Nomenclature of Extracorporeal Blood Purification Therapies for Acute Indications: The Nomenclature Standardization Conference

Hyponatremia in Critically Ill Patients Due to Continuous Venovenous Hemofiltration With Diluted Sodium Citrate

Continuous venovenous hemofiltration (CVVH) is frequently performed in critically ill patients using diluted citrate for regional anticoagulation. The impact of this renal replacement strategy on plasma sodium has not been evaluated yet. Our aim was therefore to assess the period prevalence of hyponatremia (sodium <135 mmol/L) during CVVH and discuss possible underlying mechanisms. After 48 hours of treatment, 70% of the 27 oligo-anuric critically ill patients were hyponatremic, despite the use of dialysis fluid bags (Regiocit 18/0, Phoxilium by Baxter, Deerfield, IL, and Multibic K2 by Fresenius Medical Care AG & Co. KGaA, Bad Homburg, Germany) with sodium content of 140 mmol/L. Indeed, sodium decreased from 142 ± 7 to 135 ± 3 mmol/L, p < 0.001. Sodium concentrations of employed dialysis bags were confirmed using ion chromatography. However, ionized sodium of Regiocit measured with a direct-ion selective electrode (ISE) resulted lower (~118 mmol/L), suggesting the presence of sodium-to-citrate complexes. Possible mechanisms explaining the hyponatremia development could therefore include: i) plasma water dilution; ii) a reduced Gibbs-Donnan effect, given the low albumin concentration (2.6 ± 0.8 g/dl) of our critically ill patients; iii) a negative sodium balance due to the loss of sodium-to-citrate complexes across the filter. The clinical implications of the described hyponatremia and the different contributions of the hypothesized mechanisms need to be addressed in future studies.

Haemoadsorption to remove inflammatory mediators in sepsis: past, present, and future

While a dysregulated immune response is at the center of the sepsis definition, standard care is still solely focussed on prompt administration of antimicrobial therapy, source control, resuscitation and organ supportive therapies. Extracorporeal blood purification therapies, such as haemoadsorption, have been proposed as a possible adjunctive therapy to standard care in sepsis. These adsorption devices aim to rebalance the dysregulated immune response by removal of excessive amounts of circulating inflammatory mediators, including cytokines and endotoxins. Thus far, the effects of haemoadsorption on clinical outcomes have been insufficiently studied and although its routine use is not justified based on the current evidence, multiple centers use these devices in patients with severe septic shock. This narrative review describes the most well-studied adsorption devices as well as a novel selective adsorption device called the 'IL-6-Sieve', including in vitro data showing its capturing potential. Finally, it addresses important considerations for future trials on haemoadsorption in septic patients.

Extracorporeal Blood Purification in European Pediatric Intensive Care Units: A Consensus Statement

Importance

Important advances have been made in extracorporeal blood purification therapies (EBPTs) due to new technologies and biomaterials; however, the lack of established guidelines is a factor in great variability in clinical practice. This aspect is accentuated in pediatric intensive care given the small number of patients with diverse diagnoses treated with EBPT and the technical challenges in treating small children, potentiating the risk of adverse events.

Objective

To understand what experienced users of EBPT think about its relevant issues, insight that may have implications for the design of future studies, and the application of EBPTs in patient care.

Evidence Review

Literature search was conducted using the PubMed and Embase databases between January 1, 2020, and July 15, 2024, and a combination of key medical terms. A panel of experts was formed (composed of 15 authors and pediatric intensivists) to develop a consensus statement using a modified Delphi-based model between 2022 and 2024. The panel's core team drafted the initial questionnaire, which explored EBPT use in pediatric intensive care units (PICUs), including clinical indications for initiating and discontinuing use and outcomes for assessing effectiveness and safety. SurveyMonkey was used in the distribution, completion, and revision of the questionnaire, and findings were analyzed. Panelists were asked to rank answer choices. Numerical value for each ranking was translated to a percentage defining the strength of consensus (>90% agreement from panelists signifying strong consensus; <49% signifying no consensus).

Findings

A total of 116 survey responses were received from panelists from 8 European countries. Strong consensus was achieved on 6 of 24 questions and consensus (75%-90% agreement) was reached on 18 of 24 questions. According to the panelists, the continuous renal replacement therapy standard or enhanced adsorption hemofilter and plasma exchange were of interest, representing the most applied EBPTs across various applications. While evidence on hemoadsorption is growing, it remains limited.

Conclusions and Relevance

This consensus statement on EBPTs in critically ill pediatric patients was developed by an international panel of experts in areas where clinical evidence is still limited. This consensus statement could support pediatric intensivists in bedside decision-making and guide future research on EBPTs in PICUs.

Acute kidney injury

Acute kidney injury (AKI) is a common, heterogeneous, multifactorial condition, which is part of the overarching syndrome of acute kidney diseases and disorders. This condition's incidence highest in low-income and middle-income countries. In the short term, AKI is associated with increased mortality, an increased risk of complications, extended stays in hospital, and high health-care costs. Long-term complications include chronic kidney disease, kidney failure, cardiovascular morbidity, and an increased risk of death. Several strategies are available to prevent and treat AKI in specific clinical contexts. Otherwise, AKI care is primarily supportive, focused on treatment of the underlying cause, prevention of further injury, management of complications, and short-term renal replacement therapy in case of refractory complications. Evidence confirming that AKI subphenotyping is necessary to identify precision-oriented interventions is growing. Long-term follow-up of individuals recovered from AKI is recommended but the most effective models of care remain unclear.

Fluid balance neutralization secured by hemodynamic monitoring versus protocolized standard of care in patients with acute circulatory failure requiring continuous renal replacement therapy: results of the GO NEUTRAL randomized controlled trial

PURPOSE

Net ultrafiltration (UFNET) during continuous renal replacement therapy (CRRT) can control fluid balance (FB), but is usually 0 ml·h-1 in patients with vasopressors due to the risk of hemodynamic instability associated with CRRT (HIRRT). We evaluated a UFNET strategy adjusted by functional hemodynamics to control the FB of patients with vasopressors, compared to the standard of care.

METHODS

In this randomized, controlled, open-label, parallel-group, multicenter, proof-of-concept trial, adults receiving vasopressors, CRRT since ≤ 24 h and cardiac output monitoring were randomized (ratio 1:1) to receive during 72 h a UFNET ≥ 100 ml·h-1, adjusted using a functional hemodynamic protocol (intervention), or a UFNET ≤ 25 ml·h-1 (control). The primary outcome was the cumulative FB at 72 h and was analyzed in patients alive at 72 h and in whom monitoring and CRRT were continuously provided (modified intention-to-treat population [mITT]). Secondary outcomes were analyzed in the intention-to-treat (ITT) population.

RESULTS

Between June 2021 and April 2023, 55 patients (age 69 [interquartile range, IQR: 62; 74], 35% female, Sequential Organ Failure Assessment (SOFA) 13 [11; 15]) were randomized (25 interventions, 30 controls). In the mITT population, (21 interventions, 24 controls), the 72 h FB was -2650 [-4574; -309] ml in the intervention arm, and 1841 [821; 5327] ml in controls (difference: 4942 [95% confidence interval: 2736-6902] ml, P < 0.01). Hemodynamics, oxygenation and the number of HIRRT at 72 h, and day-90 mortality did not statistically differ between arms.

CONCLUSION

In patients with vasopressors, a UFNET fluid removal strategy secured by a hemodynamic protocol allowed active fluid balance control, compared to the standard of care.

Hemoadsorption: consensus report of the 30th Acute Disease Quality Initiative workgroup

Adsorption-based extracorporeal therapies have been subject to technical developments and clinical application for close to five decades. More recently, new technological developments in membrane and sorbent manipulation have made it possible to deliver more biocompatible extracorporeal adsorption therapies to patients with a variety of conditions. There are several key rationales based on physicochemical principles and clinical considerations that justify the application and investigation of such therapies as evidenced by multiple ex vivo, experimental and clinical observations. Accordingly, unspecific adsorptive extracorporeal therapies have now been applied to the treatment of a wide array of conditions from poisoning to drug overdoses, to inflammatory states and sepsis, and acute or chronic liver and kidney failure. In response to the rapidly expanding knowledge base and increased clinical evidence, we convened an Acute Disease Quality Initiative consensus conference dedicated to such treatment. The data show that hemoadsorption has clinically acceptable short-term biocompatibility and safety, technical feasibility and experimental demonstration of specified target molecule removal. Pilot studies demonstrate potentially beneficial effects on physiology and larger studies of endotoxin-based hemoadsorption have identified possible target phenotypes for larger randomized controlled trials. Moreover, in a variety of endogenous and exogenous intoxications, removal of target molecules has been confirmed in vivo. However, some studies have raised concerns about harm, or failed to deliver benefits. Thus, despite many achievements, modern hemoadsorption remains a novel and experimental intervention with limited data, and a large research agenda.

CaCl2-Citrate Regional Anticoagulation with Continuous Veno-Venous Haemodialysis Leads to Unwanted Chloride Loading Compared to Continuous Veno-Venous Hemofiltration with Systemic Anticoagulation

INTRODUCTION

Chloride transfers during continuous renal replacement therapy (CRRT) have not been adequately described and may differ based on CRRT technique. We aimed to measure chloride mass transfer (JS,Cl) during CRRT and identify associated determinants.

METHODS

We performed a two-centre, prospective, observational study in France and Australia in ICU patients with CRRT initiated for <24 h. Patients received continuous veno-venous hemofiltration (CVVH) or continuous veno-venous haemodialysis (CVVHD, with citrate-CaCl2 regional anticoagulation). Over a 24 h period, plasma and effluent chloride concentrations were measured every 4 h to compute chloride mass transfer (JS,Cl, in mmol.min-1) using a modality-specific model, with negative value indicating chloride transfer towards the patient. Secondary outcomes were the identification of CRRT settings associated with JS,Cl (using multivariate mixed effects regression). Results are presented with median (interquartile range).

RESULTS

Between February 2021 and August 2022, we enrolled 37 patients (64 [56-71] years, 67% male), for a total of 20 CVVHD and 20 CVVH sessions. Over 24 h, plasma chloride concentrations were significantly higher, and JS,Cl significantly lower during CVVHD, compared to CVVH (-0.10 [-0.33 to 0.15] vs. 0.01 [-0.10 to 0.13] mmol.min-1, p < 0.05). With both modalities, net ultrafiltration (QUFNET) and plasma chloride concentrations were the principal determinants of JS,Cl, with higher QUFNET being associated with an increase in JS,Cl during CVVHD. Also, CVVHD sessions demonstrated a concentration gradient between the plasma and the effluent chamber of -6 [-9 to -4] mmol.L-1. Finally, CaCl2 reinjection during CVVHD accounted for 35% [32-60%] of total JS,Cl in sessions with a negative JS,Cl.

CONCLUSION

Compared to CVVH, CVVHD with regional citrate anticoagulation was associated with greater chloride mass transfer to the patient and higher plasma chloride concentrations. This was due to high dialysate chloride concentrations and CaCl2 reinjection. This effect could only be controlled by high net ultrafiltration flow rates.

Intraoperative renal replacement therapy during liver transplantation in children: Safety, efficacy and impact on survival

BACKGROUND

Intraoperative Continuous Renal Replacement Therapy (iCRRT) can prevent life-threatening complications, facilitate fluid management, and maintain metabolic homeostasis during liver transplantation (LT) in adults. There is a paucity of data in pediatric LT. We evaluated the safety, efficacy, and impact on survival of iCRRT in pediatric LT.

METHODS

We conducted a retrospective cohort study of all children requiring CRRT pre-OLT at a quaternary children's hospital from 2014 to 2022. Demographic characteristics, intraoperative events, and post-LT outcomes were compared between those who received iCRRT and those who did not.

RESULTS

Out of 306 patients who received LT, 30 (10%) were supported with CRRT at least 24 h prior to LT, of which 11 (36%) received iCRRT. The two cohorts were similar in demographics, diagnosis of liver disease, and severity of illness. The iCRRT patients experienced massive blood loss and increased transfusion requirements. There was no difference in intraoperative metabolic balance. One-year post-LT mortality rates were similar.

CONCLUSION

ICRRT is safe in critically ill children with pre-LT renal dysfunction. It optimizes fluid and blood product resuscitation while maintaining metabolic homeostasis. Candidates need to be carefully chosen for this highly resource-intensive therapy to benefit this fragile population.

PAMPs and DAMPs in Sepsis: A Review of Their Molecular Features and Potential Clinical Implications

Sepsis is a serious organ dysfunction caused by a dysregulated immune host reaction to a pathogen. The innate immunity is programmed to react immediately to conserved molecules, released by the pathogens (PAMPs), and the host (DAMPs). We aimed to review the molecular mechanisms of the early phases of sepsis, focusing on PAMPs, DAMPs, and their related pathways, to identify potential biomarkers. We included studies published in English and searched on PubMed® and Cochrane®. After a detailed discussion on the actual knowledge of PAMPs/DAMPs, we analyzed their role in the different organs affected by sepsis, trying to elucidate the molecular basis of some of the most-used prognostic scores for sepsis. Furthermore, we described a chronological trend for the release of PAMPs/DAMPs that may be useful to identify different subsets of septic patients, who may benefit from targeted therapies. These findings are preliminary since these pathways seem to be strongly influenced by the peculiar characteristics of different pathogens and host features. Due to these reasons, while initial findings are promising, additional studies are necessary to clarify the potential involvement of these molecular patterns in the natural evolution of sepsis and to facilitate their transition into the clinical setting.