A Randomized Controlled Trial of Regional Citrate Versus Regional Heparin Anticoagulation for Continuous Renal Replacement Therapy in Critically Ill Adults

Development and external validation of a prediction model for the premature circuit clotting of continuous renal replacement therapy in critically ill patients

OBJECTIVE

This study aimed to develop and validate a prediction model for premature circuit clotting of continuous renal replacement therapy (CRRT) in critically ill patients.

DESIGN

A retrospective cohort study was conducted on ICU patients undergoing CRRT. The Medical Information Mart for Intensive Care-III Clinical Database CareVue subset and Medical Information Mart for Intensive Care-IV were utilized for model development, while the eICU Collaborative Research Database was employed for external validation. Predictive factors were selected through Least Absolute Shrinkage and Selection Operator Regression and univariate logistic regression. A prediction model was then developed using binary logistic regression. Internal and external validations assessed the model's discrimination, calibration, and clinical net benefit.

RESULTS

This study encompassed 2531 patients overall, with a premature circuit clotting rate of 31.88 %. The prediction model comprises five variables: body temperature, anticoagulation, mean arterial pressure, maximum transmembrane pressure change within two hours, and vasopressor. The model demonstrated robust predictive performance, achieving an area under the receiver operating characteristic curve of 0.897 (95 % CI: 0.879-0.915) in the training set and 0.877 (95 % CI: 0.852-0.902) in the external validation set. Internal validation yielded a Brier score of 0.087, while external validation showed a Brier score of 0.120. Calibration curves indicated good model calibration for both validations. The decision curve analysis indicates that the model yields a clinical net benefit across a wide range of decision thresholds.

CONCLUSION

The model demonstrates robust discrimination, calibration, and clinical net benefit, with readily available variables indicating substantial potential for valuable clinical applications.

IMPLICATIONS FOR CLINICAL PRACTICE

Healthcare providers in the ICU can leverage the model to evaluate the risk of premature circuit clotting in critically ill patients undergoing continuous renal replacement therapy, facilitating timely intervention to mitigate its incidence.

Impact of increasing post-filter ionised calcium target on regional citrate anticoagulation efficacy in ICU continuous renal replacement therapy: the non-inferiority randomised controlled Ca-CIBLE protocol

INTRODUCTION

Continuous renal replacement therapy (CRRT) is a critical therapeutic intervention for patients with severe acute kidney injury in intensive care. However, premature filter clotting remains a significant challenge during CRRT, impacting treatment efficacy, costs and patient outcomes. Anticoagulation is essential to maintain circuit patency, with regional citrate anticoagulation (RCA) emerging as a preferred strategy due to its favourable bleeding profile. The standard target for post-filter ionised calcium (iCa) concentration during RCA-CRRT is set between 0.25 and 0.35 mmol/L, although evidence supporting this range is limited. We hypothesise that a higher post-filter iCa target (0.35-0.45 mmol/L) can provide comparable circuit patency while potentially reducing adverse effects associated with citrate administration.

METHODS AND ANALYSIS

This multicentre randomised controlled non-inferiority trial will compare a low post-filter iCa target (0.25-0.35 mmol/L) with a higher post-filter iCa target (0.35-0.45 mmol/L) in patients undergoing RCA-CRRT in the intensive care unit. A total of 412 CRRT sessions will be randomised with a 1:1 ratio into these two groups. The primary outcome is the incidence of filter clotting. Secondary outcomes include filter lifespan, post-filter iCa levels, citrate infusion rates, the occurrence of metabolic adverse effects, financial costs and blood loss.

ETHICS AND DISSEMINATION

The study has obtained approval from the ethics committee (Ethics Committee Est III, Nancy, France) and patients will be included after providing informed consent. The results will be disseminated at academic conferences and in peer-reviewed publications. All procedures were developed in order to assure data protection and confidentiality.

TRIAL REGISTRATION NUMBER

NCT05814341.

Comparison of diluted vs concentrated regional citrate anticoagulation in continuous renal replacement therapy: A quasi-experimental study

BACKGROUND

The incidence of coagulation of continuous renal replacement therapy circuits remains high. To the best of our knowledge, no scholar has published a protocol to avoid management errors when different types of citrates coexist in the same Intensive Care Unit.

AIM

To assess the safety and efficacy of the unification of two protocols with different concentrations of citrate solution.

STUDY DESING

A prospective, quasi-experimental study was carried out in the intensive care unit of a tertiary referral hospital (in Barcelona, Spain), over 3 years. Consecutive adult patients requiring continuous renal replacement therapy with citrate were included. The sample was divided into two groups, a control group (concentrated citrate) and an intervention group (diluted citrate). The decision to initiate anticoagulation with diluted (18 mmol/L) or concentrated (136 mmol/L) citrate was made based on the machine available and the decision of the doctor responsible for the patient. It was not possible to randomize the sample. Both protocols were matched with a starting citrate dose of 3.5 mmol/L, and a dialysis solution was used. Post-filter replacement was not used, and the citrate solution was the only fluid administered pre-filter.

RESULTS

The analysis included 59 circuits in the concentrated citrate group and 40 circuits in the diluted citrate group. An increased need for electrolyte replacement was observed in the diluted group (p < .001). The concentrated citrate group had a longer filter life (p < .05), and there was a slight trend toward alkalosis.

CONCLUSION

The diluted citrate group had a higher incidence of electrolyte replacement. The concentrated citrate group had longer circuit lifespan and a trend toward metabolic alkalosis, although this was not statistically significant. If these conclusions are considered, the protocol can be unified.

RELEVANCE TO CLINICAL PRACTICE

The present work aims to provide information on the differences in the use of regional anticoagulation with diluted or concentrated citrate. The objective is to pay special attention to aspects that can lead to complications. The unified protocol proposed in this paper could be extrapolated to any machine on the market that uses either of these two types of citrate concentration.

Protocolized Regional Citrate Anticoagulation during Continuous Renal Replacement Therapy: A Single Center Experience

Background

Regional citrate anticoagulation (RCA) has emerged as a treatment modality that reduces bleeding risk and filter clotting. With initial experience of using RCA with continuous renal replacement therapy (CRRT), we have formulated a working protocol based on published literature.

Objective

The study aimed to evaluate the protocol for routine use of RCA during CRRT requiring anticoagulation and evaluation of filter life.

Methodology

It is a single-center, open-label, prospective, non-randomized, non-interventional, single-arm, observational study conducted at a tertiary care hospital between September 2022 and July 2023. All adult patients with acute kidney injury (AKI) or hyperammonemia requiring CRRT and necessitating the use of anticoagulation were enrolled in the study. The study used Prisma Flex M100 AN 69 dialyzer on Prisma Flex (Baxter) CRRT machines during continuous venovenous hemodiafiltration (CVVHDF). The targeted CRRT dose in all the study patients was 25-30 mL/kg/hour. Based on the published literature, we have developed a working protocol (Appendix 1) for managing patients on CRRT using RCA.

Results

A total of 159 patients were analyzed for the study. The median [interquartile range (IQR)] filter life using RCA was 30 (12-55) hours. Filter clotting was observed in 33.3% of patients. Citrate accumulation was present in 52.25% of patients, but no CRRT was discontinued as citrate accumulation resolved after following the corrective steps in the protocol. None of the patients had citrate toxicity. Chronic liver disease (CLD) (p ≤ 0.001) and those who were post-living donor liver transplant recipients (p = 0.004) had a statistically significant increase in citrate accumulation. Also, patients who had higher lactate at baseline (6 hours post-CRRT initiation), had a higher chance of citrate accumulation.

Conclusion

Our RCA protocol provides a safe approach to regional anticoagulation during CRRT in critically ill patients.

How to cite this article

Pachisia AV, Kumar GP, Harne R, Jagadeesh KN, Patel SJ, Pal D, et al. Protocolized Regional Citrate Anticoagulation during Continuous Renal Replacement Therapy: A Single Center Experience. Indian J Crit Care Med 2024;28(9):859-865.

How to safeguard the continuous renal replacement therapy circuit: a narrative review

The high prevalence of acute kidney injury (AKI) in ICU patients emphasizes the need to understand factors influencing continuous renal replacement therapy (CRRT) circuit lifespan for optimal outcomes. This review examines key pharmacological interventions-citrate (especially in regional citrate anticoagulation), unfractionated heparin (UFH), low molecular weight heparin (LMWH), and nafamostat mesylate (NM)-and their effects on filter longevity. Citrate shows efficacy with lower bleeding risks, while UFH remains cost-effective, particularly in COVID-19 cases. LMWH is effective but associated with higher bleeding risks. NM is promising for high-bleeding risk scenarios. The review advocates for non-tunneled, non-cuffed temporary catheters, especially bedside-inserted ones, and discusses the advantages of surface-modified dual-lumen catheters. Material composition, such as polysulfone membranes, impacts filter lifespan. The choice of treatment modality, such as Continuous Veno-Venous Hemodialysis (CVVHD) or Continuous Veno-Venous Hemofiltration with Dialysis (CVVHDF), along with the management of effluent volume, blood flow rates, and downtime, are critical in prolonging filter longevity in CRRT. Patient-specific conditions, particularly the type of underlying disease, and the implementation of early mobilization strategies during CRRT are identified as influential factors that can extend the lifespan of CRRT filters. In conclusion, this review offers insights into factors influencing CRRT circuit longevity, supporting evidence-based practices and suggesting further multicenter studies to guide ICU clinical decisions.

Further improvement of circuit survival in citrate based continuous renal replacement therapy

Background

Continuous renal replacement therapy (CRRT) is the most frequently used modality of renal replacement therapy (RRT) in critical care patients with acute kidney injury (AKI). Adequate CRRT delivery can be challenging, due to problems with circuit patency. To improve circuit patency, we developed a new CRRT protocol using continuous veno-venous hemodiafiltration (CVVHDF) with 3.0 mmol/l regional citrate anticoagulation (CVVHDF/RCA3.0) as our first choice RRT modality.

Methods

Retrospective comparison of efficacy and safety of a CVVHDF/RCA3.0 protocol with our former continuous veno-venous hemofiltration protocol with 2.2 regional citrate anticoagulation (CVVH/RCA2.2) in adult critically ill patients with AKI requiring CRRT between 25 April 2020 and 24 October 2021.

Results

In total, 56 patients (257 circuits) and 66 patients (290 circuits) were included in the CVVH/RCA2.2 and CVVHDF/RCA3.0 groups, respectively. Median circuit survival was significantly higher in patients treated with CVVHDF/RCA3.0 (39.6 (IQR 19.5-67.3) hours) compared to patients treated with CVVH/RCA2.2 (22.9 (IQR 11.3-48.6) hours) (P < .001). Higher body weight and higher convective flow were associated with a lower circuit survival. Metabolic control was similar, except for metabolic alkalosis that occurred less frequently during CVVHDF/RCA3.0 (19% of patients) compared to CVVH/RCA2.2 (46% of patients) (P = .006).

Conclusions

CRRT circuit survival was longer with CVVHDF/RCA3.0 compared to CVVH/RCA2.2. CRRT circuit survival was negatively associated with higher body weight and higher convective flow.

Early experience of using regional citrate anticoagulation for continuous renal replacement therapy in critically ill patients in a resource-limited setting

AIM

Despite the superiority of regional citrate anticoagulation (RCA) in continuous renal replacement therapy (CRRT), its application is limited in resource-limited settings. We aim to explore the cost and safety of RCA for CRRT in critically ill patients, compared to usual care.

METHODS

This prospective observational study included patients requiring CRRT in a tertiary intensive care unit (ICU) from February 2022 to January 2023. They were classified to either the RCA or usual care groups based on the anticoagulation technique chosen by the treating physician, considering contraindications. The CRRT prescription follows the institutional protocol. All relevant data were obtained from the ICU CRRT-RCA charts and electronic medical records. A cost analysis was performed.

RESULTS

A total of 54 patients (27 per group) were included, with no demographic differences. Sequential Organ Failure Assessment score and lactate levels were significantly higher in the usual care group. The number of filters used were comparable (p = .108). The median filter duration in the RCA group was numerically longer (35.00 [15.50-56.00] vs. 23.00 [17.00-29.00] h), but not statistically significant (p = .253). The duration of mechanical ventilation, vasopressor requirement, and mortality were similar, but the RCA group had a significantly longer ICU stay. The rate of adverse events was similar, with four severe metabolic alkalosis cases in the RCA group. The RCA group had higher total cost per patient per day (USD 611 vs. 408; p = .013).

CONCLUSION

In this resource-limited setting, RCA for CRRT appeared safe and had clinically longer filter lifespan compared with usual care, albeit the increased cost.

Citrate and low-dose heparin combined anticoagulation in pediatric continuous renal replacement therapy

There remains no optimal anticoagulation protocol for continuous renal replacement therapy (CRRT) with regional citrate anticoagulation (RCA) in pediatric patients with elevated D-dimer levels. We aimed to assess the effects of different anticoagulation strategies on the risk of CRRT filter clotting in these patients. Pediatric patients undergoing CRRT were retrospectively grouped based on pre-CRRT D-dimer levels and anticoagulant: D-RCA group (normal D-dimer, RCA only, n = 22), D+ RCA group (elevated D-dimer, RCA only, n = 50), and D+ RCA+ systemic heparin anticoagulation (SHA) group (elevated D-dimer, RCA combined with SHA, n = 55). The risk of filter clotting and incidence of bleeding were compared among the groups. Among the groups, the D+ RCA+ SHA group had the longest filter lifespan; further, the incidence of bleeding was not increased by concurrent use of low-dose heparin for anticoagulation. Moreover, concurrent heparin anticoagulation was associated with a decreased risk of filter clotting. Contrastingly, high pre-CRRT hemoglobin and D-dimer levels and post-filter ionized calcium level > 0.4 mmol/L were associated with an increased risk of filter clotting. RCA combined with low-dose heparin anticoagulation could reduce the risk of filter clotting and prolong filter lifespan without increasing the risk of bleeding in patients with elevated D-dimer levels undergoing CRRT.

Filter Lifespan, Treatment Effect, and Influencing Factors of Continuous Renal Replacement Therapy for Severe Burn Patients

Continuous renal replacement therapy (CRRT) is often disrupted due to various factors, such as patient-related issues, vascular access complications, treatment plans, and medical staff factors. This unexpected interruption is referred to as non-selective filter stoppage and can result in additional treatment expenses. This study conducted a retrospectively analyzed 501 CRRT filters used in 62 patients with severe burns, lifespan and therapeutic effect of all filters were mainly analyzed, used logistic regression analysis was performed to identify risk factors associated with non-selective cessation filters. Out of 493 filters, 279 cases received heparin (56.60%), the median lifespan of the filter was 14.08 h (25th, 75th quantile: 7.30, 21.50); 128 cases were treated with nafamostat mesylate (26.00%), and the median lifespan of the filter was 16.42 h (10.49, 22.76); 86 cases were treated with sodium citrate (17.40%), and the median lifespan of the filter was 31.06 h (19.25, 48.75). In addition, significant differences were observed in the electrolyte index, renal function index, and procalcitonin levels before and after treatment with a single filter (P < .001). Multivariate logistic regression showed that the risk of non-selective cessation of sodium citrate anticoagulants was lower than that of heparin anticoagulation. Overall, CRRT is progressively becoming more prevalent in the treatment of patients with severe burns. The lifespan of individual filters and total patient treatment duration showed a consistent upward trend. The filter's lifespan was notably greater during sodium citrate anticoagulation when compared to nafamostat mesylate and heparin, meanwhile notably reducing the risk of non-selective cessation. Therefore, we recommend sodium citrate for anticoagulation in patients without any contraindications.

Anticoagulation in renal replacement therapies: Why heparin should be abandoned in critical ill patients?

Extracorporeal circuits used in renal replacement therapy (RRT) can develop thrombosis, leading to downtimes and reduced therapy efficiency. To prevent this, anticoagulation is used, but the optimal anticoagulant has not yet been identified. Heparin is the most widely used anticoagulant in RRT, but it has limitations, such as unpredictable pharmacokinetics, nonspecific binding to plasma proteins and cells, and the possibility of suboptimal anticoagulation or bleeding complications, specifically in critically ill patients with acute renal failure who are already at high risk of bleeding. Citrate anticoagulation is a better alternative, being considered a standard for continuous renal replacement therapy, since it is associated with a lower risk of bleeding complications and better efficacy, even in patients with acute renal failure or liver disease. The aim of this article is to provide an updated review of the different strategies of anticoagulation in renal replacement therapies that can be implemented in critical scenarios, focusing on the advantages and disadvantages of each one and the beneficial aspects of using citrate over heparin in critical ill patients.

Programs and processes for advancing pediatric acute kidney support therapy in hospitalized and critically ill children: a report from the 26th Acute Disease Quality Initiative (ADQI) consensus conference

Pediatric acute kidney support therapy (paKST) programs aim to reliably provide safe, effective, and timely extracorporeal supportive care for acutely and critically ill pediatric patients with acute kidney injury (AKI), fluid and electrolyte derangements, and/or toxin accumulation with a goal of improving both hospital-based and lifelong outcomes. Little is known about optimal ways to configure paKST teams and programs, pediatric-specific aspects of delivering high-quality paKST, strategies for transitioning from acute continuous modes of paKST to facilitate rehabilitation, or providing effective short- and long-term follow-up. As part of the 26th Acute Disease Quality Initiative Conference, the first to focus on a pediatric population, we summarize here the current state of knowledge in paKST programs and technology, identify key knowledge gaps in the field, and propose a framework for current best practices and future research in paKST.

Global Scientific Trends in Continuous Renal Replacement Therapy from 2000 to 2023: A Bibliometric and Visual Analysis

INTRODUCTION

Continuous renal replacement therapy (CRRT) is one of the most widely used blood purification and organ support methods in the ICU. However, the development process, the current status, hotspots, and future trends of CRRT remain unclear.

METHOD

The WoSCC database was used to analyze CRRT research evolution and theme trends. VOSviewer was used to construct coauthorship, co-occurrence, co-citation, and network visualizations. CiteSpace is used to detect bursts for co-occurrence items. Several important subtopics were reviewed and discussed in more detail.

RESULTS

Global publications increased from 56 in 2000 to 398 in 2023, a 710.71% increase. Blood Purification published the most manuscripts, followed by the International Journal of Artificial Organs. The USA, the San Bortolo Hospital, and Bellomo were the most productive and impactful institution, country, and author, respectively. Based on co-occurrence cluster analysis, five clusters emerged: (1) clinical applications and management of CRRT; (2) sepsis and CRRT; (3) CRRT anticoagulant management; (4) CRRT and antibiotic pharmacokinetics and pharmacodynamics; and (5) comparison of CRRT and intermittent hemodialysis. COVID-19, initiation, ECOMO, cefepime, guidelines, cardiogenic shock, biomarker, and outcome were the latest high-frequency keywords or strongest bursts, indicating the emerging frontiers of CRRT.

CONCLUSIONS

There has been widespread publication and citation of CRRT research in the past 2 decades. We provide an overview of current trends, global collaboration patterns, basic knowledge, research hotspots, and emerging frontiers.

Dynamic dosing for continuous renal replacement therapy: Service evaluation of the safety and effectiveness of titrating dose to biochemistry

Introduction

Continuous renal replacement therapy (CRRT) dose is usually fixed and primarily weight-based. Whilst this is safe, theoretically, underdosing or overdosing may occur in those requiring acute versus maintenance CRRT respectively. We have developed a dynamic dosing protocol for CRRT which individualises and updates dosing according to biochemistry. Here we describe the protocol and compare it to a fixed dose protocol to evaluate its safety and effectiveness.

Methods

We conducted a service evaluation of this novel protocol using data from consecutive non-COVID-19 admissions receiving CRRT within Barts Health NHS trust, United Kingdom (UK). Fifty admissions using the dynamic protocol were compared to historically collected data from 108 admissions who used the fixed protocol. Acute and maintenance CRRT subgroups were analysed.

Results

For the dynamic protocol 49 patients were treated with 135 CRRT circuits. One patient had two admissions. Protocol compliance (compared in one ICU) was 76% (dynamic) vs 61% (fixed) (p < 0.05). For the dynamic versus fixed protocol, median CRRT lifespan censored for reasons other than clotting was: 56 h vs 58 h RCA (ns), 27 h versus 20 h heparin (ns) and 79 h versus 22 h no anticoagulation (p < 0.05). The dynamic vs fixed protocol average CRRT dose was: 30 ml/kg/h (14-57) vs 26 ml/kg/h (20-62) (p < 0.05). The dynamic protocol generated a similar rate of increase of bicarbonate in an acute phase (RCA: 0.2 mmol/l/h vs 0.21 mmol/l/h, ns) and maintained a more stable level in a maintenance phase (RCA: -0.01 mmol/l/h vs 0.07 mmol/l/h, p < 0.05).

Discussion

Dynamic dosing for CRRT in this institution was safe and may lead to more tailored maintenance of biochemical homoeostasis.

An evaluation of different dilution modes on circuit lifespan during continuous veno-venous hemodiafiltration without anticoagulation

BACKGROUND

Circuit clotting remains a major problem during continuous kidney replacement therapy (CKRT), particularly in patients with contraindications to anticoagulant use. We hypothesized that the different options of alternative replacement fluid infusion sites might affect circuit lifespan. However, research-based evidence supporting an optimal replacement fluid infusion strategy is limited. Therefore, we aimed to evaluate the effect of three dilution modes (pre-dilution, post-dilution, and pre- to post-dilution) on circuit lifespan during continuous veno-venous hemodiafiltration (CVVHDF).

METHODS

This prospective cohort study was conducted between December 2019 and December 2020. Patients requiring CKRT were enrolled to receive pre-dilution, post-dilution, or pre- to post-dilution fluid infusion with CVVHDF. The primary endpoint was circuit lifespan, and the secondary outcomes included the clinical parameters of patients, such as changes in serum creatinine (Scr) and blood urea nitrogen (BUN) levels, 28-day all-cause mortality, and length of stay. For all patients included in this study, only the first circuit used was recorded.

RESULTS

Among the 132 patients enrolled in this study, 40 were in the pre-dilution mode, 42 were in the post-dilution mode, and 50 were in the pre- to post-dilution mode. The mean circuit lifespan was significantly longer in the pre- to post-dilution group (45.72 h, 95% CI, 39.75-51.69 h) than in the pre-dilution group (31.58 h, 95% CI, 26.33-36.82 h) and the post-dilution group (35.20 h, 95% CI, 29.62-40.78 h). There was no significant difference between the pre- and post-dilution group circuit lifespan (p > 0.05). Kaplan-Meier survival analysis revealed a significant difference between the three dilution modes (p = 0.001). No significant differences were observed in terms of changes in the Scr and BUN levels, admission day, and 28-day all-cause mortality among the three dilution groups (p > 0.05).

CONCLUSION

The pre- to post-dilution mode significantly prolonged circuit lifespan but did not reduce Scr and BUN levels, compared with the pre-dilution and post-dilution modes during CVVHDF when no anticoagulants were used.

Impact of increasing post-filter ionized calcium target on filter lifespan in renal replacement therapy with regional citrate anticoagulation: A before-and-after study

INTRODUCTION

Regional citrate anticoagulation (RCA) is the recommended method for anticoagulation in continuous renal replacement therapy (CRRT). However, the optimal post-filter ionized calcium (iCa) target level remains unclear. This study aims to assess the effect of increasing the post-filter iCa target level from 0.25-0.35 mmol/L to 0.30-0.40 mmol/L on filter lifespan until clotting during RCA-CRRT.

METHODS

This before-and-after single-center study included patients who underwent RCA-CRRT sessions without systemic anticoagulation during two periods. The first period included patients with a post-filter iCa target between 0.25 and 0.35 mmol/L, while the second period included those with a target between 0.30 and 0.40 mmol/L. The primary outcome was filter lifespan until clotting.

RESULTS

A total of 1037 CRRT sessions were analyzed, with 610 sessions in the first period and 427 sessions in the second period. After adjusting for confounding factors, there was no significant difference in filter lifespan until clotting between the two groups (hazard ratio, 1.020 [0.703; 1.481]; p = 0.92).

CONCLUSION

Increasing the post-filter iCa target level from 0.25-0.35 mmol/L to 0.30-0.40 mmol/L during RCA-CRRT does not reduce filter lifespan until clotting and may decrease unnecessary citrate exposure. However, the optimal post-filter iCa target should be individualized according to the patient's clinical and biological status.

Hypercitratemia is a mortality predictor among patients on continuous venovenous hemodiafiltration and regional citrate anticoagulation

The use of regional citrate anticoagulation (RCA) in liver failure (LF) patients can lead to citrate accumulation. We aimed to evaluate serum levels of citrate and correlate them with liver function markers and with the Cat/Cai in patients under intensive care and undergoing continuous venovenous hemodiafiltration with regional citrate anticoagulation (CVVHDF-RCA). A prospective cohort study in an intensive care unit was conducted. We compared survival, clinical, laboratorial and dialysis data between patients with and without LF. Citrate was measured daily. We evaluated 200 patients, 62 (31%) with LF. Citrate was significantly higher in the LF group. Dialysis dose, filter lifespan, systemic ionized calcium and Cat/Cai were similar between groups. There were weak to moderate positive correlations between Citrate and indicators of liver function and Cat/Cai. The LF group had higher mortality (70.5% vs. 51.8%, p = 0.014). Citrate was an independent risk factor for death, OR 11.3 (95% CI 2.74-46.8). In conclusion, hypercitratemia was an independent risk factor for death in individuals undergoing CVVHDF-ARC. The increase in citrate was limited in the LF group, without clinical significance. The correlation between citrate and liver function indicators was weak to moderate.

Calcium-Citrate Anticoagulation during Continuous Renal Replacement Therapy in Patients with Metformin Intoxication: A Case Series, Mathematical Estimation of Citrate Accumulation, and Literature Review

INTRODUCTION

Metformin intoxication causes lactic acidosis by inhibiting Krebs' cycle and oxidative phosphorylation. Continuous renal replacement therapy (CRRT) is recommended for metformin removal in critically ill patients. According to current guidelines, regional citrate anticoagulation (RCA) is the first-line strategy. However, since metformin also inhibits citrate metabolism, a risk of citrate accumulation could be hypothesized. In the present study, we monitored the potential citrate accumulation in metformin-associated lactic acidosis (MALA) patients treated with CRRT and RCA using the physical-chemical approach to acid-base interpretation.

METHODS

We collected a case series of 3 patients with MALA. Patients were treated with continuous venovenous hemofiltration (CVVH), and RCA was performed with diluted citrate solution. Citrate accumulation was monitored through two methods: the ratio between total and ionized plasma calcium concentrations (T/I calcium ratio) above 2.5 and the strong ion gap (SIG) to identify an increased concentration of unmeasured anions. Lastly, a mathematical model was developed to estimate the expected citrate accumulation during CVVH and RCA.

RESULTS

All 3 patients showed a resolution of MALA after the treatment with CVVH. The T/I calcium ratio was consistently below 2.5, and SIG decreased, reaching values lower than 6 mEq/L after 48 h of CVVH treatment. According to the mathematical model, the estimated SIG without citrate metabolism should have been around 21 mEq/L due to citrate accumulation.

CONCLUSIONS

In our clinical management, no signs of citrate accumulation were recorded in MALA patients during treatment with CVVH and RCA. Our data support the safe use of diluted citrate to perform RCA during metformin intoxication.

Meta-analysis of haematocrit and activated partial thromboplastin time as risk factors for unplanned interruptions in patients undergoing continuous renal replacement therapy

OBJECTIVE

Although continuous renal replacement therapy (CRRT) is common, unplanned interruptions often limit its usefulness. Unplanned interruption refers to the forced interruption of blood purification treatment, the failure to complete blood purification treatment goals or the failure to meet blood purification schedule times. This study aimed to evaluate the effect of haematocrit and activated partial thromboplastin time (APTT) on the incidence of unplanned interruptions in critical patients with CRRT.

METHODS

A systematic review and a meta-analysis were performed by searching the databases of China National Knowledge Infrastructure, Wanfang, VIP, China Biomedical Literature, Cochrane Library, PubMed, Web of Science and Embase from their inception to 31st March 2022 for all studies with a comparator or independent variable relating to the unplanned interruption of CRRT.

RESULTS

Nine studies involving 1165 participants were included. Haematocrit and APTT were independent risk factors for the unplanned interruption of CRRT. The higher the haematocrit level, the greater the risk of unplanned CRRT interruptions (relative risk ratio [RR] = 1.04, 95% confidence interval [CI]: 1.02, 1.07, Z = 4.27, p < 0.001). The prolongation of APPT reduced the risk of unplanned CRRT interruptions (RR = 0.94, 95% CI: 0.92, 0.96, Z = 6.10, p < 0.001).

CONCLUSION

Haematocrit and APTT are the influencing factors on the incidence of unplanned interruptions in critical patients undergoing CRRT.

Association of anticoagulation use during continuous kidney replacement therapy and 90-day outcomes: A multicentre study

Introduction

Anticoagulation is recommended during continuous kidney replacement therapy (CKRT) to prolong the filter lifespan for optimal filter performance. We aimed to evaluate the effect of anticoagulation during CKRT on dialysis dependence and mortality within 90 days of intensive care unit (ICU) admission.

Method

Our retrospective observational study evaluated the first CKRT session in critically ill adults with acute kidney injury (AKI) in Singapore from April to September 2017. The primary outcome was a composite of dialysis dependence or death within 90 days of ICU admission; the main exposure variable was anticoagulation use (regional citrate anticoagulation [RCA] or systemic heparin). Multivariable logistic regression was performed to adjust for possible confounders: age, female sex, Acute Physiology and Chronic Health Evaluation (APACHE II) score, liver dysfunction, coagulopathy (international normalised ratio[INR] >1.5) and platelet counts of less than 100,000/uL).

Results

The study cohort included 276 patients from 14 participating adult ICUs, of whom 176 (63.8%) experienced dialysis dependence or death within 90 days of ICU admission (19 dialysis dependence, 157 death). Anticoagulation significantly reduced the odds of the primary outcome (adjusted odds ratio [AOR] 0.47, 95% confidence interval [CI] 0.27-0.83, P=0.009). Logistic regression analysis using anticoagulation as a 3-level indicator variable demonstrated that RCA was associated with mortality reduction (AOR 0.46, 95% CI 0.25-0.83, P=0.011), with heparin having a consistent trend (AOR 0.51, 95% CI 0.23-1.14, P=0.102).

Conclusion

Among critically ill patients with AKI, anticoagulation use during CKRT was associated with reduced dialysis or death at 90 days post-ICU admission, which was statistically significant for regional citrate anticoagulation and trended in the same direction of benefit for systemic heparin anticoagulation. Anticoagulation during CKRT should be considered whenever possible.

Safety of Citrate Anticoagulation in CKRT: Monocentric Experience of a Dynamic Protocol of Calcium Monitoring

Regional Citrate Anticoagulation (RCA) is considered the first-line anticoagulation for Continuous Kidney Replacement Therapy (CKRT). The RCA requires strict protocols and trained staff to avoid unsafe use and ensure its benefit. We have analyzed all our CKRT prescriptions from December 2020 to April 2022 anonymously, collecting data on CKRT, lab tests, clinical conditions, and complications of RCA. In addition, in order to better detect citrate accumulation, we have performed an RCA protocol by reducing the CaTot/Ca2+ ratio cut-off from 2.50 to 2.40 and increasing the number of calcium checks according to its trend. Among the 374 patients in CKRT, 104 received RCA prescriptions, of which 11 (10.6%) were discontinued: 4 for the suspicion of citrate accumulation, 1 for the development of metabolic alkalosis, 1 for the shift to a different CKRT procedure due to the need for a higher bicarbonate dose, 4 for the elevation of hepatocytolysis indexes, and 1 due to a preemptive discontinuation following massive post-surgery bleeding. None of the patients have had citrate toxicity as indicated by a CaTot/Ca2+ greater than 2.50, and our protocol has allowed the early identification of patients who might develop clinical citrate toxicity.

Anticoagulation options for continuous renal replacement therapy in critically ill patients: a systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Continuous renal replacement therapy (CRRT) is a widely used standard therapy for critically ill patients with acute kidney injury (AKI). Despite its effectiveness, treatment is often interrupted due to clot formation in the extracorporeal circuits. Anticoagulation is a crucial strategy for preventing extracorporeal circuit clotting during CRRT. While various anticoagulation options are available, there were still no studies synthetically comparing the efficacy and safety of these anticoagulation options.

METHODS

Electronic databases (PubMed, Embase, Web of Science, and the Cochrane database) were searched from inception to October 31, 2022. All randomized controlled trials (RCTs) that examined the following outcomes were included: filter lifespan, all-cause mortality, length of stay, duration of CRRT, recovery of kidney function, adverse events and costs.

RESULTS

Thirty-seven RCTs from 38 articles, comprising 2648 participants with 14 comparisons, were included in this network meta-analysis (NMA). Unfractionated heparin (UFH) and regional citrate anticoagulation (RCA) are the most frequently used anticoagulants. Compared to UFH, RCA was found to be more effective in prolonging filter lifespan (MD 12.0, 95% CI 3.8 to 20.2) and reducing the risk of bleeding. Regional-UFH plus Prostaglandin I2 (Regional-UFH + PGI2) appeared to outperform RCA (MD 37.0, 95% CI 12.0 to 62.0), LMWH (MD 41.3, 95% CI 15.6 to 67.0), and other evaluated anticoagulation options in prolonging filter lifespan. However, only a single included RCT with 46 participants had evaluated Regional-UFH + PGI2. No statistically significant difference was observed in terms of length of ICU stay, all-cause mortality, duration of CRRT, recovery of kidney function, and adverse events among most evaluated anticoagulation options.

CONCLUSIONS

Compared to UFH, RCA is the preferred anticoagulant for critically ill patients requiring CRRT. The SUCRA analysis and forest plot of Regional-UFH + PGI2 are limited, as only a single study was included. Additional high-quality studies are necessary before any recommendation of Regional-UFH + PGI2. Further larger high-quality RCTs are desirable to strengthen the evidence on the best choice of anticoagulation options to reduce all-cause mortality and adverse events and promote the recovery of kidney function. Trial registration The protocol of this network meta-analysis was registered on PROSPERO ( CRD42022360263 ). Registered 26 September 2022.

Heterogeneity of surrogate outcome measures used in critical care studies: A systematic review

BACKGROUND

The choice of outcome measure is a critical decision in the design of any clinical trial, but many Phase III clinical trials in critical care fail to detect a difference between the interventions being compared. This may be because the surrogate outcomes used to show beneficial effects in early phase trials (which informed the design of the subsequent Phase III trials) are not valid guides to the differences between the interventions for the main outcomes of the Phase III trials. We undertook a systematic review (1) to generate a list of outcome measures used in critical care trials, (2) to determine the variability in the outcome reporting in the respiratory subgroup and (3) to create a smaller list of potential early phase endpoints in the respiratory subgroup.

METHODS

Data related to outcomes were extracted from studies published in the six top-ranked critical care journals between 2010 and 2020. Outcomes were classified into subcategories and categories. A subset of early phase endpoints relevant to the respiratory subgroup was selected for further investigation. The variability of the outcomes and the variability in reporting was investigated.

RESULTS

A total of 6905 references were retrieved and a total of 294 separate outcomes were identified from 58 studies. The outcomes were then classified into 11 categories and 66 subcategories. A subset of 22 outcomes relevant for the respiratory group were identified as potential early phase outcomes. The summary statistics, time points and definitions show the outcomes are analysed and reported in different ways.

CONCLUSION

The outcome measures were defined, analysed and reported in a variety of ways. This creates difficulties for synthesising data in systematic reviews and planning definitive trials. This review once again highlights an urgent need for standardisation and validation of surrogate outcomes reported in critical care trials. Future work should aim to validate and develop a core outcome set for surrogate outcomes in critical care trials.

Management of regional citrate anticoagulation for continuous renal replacement therapy: guideline recommendations from Chinese emergency medical doctor consensus

Continuous renal replacement therapy (CRRT) is widely used for treating critically-ill patients in the emergency department in China. Anticoagulant therapy is needed to prevent clotting in the extracorporeal circulation during CRRT. Regional citrate anticoagulation (RCA) has been shown to potentially be safer and more effective and is now recommended as the preferred anticoagulant method for CRRT. However, there is still a lack of unified standards for RCA management in the world, and there are many problems in using this method in clinical practice. The Emergency Medical Doctor Branch of the Chinese Medical Doctor Association (CMDA) organized a panel of domestic emergency medicine experts and international experts of CRRT to discuss RCA-related issues, including the advantages and disadvantages of RCA in CRRT anticoagulation, the principle of RCA, parameter settings for RCA, monitoring of RCA (mainly metabolic acid-base disorders), and special issues during RCA. Based on the latest available research evidence as well as the paneled experts' clinical experience, considering the generalizability, suitability, and potential resource utilization, while also balancing clinical advantages and disadvantages, a total of 16 guideline recommendations were formed from the experts' consensus.

Regional Citrate Anticoagulation in Continuous Renal Replacement Therapy: Is Metabolic Fear the Enemy of Logic? A Systematic Review and Meta-Analysis of Randomised Controlled Trials

BACKGROUND

Anticoagulation is recommended to maintain the patency of the circuit in continuous renal replacement therapy (CRRT). However, anticoagulation-associated complications can occur. We performed a systematic review and meta-analysis to compare the efficacy and safety of citrate anticoagulation to heparin anticoagulation in critically ill patients treated with CRRT.

METHODS

Randomised controlled trials (RCTs) evaluating the safety and efficacy of citrate anticoagulation and heparin in CRRT were included. Articles not describing the incidence of metabolic and/or electrolyte disturbances induced by the anticoagulation strategy were excluded. The PubMed, Embase, and MEDLINE electronic databases were searched. The last search was performed on 18 February 2022.

RESULTS

Twelve articles comprising 1592 patients met the inclusion criteria. There was no significant difference between the groups in the development of metabolic alkalosis (RR = 1.46; (95% CI (0.52-4.11); p = 0.470)) or metabolic acidosis (RR = 1.71, (95% CI (0.99-2.93); p = 0.054)). Patients in the citrate group developed hypocalcaemia more frequently (RR = 3.81; 95% CI (1.67-8.66); p = 0.001). Bleeding complications in patients randomised to the citrate group were significantly lower than those in the heparin group (RR 0.32 (95% CI (0.22-0.47); p < 0.0001)). Citrate showed a significantly longer filter lifespan of 14.52 h (95% CI (7.22-21.83); p < 0.0001), compared to heparin. There was no significant difference between the groups for 28-day mortality (RR = 1.08 (95% CI (0.89-1.31); p = 0.424) or 90-day mortality (RR 0.9 (95% CI (0.8-1.02); p = 0.110).

CONCLUSION

regional citrate anticoagulation is a safe anticoagulant for critically ill patients who require CRRT, as no significant differences were found in metabolic complications between the groups. Additionally, citrate has a lower risk of bleeding and circuit loss than heparin.

The effects of differing anticoagulant regimes on blood quality after cell salvage in coronary artery bypass grafting (CABG): a pilot study

BACKGROUND

Cell salvage reduces allogenic blood transfusion requirements in surgery. We present a pilot study exploring the impact of anticoagulant choice, citrate or heparin, on the quality of cell salvaged blood in adults undergoing coronary artery bypass grafting (CABG).

MATERIALS AND METHODS

Elective on pump CABG patients were randomly allocated to citrate or heparin anticoagulation. We measured red blood cell characteristics and inflammation in both the blood collection reservoir and the washed red blood cell concentrate. Postoperatively, the level of biomarkers and the coagulation profile in the peripheral blood as well as the transfusion requirements of allogenic blood products were studied.

RESULTS

Thirty eight patients were included, 19 in the citrate group and 19 in the heparin group. Baseline characteristics were similar. In the washed red blood cell concentrate, Mean Hb (g/dl) and Ht (%) were lower in the citrate group [Hb: 18.1 g/dL (SD 1.3) vs. 21.1 (1.6), p < 0.001; Ht: 59.9% (54.7-60.9) vs. 63.7% (62.3-64.8); p < 0.001]; Mean corpuscular volume (MCV, μm 3) was higher [99.1fL (9.4) vs. 88 (4.2), p < 0.001] and mean corpuscular hemoglobin concentration (MCHC, g/dl) lower in the citrate group [31.9 g/dl (29.6-32.4) vs. 33.6 (33.1-34.0) p < 0.001]. Thrombocyte count (1000/μl) was higher in the citrate group [31.0 (26.0-77.0) vs. 13.0 (10.0-39.0); p = 0.006]. There were no differences in the requirement for allogenic blood products' transfusion (intraoperatively and postoperatively) or in the coagulation parameters after washed red blood cell concentrate infusion. Higher IL-10 was found in the citrate group in the blood collection reservoir, higher neutrophil-derived myeloperoxidase (MPO) in the heparin group after washed red blood cell concentrate infusion.

CONCLUSION

Though red blood cells in washed red blood cell concentrate were more swollen and diluted in the citrate group with more residual thrombocytes, published quality guidelines were met in both groups. Our pilot study suggests that differences in inflammatory markers in the blood collection reservoir and after infusion of washed red blood cell concentrate indicate a possible pro-inflammatory effect of heparin compared to citrate. A larger study is warranted to confirm these results and their possible clinical consequences. Trial registration ClinicalTrials.gov : NCT02674906. Registered 5 February 2016.

Regional citrate anticoagulation versus systemic heparin anticoagulation for continuous kidney replacement therapy in intensive care

PURPOSE

Many intensive care units (ICUs) have transitioned from systemic heparin anticoagulation (SHA) to regional citrate anticoagulation (RCA) for continuous kidney replacement therapy (CKRT). We evaluated the clinical and health economic impacts of ICU transition to RCA.

MATERIALS AND METHODS

We surveyed all adult general ICUs in England and Wales to identify transition dates and conducted a micro-costing study in eight ICUs. We then conducted an interrupted time-series analysis of linked, routinely collected health records.

RESULTS

In 69,001 patients who received CKRT (8585 RCA, 60,416 SHA) in 181 ICUs between 2009 and 2017, transition to RCA was not associated with a change in 90-day mortality (adjusted odds ratio 0.98, 95% CI 0.89-1.08) but was associated with step-increases in duration of kidney support (0.53 days, 95% CI 0.28-0.79), advanced cardiovascular support (0.23 days, 95% CI 0.09-0.38) and ICU length of stay (0.86 days, 95% CI 0.24-1.49). The estimated one-year incremental net monetary benefit per patient was £ - 2376 (95% CI £ - 3841-£ - 911), with an estimated likelihood of cost-effectiveness of <0.1%.

CONCLUSIONS

Transition to RCA was associated with significant increases in healthcare resource use, without corresponding clinical benefit, and is highly unlikely to be cost-effective over a one-year time horizon.

Unapparent systemic effects of regional anticoagulation with citrate in continuous renal replacement therapy: a narrative review

The use of citrate, through reversible binding of calcium, has become the preferred choice for anticoagulation in continuous renal replacement therapy in the critically ill patient. Though generally considered as very efficacious in acute kidney injury, this type of anticoagulation can cause acid-base disorders as well as citrate accumulation and overload, phenomena which have been well described. The purpose of this narrative review is to provide an overview of some other, non-anticoagulation effects of citrate chelation during its use as anticoagulant. We highlight the effects seen on the calcium balance and hormonal status, phosphate and magnesium balance, as well as oxidative stress resulting from these unapparent effects. As most of these data on these non-anticoagulation effects have been obtained in small observational studies, new and larger studies documenting both short- and long-term effects should be undertaken. Subsequent future guidelines for citrate-based continuous renal replacement therapy should take not only the metabolic but also these unapparent effects into account.

Cytokine hemoadsorption with CytoSorb® in post-cardiac arrest syndrome, a pilot randomized controlled trial

BACKGROUND

Hemoadsorption (HA) might mitigate the systemic inflammatory response associated with post-cardiac arrest syndrome (PCAS) and improve outcomes. Here, we investigated the feasibility, safety and efficacy of HA with CytoSorb® in cardiac arrest (CA) survivors at risk of PCAS.

METHODS

In this pilot randomized controlled trial, we included patients admitted to our intensive care unit following CA and likely to develop PCAS: required norepinephrine (> 0.2 µg/kg/min), and/or had serum lactate > 6 mmol/l and/or a time-to-return of spontaneous circulation (ROSC) > 25 min. Those requiring ECMO or renal replacement therapy were excluded. Eligible patients were randomly allocated to either receive standard of care (SOC) or SOC plus HA. Hemoadsorption was performed as stand-alone therapy for 24 h, using CytoSorb® and regional heparin-protamine anticoagulation. We collected feasibility, safety and clinical data as well as serial plasma cytokines levels within 72 h of randomization.

RESULTS

We enrolled 21 patients, of whom 16 (76%) had out-of-hospital CA. Median (IQR) time-to-ROSC was 30 (20, 45) minutes. Ten were assigned to the HA group and 11 to the SOC group. Hemoadsorption was initiated in all patients allocated to the HA group within 18 (11, 23) h of ICU admission and conducted for a median duration of 21 (14, 24) h. The intervention was well tolerated except for a trend for a higher rate of aPTT elevation (5 (50%) vs 2 (18%) p = 0.18) and mild (100-150 G/L) thrombocytopenia at day 1 (5 (50%) vs 2 (18%) p = 0.18). Interleukin (IL)-6 plasma levels at randomization were low (< 100 pg/mL) in 10 (48%) patients and elevated (> 1000 pg/mL) in 6 (29%). The median relative reduction in IL-6 at 48 h was 75% (60, 94) in the HA group versus 5% (- 47, 70) in the SOC group (p = 0.06).

CONCLUSIONS

In CA survivors at risk of PCAS, HA was feasible, safe and was associated with a nonsignificant reduction in cytokine plasma levels. Future trials are needed to further define the role of HA after CA. Those studies should include cytokine assessment to enrich the study population.

TRIAL REGISTRATION

NCT03523039, registered 14 May 2018.

The effect of citrate in cardiovascular system and clot circuit in critically ill patients requiring continuous renal replacement therapy

We aimed to evaluate the impact of citrate on hemodynamic responses and secondary outcomes, including the filter life span, metabolic complications, and levels of inflammatory cytokines, in critically ill patients who required CRRT compared with those who underwent the heparin-free method. This prospective, multicenter, open-label randomized trial compared regional citrate anticoagulation (RCA) with a heparin-free protocol in severe acute kidney injury (AKI) patients who received continuous venovenous hemodiafiltration (CVVHDF) in the postdilution mode. We measured hemodynamic changes using the FloTrac Sensor/EV1000™ Clinical Platform at certain time points after starting CRRT (0, 6, 12, 24, 48, and 72 h.). The levels of inflammatory cytokines (IL-1β, IL-6, IL-8, IL-10 and TNF-ɑ) were measured on days 1 and 3. Forty-one patients were recruited and randomized into the heparin (n = 20) and citrate groups (n = 21). The cardiac performances were not significantly different between the 2 groups at any time point. The inflammatory cytokines declined similarly in both treatment arms. The maximum filter survival time was insignificantly longer in the RCA group than in the heparin-free group (44.64 ± 26.56 h. vs p = 0.693 in citrate and heparin free group). No serious side effects were observed for either treatment arm, even in the group of liver dysfunction patients. RCA did not affect hemodynamic changes during CRRT. Inflammatory cytokines decreased similarly in both treatment arms.The filter life span was longer in the citrate group. RCA is a valid alternative to traditional anticoagulation and results in stable hemodynamic parameters.

Circuit haemodynamics during non-citrate and regional citrate continuous renal replacement, and impact of blood flow on filter life

BACKGROUND

During continuous renal replacement therapy (CRRT) with regional citrate anticoagulation (RCA), blood flow (Qb) might affect vascular access dysfunction (AD) and, thereby, circuit life.

METHODS

Circuit life and circuit haemodynamics were studied in three intensive care units (ICUs) by analysing hemofilter device data (Prismaflex^®, Baxter, Chicago, IL). The three sites shared similar RCA protocols but differed in Qb (120-130 vs 150-200 mL/h). Non-RCA circuits were compared with RCA circuits in which the impact of Qb was also assessed.

RESULTS

About 3,981,906 min of circuit pressures were analysed in 2568 circuits in 567 patients. High-Qb RCA was associated with more extreme pressures, and greater AD (IRR 3.7 (1.93-7.08) as well as reduced filter life 21.1 (10.2-42.6) vs 27.0 (14.8-41.6) h). AD in high-Qb RCA circuits was associated with a 49% reduction in filter life, versus 24% reduction in low-Qb RCA, associated with a rise in the rate of increase in transfilter pressure.

CONCLUSIONS

High-Qb RCA-CRRT was associated with greater access dysfunction, earlier filter loss and increased haemodynamic impacts of access dysfunction, suggesting low-Qb RCA-CRRT may improve circuit mechanics, function and longevity.

Segmental citrate anticoagulation for double-filtration plasmapheresis: A case report and literature review

Regional citrate anticoagulation (RCA) has been widely used in patients with high-risk bleeding for anticoagulation in renal replacement therapy. However, scientific reports on the use of RCA in double-filtration plasmapheresis (DFPP) are limited. In the available reports, anticoagulation was not performed in the plasma component separator. However, as demonstrated in the present study, during the treatment of a patient with anti-neutrophil cytoplasmic antibody-associated vasculitis, although RCA was used for DFPP, coagulation occurred in the plasma component separator, resulting in the interruption of treatment. Thus, segmental citrate anticoagulation (SCA) was used and the filter was successfully prevented from clotting again. The present study demonstrates that SCA can more effectively prevent the clogging of the plasma separator and the plasma component separator, thereby maintaining the continuity of treatment and avoiding treatment interruption.

Validation of a Protocol for Continuous Hemodiafiltration with Regional Citrate Anticoagulation with Omni®

INTRODUCTION

Omni® (B Braun, Melsungen, Germany) is able to run continuous renal replacement therapy (CRRT) in continuous veno-venous hemofiltration (CVVH), hemodialysis (CVVHD), and hemodiafiltration (CVVHDF) modes. However, to date, there is no validated protocol to guide the use of Omni® in CVVHDF mode with regional citrate anticoagulation (RCA).

METHODS

We designed a protocol for CVVHDF-RCA tailored for Omni®. This protocol was tested in patients included in an observational study conducted in our center between January and March 2021. For all study patients, we collected baseline characteristics, laboratory results, CRRT circuit lifespan as well as plasma and effluent samples at 12, 24, 48, and 72 h of CRRT circuit initiation. At each study time point, we computed urea, creatinine, and β2-microglobulin clearance as well as effluent/blood ratios. Data from circuits in CVVHDF-RCA mode are compared with those in standard therapy (CVVHD-RCA) with the same device.

RESULTS

We analyzed ten circuits (5 patients) in CVVHDF-RCA mode and 32 (13 patients) in CVVHD-RCA mode. No adverse events related to the therapy were observed. In CVVHDF-RCA mode, median circuit running time was 68 (IQR 8.1) hours versus 46 (IQR 9.0) in CVVHD mode, p = 0.053. Therapy adaptations (dialysate rate and/or blood flow) were required in one (10%) circuit (15.6% in CVVHD mode, p = 0.56). Compared to CVVHD, CVVHDF was able to achieve similar clearance and effluent/blood ratio for urea, creatinine, and β2-microglobulin across the entire duration of circuit lifetime.

CONCLUSION

The proposed protocol for CVVHDF-RCA for Omni® was associated with similar circuit lifetime, number of required adaptations and clearances to standard CVVHD-RCA. It appears to be safe and feasible.

Regional citrate versus heparin anticoagulation for CRRT in critically ill patients: a meta-analysis of RCTS

INTRODUCTION

This study aimed to compare the efficacy and safety of citrate and heparin in continuous renal replacement therapy (CRRT) for critically ill patients.

METHODS

Searched in PubMed, Embase, and Cochrane Library databases.

RESULTS

Analyses showed that there no difference existed in mortality, metabolic alkalosis, circuit loss, and the number of transfused between the two group(RR=0.95, P=0.40; RR=1.73, P=0.40; RR=0.64, P=0.09; RR=1.05, P=0.70). The filter life of the citrate group was longer than heparin group(MD=16.98, P<0.0001). The risk of bleeding and HIT was significantly lower in the citrate(RR=0.32, P<0.00001; RR=0.55, P=0.04). The citrate group was more susceptible to hypocalcemia(RR=4.85, P=0.0004).

CONCLUSION

Citrate anticoagulant therapy should have priority for CRRT in most critically ill patients. This article is protected by copyright. All rights reserved.

Effects of regional citrate anticoagulation on thrombin generation, fibrinolysis and platelet function in critically ill patients receiving continuous renal replacement therapy for acute kidney injury: a prospective study

BACKGROUND

Regional citrate anticoagulation (RCA) is recommended for continuous renal replacement therapy (CRRT). However, filter life varies and premature filter clotting can occur. The aims of this explorative prospective study were to investigate the effects of RCA on thrombin generation, fibrinolysis and platelet function in critically ill patients receiving CRRT, to compare clotting parameters between systemic and intra-circuit blood samples, and to screen participants for coagulation disorders. We recruited critically ill adult patients admitted to a 30-bedded Intensive care unit in a tertiary care hospital who required CRRT with RCA for acute kidney injury (AKI). Patients with pre-existing thrombotic, bleeding tendencies or a CRRT duration less than 48 h were excluded. We measured coagulation and thrombophilia parameters at baseline. Thrombin generation, D-dimer and platelet function were measured pre-CRRT and at 12, 24, 36, 48 and 72 h after commencing CRRT using blood samples taken from the arterial line and the circuit.

RESULTS

At baseline, all eleven patients (mean age 62.4 years, 82% male) had Factor VIII and von Willebrand Factor concentrations above reference range and significantly increased peak thrombin generation. During CRRT, there were no significant changes in systemic maximum peak thrombin generation, time to peak thrombin generation, fibrinogen, D-dimer and platelet function analysis. We observed no significant difference between paired samples taken from the patient's arterial line and the circuit.

CONCLUSIONS

Critically ill patients with AKI requiring CRRT are hypercoagulable. Citrate used for anticoagulation during CRRT does not affect thrombin generation, D-dimer or platelet function. Systemic clotting parameters reflect intra-circuit results.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02486614. Registered 01 July 2015-Registered after recruitment of first patient. https://clinicaltrials.gov/ct2/show/NCT02486614.

How to Prolong Filter Life During Continuous Renal Replacement Therapy?

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2022. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2022 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from https://link.springer.com/bookseries/8901 .

The Next Evolution of HemoDialysis eXpanded: From a Delphi Questionnaire-Based Approach to the Real Life of Italian Dialysis Units

INTRODUCTION

Impact assessment of new technologies in chronic hemodialysis (HD) is challenging due to HD patient frailty, the complexity of HD clinical trials and practice variability among countries. Among the most recent HD innovations, medium cut-off (MCO) dialyzers present an optimized membrane geometry that provides enhanced clearances for middle and large molecular weight uremic toxins (UT). These toxins are poorly cleared by available HD techniques and largely contribute to patient morbidity and mortality. The aim of this paper is to assess the available clinical evidence about MCO membranes and to identify the next steps needed to generate conclusive data on their use in HD.

METHODS

With this purpose, we first reviewed and compared the current HD technologies aimed to improve the clearance of middle and large UT; subsequently, we used a Delphi questionnaire to identify and discuss the consensus about MCO efficacy within a large sample of the Italian Nephrology community.

RESULTS AND CONCLUSIONS

Our investigation gathered a significant degree of consensus on the beneficial role of MCO membrane and expanded HD. Finally, we used our results to propose future trial designs and clinical investigations aimed to improve evidence quality about the use of these membranes in the present clinical scenario of dialysis units.

Review of Anticoagulation in Continuous Renal Replacement Therapy

Continuous renal replacement therapy is an important, yet challenging, treatment of critically ill patients with kidney dysfunction. Clotting within the dialysis filter or circuit leads to time off therapy and impaired delivery of prescribed treatment. Anticoagulation can be used to prevent this complication; however, doing so introduces risk for unintended complications such as bleeding or metabolic derangements in patients who are already critically ill. A thorough understanding of indications, therapeutic options, and monitoring principles is necessary for safe and effective use of this strategy. This review provides clinicians important information regarding when to anticoagulate, differences in pharmacologic agents, recommended doses, routes of drug delivery, and appropriate laboratory monitoring for patients receiving anticoagulation to support continuous renal replacement therapy.

Heparin versus citrate anticoagulation for continuous renal replacement therapy in intensive care: the RRAM observational study

BACKGROUND

In the UK, 10% of admissions to intensive care units receive continuous renal replacement therapy with regional citrate anticoagulation replacing systemic heparin anticoagulation over the last decade. Regional citrate anticoagulation is now used in > 50% of intensive care units, despite little evidence of safety or effectiveness.

AIM

The aim of the Renal Replacement Anticoagulant Management study was to evaluate the clinical and health economic impacts of intensive care units moving from systemic heparin anticoagulation to regional citrate anticoagulation for continuous renal replacement therapy.

DESIGN

This was an observational comparative effectiveness study.

SETTING

The setting was NHS adult general intensive care units in England and Wales.

PARTICIPANTS

Participants were adults receiving continuous renal replacement therapy in an intensive care unit participating in the Intensive Care National Audit & Research Centre Case Mix Programme national clinical audit between 1 April 2009 and 31 March 2017.

INTERVENTIONS

Exposure - continuous renal replacement therapy in an intensive care unit after completion of transition to regional citrate anticoagulation. Comparator - continuous renal replacement therapy in an intensive care unit before starting transition to regional citrate anticoagulation or had not transitioned.

OUTCOME MEASURES

Primary effectiveness - all-cause mortality at 90 days. Primary economic - incremental net monetary benefit at 1 year. Secondary outcomes - mortality at hospital discharge, 30 days and 1 year; days of renal, cardiovascular and advanced respiratory support in intensive care unit; length of stay in intensive care unit and hospital; bleeding and thromboembolic events; prevalence of end-stage renal disease at 1 year; and estimated lifetime incremental net monetary benefit.

DATA SOURCES

Individual patient data from the Intensive Care National Audit & Research Centre Case Mix Programme were linked with the UK Renal Registry, Hospital Episode Statistics (for England), Patient Episodes Data for Wales and Civil Registrations (Deaths) data sets, and combined with identified periods of systemic heparin anticoagulation and regional citrate anticoagulation (survey of intensive care units). Staff time and consumables were obtained from micro-costing. Continuous renal replacement therapy system failures were estimated from the Post-Intensive Care Risk-adjusted Alerting and Monitoring data set. EuroQol-3 Dimensions, three-level version, health-related quality of life was obtained from the Intensive Care Outcomes Network study.

RESULTS

Out of the 188 (94.9%) units that responded to the survey, 182 (96.8%) use continuous renal replacement therapy. After linkage, data were available from 69,001 patients across 181 intensive care units (60,416 during periods of systemic heparin anticoagulation use and 8585 during regional citrate anticoagulation use). The change to regional citrate anticoagulation was not associated with a step change in 90-day mortality (odds ratio 0.98, 95% confidence interval 0.89 to 1.08). Secondary outcomes showed step increases in days of renal support (difference in means 0.53 days, 95% confidence interval 0.28 to 0.79 days), advanced cardiovascular support (difference in means 0.23 days, 95% confidence interval 0.09 to 0.38 days) and advanced respiratory support (difference in means, 0.53 days, 95% CI 0.03 to 1.03 days) with a trend toward fewer bleeding episodes (odds ratio 0.90, 95% confidence interval 0.76 to 1.06) with transition to regional citrate anticoagulation. The micro-costing study indicated that regional citrate anticoagulation was more expensive and was associated with an estimated incremental net monetary loss (step change) of -£2376 (95% confidence interval -£3841 to -£911). The estimated likelihood of cost-effectiveness at 1 year was less than 0.1%.

LIMITATIONS

Lack of patient-level treatment data means that the results represent average effects of changing to regional citrate anticoagulation in intensive care units. Administrative data are subject to variation in data quality over time, which may contribute to observed trends.

CONCLUSIONS

The introduction of regional citrate anticoagulation has not improved outcomes for patients and is likely to have substantially increased costs. This study demonstrates the feasibility of evaluating effects of changes in practice using routinely collected data.

FUTURE WORK

(1) Prioritise other changes in clinical practice for evaluation and (2) methodological research to understand potential implications of trends in data quality.

TRIAL REGISTRATION

This trial is registered as ClinicalTrials.gov NCT03545750.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 13. See the NIHR Journals Library website for further project information.

Treatment Effect of Regional Sodium Citrate Anticoagulation in Elderly Patients With High-Risk Bleeding Receiving Continuous Renal Replacement Therapy

Objective

To investigate the safety and efficacy of regional citrate anticoagulation (RCA) on elderly patients at high risk of bleeding after continuous renal replacement therapy (CRRT).

Methods

A total of 31 patients at high risk of bleeding who received CRRT in the intensive care unit were collected. The patients were divided into RCA group (n = 17) and no anticoagulation group (NA, n = 14) according to whether RCA was used or not. The levels of creatinine (Cr), blood urea nitrogen (BUN), prothrombin time (PT), activated partial thromboplastin time (APTT), total calcium (tCa), ionized calcium ion (iCa²⁺), sodium ion (Na⁺), bicarbonate ion (HCO₃⁻), tCa/iCa²⁺ ratio, and pH were observed after treatment. The filter use time, number of filters used, filter obstruction events, clinical outcomes, and safety evaluation indexes were compared post-treatment.

Results

After treatment, serum Cr and BUN levels, APTT and PT levels in the RCA group were significantly lower than the NA group. The tCa, iCa²⁺, HCO₃⁻, tCa/iCa²⁺, and pH were within the normal range after RCA treatment while Na⁺ levels saw a significant increase. In the RCA group, the filter using time was significantly longer, with significantly reduced numbers of filter use within 72 h and filter disorder events. Additionally, patients in the RCA group showed significant recovery of renal function and a significant reduction in bleeding events and in-hospital mortality.

Conclusion

RCA treatment significantly improves clinical outcome of patients at high risk of bleeding after CRRT, safely and effectively prolongs the filter life and avoids coagulation incidences.

Development and External Validation of a Model for Predicting Sufficient Filter Lifespan in Anticoagulation-Free Continuous Renal Replacement Therapy Patients

Background

Anticoagulation-free continuous renal replacement therapy (CRRT) was recommended by the current clinical guideline for patients with increased bleeding risk and contraindications of citrate. Nevertheless, anticoagulation-free CRRT yielded heterogeneous filter lifespan. Furthermore, the specific cutoff values for traditional coagulation parameters to predict sufficient filter lifespan of anticoagulation-free CRRT have not yet been determined. The purpose of our present study was to develop and validate a model for predicting sufficient filter lifespan in anticoagulation-free CRRT patients.

Methods

Patients who underwent anticoagulation-free CRRT in our center between June 2013 and June 2019 were retrospectively included. The primary outcome was sufficient filter lifespan (≥24 h). Thirty-seven predictors were included for modeling based on their clinical significance and previous reports. The final model was developed by using multivariable logistic regression analysis and was validated in a separate external cohort.

Results

The development cohort included 170 patients. Sufficient filter lifespan was observed in 80 patients. Thirteen variables were independent predictors for sufficient filter lifespan by logistic regression: body temperature, mean arterial pressure, activated partial thromboplastin time, direct bilirubin, alkaline phosphatase, blood urea nitrogen, vasopressor use, body mass index, white blood cell, platelet count, D-dimer, uric acid, and pH. The area under the curve (AUC) of the stepwise model and internal validation model was 0.82 (95% confidence interval [CI] [0.76–0.88]) and 0.8 (95% CI [0.74–0.87]), respectively. The positive predictive value and the negative predictive value of the stepwise model were 0.77 and 0.79, respectively. The validation cohort included 44 eligible patients and the AUC of the external validation model was 0.82 (95% CI [0.69–0.96]).

Conclusions

The use of a prediction model instead of an assessment based only on coagulation parameters could facilitate the identification of the patients with filter lifespan of ≥24 h when they accepted anticoagulation-free CRRT.

Comparison of two regional citrate anticoagulation modalities for continuous renal replacement therapy by a prospective analysis of safety, workload, effectiveness, and cost

BACKGROUND

Currently, regional citrate anticoagulation (RCA) is the preferred approach for continuous renal replacement therapy (CRRT), and several RCA protocols are commercially available. This study was aimed at comparing two RCA modalities for CRRT in terms of safety, workload, effectiveness, and costs.

METHODS

We prospectively evaluated two different RCA approaches in patients admitted to our intensive care unit (ICU) who needed CRRT. Patients with acute liver failure were excluded. We compared a hypertonic sodium-citrate solution 136 mmol/L added before the filter as anticoagulant during bicarbonate continuous hemodialysis (RCA-CVVHD) versus citrate-buffered replacement fluid 13.3 mmol/L infused by predilution setting in continuous venovenous hemofiltration (RCA-CVVH). Alkalosis, calcium homeostasis, nursing workload, filter lifespan, urea-creatinine metabolic control, and costs were recorded.

RESULTS

Forty-five and 31 patients who underwent RCA-CVVH and RCA-CVVHD, respectively, were included. Alkalosis-free time distributions were significantly different in favor of a higher alkalosis incidence in the RCA-CVVHD group (log-rank test χ²(1)=8.18, P=0.004). Multivariable analysis showed that RCA-CVVHD was associated with a longer filter lifespan (HR=0.47; 95% CI: 0.28-0.78), higher total cost (1362 CHF [782-1901] vs. 976 CHF [671-1353], P<0.001), and higher number of anticoagulation adjustments (9 [IQR, 4-14] vs. 2 [IQR, 1-4]). The mean urea and creatinine reduction ratios at the first 24 hours were significantly higher in the RCA-CVVHD group. Calcium homeostasis and filter downtime were similar in the two groups.

CONCLUSIONS

Pre-filter hypertonic sodium-citrate solution (136 mmol/L) results in longer filter patency and improves depuration effectiveness. However, compared to RCA-CVVHF, it causes metabolic alkalosis and increases nursing interventions and cost.

Elimination of three doses of gentamicin over three consecutive days using a polyacrylonitrile-derived filter: An in vitro assessment

INTRODUCTION

Adsorption of gentamicin in a polyacrylonitrile filter was previously evidenced in a session lasting 6 h using the NeckEpur model. We extended the study over three consecutive days to mimic the 72-h life span of a filter.

METHODS

Prismaflex^® monitor and ST150^® filter were used in the continuous diafiltration (CDF) mode at a 2.5 L/h flowrate. The daily session started with a 6-h session of CDF. Thereafter, the 5-L central compartment was changed using a bag free of gentamicin to assess gentamicin release over the following 18 h. Experiments were repeated on Day 2 and stopped at the end of the 6-h session of CDF on Day 3. The experiment was performed in duplicate.

RESULTS

At a 2.5 L/h diafiltration flowrate, the mean daily clearances of gentamicin were 5.5, 4.0, and 3.3 L/h, respectively. The mean diafiltration and adsorption ratios in the daily elimination of gentamicin were 32/68%, 58/42%, and 88/12%, respectively. During days 1 and 2, the mean amount of gentamicin released from the ST150^® filter were 14 and 34 mg, respectively.

CONCLUSION

The pharmacokinetics of gentamicin over 3 days is strongly altered by adsorption in the same filter with a progressive decrease of elimination by adsorption, suggesting saturation of the filter. One limitation of our study results from the mode of administration using a bolus dose instead of an infusion over 30 min. Adsorption adds a clearance to those of diafiltration. The time-dependency of gentamicin clearance precludes using a constant dosage regimen over the filter's life span.

Do anti-platelet drugs improve duration of continuous renal replacement therapy? A retrospective cohort study in cardiac ICU patients

OBJECTIVE

The objective of this study was to investigate the impact of anti-platelet drug/s on duration of continuous renal replacement therapy (CRRT) in those patients where anti-coagulants were not used due to certain contraindications and in cases where patients were on anti-platelet drugs and were given anti-coagulant during CRRT.

METHOD

This single-center, retrospective cohort study was conducted using the medical records patients treated with CRRT in the cardiac ICU of the inpatient urban facility, located in North India. Data was collected from only those patients who received CRRT for the duration of at least 12 h. Patient's in NAC group were not on any anti-platelet/s and did not receive anti-coagulant during CRRT. AC and AP group patients received anti-coagulant alone or were already on anti-platelet/s and did not receive anti-coagulant respectively while ACAP group patients were on anti-platelet drug/s and also received anti-coagulant during CRRT.

RESULT

Patients in AC, AP, or ACAP group showed significantly (p < 0.001) higher CRRT filter life compared to NAC group. The median CRRT filter life was significantly higher in the ACAP group compared to AC (p < 0.05) and AP (p < 0.001) groups.

CONCLUSION

This study indicates that systemic anti-platelet therapy can provide additional support in critical patients undergoing CRRT even with or without anti-coagulant therapy. However, the increase in CRRT filter life was more profound in patients who were on anti-platelet/s and also received anti-coagulant drug/s during CRRT.

Regional citrate anticoagulation "non-shock" protocol with pre-calculated flow settings for patients with at least 6 L/hour liver citrate clearance

BACKGROUND

Regional 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.

METHODS

This 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.

RESULTS

Of 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).

CONCLUSIONS

The 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.

Low Blood Flow Continuous Veno-Venous Haemodialysis Compared with Higher Blood Flow Continuous Veno-Venous Haemodiafiltration: Effect on Alarm Rates, Filter Life, and Azotaemic Control

TITLE

Low blood flow continuous veno-venous haemodialysis (CVVHD) compared with higher blood flow continuous veno-venous haemodiafiltration (CVVHDF): effect on alarm rates, filter life, and azotaemic control.

INTRODUCTION

Continuous renal replacement therapy (CRRT) can be delivered via convective, diffusive, or mixed approaches. Higher blood flows have been advocated for convective clearance efficiency and promotion of filter life. It is unclear whether a lower blood flow predominantly diffusive approach may benefit filter life and alarm rates.

MATERIALS AND METHODS

Sequential cohort study of 284 patients undergoing 874 CRRT circuits from January 2015 to August 2018 in a single university-associated tertiary referral hospital in Australia. Patients underwent a protocol of either CVVHDF at blood flow 200-250 mL/min or CVVHD at blood flow 100-130 mL/min. Machine and patient data were analysed. Outcomes of azotaemic control, filter life, and warning alarm rates were log transformed and analysed with mixed linear modelling with patient as a random effect.

RESULTS

Both groups had similar azotaemic control (effect estimate on log creatinine CVVHD vs. CVVHDF 1.04 [0.87-1.25], p = 0.68) and median filter life (CVVHDF 16.8 [8.4-90.5] h and CVVHD 16.4 [9.4-82.3] h, p = 0.97). However, circuit pressures were less extreme with a narrower distribution during CVVHD. Multivariate analysis showed CVVHD had a reduced risk of warning alarms (incidence risk ratio [IRR] 0.51 [0.38-0.70]) and femoral access placement also had a reduced risk of alarms (IRR 0.55 [0.41-0.73]).

CONCLUSION

Low blood flow CVVHD and femoral vascular access reduce alarms while maintaining azotaemic control and circuit patency thus minimizing bedside clinician workload.

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.

Complications associated with continuous renal replacement therapy

With the evolution of standardized replacement fluids, newer machines, and high flux membranes, continuous renal replacement therapy (CRRT) has made remarkable progress in the field of extracorporeal therapies. CRRT is the preferred dialytic modality for patients in intensive care unit setting (ICU). Standardized protocols are implemented by many institutions to avoid errors and ensure patient safety. However, complications related to CRRT are not uncommon. Understanding CRRT operations is essential to analyze the complications and further assist in developing measures to mitigate the risk. Overview of CRRT complications and potential preventive strategies are discussed in the current review.