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Tampe D, Korsten P, Bremer SCB, Winkler MS, Tampe B. Kinetics of Bilirubin and Ammonia Elimination during Hemadsorption Therapy in Secondary Sclerosing Cholangitis Following ECMO Therapy and Severe COVID-19. Biomedicines 2021; 9:biomedicines9121841. [PMID: 34944657 PMCID: PMC8698542 DOI: 10.3390/biomedicines9121841] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 12/03/2021] [Accepted: 12/04/2021] [Indexed: 12/14/2022] Open
Abstract
In critically ill patients, liver dysfunction often results in coagulopathy and encephalopathy and is associated with high mortality. Extracorporeal clearance of hepatotoxic metabolites, including bilirubin and ammonia, aims to attenuate further hepatocyte damage and liver injury, resulting in decreased mortality. The efficacy of hemadsorption combined with conventional hemodialysis to eliminate bilirubin and ammonia to support the liver's excretory function in acute liver injury has been described previously. However, the optimal use of liver support systems in chronic liver dysfunction due to secondary sclerosing cholangitis in critically ill patients (SSC-CIP) has not been defined yet. We herein describe the kinetics of successful bilirubin and ammonia elimination by hemadsorption in a patient with SSC-CIP after extracorporeal membrane oxygenation (ECMO) therapy for severe acute respiratory distress syndrome (ARDS) in a patient with coronavirus disease 2019 (COVID-19). During the course of the disease, the patient developed laboratory signs of liver injury during ECMO therapy before clinically detectable jaundice or elevated bilirubin levels. A diagnosis of SSC-CIP was confirmed by endoscopic retrograde cholangiopancreatography (ERCP) based on intraductal filling defects in the intrahepatic bile ducts due to biliary casts. The patient showed stable elevations of bilirubin and ammonia levels thereafter, but presented with progressive nausea, vomiting, weakness, and exhaustion. Based on these laboratory findings, hemadsorption was combined with hemodialysis treatment and successfully eliminated bilirubin and ammonia. Moreover, direct comparison revealed that ammonia is more efficiently eliminated by hemadsorption than bilirubin levels. Clinical symptoms of nausea, vomiting, weakness, and exhaustion improved. In summary, bilirubin and ammonia were successfully eliminated by hemadsorption combined with hemodialysis treatment in SSC-CIP following ECMO therapy and severe COVID-19. This observation is particularly relevant since it has been reported that a considerable subset of critically ill patients with COVID-19 suffer from liver dysfunction associated with high mortality.
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Affiliation(s)
- Désirée Tampe
- Department of Nephrology and Rheumatology, University Medical Center Göttingen, 37075 Göttingen, Germany; (D.T.); (P.K.)
| | - Peter Korsten
- Department of Nephrology and Rheumatology, University Medical Center Göttingen, 37075 Göttingen, Germany; (D.T.); (P.K.)
| | - Sebastian C. B. Bremer
- Department of Gastroenterology, Gastrointestinal Oncology and Endocrinology, University Medical Center Göttingen, 37075 Göttingen, Germany;
| | - Martin S. Winkler
- Department of Anesthesiology, Emergency and Intensive Care Medicine, University Medical Center Göttingen, 37075 Göttingen, Germany;
| | - Björn Tampe
- Department of Nephrology and Rheumatology, University Medical Center Göttingen, 37075 Göttingen, Germany; (D.T.); (P.K.)
- Correspondence: ; Tel.: +49-551-39-10575
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Singh A, Mehta Y, Trehan N. Bilirubin Removal Using CytoSorb Filter in a Cardiac Surgical Patient. J Cardiothorac Vasc Anesth 2018; 33:881-883. [PMID: 30292390 DOI: 10.1053/j.jvca.2018.08.213] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Indexed: 12/12/2022]
Affiliation(s)
- Ajmer Singh
- Department of Cardiac Anaesthesia, Institute of Critical Care and Anesthesiology, Medanta-The Medicity, Gurgaon, India
| | - Yatin Mehta
- Department of Cardiac Anaesthesia, Institute of Critical Care and Anesthesiology, Medanta-The Medicity, Gurgaon, India
| | - Naresh Trehan
- Department of Cardiac Surgery, Institute of Critical Care and Anesthesiology, Medanta-The Medicity, Gurgaon, India
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Weber C, Stummvoll H, Passon S, Falkenhagen D. Monocyte Activation and Humoral Immune Response to Endotoxins in Patients Receiving On-Line Hemodiafiltration Therapy. Int J Artif Organs 2018. [DOI: 10.1177/039139889802100610] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
With the on-line preparation of substitution fluid, an easy-to-operate and cost-effective alter-native to conventional hemodiafiltration (HDF) has been realized. The continuous filtration of dialysis fluid, furthermore, allows high volumes of exchange. Microbial contamination and subsequently endotoxins, however, may be present in dialysis fluid, and thus the microbiological safety has become a pivotal issue. In this clinical study we evaluated the safety of the Fresenius Medical Care on-line HDF system which is based on a two-stage filtration of dialysis fluid with upstream DIASAFE® and downstream on-line HDF filter. During the three-month study period we failed to detect germs or endotoxins in the substitution fluid. Augmented plasma interleukin-1β (IL-1β) and tumor necrosis factor α (TNFα) concentrations were found neither during the intradialytic period nor when pre-session values at study begin and study end were compared. In addition, changes in the anti-endotoxin core antibody levels and soluble CD14 (sCD14) concentration, or pyrogenic episodes were not observed. On-line HDF with DIASAFE® and on-line HDF filter thus represents a safe treatment modality by effectively depleting dialysis fluid of cytokine-inducing substances.
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Affiliation(s)
- C. Weber
- Centre for Biomedical Technology, Danube University Krems, Krems
| | | | - S. Passon
- Fresenius Medical Care, Bad Homburg - Germany
| | - D. Falkenhagen
- Centre for Biomedical Technology, Danube University Krems, Krems
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4
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Dieter Falkenhagen (1942–2015): A Multifaceted Scientist. Int J Artif Organs 2015; 38:617-23. [DOI: 10.5301/ijao.5000454] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2015] [Indexed: 11/20/2022]
Abstract
Dieter Falkenhagen was born in 1942 in Dresden, Germany and died in 2015. He specialized in internal medicine and nephrology. Focusing on artificial organ research, he investigated various aspects of the efficacy and safety of hemodialysis and adsorption technologies, including biocompatibility issues related to blood versus surface interactions and the adverse effects of endotoxin contamination. He studied various mathematical models to analyze efficacy and safety, and animal models to help clarify uncertainty issues. Through his studies, adsorbents were developed, resulting in Prometheus, an artificial liver support device. Anticoagulation models, including citrate perfusion, were improved and made safer by his work. He also stepped into bioreactor research to increase efficacy of liver support devices.
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Pore Size – a Key Property for Selective Toxin Removal in Blood Purification. Int J Artif Organs 2014; 37:668-78. [DOI: 10.5301/ijao.5000354] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2014] [Indexed: 12/14/2022]
Abstract
Purpose Extracorporeal blood purification systems based on combined membrane/adsorption technologies are used in acute liver failure to replace detoxification as well as to remove inflammatory mediators in sepsis patients. In addition to coating and chemical modification of the surface, pore size significantly controls the selectivity of adsorption materials. Methods This study addresses the adsorption of albumin bound liver toxins, cytokines, and representative plasma compounds on three adsorbents which differ only in pore size distribution. All three adsorbents are based on hydrophobic poly(styrene-divinylbenzene) copolymer matrices and have mean pore sizes of 15, 30, and 100 nm. Results The pores of adsorbents act as molecular sieves and prevent the entry of molecules that are larger than their molecular cut-off. The results of this study reveal that adsorbents based on styrene-divinylbenzene polymers with 15 nm pores are suitable for cytokine removal, and the same adsorbents with 30-40 nm pores are the best choice for the removal of albumin-bound toxins in the case of liver failure. Adsorbents with very large pores lack selectivity which leads to uncontrolled adsorption of all plasma proteins. Therefore, hydrophobic adsorbents with large pores offer inadequate plasma compatibility and do not fulfill the requirements for blood purification. Conclusions Biocompatibility and efficiency of adsorbents used for blood purification can improved by fine tuning of adsorbent surface pore distributions.
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Abstract
Many terms have been used to describe the collection of signs and symptoms triggered by the initial use of dialyzers. These reactions can be divided into Type A (hypersensitivity reactions, with the incidence of 4/100,000) and Type B (nonspecific reactions, incidence 3-5/100). Many different mechanisms have been postulated, including complement activation, pulmonary leukostasis, hypersensitivity to ethylene oxide, interaction between the AN69 membrane and angiotensin-converting enzyme inhibitors, and dialysate contamination. An unusual case of dialyzer reactions is presented here, involving a patient who had to discontinue peritoneal dialysis when she was admitted with fungal peritonitis. Upon initiation of hemodialysis, she experienced dyspnea and burning sensation and demonstrated significant leukopenia, thrombocytopenia, and oxygen desaturation. These reactions persisted despite double-rinsing of the dialyzers and the use of several different dialyzers with synthetic membranes (polysulfone and AN69), and a variety of sterilization methods (electron beam and gamma radiation). In the end, a simple measure was found to be effective in preventing further dialyzer reactions in this fascinating case.
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Affiliation(s)
- Robert C Yang
- Division of Nephrology, University of Western Ontario, London, Ontario, Canada.
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7
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Ward DM. Hemodialysis water: an update on safety issues, monitoring, and adverse clinical events. ASAIO J 2005; 50:xiii-xviii. [PMID: 15672772 DOI: 10.1097/01.mat.0000147887.74714.50] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Affiliation(s)
- David M Ward
- Division of Nephrology, Medical Center, University of California San Diego, CA, USA
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8
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Abstract
As an extracorporeal technique for blood purification, haemoadsorption was introduced in the early 1960s along with other physico-chemical methods. The problem of poor biocompatibility of uncoated adsorbents was resolved by coating adsorbent granules with haemocompatible membranes. Use of coated adsorbents instead of uncoated ones reduces the efficiency of haemoperfusion. As a result, for many years the use of adsorption was limited to only acute poisoning. Since the 1990s interest in the use of adsorbents in extracorporeal medical devices has been rising again. In this paper some recent developments in synthesis and application of novel uncoated medical adsorbents are discussed.
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Affiliation(s)
- Sergey V Mikhalovsky
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK.
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Gores F, Montag P, Schall C, Vienken J, Bowry SK. Verification of the chemical composition and specifications of haemodialysis membranes by NMR and GPC-FTIR-coupled spectroscopy. Biomaterials 2002; 23:3131-40. [PMID: 12102184 DOI: 10.1016/s0142-9612(02)00057-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
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.
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Affiliation(s)
- F Gores
- Polymer Standards Service GmbH, Mainz, Germany
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10
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Abstract
In recent years, hemodialytic therapies have evolved from the simple, diffusion-dependent removal of small molecular weight substances from blood to advanced therapy modalities involving the convective removal of larger uremic sloutes. The clinical benefits of removal of substances such as beta2-microglobulin (beta2-m) have been reported by several authors: elimination of large-molecular weight "uremic toxins" is now widely accepted as being beneficial to the overall quality of life of patients. This trend would not have been possible without parallel technical developments, especially that of new membranes having more open pore structures resulting in higher sieving coefficients and increased hydraulic permeability. Not all polymer types are suitable for the manufacture of high-flux membranes required for convective therapies in which large fluid volumes are exchanged. Amongst the more important criteria are: the selected polymer must be able to undergo steam sterilisation, have high endotoxin retention capabilities, be versatile for the fabrication of a range of hydraulic permeabilities and, of course, have high blood compatibility. The aim of this paper is, firstly, to review the major membrane development phases over the last quarter of a century. Secondly, the suitability of current membrane materials to meet the aforementioned requirements will be examined. Thirdly, in view of the recent, rapid proliferation of polysulfone-based membranes, dialysis membranes of the polysulfone 'family' are placed under scrutiny; membranes of this class represent a significant portion of the product portfolio of dialyser manufacturers today, yet, few end-users are able to distinguish between the salient features of the respective products because of a combination of confusing membrane nomenclature, classification, tradenames and product claims.
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Affiliation(s)
- S K Bowry
- Fresenius Medical Care, Bad Homburg, Germany.
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11
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Ledebo I. On-line Preparation of Solutions for Dialysis: Practical Aspects Versus Safety and Regulations. J Am Soc Nephrol 2002. [DOI: 10.1681/asn.v13suppl_1s78] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
ABSTRACT. On-line preparation, i.e., continuous mixing and immediate use, was introduced for dialysis fluid in 1964, and it contributed significantly to the expansion of dialysis therapy through simplified handling, improved microbiology, and enhanced efficiency. On-line prepared replacement solution for hemofiltration was shown to be clinically safe as early as 1978, but the implementation was delayed for 20 yr because of regulatory conservatism. On-line preparation of sterile and pyrogen-free solutions for infusion is based on the use of water and concentrates that contribute a minimum of microorganisms and are mixed and distributed in a hygienically designed and maintained flow path. Ultrafilters with known retention capacity are placed in strategic positions and dimensioned to remove bacteria and endotoxins, which gives a sterility assurance level of at least six magnitudes, as required by the Pharmacopoeia for sterile products. Microbiologic testing of the fluid should be applied when designing, validating, and troubleshooting on-line systems but not for routine quality control, because it only gives retrospective information. Quality assurance has to be built into a system and the way it is operated. On-line fluid preparation, when properly performed, is safe, simple, and cost-effective and enhances the efficiency as well as the biocompatibility of dialysis therapy.
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12
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Nubé MJ, Grooteman MP. Impact of contaminated dialysate on long-term haemodialysis-related complications: is it really that important? Nephrol Dial Transplant 2001; 16:1986-91. [PMID: 11572884 DOI: 10.1093/ndt/16.10.1986] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- M J Nubé
- Department of Haemodialysis and Nephrology, Medical Centre Alkmaar, Wilhelminalaan, The Netherlands
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13
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Vaslaki L, Weber C, Mitteregger R, Falkenhagen D. Cytokine induction in patients undergoing regular online hemodiafiltration treatment. Artif Organs 2000; 24:514-8. [PMID: 10916061 DOI: 10.1046/j.1525-1594.2000.06515.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
End-stage renal disease (ESRD) patients are known to suffer from chronic inflammation as the result of an ongoing subacute cytokine induction, which may contribute considerably to dialysis-related, long-term morbidity and mortality. Preparation of infusate from cytokine-inducing dialysis fluid and its administration in large quantities as well as the use of high-flux membranes bear the risk of aggravating the chronic inflammatory response among online hemodiafiltration (online HDF) patients. In order to assess the inflammatory risk associated with online HDF, we compared the cytokine induction profile of ESRD patients receiving either online HDF or low-flux hemodialysis (low-flux HD). Specifically, we measured spontaneous and lipopolysaccharide (LPS)-stimulated tumor necrosis factor alpha (TNFalpha) and interleukin-1 receptor antagonist (IL-1Ra) release during ex vivo incubation of whole blood. Ultrapure dialysis fluid and polysulfone membranes were used for both treatment modalities. LPS-stimulated release of TNFalpha and IL-1Ra was elevated for both online HDF and low-flux HD patients compared to healthy individuals (TNFalpha: 2,336 +/- 346 and 2,192 +/- 398 versus 1,218 +/- 224 pg/106 white blood cells [WBC]; IL-1Ra: 2,410 +/- 284 and 2,326 +/- 186 versus 1,678 +/- 219 pg/106 WBC). Likewise, spontaneous production of TNFalpha, but not IL-1Ra, was higher in online HDF and low-flux HD patients than in normal controls (37 +/- 32 and 22 +/- 19 versus 0.8 +/- 0.3 pg TNFalpha/106 WBC). There was no difference in spontaneous and LPS-stimulated cytokine release between both dialysis groups. In addition, intradialytic cytokine induction was not significant for either treatment modality as spontaneous and LPS-stimulated cytokine release were not increased postdialysis. These findings indicate that online HDF does not contribute to chronic leukocyte activation and, consequently, does not place ESRD patients at greater risk with respect to inflammatory morbidity and mortality.
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Affiliation(s)
- L Vaslaki
- Nephrology Unit, Erzsébet Hospital Sopron, Hungary
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Schiffl H, Fischer R, Lang SM, Mangel E. Clinical manifestations of AB-amyloidosis: effects of biocompatibility and flux. Nephrol Dial Transplant 2000; 15:840-5. [PMID: 10831638 DOI: 10.1093/ndt/15.6.840] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Highly permeable biocompatible dialysis membranes may postpone the development of AB-amyloidosis, but the relative contribution of enhanced flux or reduced inflammation by highly biocompatible membranes and sterile dialysis fluid remains unknown. METHODS In this retrospective investigation, 89 patients with end-stage renal disease maintained on regular haemodialysis for at least 10 years and treated with one type of dialysis membrane exclusively were selected for analysis. They were divided into three groups: low-flux, bioincompatible cellulose (I), low-flux, intermediately biocompatible polysulphone or PMMA (II), or high-flux, highly biocompatible polysulphone or AN69 (III). In addition, the patients were analysed according to the microbiological quality of the dialysis fluid, which had been tested regularly and was classified either as standard or as intermittently contaminated. The clinical manifestations indicative of AB-amyloidosis, namely, carpal tunnel syndrome, arthropathy and bone cysts, were diagnosed after recruitment. RESULTS Clinical symptoms were most pronounced in group I, intermediate in group II, and lowest in group III. Patients treated with intermittently contaminated dialysis fluid showed a higher prevalence of AB-amyloidosis than patients with less contaminated dialysis fluid. Logistic regression analysis demonstrated that the flux characteristics of the dialyser and the microbiological quality of the dialysis fluid as well as the biocompatibility of the dialyser were independent determinants of AB-amyloidosis. CONCLUSION It would be prudent clinical practice to employ high-flux biocompatible membranes in conjunction with ultrapure dialysis fluid for the treatment of end-stage renal disease patients who need to remain on long-term haemodialysis.
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Affiliation(s)
- H Schiffl
- Department of Internal Medicine, Klinikum Innenstadt, University of Munich, Germany
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Hoenich NA, Stamp S, Roberts SJ. A microdomain-structured synthetic high-flux hollow-fiber membrane for renal replacement therapy. ASAIO J 2000; 46:70-5. [PMID: 10667721 DOI: 10.1097/00002480-200001000-00019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
A prospective crossover clinical study evaluated solute removal and biocompatibility of a tailored, hydrophobic-hydrophilic microdomain structure produced from a blend of polyamide, polyarylethersulfone, and polyvinylpyrrolidone (Polyflux) compared with Fresenius Polysulfone in dialyzers of similar surface area. The clearance of small molecules (urea, creatinine, and phosphate) for both membranes was comparable. Plasma levels of beta2 microglobulin were reduced at the end of treatment with both membranes (49.8% of pretreatment values for Polyflux; 45.9%, Fresenius Polysulfone) and was associated with the recovery of 207 +/- 84 mg of beta2 microglobulin from the dialyzing fluid for Polyflux compared with 147 +/- 29 for Fresenius Polysulfone (p = 0.12). The dialyzing fluid also contained 7,758 mg of protein when using Polyflux compared with 7,793 mg using Fresenius Polysulfone (standard error of difference for any pair was 511 mg). No albumin was present in the dialysis fluid for either membrane. Neutropenia, platelet adhesion to the membrane, and complement activation characterized by C3a, C5a, and SC5b-9 generation were slight and independent of membrane type. Membrane thrombus generating potential measured by thrombin:antithrombin III were also similar. These results indicate that the tailored, hydrophobic-hydrophilic microdomain structure of the membrane results in a favorable biocompatibility profile and clinically acceptable solute removal similar to the widely used Fresenius Polysulfone membrane.
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Affiliation(s)
- N A Hoenich
- Department of Nephrology, University of Newcastle, Newcastle upon Tyne, United Kingdom
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Abstract
On-line hemodiafiltration (HDF) provides the largest amount of blood purification over a wide molecular weight spectrum achievable with present renal replacement therapies. When used with state of the art dialysis membranes and treatment systems, the biocompatibility of on-line HDF is as high as can presently be defined. From an economic perspective, the added cost of the ultrafilters used to prepare the substitution solution is balanced by the therapeutic benefits of HDF. For optimal HDF, the ultrafiltration rate must be maximized with respect to the blood flow rate. In on-line HDF systems, the excess volume ultrafiltered, approximately 20 to 30 liters per treatment, is automatically replaced, preferably in postdilution mode, by a substitution solution that is continuously generated by stepwise ultrafiltration of dialysate. When properly prepared, this fluid fulfills the quality demands of commercially available infusion solutions; that is, it can be referred to as sterile and pyrogen-free. The most important factors in preparing substitution solution are the quality of the water, of the concentrates, of the ultrafilters, and the microbiological status of the entire flow path. The clinical safety of substitution solution prepared on-line has been documented by long-term users of on-line systems. Results from clinical studies with on-line HDF confirm the overall increased clearance of solutes in relation to high-flux dialysis using the same membrane.
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Affiliation(s)
- I Ledebo
- Gambro Renal Care R&D, Lund, Sweden.
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17
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Abstract
With increasing awareness about the degree and the potential impact of microbiological contamination in dialysis fluids, there is a desire to improve their microbiological quality. To achieve this goal, the origin of the microbiological contamination has to be identified. The water, the bicarbonate concentrate, and the fluid distribution system can be major contributors. Regular disinfection of the entire fluid path is necessary to prevent the formation of biofilm. The bicarbonate concentrate should be handled with special attention because it constitutes an excellent growth medium for microflora that may not be detected with regular assays. With a well maintained reverse osmosis (RO) system, frequent disinfection of the entire flow path, and microbiological awareness, it is possible to produce dialysis fluid that meets the most stringent standard (<10(2) colony forming units (CFU)/ml and <0.25 IU/ml of endotoxin). Adding a step of ultrafiltration just before the dialyzer can make the dialysis fluid ultrapure (<10(-1) CFU/ ml and <0.03 IU/ml). One additional step of controlled ultrafiltration provides sterile and pyrogen-free fluids (<10(-6) CFU/ml and <0.03 IU/ml) that can be used for infusion.
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Affiliation(s)
- I Ledebo
- Renal Care R&D, Gambro, Lund, Sweden.
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