Circuit Clotting Research Articles

Continuous renal replacement therapy is a safe and effective modality for the initial management of dogs with acute kidney injury.

To describe the management of dogs with acute kidney injury (AKI) by continuous renal replacement therapy (CRRT), and to investigate the relationship between a prescribed CRRT dose, the hourly urea reduction ratio (URR), and the overall efficacy. 45 client-owned dogs diagnosed with severe AKI, receiving 48 CRRT treatments at a veterinary teaching hospital. Retrospective study. Search of medical records of dogs with AKI managed by CRRT. Median serum urea and creatinine at CRRT initiation were 252 mg/dL [Inter quartile range (IQR), 148 mg/dL; range, 64 to 603 mg/dL] and 9.0 mg/dL (IQR, 7 mg/dL; range, 4.3 to 42.2 mg/dL), respectively. Median treatment duration was 21 hours (IQR, 8.8 hours; range, 3 to 32 hours). Systemic heparinization and regional citrate anticoagulation were used in 24 treatments each (50%). The prescribed median CRRT dose for the entire treatment was 1 mL/kg/min (IQR, 0.4 mL/kg/min; range, 0.3 to 2.5 mL/kg/min). The median hourly URR was 4% (IQR, 1%; range, 2% to 12%), overall URR was 76% (IQR, 30%; range, 11% to 92%) and median Kt/V was 2.34 (IQR, 1.9; range, 0.24 to 7.02). The CRRT dose was increased gradually from 0.9 mL/kg/min to 1.4 mL/kg/min (P < .001) and the hourly URR decreased from 6.5% to 5.5% (P = .05). The main complication was clotting of the extra-corporeal circuit, occurring in 6/48 treatments (13%). Twenty-four dogs (53%) survived to discharge. CRRT is safe when the prescription is based on the current veterinary guidelines for gradual urea reduction. Treatment efficacy can be maximized by gradually increasing the dose according to the actual URR.

Risk for excessive anticoagulation during hemodialysis is associated with type of vascular access and bedside coagulation testing: Results of a cross-sectional study.

Recommendations and practice patterns for heparin dosing during hemodialysis show substantial heterogeneity and are scantly supported by evidence. This study assessed the variability in unfractionated heparin (UFH) dosing during hemodialysis and its clinical and biological anticoagulatory effects, and identified explanatory factors of heparin dosing. Cross-sectional study assessing UFH dosing, coagulation tests - activated partial thromboplastin time (aPTT) and activated clotting time (ACT) before dialysis start, 1 h after start and at treatment end (4 h) - and measurement of residual blood compartment volume of used dialyzers. 101 patients, 58% male, with a median dialysis vintage of 33 (6-71) months received hemodialysis using a total UFH dose of 9,306 ± 4,079 (range 3,000-23,050) IU/session. Use of a dialysis catheter (n = 56, 55%) was associated with a 1.4 times higher UFH dose (p < 0.001) irrespective of prior access function. aPTT increased significantly more than ACT both 1 h and 4 h after dialysis start, independent of the dialysis access used. 53% of patients with catheter access and ACT ratio < 1.5, 1 h after dialysis start had simultaneous aPTT ratios > 2.5. Similar findings were present at 1 h for patients with AVF/AVG and at dialysis end for catheter use. No clinically significant clotting of the extracorporeal circuit was noted during the studied sessions. Dialyzer's blood compartment volume was reduced with a median of 9% (6-20%) without significant effect of UFH dose, aPTT or ACT measurements and vascular access type. UFH dose adaptations based on ACT measurements frequently result in excessive anticoagulation according to aPTT results. Higher doses of UFH are used in patients with hemodialysis catheters without evidence that this reduces dialyzer clotting.

Frequent Circuit Clotting in a COVID-19 Patient on ECMO and CRRT

Frequent Circuit Clotting in a COVID-19 Patient on ECMO and CRRT

Regional citrate anticoagulation vs systemic heparin anticoagulation for double-filtration plasmapheresis.

Double-filtration plasmapheresis (DFPP) has been utilized for immunomodulation in kidney transplantation. Anticoagulation is important to maintain circuit patency during DFPP. We aimed to compare the efficacy and safety of regional citrate anticoagulation (RCA) with systemic heparin anticoagulation during DFPP in kidney transplant recipients. A retrospective cohort study was conducted to compare the efficacy and safety of RCA (RCA-DFPP) to systemic heparin anticoagulation (Hep-DFPP) for DFPP among kidney transplant recipients in a single tertiary center. A total of 112 sessions of DFPP were performed for 23 subjects, of which 62 sessions were RCA-DFPP and 50 sessions were Hep-DFPP. There were 13 sessions (11.6%) of premature circuit clotting, 10 sessions (16.1%) for RCA-DFPP and 3 sessions (6.0%) for Hep-DFPP (P=.10). All premature circuit clotting episodes occurred in subjects who underwent DFPP through a vascular catheter. Premature circuit clotting was associated with the use of a vascular catheter (odds ratio [OR] 14.2, 95% confidence interval [CI] 2.7-73.7; P < .01) and high postfilter ionized calcium (OR 12.7, 95% CI 1.4-112.5; P < .01). There was no major bleeding event. Hep-DFPP was associated with higher occurrence of hypocalcemia (OR 1.1, 95% CI 1.0-1.2; P < .01) and metabolic acidosis (OR 1.4, 95% CI 1.2-2.0; P=.04), while hypomagnesemia was more common for RCA-DFPP (OR 2.9, 95% CI 1.1-7.4; P=.03). Amongst kidney transplant patients who receive DFPP therapy, RCA-DFPP may be comparable to Hep-DFPP for the maintenance of circuit patency. Functioning vascular access is vital in avoiding premature clotting of the circuit. Close monitoring of electrolyte imbalances and coagulopathy related to DFPP is recommended.

Prevalence and outcomes of patients developing heparin-induced thrombocytopenia during extracorporeal membrane oxygenation.

Unfractionated heparin (UFH) is the commonly used anticoagulant to prevent clotting of the ECMO circuit and thrombosis of the cannulated vessels. A side effect of UFH is heparin-induced thrombocytopenia (HIT). Little is known about HIT during ECMO and the impact of changing anticoagulation in ECMO patients with newly diagnosed HIT. The aim of the study was to determine the prevalence, complications, impact of switching anticoagulation to argatroban and outcomes of patients developing heparin-induced thrombocytopenia (HIT) during either veno-venous (VV) or veno-arterial (VA) ECMO. Retrospective observational single centre study of prospectively collected data of consecutive patients receiving VV ECMO therapy for severe respiratory failure and VA ECMO for circulatory failure from January 2006 to December 2016 of the Medical intensive care unit (ICU) of the University Hospital of Regensburg. Treatment of HIT on ECMO was done with argatroban. 507 patients requiring ECMO were included. Further HIT-diagnostic was conducted if HIT-4T-score was ≥4. The HIT-confirmed group had positive HIT-enzyme-linked-immunosorbent-assay (ELISA) and positive heparin-induced-platelet-activation (HIPA) test, the HIT-suspicion group a positive HIT-ELISA and missing HIPA but remained on alternative anticoagulation until discharge and the HIT-excluded group a negative or positive HIT-ELISA, however negative HIPA. These were compared to group ECMO-control without any HIT suspicion. The prevalence of HIT-confirmed was 3.2%, of HIT-suspicion 2.0% and HIT-excluded 10.8%. Confirmed HIT was trendwise more frequent in VV than in VA (3.9 vs. 1.7% p = 0.173). Compared to the ECMO control group, patients with confirmed HIT were longer on ECMO (median 13 vs. 8 days, p = 0.002). Different types of complications were higher in the HIT-confirmed than in the ECMO-control group, but in-hospital mortality was not different (31% vs. 41%, p = 0.804). HIT is rare on ECMO, should be suspected, if platelets are decreasing, but seems not to increase mortality if treated promptly.

Hospital-Acquired Anemia in Patients Hospitalized in the Intensive Care Unit: A Retrospective Cohort Study.

Hospital-acquired anemia (HAA) is prevalent in patients hospitalized in the intensive care unit (ICU). Iatrogenic blood loss (IBL) may aggravate existing anemia or lead to a need for red blood cell (RBC) transfusion. The aim of our study was to analyze hemoglobin (Hb) concentration changes in up to 14 days, as well as all potential sources of IBL, in consecutive patients admitted to the intensive care unit (ICU) in the years 2020–2021. Patients admitted due to bleeding were excluded. Anemia on admission was present in 218 (58.8%) patients—47 (48.9%) surgical and 171 (62.2%) non-surgical (p = 0.02). Gradual decrease in Hb was seen in all ICU patients. Eighty-one (21.8%) patients required RBC transfusion. The first unit of RBC was transfused on day 7 (IQR 2–13) and the second on day 11 (IQR 4–15) of ICU hospitalization. The median admission Hb in patients who required RBC transfusion was 10.2 (IQR 8.5–11.8) and, in those who did not require transfusion, it was 12.0 (IQR 10.2–13.6) g/dL (p < 0.01). Anemia on admission was associated with a need for RBC transfusion (p < 0.01). Average decrease in Hb during the first week of ICU hospitalization in patients with and without anemia on admission was 1.2 (IQR 0.2–2.3) and 2.8 (IQR 1.1–3.8) g/dL (p < 0.01), respectively. Percentage of patients who bled at the insertion site of invasive devices was as follows: percutaneous tracheostomy—46.7%, therapeutic plasma exchange (TPE) catheter—23.8%, dialysis catheter—13.3%, gastrostomy—9.5%, central venous catheter—7.8%. Moreover, circuit clotting occurred in 17.7 and 9.5% of patients undergoing dialysis and TPE, respectively. Median blood loss for repeated laboratory testing in our study population was 13.7 (IQR 9.9–19.3) mL per patient daily. Anemia is highly prevalent among medical and surgical patients on admission to ICU and is associated with RBC transfusion. Patients who required RBC transfusion had significantly lower daily Hb concentrations. Severity of disease did not seem to have impact on Hb concentration. IBL associated with invasive devices and extracorporeal therapies is frequent in ICU patients and may lead to a gradual decrease in Hb concentration. Further studies are required to analyze causes of HAA in the ICU.

Feasibility and Efficacy of Sustained Low-Efficiency Dialysis in Critically Ill Children with Severe Acute Kidney Injury.

To examine the feasibility, efficacy, and safety of sustained low-efficiency dialysis (SLED) in hemodynamically unstable, critically ill children. Critically ill patients, 1-18 y old with hemodynamic instability (≥ 1 vasoactive drugs) and severe acute kidney injury (AKI) requiring kidney replacement therapy (KRT) in a tertiary care pediatric intensive care unit were prospectively enrolled. Patients weighing ≤ 8kg or with mean arterial pressure < 5th percentile despite > 3 vasoactive drugs, were excluded. Patients underwent SLED until hemodynamically stable and off vasoactive drugs, or lack of need for dialysis. The primary outcome was the proportion of patients in whom the first session of SLED was initiated within 12h of its indication and completed without premature (< 6h) termination. Efficacy was estimated by ultrafiltration, urea reduction ratio (URR), and equilibrated Kt/V. Other outcomes included: changes in hemodynamic scores, circuit clotting, adverse events, and changes in indices on point-of-care ultrasonography and echocardiography. Between November 2018 and March 2020, 18 patients with median age 8.6 y and vasopressor dependency index of 83.2, underwent 41 sessions of SLED. In 16 patients, SLED was feasible within 12h of indication. No session was terminated prematurely. Ultrafiltration achieved was 4.0 ± 2.2mL/kg/h, while URR was 57.7 ± 16.2% and eKt/V 1.17 ± 0.56. Hemodynamic scores did not change significantly. Asymptomatic hypokalemia was the chief adverse effect. Sessions were associated with a significant improvement in indices on ultrasound and left ventricular function. Fourteen patients died. SLED is feasible, safe, and effective in enabling KRT in hemodynamically unstable children with severe AKI.

Regional Citrate Anticoagulation and Systemic Anticoagulation during Pediatric Continuous Renal Replacement Therapy: A Systematic Literature Review.

Background: Clotting is a major drawback of continuous renal replacement therapy (CRRT) performed on critically ill pediatric patients. Although anticoagulation is recommended to prevent clotting, limited results are available on the effect of each pharmacological strategy in reducing filter clotting in pediatric CRRT. This study defines which anticoagulation strategy, between regional citrate anticoagulation (RCA) and systemic anticoagulation with heparin, is safer and more efficient in reducing clotting, patient mortality, and treatment complications during pediatric CRRT. Methods: A systematic literature review was run considering papers published in English until December 2021 and describing patients’ and treatments’ complications in CRRT performed with heparin and RCA on patients aged less than 18 years. Results: Eleven studies were considered, cumulatively comprising 1.706 CRRT sessions (62% with systemic anticoagulation and 38% with RCA). Studies have consistently identified RCA’s superiority over systemic anticoagulation with heparin in prolonging circuit life. The pooled estimate (95% CI) of filter clotting risk showed that RCA is a protective factor for clotting risk (RR = 0.204). Conclusions: RCA has a potential role in prolonging circuit life and seems superior to systemic anticoagulation with heparin in decreasing the risk of circuit clotting during CRRT performed in critically ill pediatric patients.

A Role of Circuit Clotting and Strategies to Prevent It during Blood Purification Therapy with oXiris Membrane: An Observational Multicenter Study

Introduction: Membrane fouling is a significant complication potentially reducing clinical effects of extracorporeal blood purification (EBP) in critically ill septic patients with acute kidney injury. Although fascinating, the effect of heparin coating in preventing membrane fouling is currently unknown. This multicenter prospective study aims to preliminary describe the incidence, associated factors, and clinical consequences of premature circuit clotting in a cohort of adult critically ill septic patients treated with EBP using a high biocompatible heparin-coated hemodiafilter characterized by advanced adsorption properties. Methods: This study was a retrospective analysis of prospectively entered data in the oXirisNet Registry; overall, 97 septic patients undergoing EBP with oXiris between May 2019 and March 2020 were enrolled in this study. Patients were divided into two groups according to the occurrence of filter clotting (premature vs. nonpremature). Logistic regression analysis was used to identify factors associated with premature circuit clotting. Results: Premature clotting occurred in 18 (18.6%) patients. Results of the multivariate logistic regression analysis demonstrated that hematocrit (p = 0.02, odds ratio [OR] 1.15 [1.05; 1.30]), serum procalcitonin (PCT) (p = 0.03, OR 1.1 [1.05; 1.2]), and anticoagulation strategy (p = 0.05 at Wald’s test) were independent predictors of circuit clotting. Systemic anticoagulation (p = 0.02, OR 0.03 [0.01; 0.52]) and regional citrate anticoagulation (p = 0.10, OR 0.23 [0.04; 1.50]) were both protective factors if compared to no-anticoagulation strategy. Patients with nonpremature circuit clotting showed more rapid recovery from hemodynamic instability, pulmonary hypo-oxygenation, and electrolyte disorders and greater improvement of inflammatory markers and SOFA scores. Conclusion: Although in this study the incidence of premature circuit clotting was relatively low (18.6%) compared to previously reported values (54%), membrane clotting in adult critically ill septic patients could cause clinically relevant interferences with treatment performances. Prevention of clotting should be based on avoiding higher patients’ hematocrit, high serum PCT, and no-anticoagulation strategy which resulted as independent predictors of circuit clotting.

Simultaneous Liver-Kidney Transplantation and the Use of Intraoperative Dialysis: A Monocenter Study

Simultaneous liver and kidney transplants (SLKT) represent 1.1% of all liver transplants in Poland. Patients undergoing SLKT experience a longer operation time and concurrent kidney dysfunction may aggravate metabolic derangement associated with the procedure. The benefits of intraoperative dialysis (ioHD) in these patients have not been determined. A retrospective observational study of all adult patients undergoing SLKT in our center from January 2009 till December 2016. Study group consisted of 10 patients with End-Stage Kidney Disease (0.9% of all liver transplants): 6 patients treated with ioHD during SLKT (group 1) and 4 patients managed conservatively (group 2). All recipients were on chronic dialysis. The mean calculated Model for End-Stage Liver Disease score was 21 ± 0.9 in group 1 and 30 ± 9.5 in group 2 (P=.009). The mean preoperative serum potassium was 4.7 ± 0,6 mmol/L in group 1 and 3.97 ± 1,02 in group 2. Intraoperative serum potassium levels were comparable between the groups, but the maximum lactate and minimum bicarbonate levels were significantly worse in group 2. Postreperfusion syndrome occurred in no patient. Dialysis circuit clotting occurred in 50% of ioHD. Six patients (2 in group 1) required renal replacement therapy after SLKT; no patient was on dialysis on discharge. Three patients died within 1 year after surgery (2 in group 2). No patient developed intraoperative hyperkalemia or postreperfusion syndrome. We observed a high frequency of circuit system clotting during ioHD. Clinical benefits of intraoperative hemodialysis during SLKT need to be determined in a larger study.

Coagulation abnormalities in patients with COVID-19 on venovenous ECLS increased risk for technical complications and support times but had no impact on survival.

BackgroundPatients with severe coronavirus disease‐19 (COVID‐19)‐associated acute respiratory distress on venovenous extracorporeal lung support (V‐V ECLS) showed a high incidence of vascular as well as ECLS‐related thrombotic complications. The latter may influence the outcome of the patients.MethodsThis is a retrospective monocentric study on prospectively collected data of technical complications including 69 adult COVID‐19 patients on V‐V ECLS (ECLS Registry, March 2020 until April 2021) without and with system exchanges. Alterations in ECLS‐specific data, hemolysis, coagulation, and hemostasis parameters were analyzed.ResultsEvery second COVID‐19 patient on V‐V ECLS developed technical complications. Optimized ECLS management at our ECLS center reduced cases of acute clot formation (pump head thrombosis, acute oxygenator thrombosis) (17%), and allowed early identification of progressive clotting processes (worsened gas transfer, coagulation disorder) (14%, 54%) with a significant overhang of hyperfibrinolysis (37%). Although COVID‐19 disease and technical complications caused the prolonged length of stay at the intensive care unit and ECLS support times, the proportion of successful weaning and survival rates were comparable with patients without system exchange.ConclusionThe survival of ECLS patients with COVID‐19 was independent of the requirement for system exchange due to technical‐induced coagulation disorders. Close monitoring for circuit clotting is mandatory in COVID‐19 patients and is one prerequisite for successful organ support in these difficult patients.

Retrospective analysis comparing complication rates of centrifuge vs membrane-based therapeutic plasma exchange in the pediatric population.

There are two conventional modalities used to perform therapeutic plasma exchange (TPE): centrifuge TPE (cTPE) or membrane TPE (mTPE). There is limited data on complications with mTPE. We sought to better understand the patient and machine complications of mTPE compared to cTPE. We hypothesize that our protocol for mTPE using heparin anticoagulation is well-tolerated. In this retrospective cohort study of children <21 years of age, we evaluated differences in patient and machine characteristics and complications between cTPE (with citrate anticoagulation) vs mTPE (with heparin anticoagulation). Of the 105 patients who met inclusion/exclusion criteria, 63 received cTPE and 42 mTPE via Prismaflex. Those who used mTPE were younger (4.8 ± 2.8 years vs 15.2 ± 3.7 years, P=.0001) and weighed less (19.5 ± 10.6 vs 71.7 ± 28.5 kg, P=.0001). There were no significant differences in patient-related complications or indications for TPE between the two modalities. Of the 1031 therapies performed,1003 therapies were analyzed (646 using cTPE and 357 using mTPE) due to exclusion criteria. No significant difference in patient complications were detected between groups. Machine-related complications were infrequent in both approaches. More circuits clotted during mTPE than during cTPE (6.7% [24/357] vs 0% [0/646]; P < 0.001). Although we use mTPE in smaller children, we showed low rates of complications that were not statistically different from cTPE performed in older children. While the overall rate of circuit clotting using mTPE was low, it occurred more commonly than with cTPE.

POS-619 HEPARIN-GRAFTED DIALYZER USE IS SAFE IN CASE OF HEPARIN-INDUCED THROMBOCYTOPENIA

Patients who present with immune-mediated heparin-induced thrombocytopenia (HIT) should not be administered heparin to prevent clotting of the extracorporeal circuit during hemodialysis. No data exist on the safety of the use of a heparin-grafted dialyzer in patients with HIT.

Comparison of the injection of low-molecular weight heparin in the arterial vs. venous blood line for preventing extracorporeal circuit clotting during hemodialysis.

Low-molecular weight heparins (LMWH) are widely used for preventing clotting during hemodialysis (HD). Although injection in the venous blood line is recommended to avoid initial loss of LMWH through the dialyzer, LMWH is still frequently administered in the arterial blood line at the start of dialysis. This study aimed to compare the safety and efficacy of the same enoxaparin dose administered through the venous blood line or arterial blood line. We also evaluated antifactor Xa (aXa) activity according to the injection route and dialysis modalities: high-flux (HF) HD, medium cut-off (MCO) HD, and online hemodiafiltration (OL-HDF). Forty-three patients were studied over 18 consecutive dialysis sessions using a fixed enoxaparin dose (20 or 40 mg), first administered through the arterial blood line bolus and then through the venous blood line for another 18 sessions. Compared to arterial blood line administration, venous blood line bolus resulted in a significant increase in median post-dialysis aXa activity: 0.16 (0.1-0.6) IU/ml versus 0.31 (0.1-1.3) IU/ml, respectively, p=0.006. After arterial blood line bolus of 40 mg enoxaparin, median post-dialysis aXa activity was significantly lower with OL-HDF compared to HF-HD: 0.14 (0.1-0.35) versus 0.32 (0.15-0.49), p=0.02. A trend for lower clotting within lines and bubble trap using venous blood line bolus was observed. In conclusion, venous blood line enoxaparin injection is safe in OL-HDF patients. However, in HF-HD and MCO-HD, venous blood line injection of 40 mg enoxaparin may increase overdosing risk. Thus, aXa activity should be monitored in HF-HD and MCO-HD patients at risk of bleeding and/or on vitamin K antagonists and careful surveillance is required when administering a 40 mg enoxaparin dose through the venous blood line route.

Non-anticoagulation pediatric continuous renal replacement therapy methods to increase circuit life.

Acute kidney injury (AKI) is a clinical condition characterized by an abrupt increase in serum creatinine levels due to functional changes in the kidneys from a newfound insult or injury. For supportive treatment, continuous renal replacement therapy (CRRT) is one of the most widely used modalities due to its precise control of fluid balance over extended periods of time. However, its complications include circuit clotting, the most frequent cause for CRRT interruption. Vascular access and circuit management were found to be major determinants of performance efficiency. Anticoagulation required to prevent clotting has the downside of increasing the risk of bleeding, especially in the setting of overdosage. Hence, a delicate balance needs to be maintained consistently. This study explores the adequacy of non-anticoagulation measures in the prevention of circuit clotting. A comprehensive literature search was conducted using PubMed/Medline and Embase databases to include all relevant studies. The most-effective CRRT catheter would be made of nonthrombogenic material, noncuffed and nontunneled with separate lumens for arterial and venous blood. Further, studies show that blood flow during the process is optimized at 200 ml/min, which can be lowered in the pediatric population due to more narrow catheters. Platelet count and hematocrit need to be closely monitored as levels above 450,000 × 106 /L and 0.40, respectively, increase risk of clotting. Predilution is a non-anticoagulation technique to reduce the risk of clotting by returning replacement solution to the blood before it reaches the filter. Also, biocompatible membranes such as polyacrylonitrile or polysulfone activate the coagulation cascade significantly less than the conventional cellulose-based membranes, thereby reducing clotting chances. With the advent of such techniques and maneuvers, anticoagulation can be efficiently maintained in patients undergoing CRRT without increasing the risk of bleeding.

UK national survey of anticoagulation in extra-corporeal photopheresis-Is it time for a UK consensus statement?

Extra-corporeal photopheresis (ECP) requires anticoagulation to prevent circuit clotting. Unfractionated heparin (UFH) is currently the only anticoagulant licensed for the ECP system in use in the United Kingdom (UK). Acid citrate dextrose-A (ACD-A) is the preferred anticoagulant for most other apheresis procedures. Anecdotal evidence suggested variability in ECP practice across the UK with some providers using off-label ACD-A. We developed a survey together with the UK Photopheresis Society to establish current practice. This was distributed to all 17 ECP providers covering 34 UK sites. Significant variability in practice was demonstrated with only 36% of responding providers (5/14) using UFH exclusively and 29% (4/14) using ACD-A as standard. This survey highlights the need for a UK consensus.

Kidney Replacement Therapy for Patients Requiring Cardiopulmonary Bypass Support during Cardiac Surgery.

Kidney Replacement Therapy for Patients Requiring Cardiopulmonary Bypass Support during Cardiac Surgery.

Anticoagulation in patients with acute kidney injury undergoing kidney replacement therapy.

Kidney replacement therapy (KRT) is used to provide supportive therapy for critically ill patients with severe acute kidney injury and various other non-renal indications. Modalities of KRT include continuous KRT (CKRT), intermittent hemodialysis (HD), and sustained low efficiency daily dialysis (SLED). However, circuit clotting is a major complication that has been investigated extensively. Extracorporeal circuit clotting can cause reduction in solute clearances and can cause blood loss, leading to an upsurge in treatment costs and a rise in workload intensity. In this educational review, we discuss the pathophysiology of the clotting cascade within an extracorporeal circuit and the use of various types of anticoagulant methods in various pediatric KRT modalities.

Non-pharmacological interventions for preventing clotting of extracorporeal circuits during continuous renal replacement therapy.

Non-pharmacological interventions for preventing clotting of extracorporeal circuits during continuous renal replacement therapy.

Comparison of the injection of low molecular weight heparin in arterial or venous bloodline for preventing extracorporeal circuit clotting during hemodialysis

Low molecular weight heparins (LMWH) are widely used for preventing clotting during hemodialysis (HD). Although injection in venous bloodline (VBL) is recommended to avoid initial loss of LMWH through the dialyzer, LMWH is still frequently administered in the arterial blood line (ABL) at the start of dialysis. The aim of this study was to compare the efficacy and safety of same enoxaparin dose administered through VBL or ABL. We also evaluated antifactor Xa (aXa) activity according to the injection route and dialysis modalities: high-flux (HF) HD, medium cut-off (MCO) HD and on-line hemodiafiltration (OL-HDF). This open, single-center prospective study was conducted at the Poitiers university Hospital HD unit. Forty-three patients were studied over 18 consecutive dialysis sessions using a fixed enoxaparin dose (20 or 40 mg) first administered through ABL bolus and then through VBL for another 18 sessions. Compared to ABL, VBL bolus resulted in significant increase in median post-dialysis aXa activity: 0.16 (0.1–0.6) IU/mL vs. 0.31 (0.1–1.3) IU/mL, respectively, P = 0.006. After ABL bolus of enoxaparin 40 mg, median post-dialysis aXa activity was significantly lower with OL-HDF compared to HF-HD: 0.14 (0.1–0.35) vs. 0.32 (0.15–0.49), P = 0.02. A trend for lower clotting within lines and bubble trap using VBL bolus was observed. In conclusion, VBL enoxaparin injection is safe in OL-HDF patients. However, in HF-HD and MCO-HD, VBL injection of enoxaparin 40 mg may increase overdosing risk. Thus, aXa activity should be monitored in HF-HD and MCO-HD patients at risk of bleeding and/or on vitamin K antagonists, and careful surveillance is required when administering enoxaparin dose 40 mg through the VBL route.