Progress in dialysis technology: membrane selection and patient outcome

Red blood cell distribution width at admission predicts outcome in critically ill patients with kidney failure: a retrospective cohort study based on the MIMIC-IV database

PURPOSE

We aimed to explore whether red blood cell distribution width (RDW) could serve as a biomarker to predict outcomes in critically ill patients with kidney failure in this study.

MATERIALS AND METHODS

This retrospective study was conducted with the Medical Information Mart for Intensive Care IV (MIMIC-IV).A total of 674 patients were divided into three groups based on tertiles of RDW. We used the generalized additive model, Kaplan-Meier curve, and Cox proportional hazards models to evaluate the association between RDW and clinical outcomes. We then performed subgroup analyses to investigate the stability of the associations between RDW and all-cause mortality.

RESULTS

Nonlinear and J-shaped curves were observed in the generalized additive model. Kaplan-Meier analysis showed that patients with elevated RDW had a lower survival rate. The Cox regression model indicated that high levels of RDW were most closely associated with ICU mortality and 30-day mortality (HR = 4.71, 95% CI: 1.69-11.64 and HR = 6.62, 95% CI: 2.84-15.41). Subgroup analyses indicated that the associations between RDW and all-cause mortality were stable.

CONCLUSIONS

Elevated levels of RDW were associated with an increased risk of all-cause mortality, and RDW could be an independent prognostic factor for kidney failure.

Peritoneal Dialysis in the Sudan

Background

End-stage renal disease is a significant social and economic burden on the Sudan. Continuous ambulatory peritoneal dialysis (CAPD) was recently introduced as a national service and is provided free of charge by the Federal State. We present here an overview of our experience and outcomes after the first 20 months of operation of the National Program, displaying its organization and patient and technique survival, peritonitis rates, and adequacy parameters of the first patients to undergo CAPD.

Methods

As a national experiment, the program was sequentially launched in 5 adult and 2 pediatric centers in Khartoum, the capital city of the country. The data include the entire 111 patients who underwent CAPD from June 2005 to January 2007. All data were reported to, and analyzed at, the head office of the Sudan National Peritoneal Dialysis Program.

Results

CAPD is the modality exclusively utilized thus far. Automated PD will be added to the program this year. By 30 January 2007, the total number of patients enrolled was 111. Their age range was 1 – 75 (median 56) years. 20 patients (18%) were shifted to hemodialysis and 5 patients received living related kidney transplants. Two died of severe septicemia due to peritonitis; 16 (14%) others died of non-PD-related causes. There were 60 cases of peritonitis in 839 patient-months, which equates to an overall peritonitis rate of 1 episode every 14 months (0.87 episodes per year at risk). The individual center rates varied. A critical review of cases at the end of the first year showed a statistically significant age difference, with peritonitis being more common in the younger patients. Mean age of patients that developed peritonitis was 30.53 years, whereas that for peritonitis-free patients was 44.09 years ( p = 0.025). All patients that had peritonitis presented with abdominal pain and had a cloudy effluent; none had exit-site or tunnel infection. The culture-negative peritonitis rate was 53%. Pseudomonas species were responsible for 13.3% and Staphylococcus aureus for 6.7%. Touch contamination was the likely mechanism behind 46.7% of the episodes. There were 3 cases of refractory peritonitis and a single case of relapsing peritonitis. Concerning PD adequacy, average Kt/V urea was 1.74; weekly creatinine clearance was 62.5 L/1.73 m2. Average normalized protein catabolic rate, as a measure of dietary protein intake in patients in a steady state, was 1.17 g/kg. These measures indicate that the overall program adequacy was satisfactory and the values fall within the recommended ranges.

Conclusion

The first 20 months of operation of the Sudan's National Peritoneal Dialysis Program have proven that it is a promising project with multifaceted success. The adequacy indicators are acceptable but the cumulative peritonitis incidence is above that recommended, indicating several areas for potential improvement. Although CAPD is highly cost-effective, ongoing difficulties, including the cost of medications and laboratory tests, are being sorted out with official support and public involvement.

Continuous ambulatory peritoneal dialysis in Egypt: progression despite handicaps

BACKGROUND

Despite the well-known advantages of continuous ambulatory peritoneal dialysis (CAPD), it continues to be grossly underutilized in many developing countries. However, some developing countries, such as Mexico, use the modality very effectively. In view of this, we started the first CAPD program in Egypt.

METHODS

Since its start in 1997, our program has treated 33 patients. Straight double-cuffed Tenckhoff catheters were surgically placed in all patients. Twin-bag systems were used. All patients underwent monthly clinical and biochemical assessment and measurement of Kt/V urea. Peritonitis and exit-site infection rates were monitored.

RESULTS

Most treated patients were adult and female. Mean age was 31.7 years and mean follow-up duration was 18 months. Peritonitis rate was 1 episode /21.3 months and was easily managed in most patients. Staphylococcus aureus was the most commonly isolated organism (24%) but 49% of cases were culture negative. There were no exit-site infections. Mean weekly Kt/V urea was 1.78 +/- 0.23.

CONCLUSION

We report the successful development of a small CAPD program in Egypt, made possible by well-established financial support, a motivated team of doctors and nurses, and good patient selection and training.

Blood cleaner on-chip design for artificial human kidney manipulation

A novel design of a blood cleaner on-chip using an optical waveguide known as a PANDA ring resonator is proposed. By controlling some suitable parameters, the optical vortices (gradient optical fields/wells) can be generated and used to form the trapping tools in the same way as optical tweezers. In operation, the trapping force is formed by the combination between the gradient field and scattering photons by using the intense optical vortices generated within the PANDA ring resonator. This can be used for blood waste trapping and moves dynamically within the blood cleaner on-chip system (artificial kidney), and is performed within the wavelength routers. Finally, the blood quality test is exploited by the external probe before sending to the destination. The advantage of the proposed kidney on-chip system is that the unwanted substances can be trapped and filtered from the artificial kidney, which can be available for blood cleaning applications.

The characteristics of new semi-quantitative method for diagnosing proteinuria by using random urine samples

We assessed the characteristics of the new semi-quantitative test paper (Clinitek ATLAS Pro(12)) using random urine samples. Three hundred urine samples were analyzed using either the new test paper, conventional dipsticks, quantitative (P/C ratio), or immunological quantitative methods (A/C ratio). Our study showed that the new test paper is highly sensitive and specific for the detection of urinary protein. The new test paper also detected the urine protein more accurately than the conventional test and has a lower false-positive rate. In addition, the new test paper detected 14 of the 300 patients (4.7%) as dilute urine samples needing reassessment. Seventeen of the 300 samples tested were negative with conventional dipsticks but positive with the new test paper. The new semi-quantitative test paper not only has higher sensitivity than the conventional dipstick method, but also has potential to detect dilute samples.

Identifying patients with chronic kidney disease from general practice computer records

BACKGROUND

Chronic kidney disease (CKD) is an important predictor of end-stage renal disease, as well as a marker of increased mortality. The New Opportunities for Early Renal Intervention by Computerised Assessment (NEOERICA) project aimed to assess whether people with undiagnosed CKD who might benefit from early intervention could be identified from GP computer records.

METHODS

The simplified Modification of Diet in Renal Disease (MDRD) equation was used to estimate glomerular filtration rate (GFR) and determine stage of CKD in patients from 12 practices in Surrey, Kent and Greater Manchester with SCr recorded in their notes. Further data were extracted on associated co-morbidities and potentially modifiable risk factors.

RESULTS

One quarter (25.7%; 28,862/112,215) had an SCr recorded and one in five (18.9%) of them had a GFR <60 ml/min/1.73 m2 (equivalent to Stage 3-5 CKD), representing 4.9% of the population. Only 3.6% of these were recorded as having renal disease. Three-quarters (74.6%; 4075/5449) of those with Stage 3-5 CKD had one or more circulatory diseases; 346 were prescribed potentially nephrotoxic drugs and over 4000 prescriptions were issued for drugs recommended to be used with caution in renal impairment.

CONCLUSIONS

Patients with CKD can be identified by searching GP computer databases; along with associated co-morbidities and treatment. Results revealed a similar rate of Stage 3-5 CKD to that found previously in the USA. The very low rate of recording of renal disease in patients found to have CKD indicates scope for improving detection and early intervention.

Emerging drugs for renal failure

Renal failure involves a significant impairment of the essential functions of the kidney, which can be either acute with sudden and rapid onset (acute renal failure [ARF]) or chronic with gradual onset (chronic renal failure [CRF]). ARF, if detected early, may be halted or reversed, whereas CRF is generally irreversible. Without treatment or intervention, both forms of renal failure lead to end stage renal failure (ESRF) or end stage renal disease (ESRD), requiring renal replacement therapy (RRT) in the form of dialysis or renal transplantation for survival. However, provision of RRT requires expert teams working in specialised units, making therapy of patients with renal failure expensive; furthermore, RRT is complex, with its own complications. Although pharmacological interventions have shown promise in experimental models, these have not been as successful in the clinical setting (e.g., administration of atrial natriuretic peptide, low-dose dopamine). At present, drugs are administered during CRF to either reduce one of the many risk factors of CRF (e.g., angiotensin-converting enzyme inhibitors, statins) or to deal with the consequences of CRF (e.g., erythropoietin, calcitriol). Recent evidence suggests that some of these interventions may provide further direct beneficial effects via reduction of renal inflammation. Although these interventions have greatly improved the prospects for patients suffering ESRF, the development of novel drugs and therapies with which to reduce the consequences of renal failure and ESRD remain topics of great interest. This article reviews the therapies available for the prevention and management of renal failure in adults and describes, in detail, emerging drugs and novel interventions that may soon become available for the treatment or prevention of ESRF.

Rights of chronic renal failure patients undergoing chronic dialysis therapy

The Patient Advocacy Committee of the International Federation of Kidney Foundations (IFKF) has developed a document proposing a set of rights for individuals with end stage renal failure (ESRF). These rights have been approved by the Board of Directors of the IFKF. Twenty rights have been developed and are organized into the following categories: (i) need of treatment and choice of patients; (ii) treatment of ESRF by haemodialysis; (iii) treatment of ESRF by peritoneal dialysis; and (iv) renal transplantation. It is the hope of this Committee and the IFKF that this document will provide a stimulus to more scientific inquiry and discussion as to what rights do patients possess with regard to treatment of chronic kidney disease, regardless of where they live or what may be their economic, social, ethnic or political status.

Verification of the chemical composition and specifications of haemodialysis membranes by NMR and GPC-FTIR-coupled spectroscopy

The chemical composition of a dialysis membrane is decisive towards determining its physical and biochemical properties--two fundamental determinants of the success of therapy offered to patients suffering from chronic renal failure. From the vast variety of synthetic polymers available, only a few are suitable for the manufacture of dialysis membranes that have to conform to the diverse demands of modern haemodialysis and related therapies. Recently, a membrane labelled as polyamide (Polyamide S) has caused some confusion to end-users in that the product specification for the membrane is given as 'polyarylethersulfone' or simply as Polyamide S membrane. As the chemical and physical properties of these two polymer types are distinctly different, it is unclear whether the functional characteristics of Polyamide S are to be attributed to polyamide, polyarylethersulfone, or, to both polymers. We therefore undertook investigations to ascertain the exact chemical nature of the Polyamide S membrane using a series of chemical analytical tools and an appropriate polyamide reference. The analytical techniques were conventional gel permeation chromatography (GPC), GPC-FTIR coupled spectroscopy using dimethyl acetamide and hexafluoroisopropanol as solvents and nuclear magnetic resonance spectroscopy. Glass transition temperature measurements and quantitative elemental analysis were also carried out. None of the analytical techniques used showed any traces of polyamide in Polyamide S; no aliphatic or aromatic polyamide chemical entities were detected in any of the samples tested. The Polyamide S dialysis membrane thus comprises, solely, of polyarylethersulfone, which is also known as polyethersulfone.

The epidemiology of end-stage renal disease in Iran in an international perspective

INTRODUCTION

The epidemiology of end-stage renal disease (ESRD) and renal replacement therapy (RRT) is under continuous evolution all over the world. We report here the epidemiological analysis of ESRD and RRT in Iran and discuss it against the background of the international situation.

METHODS

This epidemiological report is based on data from centre questionnaires which were collected in Iran from 1997 onwards, with a response rate of 100%.

RESULTS

The prevalence/incidence of RRT patients were 238/49.9 p.m.p. in the year 2000. Haemodialysis and kidney transplantation were the most common RRT modalities, accounting for 53.7% and 45.5% of prevalent RRT patients, respectively. The proportion treated by peritoneal dialysis was very low (<1%). Home haemodialysis was not performed. The majority of haemodialysis centres used synthetic membranes (70%) and 100% of the sessions were performed using acetate as a buffer; 42.5% of haemodialysis patients were treated with a twice-weekly regimen, whilst 49.6% were on the standard thrice-weekly regimen. The majority of RRT patients in Iran were young to middle aged. The great majority of renal allografts came from living donors (mainly unrelated to recipients). The main renal diseases leading to ESRD were diabetes and hypertension. The third most common category was "cause unknown".

CONCLUSION

The epidemiology of RRT in Iran is characterized by: (i) young patient age (younger than the international average); (ii) high proportion of patients receiving renal allograft; (iii) use of living-unrelated donors as the major source of renal allografts.

The epidemiology of end-stage renal disease in the Baltic countries: an evolving picture

INTRODUCTION

The epidemiology of end-stage renal disease (ESRD) and renal replacement therapy (RRT) is under continuous evolution all over the world. Of particular interest is the development of RRT in the countries of the former Soviet bloc which underwent great political and socio-economical changes in the last decade. We report here the epidemiological analysis of ESRD and RRT in the three Baltic countries: Lithuania, Estonia, Latvia. Subjects and methods. This epidemiological report is based on data from centre questionnaires which were collected from 1996 onwards, with a response rate of 98-99%.

RESULTS

The prevalence/incidence of RRT patients in 1999 were 213/99.5 p.m.p. in Lithuania, 186/45.5 p.m.p. in Estonia and 172/55.8 p.m.p. in Latvia. Haemodialysis (HD) was the most common RRT modality in Lithuania (60% of prevalent patients), but not in Estonia (29%), while in Latvia it was nearly as common as renal transplantation (45 and 46%, respectively). Home HD was not performed. The proportion treated by peritoneal dialysis (PD) was very low in Lithuania (4% of RRT patients), while the percentage was higher in Latvia (9%) and Estonia (20.4%). The percentage of patients on RRT treated by renal transplantation was high throughout, representing the main modality of treatment in Estonia (50.5% of RRT prevalent patients, 94 p.m.p.) and in Latvia (46%, 79 p.m.p.) and being high in Lithuania (36%, 77 p.m.p.). The main renal diseases leading to ESRD were glomerulonephritis, pyelonephritis and diabetes.

CONCLUSION

The epidemiology of RRT in the Baltic countries is undergoing rapid changes. Transplantation has reached an impressive level. A high percentage of RRT patients live with a functioning graft.