morbidity in patients treated with conventional thrice-weekly dialysis. The improved outcomes obtained with more frequent dialysis schedules have reawakened interest in home hemodialysis. More frequent dialysis also appears to reduce inflammation, and whether combining more frequent dialysis with use of ultrapure dialysate will have an additive effect on inflammation and its consequences remains unclear. Routinely producing ultrapure dialysate in a home environment with a conventional hemodialysis machine poses technical challenges related to the design of the equipment and the intermittent nature of hemodialysis. Solutions to these problems include use of a system in which the water-treatment equipment is fully integrated with the dialysis machine, use of dry-powder cartridges or sterile prepackaged liquids for bicarbonate concentrate, and use of a bacteria-retentive and endotoxin-retentive filter for final purification of the dialysate immediately before it enters the dialyzer. Alternatively, ultrapure dialysate may be achieved with newer machines designed specifically for home hemodialysis that use a new batch of dialysate for each treatment. The volume of dialysate available with these machines, however, currently limits their use to short-daily dialysis.