Use of Fluoride as a Marker Solute to Quantify the Current Effective Delivered Dose in Continuous Renal Replacement Therapy: An “in vitro” Study

2020 ◽  
Vol 49 (6) ◽  
pp. 685-691
Author(s):  
Gianluca Villa ◽  
Vittorio Bocciero ◽  
Mauro Neri ◽  
Diego Pomarè Montin ◽  
Elena Angeli ◽  
...  

<b><i>Background:</i></b> The <i>current effective delivered dose</i> is a quality indicator for continuous renal replacement therapy. Its periodic assessment might enable physicians to deliver personalised treatments. Yet, its quantification as by extracorporeal urea clearance (Cl) is cumbersome and thus often neglected in routine practice. The aim of this in vitro study is to demonstrate the non-inferior effectiveness of assessing the <i>current effective delivered dose</i> using a simpler, cheaper and faster approach based on measurement of fluoride rather than urea extracorporeal Cl. <b><i>Methods:</i></b> We compared urea and fluoride removal in 3 post-dilution continuous veno-venous haemofiltration (CVVH) and 3 continuous veno-venous haemodialysis (CVVHD) in vitro experimental models. Experiments ran for 180 min, using 3 L of human blood, heparin anticoagulation and a machine dose of 30 mL/kg/h. Urea and fluoride were measured in the inflow, outflow and effluent lines to compare sieving coefficients (SC), saturation coefficients (SA) and transmembrane Cls. <b><i>Results:</i></b> In CVVH, the median SC values were 1.06 (1.02–1.07) and 1.02 (1.01–1.04) for fluoride and urea, respectively (discrepancy of 4.3%), while transmembrane convective Cls were 31.28 (30.01–31.31) mL/kg/h and 30.30 (29–31.85) mL/kg/h (discrepancy of 3.13%), respectively. In CVVHD, the median SA values were 1.01 (0.96–1.02) and 1 (0.95–1.01) for fluoride and urea, respectively (discrepancy of 1.6%), while transmembrane dialytic Cls were 30.26 (29.52–31.32) mL/kg/h and 31.16 (30–31.75) mL/kg/h (discrepancy of –2.97%), respectively. <b><i>Conclusion:</i></b> Fluoride transmembrane removal was close to that observed with urea, in terms of SC, SA and transmembrane Cl. Fluoride seems as much accurate as urea in assessing the <i>current effective delivered dose</i> during both CVVH and CVVHD and might therefore be adopted for dose measurement. Besides accuracy, fluoride bedside assessment could present many advantages over urea, particularly in terms of availability, costs, time requirement and rapidity of assessment.

2020 ◽  
Vol 43 (12) ◽  
pp. 758-766 ◽  
Author(s):  
Frédéric Joseph Baud ◽  
Pascal Houzé ◽  
Jean-Herlé Raphalen ◽  
Anaïs Winchenne ◽  
Pascal Philippe ◽  
...  

Introduction: In continuous renal replacement therapy, conduction and convection are controlled allowing prescribing dosage regimen improving survival. In contrast, adsorption is an uncontrolled property altering drug disposition. Whether adsorption depends on flowrates is unknown. We hypothesized an in vitro model may provide information in conditions mimicking continuous renal replacement therapy in humans. Methods: ST150®-AN69 filter and Prismaflex dialyzer, Baxter-Gambro were used. Simulated blood flowrate was set at 200 mL/min. The flowrates in the filtration (continuous filtration), dialysis (continuous dialysis), and diafiltration (continuous diafiltration) were 1500, 2500, and 4000 mL/h, respectively. Routes of elimination were assessed using NeckEpur® analysis. Results: The percentages of the total amount eliminated by continuous filtration, continuous dialysis, and continuous diafiltration were 82%, 86%, and 94%, respectively. Elimination by effluents and adsorption accounted for 42% ± 7% and 58% ± 5%, 57% ± 7% and 43% ± 6%, and 84% ± 6% and 16% ± 6% of amikacin elimination, respectively. There was a linear regression between flowrates and amikacin clearance: Y = 0.6 X ± 1.7 (R2 = 0.9782). Conversely, there was a linear inverse correlation between the magnitude of amikacin adsorption and flowrate: Y = –16.9 X ± 84.1 (R2 = 0.9976). Conclusion: Low flowrates resulted in predominant elimination by adsorption, accounting for 58% of the elimination of amikacin from the central compartment in the continuous filtration mode at 1500 mL/h of flowrate. Thereafter, the greater the flowrate, the lower the adsorption of amikacin in a linear manner. Flowrate is a major determinant of adsorption of amikacin. There was an about 17% decrease in the rate of adsorption per increase in the flowrate of 1 L/min.


2019 ◽  
Vol 43 (2) ◽  
pp. 87-93 ◽  
Author(s):  
Pascal Houzé ◽  
Frédéric Joseph Baud ◽  
Jean-Herlé Raphalen ◽  
Anaïs Winchenne ◽  
Sonia Moreira ◽  
...  

Introduction: Continuous renal replacement therapy is not presently recommended in the treatment of life-threatening hyperkalemia. There are no specific recommendations in hemodialysis to treat hyperkalemia. We hypothesized an in vitro model may provide valuable information on the usefulness of continuous renal replacement therapy to treat severe hyperkalemia. Methods: A potassium-free solute was used instead of diluted blood for continuous renal replacement therapy with a simulated blood flowrate set at 200 mL/min. The mode of elimination included continuous filtration, continuous dialysis, and continuous diafiltration using a flowrate of 4000 mL/min for continuous filtration and continuous dialysis modes, and a ratio of 2500/1500 in the continuous diafiltration mode. Results: The mean initial potassium in the central compartment was 10.1 ± 0.4 mmol/L. The clearances in the continuous diafiltration, continuous filtration, and continuous dialysis were 3.4 ± 0.5, 3.6 ± 0.1, and 3.7 ± 0.1 L/h, respectively, not significantly different. Continuous dialysis resulted in the lowest workload for staff. Increasing the continuous dialysis flowrates from 2000 to 8000 mL/h increased clearance from 2.3 ± 0.3 to 6.2 ± 0.8 L/h. The delays in decreasing the potassium concentration to 5.5 mmol/L dropped from 120 to 45 min, respectively. Potassium eliminated in the first hour increased from 18 to 38 mmol that compared favorably with hemodialysis. Decrease in simulated blood flowrate from 200 to 50 mL/min moderately but significantly decreased the clearance from 3.7 to 3.0 L/h. Conclusion: Hyperkalemia is efficiently treated by continuous renal replacement therapy using the dialysis mode. Caution is needed to prevent the onset of severe hypokalemia within 40 min after initiation of the session.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Lauren Andrews ◽  
Scott Benken ◽  
Xing Tan ◽  
Eric Wenzler

Abstract Background To evaluate the transmembrane clearance (CLTM) of apixaban during modeled in vitro continuous renal replacement therapy (CRRT), assess protein binding and circuit adsorption, and provide initial dosing recommendations. Methods Apixaban was added to the CRRT circuit and serial pre-filter bovine blood samples were collected along with post-filter blood and effluent samples. All experiments were performed in duplicate using continuous veno-venous hemofiltration (CVVH) and hemodialysis (CVVHD) modes, with varying filter types, flow rates, and point of CVVH replacement fluid dilution. Concentrations of apixaban and urea were quantified via liquid chromatography-tandem mass spectrometry. Plasma pharmacokinetic parameters for apixaban were estimated via noncompartmental analysis. CLTM was calculated via the estimated area under the curve (AUC) and by the product of the sieving/saturation coefficient (SC/SA) and flow rate. Two and three-way analysis of variance (ANOVA) models were built to assess the effects of mode, filter type, flow rate, and point of dilution on CLTM by each method. Optimal doses were suggested by matching the AUC observed in vitro to the systemic exposure demonstrated in Phase 2/3 studies of apixaban. Linear regression was utilized to provide dosing estimations for flow rates from 0.5–5 L/h. Results Mean adsorption to the HF1400 and M150 filters differed significantly at 38 and 13%, respectively, while mean (± standard deviation, SD) percent protein binding was 70.81 ± 0.01%. Effect of CVVH point of dilution did not differ across filter types, although CLTM was consistently significantly higher during CRRT with the HF1400 filter compared to the M150. The three-way ANOVA demonstrated improved fit when CLTM values calculated by AUC were used (adjusted R2 0.87 vs. 0.52), and therefore, these values were used to generate optimal dosing recommendations. Linear regression revealed significant effects of filter type and flow rate on CLTM by AUC, suggesting doses of 2.5–7.5 mg twice daily (BID) may be needed for flow rates ranging from 0.5–5 L/h, respectively. Conclusion For CRRT flow rates most commonly employed in clinical practice, the standard labeled 5 mg BID dose of apixaban is predicted to achieve target systemic exposure thresholds. The safety and efficacy of these proposed dosing regimens warrants further investigation in clinical studies.


2020 ◽  
pp. 039139882097614
Author(s):  
Frédéric J Baud ◽  
Vincent Jullien ◽  
Tarik Abarou ◽  
Benoît Pilmis ◽  
Jean-Herlé Raphalen ◽  
...  

Introduction: Continuous renal replacement therapy (CRRT) efficiently eliminates fluconazole. However, the routes of elimination were not clarified. Adsorption of fluconazole by filters is a pending question. We studied the elimination of fluconazole in a model mimicking a session of CRRT in humans using the NeckEpur® model. Two filters were studied. Methods: The AV1000®-polysulfone filter with the Multifiltrate Pro. Fresenius and the ST150®-polyacrylonitrile filter with the Prismaflex. Baxter-Gambro were studied. Continuous filtration used a flowrate of 2.5 L/h in post-dilution only. Session were made in duplicate. Routes of elimination were assessed using the NeckEpur® model. Results: The mean measured initial fluconazole concentration (mean ± SD) for the four sessions in the central compartment (CC) was 14.9 ± 0.2 mg/L. The amount eliminated from the CC at the end of 6 h-session at a 2.5 L/h filtration flowrate for the AV1000®-polysulfone and the ST150®-polyacrylonitrile filters were 90%–93% and 96%–94%, respectively; the clearances from the central compartment (CC) were 2.5–2.6 and 2.4–2.3 L/h, respectively. The means of the instantaneous sieving coefficient were 0.94%–0.91% and 0.99%–0.91%, respectively. The percentages of the amount eliminated from the CC by filtration/adsorption were 100/0%–95/5% and 100/0%–100/0%, respectively. Conclusion: Neither the ST150®-polyacrylonitrile nor the AV1000®-polysulfone filters result in any significant adsorption of fluconazole.


Author(s):  
Dariusz Onichimowski ◽  
Joanna Maria Wolska ◽  
Radosław Borysiuk ◽  
Marcin Mieszkowski ◽  
Zuzanna Stępień ◽  
...  

Introduction: Extracorporeal blood purification techniques have become a well-established part of routine practice in intensive therapy units. Ensuring appropriate anticoagulation to prevent the clotting of the circuit is the major concern while applying these techniques. Aim: The aim of this paper is to present methods of systemic anticoagulation which are currently used in continuous extracorporeal blood purification techniques. Ma t e r i a l and me thods : This work is based on the available literature and the experience of the authors. Re sul t s and di s cus s ion: The prevention of clotting in the extracorporeal circuit may be achieved through regional or systemic anticoagulation. Systemic anticoagulation is usually achieved by administration of unfractionated heparin. The most common complications include bleeding; additionally, there is a risk of type II thrombocytopenia occurring. Systemic anticoagulation may also be provided through administration of low molecular weight heparins. Some research papers have discussed the use of thrombin antagonists (argatroban, bivalirudin) and heparinoids (danaparoid, fondaparinux), as well as platelet inhibitors as systemic anticoagulants. It is also possible to conduct extracorporeal blood purification without anticoagulation. C o n c l u s i o n s : The introduction of continuous extracorporeal blood purification techniques into everyday practice of intensive care units has brought many unquestioned benefits to the patients treated in this setting. On the other hand, it means that doctors need to show an in-depth knowledge of the anticoagulation methods. Despite the wider use of regional anticoagulation during continuous renal replacement therapy, systemic anticoagulation is still important. This is especially when therapies with high blood flow are performed and contraindications to citrate use are present.


2019 ◽  
Vol 48 (1) ◽  
pp. 60-66 ◽  
Author(s):  
Mauro Neri ◽  
Anna Lorenzin ◽  
Massimo de Cal ◽  
Alessandra Brendolan ◽  
Nicola Marchionna ◽  
...  

Background: ACUsmart (Medica S.P.A., Italy) is a new-generation, continuous renal replacement therapy (CRRT) machine for critically ill patients with acute kidney injury. We designed a multicenter international pilot study to provide a description of outlines of the ACUsmart system, evaluation aspects of functionality, usability, and feasibility, discriminating reasons of possible treatment’s withdrawals or discontinuations and highlighting strong and weak points of the machine. Methods: Data of 23 CRRT (and 11 plasma exchange) treatments were collected from 4 intensive care units. Parameters such as treatment duration, downtime, delivered dose, and number and type of alarms were recorded. The general perception of the machine was quantified through the administration of a survey to each component of the evaluating staff. Results: A total treatment time of 447 h was carried with ACUsmart. Eleven continuous veno-venous hemofiltration, 4 continuous veno-venous hemodialysis , and 8 continuous veno-venous hemodiafiltration were performed. The average percentage of net treatment duration with respect to total treatment duration was 92.37%. The mean prescribed dose and delivered dose were 26.33 and 24.10 mL/kg/h, respectively. In general, the machine was rated by users involved as practical and easy to use, although few components need to be slightly improved. Conclusion: ACUsmart is a new multifunctional machine that meets most of the features required in a fourth-generation CRRT equipment.


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