Rationale for Water Purification System for Hemodialysis

Dr. Richard A Ward

UpToDate - http://www.uptodate.com/contents/water-purification-systems-in-hemodialysis

Hemodialysis patients are particularly vulnerable to contaminants in the water used to prepare concentrate and dialysate, or in water used for reprocessing dialyzers. Compared to healthy individuals, hemodialysis patients are exposed to extremely large volumes of water, have inadequate barriers to such toxins, and cannot easily eliminate contaminants:

• The estimated water intake of a healthy individual is 2 L per day or 14 L per week. By comparison, a hemodialysis patient may be exposed to 350 to 500 L of water per week, depending upon their treatment time and dialysate flow rate.
• With normal individuals, the gastrointestinal tract separates blood from contaminants in the water. By comparison, the barrier between blood and water in hemodialysis patients is a thin membrane, through which transfer of contaminants is limited only by the size of the contaminant.
• When dialyzers are reused, water is introduced into the blood compartment of the dialyzer during reprocessing. Contaminants in this water may be trapped in the blood compartment and the patient directly exposed to them during the next dialysis treatment.
• Hemodialysis patients are unable to renally excrete any contaminants taken up from the dialysate.

Accumulated experience, combined with the observation that some of the most toxic contaminants arise from municipal water treatment practices, suggests that no municipal water can be considered safe for direct use in hemodialysis applications. All dialysis facilities therefore require a properly designed and maintained water treatment system to safeguard patients [1].

Restless legs syndrome enhances cardiovascular risk and mortality in patients with end-stage kidney disease undergoing long-term haemodialysis treatment

Gaetano La Manna 1, Fabio Pizza2, Elisa Persici1, Olga Baradi1,Glogia Comali1, Maria Laura Cappucilli1,
Francesca Centofanti1, Elisa Carretta3, Giuseppe Plazzi2, Luigi Colì1, Pasquale Montagna2 and Sergio Stefoni1

¹Nephrology Dialysis and Renal Transplantation Unit

²Department of Neurologica Fl Sciences

³Department of Medicine and Public Health, University of Bologna, Italy

Abstract

Background.  Restless legs syndrome (RLS) is a sensorimotor neurological disorder characterized by paraesthesia, dysaesthesia and the irresistible urge to move the legs especially at night. Its prevalence is much higher among dialysis patients at 12 to 62% compared to 3 to 9% in the general population. Here, we investigated the association between RLS and cardiovascular events risk and laboratory parameters in end-stage kidney disease (ESKD) patients on dialysis.

Methods. One hundred ESKD patients undergoing haemodialysis were enrolled in an 18-month prospective observational study. The main outcomes were the associations of RLS with new cardiovascular events and cardiovascular mortality.

Results. RLS affected 31% of the study population. It was associated with female gender, gradual reduction in residual diuresis, lower albumin (P = 0.039) and inflammation, but not the dialysis parameters Kt/V and URR. During observation, 47% of patients experienced new cardiovascular events (64.5% with and 39.1% without RLS; P = 0.019). New cardiovascular events increased with severity of RLS [intermittent (I-RLS) vs continuous (C-RLS)]. Mortality was 20.0% in all patients, 32.3% in those with and 14.5% in patients without RLS (P = 0.04). In patients with I-RLS, mortality was 23.8% compared to 55.6% in patients with C-RLS (P = 0.014). Multivariate analysis confirmed the relationship between RLS and mortality.

Conclusions. This study confirmed the high prevalence of RLS among dialysis patients and the associations between the severity of RLS and the risk of new cardiovascular events and higher short-term mortality.

Need to share very touching song withh Dads.."Happy Father's Day"

We have today posted the National Renal Registry Directory of NGO and Private Dialysis Centres in Malaysia 2011 published by The Malaysian Society of Nephrology.

Warmest regards....MalaysianKidneySPA

Biosimilar recombinant human erythropoietin induces the production of neutralizing antibodies

Kearkiat Praditpornsilpa, Khajohn Tiranathanagul, Pawinee Kupatawintu,Saengsuree Jootar, TaninIntragumtornchai, Kriang Tungsanga, Tanyarat Teerapornlertratt, Dusit Lumlertkul, Natavudh Townamchai, Paweena Susantitaphong, Pisut Katavetin, Talerngsak Kanjanabuch, Yingyos Avihingsanon and Somchai Eiam-Ong

Kidney International , (23 March 2011) | doi:10.1038/ki.2011.68

Recombinant human erythropoietin (r-HuEpo) has been used for the treatment of renal anemia. With the loss of its patent protection, there has been an upsurge of more affordable biosimilar agents, increasing patient access to treatment for these conditions. The complexity of the manufacturing process for these recombinant proteins, however, can result in altered properties that may significantly affect patient safety. As it is not known whether various r-HuEpo products can be safely interchanged, we studied 30 patients with chronic kidney disease treated by subcutaneous injection with biosimilar r-HuEpo and who developed a sudden loss of efficacy. 


Sera from 23 of these patients were positive for r-HuEpo-neutralizing antibodies, and their bone marrow biopsies indicated pure red-cell aplasia, indicating the loss of erythroblasts. Sera and bone marrow biopsies from the remaining seven patients were negative for anti-r-HuEpo antibodies and red-cell aplasia, respectively. The cause for r-HuEpo hyporesponsiveness was occult gastrointestinal bleeding. Thus, subcutaneous injection of biosimilar r-HuEpo can cause adverse immunological effects. A large, long-term, pharmacovigilance study is necessary to monitor and ensure patient safety for these agents.

Effect of increasing dialysate flow rate on diffusive mass transfer of urea, phosphate and β₂-microglobulin during clinical haemodialysis 

Jai P BhimaniJai, Roemary Ouseph and Richard A Ward

Dept of Med. University of Louisville, 615 S. Preston St. Louisville, KY 40202-1718 USA

Nephrol. Dial. Transplant. (2010)25 (12): 3990-3995, doi: 10.1093/ndt/gfq326

Abstract:
Background. Diffusive clearance depends on blood and dialysate flow rates and the overall mass transfer area coefficient (K_oA) of the dialyzer. Although K_oAshould be constant for a given dialyzer, urea K_oA has been reported to vary with dialysate flow rate possibly because of improvements in flow distribution. This study examined the dependence of K_oA for urea, phosphate and β₂-microglobulin on dialysate flow rate in dialyzers containing undulating fibers to promote flow distribution and two different fiber packing densities.

Methods. Twelve stable haemodialysis patients underwent dialysis with four different dialyzers, each used with a blood flow rate of 400 mL/min and dialysate flow rates of 350, 500 and 800 mL/min. Clearances of urea, phosphate and β₂-microglobulin were measured and K_oA values calculated.

Results. Clearances of urea and phosphate, but not β₂-microglobulin, increased significantly with increasing dialysate flow rate. However, increasing dialysate flow rate had no significant effect on K_oA or K_o for any of the three solutes examined, although K_o for urea and phosphate increased significantly as the average flow velocity in the dialysate compartment increased.

Conclusions. For dialyzers with features that promote good dialysate flow distribution, increasing dialysate flow rate beyond 600 mL/min at a blood flow rate of 400 mL/min is likely to have only a modest impact on dialyzer performance, limited to the theoretical increase predicted for a constant K_oA.

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Daulat Tuanku

Salutations & Heartiest Congratulations

His Majesty The Yang Di-Pertuan Agong

Al-Wathiqu Billah Tuanku Mizan 

Zainal Abidin Ibni Al-Marhum Sultan Mahmud

Al-Muktafi Billah Shah

Her Majesty The Raja Permaisuri Agong

Tuanku Nur Zahirah

on the occasion of 

His Majesty's Official Birthday

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Best Wishes and Warmest Regards

MalaysianKidneySPA