Filter Lifespan Research Articles

Decreased CRRT Filter Lifespan in COVID-19 ICU Patients.

(1) Background: Increased thromboembolic events and an increased need for continuous renal replacement therapy (CRRT) have been frequently reported in COVID-19 patients. Our aim was to investigate CRRT filter lifespan in intensive care unit (ICU) COVID-19 patients. (2) Methods: We compared CRRT adjusted circuit lifespan in COVID-19 patients admitted for SARS-CoV-2 infection to a control group of patients admitted for septic shock of pulmonary origin other than COVID-19. Both groups underwent at least one session of CRRT for AKI. (3) Results: Twenty-six patients (13 in each group) were included. We analysed 117 CRRT circuits (80 in the COVID-19 group and 37 in the control group). The adjusted filter lifespan was shorter in the COVID-19 group (17 vs. 39 h, p < 0.001). This trend persisted after adjustment for confounding factors (−14 h, p = 0.037). Before CRRT circuit clotting, the COVID-19 group had a more procoagulant profile despite higher heparin infusion rates. Furthermore, we reported a decreased relation between activated partial thromboplastin time (aPTT) and cumulative heparin dose in COVID-19 patients when compared to historical data of 23,058 patients, suggesting a heparin resistance. (4) Conclusion: COVID-19 patients displayed a shorter CRRT filter lifespan that could be related to a procoagulant profile and heparin resistance.

Optimal Design of Off-Road Utility Terrain Vehicle Air Filter Intake

The air filters applied in utility terrain vehicles (UTVs), which are usually driven on dust-prone unpaved roads, employ a two-stage air cleaner that increases the lifespan of the filter element by using a pre-cleaner stage in the air filter intake housing to centrifugally separate any dust particles contained in the intake air before sending the cleaned air to the primary filter. Thus, maximizing the centrifugation capacity by properly modifying the geometry of the intake air passage in the filter housing is important to ensure engine performance and filter lifespan. The geometry of the pre-cleaner air passage was therefore optimized in this study in terms of the inclination angle and air passage location angle using a computational flow analysis to maximize the centrifugal removal of dust particles. The resulting overall pre-cleaner efficiency and overall pre-cleaner efficiency per pressure drop were then used as the objective functions to maximize the dust particle removal capacity according to centrifugation speed. The method demonstrated in this study for optimizing air filter intake geometry can be used to improve and prolong the performance of UTV engines.

Regional citrate anticoagulation versus low molecular weight heparin for CRRT in hyperlactatemia patients: A retrospective case-control study

There were controversial opinions on the use of regional citrate anticoagulation (RCA) versus low molecular weight heparin (LMWH) for continuous renal replacement therapy (CRRT) in hyperlactatemia patients, which was considered as one of the contraindications of citrate. The aim of our present study is to evaluate the efficacy and safety of RCA versus LMWH for CRRT in hyperlactatemia patients. Adult patients with hyperlactatemia who underwent RCA or LMWH CRRT in our center between January 2014 and March 2018 were retrospectively recruited. Filter lifespan, ultrafiltration, purification, bleeding, citrate accumulation, filter clot, and the infusion of blood production were evaluated as endpoints. Of the 127 patients included in the original cohort, 81 and 46 accepted RCA and LMWH CRRT, respectively. The filter lifespan was significantly prolonged in the RCA group compared to the LMWH group (44.25 h [2 -83] vs. 24 h [4 -67], p < 0.001). The accumulated filter survival proportions were significantly improved in the RCA group compared to the LMWH group in the original cohort (p < 0.001) as well as the matched group (p < 0.001). The filters clotted more frequently in the LMWH group than in the RCA group in both of the original (52.2% vs 26.8%, p = 0.001) and matched cohort (58.6% vs 19.4%, p = 0.001). The bleeding complication was significantly reduced in the RCA group than in the LMWH group in the matched cohort (28.6% vs 4.5%, p = 0.04). In critically ill patients with hyperlactatemia requiring CRRT, RCA is superior to LMWH in terms of filter lifespan and bleeding risk without significantly increased risk of citrate accumulation and citrate related metabolic complications. RCA most likely is a safe and effective anticoagulation method for CRRT in patients with hyperlactatemia.

Feasibility and efficacy of modified fixed citrate concentration protocol using only commercial preparations in critically ill patients: a prospective cohort study with a historical control group

BackgroundThe cumbersome program and the shortage of commercial solution hindered the regular application of regional citrate anticoagulation (RCA). It is urgent to simplify the protocol using only commercial preparations. The aim of this study was to explore the feasibility and efficacy of the modified protocol for continuous veno-venous hemofiltration (CVVH) in unselected critically ill patients.MethodsA prospective cohort study was conducted in 66 patients who received a new protocol combining fixed citrate concentration with modified algorithm for supplements (i.e., fixed protocol), and compared the efficacy, safety and convenience for this group to a historical control group with a traditional protocol (n = 64), where citrate was titrated according to the circuit ionized calcium concentration (i.e., titrated protocol). The convenience was defined as the demand for monitoring test and dose adjustment of any supplement.ResultsThe filter lifespan was 63.2 ± 16.1 h in the fixed group and 51.9 ± 17.7 h in the titrated group, respectively. Kaplan-Meier survival analysis demonstrated longer circuit lifetime for fixed group (log-rank, p = 0.026). The incidence of circuit clotting was lower in the fixed protocol (15.2% vs. 29.7% in the titrated protocol, p = 0.047). Moreover, compared with the titrated group, patients with fixed protocol had less demand for monitoring test and dose adjustment of any supplement (the number of times per person per day) (3.3 [IQR 2.3–4.5] vs. 5.7 [IQR 3.3–6.9], p = 0.001 and 1.9 [IQR 0.5–2.7] vs. 6.3 [IQR 4.2–7.9], p < 0.001; respectively). No new onset bleeding complications occurred in all patients. The overall incidence of suspected citrate accumulation was 4.6% and there was no difference between the two groups (p = 0.969), yet a lower rate of metabolic alkalosis was found in the fixed group (3.0% vs. 14.1%, p = 0.024).ConclusionsOur modified fixed citrate concentration protocol is feasible, safe and effective to enhance the circuit lifespan and the convenience of implementation while maintaining a similar safety when compared to the traditional protocol. Using only commercial preparations may be helpful for widespread application of RCA.Trial registrationClinicaltrials.gov. NCT02663960. Registered 26 January 2016.

Continuous renal replacement therapy without anticoagulation in critically ill patients at high risk of bleeding: A systematic review and meta-analysis.

The current clinical guideline recommends continuous renal replacement therapy (CRRT) proceed without anticoagulation in patients with contraindication to citrate and increased bleeding risk. Nevertheless, the efficacy of anticoagulation-free CRRT remains inconsistent. The purpose of our present systematic review is to evaluate the efficacy and safety of anticoagulant-free CRRT based on the current literatures. The primary outcomes were filter lifespan and risk factors for filter failure. Seventeen observational studies and three randomized controlled trials were included in our present meta-analysis. There was no significant difference in filter lifespan and azotemic control between the anticoagulation-free and systemic heparin group. The regional citrate anticoagulation (RCA) protocol seems to be superior to the anticoagulation-free protocol in terms of filter lifespan (WMD -23.01, 95% CI [-28.62, -17.39], p<0.001; I2 =0%, p=0.53) and azotemic control. Nafamostat protocol could significantly prolong filter lifespan (WMD -8.4, 95% CI [-9.9, -6.9], p<0.001; I2 =33.7%, p=0.21) as compared with anticoagulation-free protocol without better azotemic control. The conventional coagulation parameters showed poor predictive performence for filter failure and the necessity of anticoagulants use before CRRT. Currently, the optimal choice of anticoagulation strategy for critically ill patients with increased bleeding risk could be RCA under close monitoring.

Dialysis Filter Life, Anticoagulation, and Inflammation in COVID-19 and Acute Kidney Injury.

In recent studies, 5%–20% of hospitalized patients with coronavirus disease 2019 (COVID-19) developed AKI requiring RRT (CoV-AKI-RRT) (1,2) (L. Chan et al., unpublished observations). Hypercoagulability has been recognized as a salient feature of COVID-19 in the critically ill (3,4) and there have been anecdotal accounts of unexpectedly frequent dialysis filter clotting. However, there are limited data describing the magnitude of the problem. A recent report described clotting events in 28 of 29 patients with CoV-AKI-RRT and shorter filter lifespan compared with a historical control, but no details were provided regarding anticoagulation (4). Our objective was to examine the delivery of RRT and circuit interruptions in patients with CoV-AKI-RRT in comparison with those in the pre-COVID-19 era. With approval of the Institutional Review Board, waiver of informed consent, and in accordance with the Declaration of Helsinki, we conducted a retrospective single-center study, ancillary from our previously reported cohort (2). We identified hospitalized patients with COVID-19 (positive severe acute respiratory syndrome coronavirus 2 RNA PCR by nasopharyngeal swab) and AKI, who underwent RRT by sustained low-efficiency dialysis (SLED) for ≥8 hours in an intensive care unit between March and April of 2020 (study period: 4 weeks) by either prolonged intermittent or continuous RRT modality (5,6) using Fresenius 2008K/K2 (Bad Homburg, Germany) machines. At our hospital, continuous venovenous hemodiafiltration (CVVHDF) with PrismaFlex (Deerfield, IL) machines was restricted to the neurointensive care unit and was not expanded during the pandemic due to logistics. As pre-COVID-19 control, we included consecutive patients (reverse chronological order) with AKI without COVID-19 who underwent SLED in December of 2019. Electronic medical records were accessed and RRT flowsheets were manually reviewed to extract timing of initiation and interruption, blood flow rate (BFR), dialysate flow rate, and filter transmembrane pressure (TMP). Standard BFR was 200 …

Effect of Regional Citrate Anticoagulation vs Systemic Heparin Anticoagulation During Continuous Kidney Replacement Therapy on Dialysis Filter Life Span and Mortality Among Critically Ill Patients With Acute Kidney Injury

Although current guidelines suggest the use of regional citrate anticoagulation (which involves the addition of a citrate solution to the blood before the filter of the extracorporeal dialysis circuit) as first-line treatment for continuous kidney replacement therapy in critically ill patients, the evidence for this recommendation is based on few clinical trials and meta-analyses. To determine the effect of regional citrate anticoagulation, compared with systemic heparin anticoagulation, on filter life span and mortality. A parallel-group, randomized multicenter clinical trial in 26 centers across Germany was conducted between March 2016 and December 2018 (final date of follow-up, January 21, 2020). The trial was terminated early after 596 critically ill patients with severe acute kidney injury or clinical indications for initiation of kidney replacement therapy had been enrolled. Patients were randomized to receive either regional citrate anticoagulation (n = 300), which consisted of a target ionized calcium level of 1.0 to 1.40 mg/dL, or systemic heparin anticoagulation (n = 296), which consisted of a target activated partial thromboplastin time of 45 to 60 seconds, for continuous kidney replacement therapy. Coprimary outcomes were filter life span and 90-day mortality. Secondary end points included bleeding complications and new infections. Among 638 patients randomized, 596 (93.4%) (mean age, 67.5 years; 183 [30.7%] women) completed the trial. In the regional citrate group vs systemic heparin group, median filter life span was 47 hours (interquartile range [IQR], 19-70 hours) vs 26 hours (IQR, 12-51 hours) (difference, 15 hours [95% CI, 11 to 20 hours]; P < .001). Ninety-day all-cause mortality occurred in 150 of 300 patients vs 156 of 296 patients (Kaplan-Meier estimator percentages, 51.2% vs 53.6%; unadjusted difference, -2.4% [95% CI, -10.5% to 5.8%]; unadjusted hazard ratio, 0.91 [95% CI, 0.72 to 1.13]; unadjusted P = .38; adjusted difference, -6.1% [95% CI, -12.6% to 0.4%]; primary adjusted hazard ratio, 0.79 [95% CI, 0.63 to 1.004]; primary adjusted P = .054). Of 38 prespecified secondary end points, 34 showed no significant difference. Compared with the systemic heparin group, the regional citrate group had significantly fewer bleeding complications (15/300 [5.1%] vs 49/296 [16.9%]; difference, -11.8% [95% CI, -16.8% to -6.8%]; P < .001) and significantly more new infections (204/300 [68.0%] vs 164/296 [55.4%]; difference, 12.6% [95% CI, 4.9% to 20.3%]; P = .002). Among critically ill patients with acute kidney injury receiving continuous kidney replacement therapy, anticoagulation with regional citrate, compared with systemic heparin anticoagulation, resulted in significantly longer filter life span. The trial was terminated early and was therefore underpowered to reach conclusions about the effect of anticoagulation strategy on mortality. ClinicalTrials.gov Identifier: NCT02669589.

Regional citrate anticoagulation vs no-anticoagulation for CRRT in hyperlactatemia patients with increased bleeding risk: A retrospective cohort study.

There are controversial opinions on the use of regional citrate anticoagulation (RCA) continuous renal replacement therapy (CRRT) in hyperlactatemia patients with increased bleeding risk. Patients with hyperlactatemia and increased bleeding risk who accepted RCA or no-anticoagulation CRRT in our center were retrospectively included. Eighty patients who underwent RCA-CRRT and 47 patients received no-anticoagulation CRRT were included. Filter lifespan was significantly longer in the RCA group than the no-anticoagulation group (44.5hours [2-89] vs 24.5hours [1.5-70], P<.001). The adjusted results demonstrated that patients in the no-anticoagulant group had significantly higher risk of filter failure (HR=4.765, 95% CI 2.703-8.4, P<.001). Bleeding episodes occurred in 19 (24.1%) and 22 (46.8%) patients in the RCA and no-anticoagulation group, respectively (P=.012). The overall citrate accumulation (CA) rate was 5% in the RCA group. Patient mortality was associated with the comorbidity of hypertension, increased serum lactate level, and increased SOFA score. After matching, the filter lifespan was significantly longer in the RCA group than the no-anticoagulation group. With careful monitoring and timely adjustment, RCA most likely was safe and effective for CRRT in hyperlactatemia patients with increased bleeding risk.

Adding Heparin to Citrate in Continuous Renal Replacement Therapy May Extend Filter Lifespan in COVID-Related AKI

Adding Heparin to Citrate in Continuous Renal Replacement Therapy May Extend Filter Lifespan in COVID-Related AKI

Monitoring Anticoagulation with Unfractionated Heparin on Renal Replacement Therapy. Which is the Best aPTT Sampling Site?

BackgroundControlled anticoagulation is key to maintaining continuous blood filtration therapies. Objective: The study aimed to compare different blood sampling sites for activated partial thromboplastin time (aPTT) to evaluate anticoagulation with unfractionated heparin (UFH) in continuous renal replacement therapy (CRRT) and identify the most appropriate sampling site for safe patient anticoagulation and increased filter life span.MethodThe study was a prospective observational single-centre investigation targeting intensive care unit (ICU) patients on CRRT using an anticoagulation protocol based on patient characteristics and a weight-based modified nomogram. Eighty-four patients were included in the study. Four sampling sites were assessed: heparin free central venous nondialysis catheter (CVC), an arterial line with heparinised flush (Artery), a circuit access line (Access), and a circuit return line (Postfilter). Blood was sampled from each of four different sites on every patient, four hours after the first heparin bolus. aPTT was determined using a rapid clot detector, point of care device.ResultsA high positive correlation was obtained for aPTT values between CVC and Access sampling sites (r (84) =0.72; p <0 .05) and a low positive correlation between CVC and Arterial sampling site (r (84) =0.46, p < 0.05). When correlated by artery age, the young Artery (1-3 day old) correlates with CVC, Access and Postfilter (r (45) = 0.74, p >0.05). The aPTT values were significantly higher at Postfilter and Arterial sampling site, older than three days, compared to the CVC sampling site (p<0.05).ConclusionConsidering patient bleeding risks and filter life span, the optimal sampling sites for safe assessment of unfractionated heparin anticoagulation on CRRT during CVVHDF were the central venous catheter using heparin free lavage saline solution, a heparinised flushed arterial catheter not older than three days, and a circuit access line.

An optimum design for air filter housing-louver: Enhancing filter life-time

The design of filter housing and louver have been focused on the filter protection from rain. Up till now the effect of air-flow behavior on the filter life-span has not been considered. All filters have to be changed at the same time, which causes expensive maintenance and the plant to be shut down. Sometimes, the filter needs to be changed earlier than its real-life. The main aim of this work is to design a louver shape which obtains a consistent airflow through the filter housing in each channel. The airflow through the filter housing of four different shapes of the louver were simulated in two-dimensional models. The filter size was fixed at 60 × 60 cm. The three filters were set series for the filter housing height at 180 cm. CFD models used in this work to determine the optimum filter housing and louver shape for pressure drop reduction and uniform airflow distribution. The results showed that the optimum filter housing angle was found to be 45° at the largest louver size with the same size of inlet and outlet channels (H/L/Z = 1/1/1). The design of filter housing and louver can be indicated the best airflow behavior and the optimum cost.

P1089REGIONAL CITRATE ANTICOAGULATION VERSUS LOW MOLECULAR WEIGHT HEPARIN ANTICOAGULATION FOR CONTINUS VENOVENOUS HEMOFILTRATION IN PATIENTS WITH SEVERE HYPERCALCEMIA: A RETROSPECTIVE CASE-CONTROL STUDY

Abstract Background and Aims Severe hypercalcemia, poor conservative treatment effect, or combined with renal dysfunction, heart failure, intermittent hemodialysis treatment is recommended. But calcium-free hemodialysis could cause rebound of serum calcium, hypovolemia and hypotension. Continuous renal replacement therapy (CRRT) is the most commonly used treatment in critically ill patients with severe AKI. Some case reports showed that CRRT successed control calcium with stable hemodynamics, no rebound hypercalcemia, but there was only one case used continuous venovenous hemofiltration (CVVH). During CVVH treatment, clotting in the extracorporeal circuit shortens the filter and catheter lifespan, causes blood loss, and decreases solute clearance, consequently, reduces the effectiveness of CVVH and increases the treatment cost and medical stuff’s workload. So how to safely decrease calcium level and how to choose appropriate anticoagulants during CVVH in esvere hypercalcemia patients is a challenging work. We conducted a retrospective study to evaluate the efficacy and safety of regional citrate anticoagulation (RCA) versus low molecular weight heparin (LMWH) anticoagulation for CVVH in severe hypercalcemia patients. Method Between January 2014 and May 2019, severe hypercalcemia patients requiring CVVH were screened and divided into the RCA and LMWH-anticoagulation group according to the CVVH anticoagulation strategy they accepted. Serum calcium reduction rate (RRSeCa), filter lifespan, bleeding, totCa/ionCa ratio, citrate accumulation, and catheter occlusion were evaluated as outcomes. Results Of the 33 included patients, RCA and LMWH-anticoagulation were employed for CVVH in 14 and 43 filters, respectively. The serum calcium reduction rate (RRSeCa) was not significantly different between the LMWH-anticoagulation and RCA group (P = 0.320). Compared to LMWH-anticoagulation, RCA significantly prolonged the filter lifespan (&amp;gt; 72 hours vs. 24.0 hours [IQR, 15.0-26.0], P = 0.012). The incidence of filter failure was 55.8% (24/43) in the LMWH -anticoagulation group and 21.4% (3/14) in the RCA group (P = 0.033), respectively. The adjusted results demonstrated that RCA could significantly reduce the risk of filter failure (P = 0.028, 95% CI 0.076-0.859, HR = 0.255). No citrate accumulation was observed in RCA-CVVH patients. Conclusion In patients with severe hypercalcemia who underwent CVVH, both RCA CVVH and LMWH-anticoagulation CVVH could effectively decrease calcium levels. RCA CVVH had better filter lifespan and no obvious adverse events, compared with the LMWH-anticoagulation CVVH. Further prospective, randomized, control studies are warranted to obtain robust evidences.

P0625CONTINUOUS RENAL REPLACEMENT THERAPY WITHOUT ANTICOAGULATION IN CRITICALLY ILL PATIENTS AT HIGH RISK OF BLEEDING-A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract Background and Aims Continuous renal replacement therapy (CRRT) has been widely used in the critical care setting and anticoagulation is usually necessitated. However, critically ill patients are commonly at incremental risk of bleeding, which contributed to the hesitation of anticoagulant use for CRRT in clinical practice. The current guideline recommended CRRT proceed without anticoagulation in patients with contraindication to citrate and increased bleeding risk. Nevertheless, the efficacy of anticoagulation-free CRRT remains inconsistent. Therefore, the purpose of our present systematic review is to evaluate the efficacy and safety of anticoagulant-free CRRT based on the current literatures. Method We conducted a comprehensive search of PubMed (US National Library of Medicine, Bethesda, MD, USA), Cochrane Library databases and EMBASE from database inception to January 12, 2019 for potential candidate studies. Studies included adult critically ill (age &amp;gt; 18 years) patients with increased bleeding risk, and underwent CRRT without anticoagulation were considered for the inclusion. Results Finally, 17 observational studies and 3 randomized controlled trials with 1615 patients were included in our present meta-analysis. There was no significant difference in filter lifespan between the anticoagulation-free and systemic heparin group. The filter lifespan was significantly prolonged in the citrate (WMD -23.01, 95%CI [-28.62, -17.39], P &amp;lt; 0.001; I2 = 0%, P = 0.53) and nafamostat (WMD -8.4, 95%CI [-9.9, -6.9], P &amp;lt; 0.001; I2 = 33.7%, P = 0.21) groups, compared with anticoagulation-free group. The averaged filter lifespan of the anticoagulation-free CRRT ranged from 10.2 to 52.5 hours. Conclusion The filter lifespan in anticoagulation-free patients with increased bleeding risk was comparable to that in patients without increased bleeding risk underwent systemic heparin anticoagulation CRRT. Nafamostat was not recommended for CRRT anticoagulation due to its drawbacks. Currently, the optimal choice of anticoagulation strategy for critically ill patients without citrate contraindications at high risk of bleeding should be regional citrate anticoagulation. Further studies should focus on the special cut-off value of activated partial thromboplastin time (APTT), international normalized ratio (INR) and platelet (PLT) count, at which the anticoagulation-free CRRT would be beneficial.

P1074SIMPLIED REGIONAL CITRATE ANTICOULATION USING A CALCIUM-CONTAINING REPLACEMENT SOLUTION FOR RENAL REPLACEMENT THERAPY: A RANDOMIZED CONTROLLED CLINICAL TRIAL

Abstract Background and Aims A simplified protocol for Regional citrate anticoagulation (RCA) using a commercial calcium-containing replacement solution, without a continuous calcium infusion, is more efficient to be used in continuous renal replacement therapy (CRRT). We aim to design a randomized prospective pilot trial to compare the safety and efficacy between calcium-free and calcium-containing replacement solution in CRRT with RCA. Method Of the 59 patients who requiring CRRT and being treated with RCA-based continuous venovenous hemodiafiltration (CVVHDF) enrolled, 31 patients were randomized to calcium-containing group and 28 to calcium-free replacement solution group. Primary endpoints were filters lifespan. Secondary endpoints were mortality, kidney function recovery and severe complications rates. Time spent on fluids preparation before CRRT and the amount of 4% trisodium citrate solution pumped during CRRT were recorded. Serum and effluent citrate and calcium concentration during CVVHDF were measured during CRRT. Results Filters lifespan were superior for calcium-containing group (mean 58.06 versus 47.12 hours, P=0.05). Mortality and renal outcome were comparable between groups during hospitalization: 10/31 (33.26%) of calcium-containing group patients died versus 13/28 (46.43%) of calcium-free group patients, and 16/31 (51.61%) of calcium-containing group patients had kidney function recovery versus 15/28 (53.57%) of calcium-containing group (P = 0.265). Only 5 patients showed the symptoms and signs of hypocalcemia or citrate toxicity in this study. The mean CRRT preparation time in calcium-containing group: 25.5 minutes, was significantly shorter than calcium-free group: 43.7 minutes (p&amp;lt;0.001). The serum and effluent calcium concentration was slightly lower in calcium-containing group during CRRT. While, the mean 4% trisodium citrate solution infusion rate was similar between groups (161.5 mL/h versus 157.4 mL/h, P=0.376). Conclusion Patients treated with calcium-containing or calcium-free replacement solution have similar clinical outcomes. Since the calcium-containing replacement solution based RCA has longer filter lifespan and obviates the need for a separate venous catheter and intravenous calcium preparation for continuous intravenous calcium infusion, it is more efficient to be used in clinical practice and superior to the calcium-free replacement solution.

P0635MYOGLOBIN CLEARANCE IN CVVHD USING HIGH CUT-OFF FILTER VERSUS CVVHDF WITH REGIONAL CITRAT ANTICOAGULATION: A PROSPECTIVE RANDOMIZED CONTROLLED TRIAL

Abstract Background and Aims Acute kidney injury (AKI) is frequent among critically ill patients and it is associated with high mortality. Rhabdomyolysis is a distinct cause of AKI. As myoglobin has renal toxic effects, clearance via continuous renal replacement therapy (CRRT) may be favourable. Current international guidelines recommend regional citrate anticoagulation (RCA). Clinical data comparing different modalities of CRRT addressing myoglobin clearance are lacking. Hemofiltration is recommended to eliminate myoglobin, which requires systemic anticoagulation. RCA would be impractical due to the high citrate load as a result of the higher blood flow. Continuous veno-venous hemodiafiltration (CVVHDF) is one opportunity to realize lower citrate load and maintain middle molecule clearance. Another approach may be the application of hemodialysis with high cut-off (HCO) membranes with a pore size larger than 0.01 μm in CVVHD (CVVHD-HCO). We have previously shown that CVVHD-HCO is superior to conventional high-flux dialyser regarding the clearance of β2-microglobulin. Based on this finding, we analyzed of various etiologiesre Filter lilifespan mit dem efonnummer der Virologie zum Befunderfragenmyoglobin clearance with CVVHDF compared to CVVHD-HCO with RCA. Method The present study is a prospective, randomized, single-blinded, monocentric trial. We enrolled patients from May 2017 to September 2018 in our 28-bed medical ICU at the University Hospital Leipzig. We screened 430 patients with AKI and indication for RRT for eligibility. A total of 70 patients underwent randomisation 1:1 into the intervention (CVVHD-HCO, high cut-off dialyzer Ultraflux EMiC2) and control group (CVVHDF, high-flux dialyzer Ultraflux AV1000S). The concentrations of myoglobin (17053 Dalton (Da), urea (60 Da), creatinine (113 Da), β2-microglobulin 11800 Da), interleukin 6 (IL-6, 26000 Da) and albumin (66470 Da) were measured before (pre) and after (post) the dialyzer 1, 6, 12, 24 and 48 h after initiating CRRT. We hypothesized non-inferiority of CVVHD-HCO versus CVVHDF regarding myoglobin clearance (primary end-point). Results Myoglobin clearance showed non-inferiority in the intervention group for all time points. The dialyzer in the intervention group resulted in even a better myoglobin clearance during the whole study period. (Table 1). Clearance values for urea and creatinine were equal and there was no albumin loss in both groups.β2-microglobulin clearance was significantly better in the intervention group than in the control group at all time points. The clearance of IL-6 was also better at T0 in the intervention group. The filter lifespan was 51.5 hours (CI: 44.24; 58.76) in the control group and 62.3 hours (CI 56.83; 67.7) in the intervention group (log-rank, p=0,029). Conclusion Myoglobin can be reliably cleared using both CVVHD-HCO and CVVHDF. Nevertheless, the plasma specific clearance rate of myoglobin was higher with CVVHD-HCO. High myoglobin levels are associated with AKI and higher mortality rates and on this account clearance of myoglobin represents a relevant clinical issue.

Regional citrate anticoagulation versus no-anticoagulation for continuous venovenous hemofiltration in patients with liver failure and increased bleeding risk: A retrospective case-control study.

ObjectiveThere are controversial opinions on anticoagulation for continuous venovenous hemofiltration (CVVH) in patients with liver failure (LF) and increased bleeding risk. Therefore, we conducted a retrospective study to evaluate the efficacy and safety of regional citrate anticoagulation (RCA) versus no-anticoagulation for CVVH in these patients.MethodsThe included patients were divided into RCA and no-anticoagulation group according to the CVVH anticoagulation strategy they accepted for CVVH. Filter lifespan, bleeding, citrate accumulation, catheter occlusion, and totCa/ionCa ratio were evaluated as outcomes.ResultsIn the original cohort, the filter lifespan of the RCA group (41 patients, 79 filters) was significantly longer than the no-anticoagulation group (62 patients, 162 filters) (> 72 hours vs 39.5 hours (IQR 31.2–47.8), P = 0.002). The adjusted results demonstrated that RCA could significantly reduce the risk of filter failure (HR = 0.459, 95%CI 0.26–0.82, P = 0.008). Four episodes of totCa/ionCa > 2.5 were observed in the RCA group and continuously accepted RCA-CVVH after the reduction of citrate dose and blood flow. No obvious citrate accumulation was observed in these patients. In the matched cohort, the filter lifespan of the RCA group was significantly longer than the no-anticoagulation group (P = 0.013) as well. No significant difference in the episodes of totCa/ionCa > 2.5 was observed between the two matched groups (P = 0.074). Both in the original cohort and the matched cohort, the bleeding, acidosis, alkalosis, and catheter occlusion incidences were not significantly different between the two groups.ConclusionsIn LF patients with increased bleeding risk who underwent CVVH, RCA could prolong the filter lifespan and be safely used with careful blood gas monitoring and citrate dose adjusting. Further prospective, randomized, control studies are warranted to obtain robust evidences.

Continuous Renal Replacement Therapy in Venovenous Extracorporeal Membrane Oxygenation: A Retrospective Study on Regional Citrate Anticoagulation.

Systemic infusion of unfractionated heparin (UFH) is the standard anticoagulation technique for continuous renal replacement therapy (CRRT) during extracorporeal membrane oxygenation (ECMO), but often fails to avoid CRRT circuit clotting. The aim of this study was to assess, in patients undergoing CRRT during venovenous ECMO (vv-ECMO), the efficacy and safety of adding regional citrate anticoagulation (RCA) for CRRT circuit anticoagulation (RCA + UFH group) compared with the sole systemic heparin anticoagulation (UFH group). We performed a retrospective chart review (2009-2018) of patients treated with CRRT during ECMO. We evaluated filter life span, rate of CRRT circuit clotting, and coagulation parameters. The incidence of citrate anticoagulation-related complications was recorded. Forty-eight consecutive adult patients underwent CRRT during vv-ECMO in the study period. The incidence of CRRT circuit clotting was lower in the RCA + UFH group (11% vs. 38% in the UFH group, p < 0.001). Log-rank survival analysis demonstrated longer circuit lifetime for RCA + UFH group. No complication ascribable to citrate anticoagulation was recorded. Regional citrate anticoagulation resulted a feasible, safe, and effective technique as additional anticoagulation for CRRT circuits during ECMO. Compared with systemic heparinization only, this technique allowed to reduce the rate of CRRT circuit clotting.

Regional citrate anticoagulation versus low molecular weight heparin anticoagulation for continuous venovenous hemofiltration in patients with severe hypercalcemia: a retrospective cohort study

Purpose We conducted a retrospective study to evaluate the efficacy and safety of regional citrate anticoagulation (RCA) versus those of low molecular weight heparin (LMWH) anticoagulation for CVVH in severe hypercalcemia patients. Methods Between January 2014 and May 2019, 33 severe hypercalcemia patients underwent CVVH. Patients were divided into the RCA and LMWH groups. Calcium-free replacement solution was used. Serum total calcium reduction rate (RRSeCa), filter lifespan, bleeding, totCa/ionCa ratio, citrate accumulation, and catheter occlusion were evaluated as outcomes. Results RCA and LMWH were employed for CVVH in 14 and 43 filters, respectively. RRSeCa was not significantly different between the LMWH and RCA groups (p = .320), but RCA-CVVH was more effective in reducing ionized calcium at half of the time points (p < .05). RCA significantly prolonged the median filter lifespan (>72 h vs. 24.0 h [IQR, 15.0–26.0], p = .012). The incidence of filter failure was 55.8% (24/43) in the LMWH group and 21.4% (3/14) in the RCA group (p = .033). The adjusted results demonstrated that RCA could significantly reduce the risk of filter failure (p = .043, 95% CI 0.059–0.957, HR = 0.238). No citrate accumulation or bleeding episodes were observed in the RCA-CVVH group. Seven bleeding episodes (7/43, 16.3%) occurred in the LMWH-CVVH group. Conclusions In patients with severe hypercalcemia who underwent CVVH, RCA more effectively decreased calcium levels and had a superior filter lifespan and no obvious adverse events compared with LMWH. Further prospective, randomized, controlled studies are warranted to obtain robust evidence.

Regional citrate versus systemic heparin anticoagulation for continuous renal replacement therapy in critically ill children.

Anticoagulation is used to prevent filter clotting in patients undergoing continuous renal replacement therapy. Regional citrate anticoagulation is associated with lower rates of bleeding complications and prolongs the filter life span; however, a number of metabolic side effects had been associated with this therapy. The aim of this study was to evaluate the effect and safety of citrate versus heparin anticoagulation for continuous renal replacement therapy in critically ill children. A retrospective comparative cohort study. Department of Pediatric Intensive Care, Acibadem Mehmet Ali Aydınlar University School of Medicine. From August 2016 to August 2018, 45 patients (19 in the citrate group and 26 in the heparin group) were included. A total of 101 hemofilters were used in all therapies: 44 in the citrate group (total continuous renal replacement therapy time: 2699 h) and 57 in the heparin group (total continuous renal replacement therapy time: 2383 h). The median circuit lifetime was significantly longer for regional citrate anticoagulation (53.0; interquartile range, 40-70 h) than for heparin anticoagulation (40.25; interquartile range, 22.75-53.5 h; p = 0.025). Mortality rates were similar in both groups (31.58% vs 30.77%). The most common indication for dialysis was hypervolemia in both groups. Transfusion rates were 1.65 units (interquartile range, 0.5-2.38) with heparin and 0.8 units (interquartile range, 0.3-2.0) with citrate (p = 0.32). Clotting-related hemofilter failure occurred in 11.36% of filters in the citrate group compared with 26.31% of filters in the heparin group. Our study showed that citrate is superior in terms of safety and efficacy, with longer filter life span. Regional citrate should be considered as a better anticoagulation method than heparin for continuous renal replacement therapy in critically ill children.

Clinical Survey of Decreased Blood Flow Rate in Continuous Renal Replacement Therapy: A Retrospective Observational Study.

Background Continuous renal replacement therapy (CRRT) is an essential procedure for patients with acute kidney injury in intensive care. It is important to maintain an adequate blood flow rate during CRRT. Several previous studies have reported the relationships between blood flow rate and filter lifespan, or circuit life, in CRRT. Here, we aim at elucidating the incidence and factors associated with a decreased blood flow rate in CRRT. Methods This is a retrospective observational study. From January 2014 to June 2017, 119 patients who underwent CRRT in the intensive care unit were enrolled. The definition of a decreased blood flow rate included situations in which the medical staff needed to decrease the blood flow volume. We statistically analyzed the association of the decreased blood flow rate with patients' clinical characteristics. Results Of 119 patients, 52 required a decreased blood flow rate during CRRT. Almost half of the cases occurred within one day of starting CRRT. None of the clinical factors (age, sex, height, sequential organ failure assessment (SOFA) score, catheter position, systemic infection, albumin, hemoglobin, and activating coagulation time) were significantly associated with decreased blood flow rate. Conclusions A decreased blood flow rate often occurs during CRRT. Clinical factors significantly associated with the occurrence of the decreased blood flow rate were not detected in the current study. Further investigation regarding the occurrence of a decreased blood flow is warranted.