Extracorporeal Blood Circuit Research Articles

Residual Red Blood Cell Volume in Extracorporeal Blood Circuit after Hemodialysis: A Single-Center Study.

The factors contributing to blood loss during hemodialysis (HD) procedures remain underexplored. This study aimed to quantify blood loss during HD and identify the potential factors associated with it. The study included 70 ESRD patients undergoing HD. After dialysis, the extracorporeal blood circuits were rinsed with 1,000 mL of 0.05% NH3 solution in distilled water, and hemoglobin levels were measured. Univariate regression was used to assess the linear relationship between residual red blood cell (RBC) volume and various parameters, including HD mode, dialyzer surface area, ultrafiltration goal, hypotension during HD, blood flow rate, activated partial thromboplastin time, and C-reactive protein. Multivariate regression was also conducted to explore the relationships among these parameters. The mean RBC volume remaining in the extracorporeal blood circuit after HD was 1.6 ± 0.9 mL (mode: 1.0, range: 0.3-6.5 mL). When converted to whole blood volume per patient, the mean blood volume was 5.3 ± 3.0 mL (median: 4.1 mL, mode: 4.0 mL, range: 1.0-19.0 mL). Multivariate analysis identified the dialyzer surface area as the only significant determinant of residual RBC volume. After HD, the remaining RBC volume in the extracorporeal blood circuit varies from 1.6 to 6.5 mL. When the RBC volume was converted to whole blood volume for each case, the blood loss ranged from 1.0 to 19.0 mL. Dialyzer surface area was the only significant determinant of residual RBC volume.

#1129 Systematic reporting of extracorporeal blood losses in a large dialysis provider organization

Abstract Background and Aims The assessment of adverse safety events is important for the risk assessment of major blood loss from the extracorporeal blood circuit during hemodialysis (HD). Such blood loss has been proven to result in a low double-digit number of fatal events per year in the USA. The frequency in Europe is not mandatorily recorded. The mechanisms of blood loss in the venous leg of the system, undetected by the alarm system of the dialysis machines, are not generally known and further patient and structure-related risks are not yet systematically recorded, evaluated and improved. Method We set up a web-based intranet database (“Event Management”) to record serious adverse events affecting patients during or around dialysis treatments in all 174 kidney centers of the Kuratorium für Dialyse und Nierentranspantation in Germany (KfH). This system is accessed via intranet within the KfH organization. Nursing and medical staff are regularly trained and informed about this system. The entry of event data that have endangered or harmed patients is mandatory. Results 141 reports of blood loss were identified for a total of approximately 3 million hemodialysis treatments performed in 174 renal centers in between 2020 and 2022, including venous needle loss due to complications in the extracorporeal blood circuit, 15 of which required inpatient treatment. The breakdown of the causes and consequences of blood losses is shown in the Figure. Conclusion Venous disconnection must be reduced by earlier detection with appropriate technical and patient-adapted measures. Patients should be educated about their individual risk and about individual measures to manage risk. Identification of patient-specific and shunt-specific risk factors is necessary. Patient-related risk factors include cognitive impairment, frailty, and dialysis in special areas (ICU, isolation area, nocturnal dialysis). Monitoring systems (blood sensors) currently on the market have good technical blood detection sensitivity. Such systems should be investigated with regard to their clinical benefit according to the rules of evidence-based medicine before their broad introduction into routine care.

Optimal Settings at Initiation of Veno-Venous Extracorporeal Membrane Oxygenation: An Exploratory In-Silico Study.

The Extracorporeal Life Support Organisation (ELSO) recommends initiating veno-venous extracorporeal membrane oxygenation (ECMO) with sweep gas flow rate () of 2 L/min and extracorporeal circuit blood flow () of 2 L/min. We used an in-silico model to examine the effect on gas exchange of initiating ECMO with different and , and the effect of including 5% in sweep gas. This was done using a set of patient examples, each with different physiological derangements at baseline (before ECMO). When ECMO was initiated following ELSO recommendations in the patient examples with significant hypercapnia at baseline, sometimes fell to < 50% of the baseline , a magnitude of fall associated with adverse neurological outcomes. In patient examples with very low baseline arterial oxygen saturation (), initiation of ECMO did not always increase to > 80%. Initiating ECMO with of 1 L/min and of 4 L/min, or with sweep gas containing 5% , of 2 L/min, and of 4 L/min, reduced the fall in and increased the rise in compared to the ELSO strategy. While ELSO recommendations may suit most patients, they may not suit patients with severe physiological derangements at baseline.

Non-occlusive pumping principle for blood pump application

AbstractRoller pumps are used in medicine to pump blood in extracorporeal blood circuits. Blood is subjected to mechanical stress in these peristaltic pumps, due to the complete tube occlusion. This stress causes damage to red blood cells (hemolysis). We present a novel peristaltic pumping principle that addresses these issues. In contrast to conventional roller pumps, the tube is stimulated by a circulating eccentric oscillation. Therefore, this type of pump does not require complete tube occlusion. The blood is less mechanically stressed and hemolysis is reduced by 55% compared to a roller pump.

Extracorporeal Immunomodulation Treatment and Clinical Outcomes in ICU COVID-19 Patients.

OBJECTIVES:To evaluate safety and clinical outcomes of extracorporeal immunomodulation treatment with a selective cytopheretic device (SCD) in COVID-19 ICU patients with multiple organ failure.DESIGN:Two-center, prospective, single-arm treatment clinical trial.SETTING:ICUs at two academic medical centers between September 2020 and July 2021.PATIENTS:Twenty-two COVID-10 patients in the ICU with acute respiratory distress syndrome who required mechanical ventilation. Nearly all included patients in the intervention group except one had acute kidney injury requiring continuous renal replacement therapy (CRRT). Sixteen subjects meeting enrollment criteria were selected as contemporaneous controls from a concurrent prospective registry CRRT trial.INTERVENTION:Treatment with an SCD integrated into a continuous renal replacement extracorporeal blood circuit for up to 10 days to provide autologous leukocyte cell processing to immunomodulate the hyperinflammatory disease state of COVID-19.MEASUREMENTS AND MAIN RESULTS:SCD treatment in COVID-19 ICU patients with multiple organ failure demonstrated an acceptable safety profile with no device-related serious adverse events. Treatment of these patients resulted in the selective removal of highly activated circulating leukocytes as determined by flow cytometry. Significant reductions were observed in the elevated plasma levels of eight cytokines and biomarkers, including interleukin (IL)6, IL15, IL10, and soluble ST2, which are predictive of mortality in COVID-19 patients. Significant improvements of leukocytosis and Po2/Fio2 ratios occurred during treatment not observed in the control group. SCD-treated subjects had a reduction in 60-day mortality of 50% compared with 81% in the control cohort. The subjects who received greater than 96 hours of SCD treatment, per protocol, had a further reduction in mortality to 31% (p < 0.012).CONCLUSIONS:Extracorporeal immunomodulation therapy with an SCD demonstrated safety without any device-related serious adverse events. As a rescue therapy in COVID-19 ICU patients progressing to multiple organ failure despite maximal pharmacologic and organ support interventions, SCD treatment resulted in improved clinical outcomes. This autologous leukocyte cell processing technology may provide a new approach in the treatment of unremitting hyperinflammation of COVID-19.

Partial Extracorporeal Circuit Blood Primes Are Safe and Do Not Decrease Hematocrit in Small Children

Partial Extracorporeal Circuit Blood Primes Are Safe and Do Not Decrease Hematocrit in Small Children

Regional citrate anticoagulation \u201cnon-shock\u201d protocol with pre-calculated flow settings for patients with at least 6\u2009L/hour liver citrate clearance

BackgroundRegional citrate anticoagulation (RCA) for the prevention of clotting of the extracorporeal blood circuit during continuous kidney replacement therapy (CKRT) has been employed in limited fashion because of the complexity and complications associated with certain protocols. Hypertonic citrate infusion to achieve circuit anticoagulation results in variable systemic citrate- and sodium load and increases the risk of citrate accumulation and hypernatremia. The practice of “single starting calcium infusion rate for all patients” puts patients at risk for clinically significant hypocalcemia if filter effluent calcium losses exceed replacement. A fixed citrate to blood flow ratio, personalized effluent and pre-calculated calcium infusion dosing based on tables derived through kinetic analysis enable providers to use continuous veno-venous hemo-diafiltration (CVVHDF)-RCA in patients with liver citrate clearance of at least 6 L/h.MethodsThis was a single-center prospective observational study conducted in intensive care unit patients triaged to be treated with the novel pre-calculated CVVHDF-RCA “Non-shock” protocol. RCA efficacy outcomes were time to first hemofilter loss and circuit ionized calcium (iCa) levels. Safety outcomes were surrogate of citrate accumulation (TCa/iCa ratio) and the incidence of acid-base and electrolyte complications.ResultsOf 53 patients included in the study, 31 (59%) had acute kidney injury and 12 (22.6%) had the diagnosis of cirrhosis at the start of CVVHDF-RCA. The median first hemofilter life censored for causes other than clotting exceeded 70 h. The cumulative incidence of hypernatremia (Na > 148 mM), metabolic alkalosis (HCO3- > 30 mM), hypocalcemia (iCa < 0.9 mM) and hypercalcemia (iCa > 1.5 mM) were 1/47 (1%), 0/50 (0%), 1/53 (2%), 1/53 (2%) respectively and were not clinically significant. The median (25th–75th percentile) of the highest TCa/iCa ratio for every 24-h interval on CKRT was 1.99 (1.91–2.13).ConclusionsThe fixed citrate to blood flow ratio, as opposed to a titration approach, achieves adequate circuit iCa (< 0.4 mm/L) for any hematocrit level and plasma flow. The personalized dosing approach for calcium supplementation based on pre-calculated effluent calcium losses as opposed to the practice of “one starting dose for all” reduces the risk of clinically significant hypocalcemia. The fixed flow settings achieve clinically desirable steady state systemic electrolyte levels.

Arterial Versus Venous Port Site Administration of Nadroparin for Preventing Thrombosis of Extracorporeal Blood Circuits in Patients Receiving Hemodiafiltration Treatment

IntroductionAdministration of low-molecular-weight heparins (LMWHs) is necessary for preventing extracorporeal circuit thrombosis during hemodialysis. A substantial amount of LMWH is removed with online hemodiafiltration (OL-HDF) when administered through the inlet site of the extracorporeal circuit. Consequently, administration of LMWH at the outlet site appears to be more efficient. In this study we aimed to compare the effects of nadroparin calcium (NAD) administered through the outlet versus the inlet port site in postdilution OL-HDF and assess the NAD dose reduction.MethodsForty-nine hemodialysis patients were included in 3 consecutive 6-week studies as follows: phase I, inlet port line; phase II, outlet port line; and phase III, outlet port line with reduced dose. We evaluated clotting in the hemodialyzer and venous bubble trap, the dialysis dose (Kt/V), and substitution volume.ResultsThirty four percent, 63%, and 66% were categorized as “white” during phases I, II, and III, respectively. During phases I, II, and III, 75%, 93%, and 95% of the venous bubble traps were “clean,” and 9%, 0.6%, and 0.4% of the dialyzers clotted, respectively. Average NAD dose was 0.43 ml during phase I and 0.3 ml during phase II. During phase III, the LMWH dose was reduced by 33% to 50% in 15 patients. In phase III, Kt/V improved from 1.64 to 1.75 and substitution volume increased from 20.18 to 21.96 L.ConclusionsWhen using OL-HDF, a single administration of NAD at the outlet port line allows for a significant dose reduction and was associated with improved dialysis performance.

A Scientific Symposium "Artificial Organs Today: From in Vitro Assessment to Human Therapies" on the Occasion of the Celebration of the 40th Anniversary of the Macedonian Academy of Sciences and Arts.

On the occasion of the celebration of the 40th anniversary of the Macedonian Academy of Sciences and Arts (MASA) the Macedonian Society of Nephrology, Dialysis, Transplantation and Artificial Organs (MSNDTAO) organized a one day symposium titled: "Artificial Organs Today: From in vitro assessment to human therapies", on September 28, 2007 at the Macedonian Academy of Sciences and Arts. The following sessions were held: Artificial Organs in Front of the Ageing Populations; System Requirements for Artificial Organ Technology; Tools for Artificial Organ Technology; Extracorporeal Blood Circuits in Organ Replacement Therapies; Treatment Options for Blood Purification Therapies. Presentation were delivered by: Horst Klinkmann, Germany; Jörg Vienken, Germany; Jens Hartmann, Austria; Udo Losert, Austria; Jan Wojcicki, Poland; Helmut Mann and Siegfried Stiller, Germany; Beat Walpoth, Switzerland; Juan F. del Cañizo, Spain; Borce Georgievski, Macedonia; Bernd Stegmayr, Sweden; Momir Polenakovic, Macedonia; Petar Kes, Croatia; Aleksandar Sikole, Macedonia; Wolfgang Ramlow, Germany; Dieter Falkenhagen, Austria. These meetings are significant for the application and development of the artificial organs in patients.

Contrast-Enhanced Ultrasonography as a Novel Method for the Dynamic Visualization of Blood Flow and Fiber Blockage in Dialyzers: A Feasibility Study

The capillary dialyzer represents the central element of the extracorporeal blood circuit of a therapy system for hemodialysis. The aim of this study was to assess the blood-flow characteristics of dialyzers with the help of modern ultrasound techniques. Five brand-new dialyzers (FX80 classix, Fresenius Medical Care, Bad Homburg, Germany) and five dialyzers after a dialysis session were analyzed by different ultrasound techniques to detect functional and structural changes. B-mode and Doppler techniques were not suitable to describe differences in brand-new and clinically applied dialyzers. Contrast-enhanced ultrasonography, however, was able to visualize blood-flow profiles in the capillaries. Although dialyzers displayed no signs of clinical dysfunction, contrast-enhanced ultrasonography was able to detect blocked capillaries of varying degrees after a dialysis session in all five examined dialyzers. Consequently, the blood-flow velocity was higher in the remaining unblocked capillaries in comparison to the velocity in the brand-new dialyzers. This information may be helpful for improving the geometric design of dialyzers, including their capillary membranes, and optimizing anti-coagulation strategies in hemodialysis patients.

Central venous access.

Central venous catheterization is the placement of a catheter in such a manner that its tip is positioned within the proximal third of the superior vena cava, the right atrium or the inferior vena cava. It is indicated when access for administration of drugs or extracorporeal blood circuits and haemodynamic monitoring or interventions is needed. When inserting a central venous catheter, appropriate preparation and asepsis, positioning of the patient, and the use of ultrasound should be considered. Compared to the landmark method of localization, ultrasound can account for anatomical variations, facilitate visualization of venous puncture, and safeguard against inadvertent arterial puncture. In the Seldinger technique, which is the primary mode of central venous catheterization, a needle is passed towards the chosen vessel. Once the needle is in the vein, a guidewire is introduced through the needle into the vessel and the needle is removed. Following a small skin incision at the base of the guidewire, a dilator is advanced over the guidewire and then taken out. Subsequent to this, the central venous catheter is railroaded over the guidewire into the vein and the guidewire is withdrawn. Complications of central venous catheterization can be mechanical, infectious or thrombotic.

Blood purification by nonselective hemoadsorption prevents death after traumatic brain injury and hemorrhagic shock in rats.

Patients who sustain traumatic brain injury (TBI) and concomitant hemorrhagic shock (HS) are at high risk of high-magnitude inflammation which can lead to poor outcomes and death. Blood purification by hemoadsorption (HA) offers an alternative intervention to reduce inflammation after injury. We tested the hypothesis that HA would reduce mortality in a rat model of TBI and HS. Male Sprague Dawley rats were subjected to a combined injury of a controlled cortical impact to their brain and pressure-controlled HS. Animals were subsequently instrumented with an extracorporeal blood circuit that passed through a cartridge for sham or experimental treatment. In experimental animals, the treatment cartridge was filled with proprietary beads (Cytosorbents, Monmouth Junction, NJ) that removed circulating molecules between 5 kDa and 60 kDa. Sham rats had equivalent circulation but no blood purification. Serial blood samples were analyzed with multiplex technology to quantify changes in a trauma-relevant panel of immunologic mediators. The primary outcome was survival to 96 hours postinjury. Hemoadsorption improved survival from 47% in sham-treated rats to 86% in HA-treated rats. There were no treatment-related changes in histologic appearance. Hemoadsorption affected biomarker concentrations both during the treatment and over the ensuing 4 days after injury. Distinct changes in biomarker concentrations were also measured in survivor and nonsurvivor rats from the entire cohort of rats indicating biomarker patterns associated with survival and death after injury. Blood purification by nonselective HA is an effective intervention to prevent death in a combined TBI/HS rat model. Hemoadsorption changed circulating concentrations of multiple inmmunologically active mediators during the treatment time frame and after treatment. Hemoadsorption has been safely implemented in human patients with sepsis and may be a treatment option after injury.

A mathematical model of CO2, O2 and N2 exchange during venovenous extracorporeal membrane oxygenation

BackgroundVenovenous extracorporeal membrane oxygenation (vv-ECMO) is an effective treatment for severe respiratory failure. The interaction between the cardiorespiratory system and the oxygenator can be explored with mathematical models. Understanding the physiology will help the clinician optimise therapy. As others have examined O2 exchange, the main focus of this study was on CO2 exchange.MethodsA model of the cardiorespiratory system during vv-ECMO was developed, incorporating O2, CO2 and N2 exchange in both the lung and the oxygenator. We modelled lungs with shunt fractions varying from 0 to 1, covering the plausible range from normal lung to severe acute respiratory distress syndrome. The effects on PaCO2 of varying the input parameters for the cardiorespiratory system and for the oxygenator were examined.ResultsPaCO2 increased as the shunt fraction in the lung and metabolic CO2 production rose. Changes in haemoglobin and FIO2 had minimal effect on PaCO2. The effect of cardiac output on PaCO2 was variable, depending on the shunt fraction in the lung.PaCO2 decreased as extracorporeal circuit blood flow was increased, but the changes were relatively small in the range used clinically for vv-ECMO of > 2 l/min. PaCO2 decreased as gas flow to the oxygenator rose and increased with recirculation. The oxygen fraction of gas flow to the oxygenator had minimal effect on PaCO2.ConclusionsThis mathematical model of gas exchange during vv-ECMO found that the main determinants of PaCO2 during vv-ECMO were pulmonary shunt fraction, metabolic CO2 production, gas flow to the oxygenator and extracorporeal circuit recirculation.

Extra Corporeal Oxygenation &amp; Ozonation, EBOO &amp; AQUAPHERESIS method of Ozone Therapy, Clinical Application in Chronic Diseases

Introduction: The top 10 causes of death around the world are usually ranked with heart diseases, cancers, drugs/medication/iatrogenic chemicals, strokes etc. These are totally detectable, predictable, avoidable, preventable because it is classified as non-communicable diseases. Acute diseases are denoted by acute inflammation which has intensive cell-cell communications, resulting intensive repair rebuilding rehabilitation and it is life extending. Often it is self defensive and we over come it. The real culprit for chronic diseases is chronic inflammations, denoted by constant &amp; silent, undetectable &amp; insensible lost of cell-cell signaling, basement membrane disease, tight junction destructions, mitochondrial dysfunctions, mismatched metabolism, nutritional losses, mineral depletion, hormonal imbalances, opportunistic antigenicity wasting away the helpful immunity, leading to immune senescence &amp; stem cell depletions eventually leading to chronic degeneration and devastating incapacitated regeneration ability. Often it is self destructive and we usually succumb to it. Mitochondrial decay &amp; incapacitation of oxygenation and aerobic respiration failure leading to chronic anaerobic conditions breeding many chronic diseases Ozone therapy is one of the best method to reverse chronic diseases. Its hormetic response curve of 10 to 80 gamma units typically reveals the secret of ozone healing hormesis. The low dose concept is to be respected all time. And with in safety limits we can practice low &amp; escalating dosage, with increasing in volume of blood exposure to ozone, to evolve from minor AHT to major AHT, all the way into continuous auto-hemotherapy via extra-corporeal blood circuits with the proper method. Its action on mitochondrial health and its regenerative power is well known and documented. METHOD: 1. Ozone properties &amp; therapeutic applications &amp; methods of extracorporeal circuits 2. EBOO / AQUAPHERESIS set up &amp; therapy method 3. Safeties &amp; precautions, limitations &amp; patient selections 4. Selections of machines &amp; GED gas exchange devices 5. Therapeutic steps for patient, and adjuvant photonic therapy 6. Post therapeutic monitoring &amp; documentations 7. Clinical results of various cases treated with EBOO &amp; AQUAPHERESIS RESULTS: Definition of extra corporeal circulations method would be discussed. Original EBOO therapy method and scientific studies would be reviewed. A modified economical method of EBOO would be illustrated. A further improvised AQUAPHERESIS method of continuous blood ozonation / oxygenations would be illustrated and discussed. To ensure safety and long term success, selection of machines, materials, circuits, disposables, disposal of dialysates &amp; ozone residue, all the way to selections of dialyzer &amp; GED gas exchange devices would be discussed. Dangers of wrong machines and wrong GED/Dialyzers with related precautions to be considered during EBOO &amp; AQUAPHERESIS would be discussed. A few case study would be illustrated and discussed CONCLUSIONS: Ozone is a wonderful new well known medical drug. Its benefits is vast &amp; economically easily available. Within the safety limits we can extend the ozonation &amp; oxygenation of blood to a much longer, larger therapeutic window via the extra corporeal circuit method. Both EBOO &amp; AQUAPHERESIS are additional interesting method to deliver ozone therapy to patient reaping also the benefits of plasma apheresis in AQUAPHERESIS method. With correct knowledge and higher standard of machines &amp; disposables, these methods are safe and effective to be applied to patient and it deliver significant result clinically. Further studies are encouraged &amp; worth explored.

Detection of ventricular premature beats based on the pressure signals of a hemodialysis machine

Monitoring of ventricular premature beats (VPBs), being abundant in hemodialysis patients, can provide information on cardiovascular instability and electrolyte imbalance. In this paper, we describe a method for VPB detection which explores the signals acquired from the arterial and the venous pressure sensors, located in the extracorporeal blood circuit of a hemodialysis machine. The pressure signals are mainly composed of a pump component and a cardiac component. The cardiac component, severely overshadowed by the pump component, is estimated from the pressure signals using an earlier described iterative method. A set of simple features is extracted, and linear discriminant analysis is performed to classify beats as either normal or ventricular premature. Performance is evaluated on signals from nine hemodialysis treatments, using leave-one-out crossvalidation. The simultaneously recorded and annotated photoplethysmographic signal serves as the reference signal, with a total of 149,686 normal beats and 3574 VPBs. The results show that VPBs can be reliably detected, quantified by a Youden’s J statistic of 0.9, for average cardiac pulse pressures exceeding 1 mmHg; for lower pressures, the J statistic drops to 0.55. It is concluded that the cardiac pressure signal is suitable for VPB detection, provided that the average cardiac pulse pressure exceeds 1 mmHg.

Efficacy and safety of low-dose heparin in hemodialysis.

The dose of unfractionated heparin (UFH) administered during hemodialysis (HD) varies widely. This prospective study evaluated the safety and efficacy of UFH dose de-escalation. Sixty-six prevalent patients on HD receiving UFH per standard-dose protocol (load dose [LD] 50-75 units/kg, maintenance dose [MD] 500-1000 units/hour) had heparin prescription converted to low-dose protocol (start LD 15 units/kg and MD 500 units/hour; dose adjusted in small increments based on assessments of extracorporeal blood circuit). Coagulation parameters, dialysis adequacy, dialyzer clotting, anemia management, and dialyzer reuse rates were compared based on the heparin protocol. Mean(SD) UFH dose per HD session, before and after protocol conversion, was 6178(2644) and 2913(1116) units, respectively (P < 0.0001). This corresponded to LD 52.1(16.6) units/kg and MD 615(207) units/hour with standard-dose protocol, and LD 18.3(6.5) units/kg and MD 505(27) units/hour with low-dose protocol (P < 0.0001). Mid and postdialysis aPTT was 55.3(31.2) and 35.1(7.8) seconds before, and 37.3(12.9) and 31.5(5.3) seconds after conversion (P = 0.007 and 0.003, respectively); no significant changes in D-dimer levels occurred. Low-dose UFH was associated with a small increase in URR and spKt/V (73.0 and 1.54) compared with dialysis clearance on standard-dose UFH (71.2 and 1.48, respectively, P = 0.02). Weekly dose of ESA decreased by 2388 units postconversion (P = 0.03), while hemoglobin levels and the weekly dose of intravenous iron did not change (P = 0.16 and 0.78). A small rise in the rate of moderate dialyzer clotting at the end of HD was noted with low-dose UFH (5.7% vs. 7.5%, P = 0.002); the rate of severe dialyzer clotting events did not change (P = 0.91). No change in the dialyzer reuse rate was noted (18.5 vs. 17.0 treatments, P = 0.26). Low-dose heparinization did not compromise dialysis adequacy and permitted ESA dose reduction. Our findings suggest that in prevalent patients on HD, UFH dose of 15-20 units/kg loading and 500 units/hour maintenance was medically safe and effective.

A case of heparin-induced thrombocytopenia (HIT) triggered by methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia

Heparin-induced thrombocytopenia (HIT) is a potentially life-threatening complication of heparin anticoagulation. Recently, infection has been implicated in the development of HIT. We herein present a case of HIT diagnosed by a repeated functional assay. A 67-year-old female with diabetic nephropathy was admitted to our hospital with hypoxemia caused by volume overload. Due to her diuretic-resistant condition, dialysis therapy anticoagulated with low-molecular-weight heparin (LMWH) was initiated. The coagulation of the whole extracorporeal blood circuit occurred on day 13. Methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia derived from a catheter-related bloodstream infection (CRBSI) was detected on day 15. Based on the hypercoagulable state due to infection, we increased the heparin dose during dialysis therapy; however, coagulation of the dialysis circuit persisted. We suspected HIT on day 17 in spite of a normal platelet count and performed a functional assay, which was negative. Since thrombocytopenia subsequently developed, the functional assay was repeated and a positive result was obtained on day 27, which definitely established a diagnosis of HIT. Based on the present clinical course, MSSA bacteremia appears to have contributed to the pathogenesis of HIT.

Citrate anticoagulation in the ICU: the Leeds experience.

Continuous renal replacement therapy (CRRT) is widely used in the management of critically ill patients with acute kidney injury. It requires effective anticoagulation of the extracorporeal blood circuit. Although heparin is the most commonly prescribed anticoagulant, there are issues associated with heparin, and there has been increasing interest in regional citrate anticoagulation as an alternative. In 2013, The Leeds Teaching Hospitals NHS Trust switched from heparin to citrate anticoagulant for CRRT in intensive care units (ICUs) across the Trust. This article examines the reasons for the switch, the implementation of citrate and the impact of this quality-improvement project in terms of patient outcome data and feedback from the ICU nursing team.

Extracorporeal delivery of a therapeutic enzyme.

To remove circulating harmful small biochemical(s)/substrates causing/deteriorating certain chronic disease, therapeutic enzyme(s) delivered via vein injection/infusion suffer(s) from immunoresponse after repeated administration at proper intervals for a long time and short half-lives since delivery. Accordingly, a novel, generally-applicable extracorporeal delivery of a therapeutic enzyme is proposed, by refitting a conventional hemodialysis device bearing a dialyzer, two pumps and connecting tubes, to build a routine extracorporeal blood circuit but a minimal dialysate circuit closed to circulate the therapeutic enzyme in dialysate. A special quantitative index was derived to reflect pharmacological action and thus pharmacodynamics of the delivered enzyme. With hyperuricemic blood in vitro and hyperuricemic geese, a native uricase via extracorporeal delivery was active in the dialysate for periods much longer than that in vivo through vein injection, and exhibited the expected pharmacodynamics to remove uric acid in hyperuricemic blood in vitro and multiple forms of uric acid in hyperuricemic geese. Therefore, the extracorporeal delivery approach of therapeutic enzymes was effective to remove unwanted circulating small biochemical(s)/substrates, and was expected to avoid immunogenicity problems of therapeutic enzymes after repeated administration at proper intervals for a long time due to no contacts with macromolecules and cells in the body.

Continuous Renal Replacement Therapy and Anticoagulation: What Are the Options?

Continuous renal replacement therapy is currently used as a standard treatment for acute kidney injury in the intensive care unit, particularly for patients with unstable hemodynamic status. Because this therapy is continuous, for days or weeks, and the extracorporeal blood circuit is large, the circuit is prone to clotting. Several methods of keeping the extracorporeal circuit patent are available, including heparin infusion, flushes with physiological saline, use of thrombin inhibitors, and citrate. This article reviews methods for continuous renal replacement therapy, anticoagulation, efficacy, and implications for bedside critical care.