Recent Advances in Kidney Replacement Therapy in Infants: A Review

Kidney replacement therapy (KRT) is used to treat children and adults with acute kidney injury (AKI), fluid overload, kidney failure, inborn errors of metabolism, and severe electrolyte abnormalities. Peritoneal dialysis and extracorporeal hemodialysis/filtration can be performed for different durations (intermittent, prolonged intermittent, and continuous) through either adaptation of adult devices or use of infant-specific devices. Each of these modalities have advantages and disadvantages, and often multiple modalities are used depending on the scenario and patient-specific needs. Traditionally, these therapies have been challenging to deliver in infants due the lack of infant-specific devices, small patient size, required extracorporeal volumes, and the risk of hemodynamic stability during the initiation of KRT. In this review, we discuss challenges, recent advancements, and optimal approaches to provide KRT in hospitalized infants, including a discussion of peritoneal dialysis and extracorporeal therapies. We discuss each specific KRT modality, review newer infant-specific devices, and highlight the benefits and limitations of each modality. We also discuss the ethical implications for the care of infants who need KRT and areas for future research.

Continuous renal replacement therapy in neonates and children: what does the pediatrician need to know? An overview from the Critical Care Nephrology Section of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC)

Continuous renal replacement therapy (CRRT) is the preferred method for renal support in critically ill and hemodynamically unstable children in the pediatric intensive care unit (PICU) as it allows for gentle removal of fluids and solutes. The most frequent indications for CRRT include acute kidney injury (AKI) and fluid overload (FO) as well as non-renal indications such as removal of toxic metabolites in acute liver failure, inborn errors of metabolism, and intoxications and removal of inflammatory mediators in sepsis. AKI and/or FO are common in critically ill children and their presence is associated with worse outcomes. Therefore, early recognition of AKI and FO is important and timely transfer of patients who might require CRRT to a center with institutional expertise should be considered. Although CRRT has been increasingly used in the critical care setting, due to the lack of standardized recommendations, wide practice variations exist regarding the main aspects of CRRT application in critically ill children.     Conclusion: In this review, from the Critical Care Nephrology section of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC), we summarize the key aspects of CRRT delivery and highlight the importance of adequate follow up among AKI survivors which might be of relevance for the general pediatric community. What is Known: • CRRT is the preferred method of renal support in critically ill and hemodynamically unstable children in the PICU as it allows for gentle removal of fluids and solutes. • Although CRRT has become an important and integral part of modern pediatric critical care, wide practice variations exist in all aspects of CRRT. What is New: • Given the lack of literature on guidance for a general pediatrician on when to refer a child for CRRT, we recommend timely transfer to a center with institutional expertise in CRRT, as both worsening AKI and FO have been associated with increased mortality. • Adequate follow-up of PICU patients with AKI and CRRT is highlighted as recent findings demonstrate that these children are at increased risk for adverse long-term outcomes.

New perspectives in pediatric dialysis technologies: the case for neonates and infants with acute kidney injury

Advancements in pediatric dialysis generally rely on adaptation of technology originally developed for adults. However, in the last decade, particular attention has been paid to neonatal extracorporeal therapies for acute kidney care, an area in which technology has made giant strides in recent years. Peritoneal dialysis (PD) is the kidney replacement therapy (KRT) of choice in the youngest age group because of its simplicity and effectiveness. However, extracorporeal blood purification provides more rapid clearance of solutes and faster fluid removal. Hemodialysis (HD) and continuous KRT (CKRT) are thus the most used dialysis modalities for pediatric acute kidney injury (AKI) in developed countries. The utilization of extracorporeal dialysis for small children is associated with a series of clinical and technical challenges which have discouraged the use of CKRT in this population. The revolution in the management of AKI in newborns has started recently with the development of new CKRT machines for small infants. These new devices have a small extracorporeal volume that potentially prevents the use of blood to prime lines and dialyzer, allow a better volume control and the use of small-sized catheter without compromising the blood flow amount. Thanks to the development of new dedicated devices, we are currently dealing with a true "scientific revolution" in the management of neonates and infants who require an acute kidney support.

CARPEDIEM® for continuous kidney replacement therapy in neonates and small infants: a French multicenter retrospective study

BACKGROUND

The Cardio-Renal Pediatric Dialysis Emergency Machine (CA.R.P.E.D.I.E.M.®) device is a continuous kidney replacement therapy (CKRT) equipment dedicated to neonates and small infants. This study aimed to assess the effectiveness, feasibility, outcomes, and technical considerations relating to CARPEDIEM® use.

METHODS

This retrospective multicenter study included 19 newborns and six infants receiving CARPEDIEM® in five French pediatric and neonatal intensive care units. Laboratory parameters were collected at the initiation and end of the first CARPEDIEM® session. Results are presented as median [IQR] (range).

RESULTS

At initiation, age was 4 days [2-13] (1-1134) with a body weight of 3.3 kg [2.5-4] (1.3-11.1). Overall, 131 sessions and 2125 h of treatment were performed. Treatment duration per patient was 42 h [24-91] (8-557). Continuous veno-venous hemofiltration (CVVH) was performed in 20 children. Blood flow rate was 8 mL/kg/min [6-9] (3-16). The effluent flow rate for CVVH was 74 mL/kg/h [43-99] (28-125) and net ultrafiltration (UF) 6 mL/kg/h [2-8] (1-12). In the five children treated by hemodialysis, the blood and dialysate flow rates were 6 mL/kg/min [5-7] (4-7) and 600 mL/h [300-600] (120-600), respectively, while session duration was 8 h [6-12] (2-24). Most infants required a catheter between 4.5 and 6.5 French. Hemodynamic instability with a need for volume replacement occurred in 31 sessions (23%). Thrombocytopenia was observed in 29 sessions (22%). No hemorrhage occurred; all the patients survived the sessions, but only eight patients (32%) were alive at hospital discharge.

CONCLUSIONS

These data confirm that the use of CARPEDIEM® is safe and effective in critically ill neonates and infants. A higher resolution version of the Graphical abstract is available as Supplementary information.

Worldwide Exploration of Renal Replacement Outcomes Collaborative in Kidney Disease (WE-ROCK)

Introduction

Continuous renal replacement therapy (CRRT) is used for the symptomatic management of acute kidney injury (AKI) and fluid overload (FO). Contemporary reports on pediatric CRRT are small and single center in design. Large international studies evaluating CRRT practice and outcomes are lacking. Herein, we describe the design of a multinational collaborative.

Methods

The Worldwide Exploration of Renal Replacement Outcomes Collaborative in Kidney Disease (WE-ROCK) is an international collaborative of pediatric specialists whose mission is to improve short- and long-term outcomes of children treated with CRRT. The aims of this multicenter retrospective study are to describe the epidemiology, liberation patterns, association of fluid balance and timing of CRRT initiation, and CRRT prescription with outcomes.

Results

We included children (n = 996, 0-25 years) admitted to an intensive care unit (ICU) and treated with CRRT for AKI or FO at 32 centers (in 7 countries) from 2018 to 2021. Demographics and clinical characteristics before CRRT initiation, during the first 7 days of both CRRT, and liberation were collected. Outcomes include the following: (i) major adverse kidney events at 90 days (mortality, dialysis dependence, and persistent kidney dysfunction), and (ii) functional outcomes (functional stats scale).

Conclusion

The retrospective WE-ROCK study represents the largest international registry of children receiving CRRT for AKI or FO. It will serve as a broad and invaluable resource for the field of pediatric critical care nephrology that will improve our understanding of practice heterogeneity and the association of CRRT with clinical and patient-centered outcomes. This will generate preliminary data for future interventional trials in this area.

Comparison of nafamostat mesilate to citrate anticoagulation in pediatric continuous kidney replacement therapy

BACKGROUND

Regional citrate anticoagulation (RCA) is the preferred continuous kidney replacement therapy (CKRT) anticoagulation strategy for children in the USA. Nafamostat mesilate (NM), a synthetic serine protease, is used widely for CKRT anticoagulation in Japan and Korea. We compared the safety and efficacy of NM to RCA for pediatric CKRT.

METHODS

Starting June 2019, the most recent 100 medical records of children receiving CKRT with either RCA or NM were reviewed retrospectively, at one children's hospital in Japan (NM) and one in the USA (RCA). The number of hours a single CKRT filter was in use, was the primary outcome. Safety was assessed by bleeding complications for the NM group and citrate toxicity leading to RCA discontinuation or electrolyte imbalance in the RCA group.

RESULTS

Eighty patients received NM and 78 patients received RCA. Median filter life was longer for the NM group (NM: 38 [22, 74] vs. RCA: 36 [17, 66] h, p = 0.02). When filter life was censored for discontinuation other than clotting, the 60-h survival rate was higher for RCA (71% vs. 54%). The hazard ratio comparing NM over RCA varied over time (HR 0.7; 0.2-1.5, p = 0.33 at 0 h to HR 5.5; 1.3-23.7, p = 0.334 at 72 h). The lack of difference in filter survival persisted controlling for filter surface area, catheter diameter, and pre-CKRT platelet count. Major bleeding rates did not differ between groups (NM: 5% vs. RCA: 9%).

CONCLUSIONS

RCA and NM provide satisfactory anticoagulation for CKRT in children with no difference in major bleeding rates. A higher resolution version of the Graphical abstract is available as Supplementary information.

Kidney support for babies: building a comprehensive and integrated neonatal kidney support therapy program

Kidney support therapy (KST), previously referred to as Renal Replacement Therapy, is utilized to treat children and adults with severe acute kidney injury (AKI), fluid overload, inborn errors of metabolism, and kidney failure. Several forms of KST are available including peritoneal dialysis (PD), intermittent hemodialysis (iHD), and continuous kidney support therapy (CKST). Traditionally, extracorporeal KST (CKST and iHD) in neonates has had unique challenges related to small patient size, lack of neonatal-specific devices, and risk of hemodynamic instability due to large extracorporeal circuit volume relative to patient total blood volume. Thus, PD has been the most commonly used modality in infants, followed by CKST and iHD. In recent years, CKST machines designed for small children and novel filters with smaller extracorporeal circuit volumes have emerged and are being used in many centers to provide neonatal KST for toxin removal and to achieve fluid and electrolyte homeostasis, increasing the options available for this unique and vulnerable group. These new treatment options create a dramatic paradigm shift with recalibration of the benefit: risk equation. Renewed focus on the infrastructure required to deliver neonatal KST safely and effectively is essential, especially in programs/units that do not traditionally provide KST to neonates. Building and implementing a neonatal KST program requires an expert multidisciplinary team with strong institutional support. In this review, we first describe the available neonatal KST modalities including newer neonatal and infant-specific platforms. Then, we describe the steps needed to develop and sustain a neonatal KST team, including recommendations for provider and nursing staff training. Finally, we describe how quality improvement initiatives can be integrated into programs.

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

INTRODUCTION

Acute kidney injury (AKI) is a clinical condition characterized by an abrupt increase in serum creatinine levels due to functional changes in the kidneys from a newfound insult or injury. For supportive treatment, continuous renal replacement therapy (CRRT) is one of the most widely used modalities due to its precise control of fluid balance over extended periods of time. However, its complications include circuit clotting, the most frequent cause for CRRT interruption. Vascular access and circuit management were found to be major determinants of performance efficiency. Anticoagulation required to prevent clotting has the downside of increasing the risk of bleeding, especially in the setting of overdosage. Hence, a delicate balance needs to be maintained consistently.

METHODS

This study explores the adequacy of non-anticoagulation measures in the prevention of circuit clotting. A comprehensive literature search was conducted using PubMed/Medline and Embase databases to include all relevant studies.

FINDINGS

The most-effective CRRT catheter would be made of nonthrombogenic material, noncuffed and nontunneled with separate lumens for arterial and venous blood. Further, studies show that blood flow during the process is optimized at 200 ml/min, which can be lowered in the pediatric population due to more narrow catheters. Platelet count and hematocrit need to be closely monitored as levels above 450,000 × 10⁶ /L and 0.40, respectively, increase risk of clotting. Predilution is a non-anticoagulation technique to reduce the risk of clotting by returning replacement solution to the blood before it reaches the filter. Also, biocompatible membranes such as polyacrylonitrile or polysulfone activate the coagulation cascade significantly less than the conventional cellulose-based membranes, thereby reducing clotting chances.

DISCUSSIONS

With the advent of such techniques and maneuvers, anticoagulation can be efficiently maintained in patients undergoing CRRT without increasing the risk of bleeding.

Thromboembolic Complications of Vascular Catheters Used for Pediatric Continuous Renal Replacement Therapy: Prevalence in a Single-Center, Retrospective Cohort

OBJECTIVES

Pediatric venous thromboembolic events are commonly associated with in situ central venous catheters. The risk for severe venous thromboembolism increases if a larger portion of the vessel lumen is occupied by the central venous catheter. A functioning vascular catheter is required when the continuous renal replacement therapy is used in critically ill children. Due to the high blood flow required for continuous renal replacement therapy, the external diameter of the catheter needs to be larger than a conventional central venous catheter used for venous access, potentially increasing the risk of venous thromboembolism. However, children on continuous renal replacement therapy often receive systemic anticoagulation to prevent filter clotting, possibly also preventing venous thromboembolism. The frequency of catheter-related venous thromboembolic events in this setting has not been described. Our main objective was to determine the prevalence of catheter-related venous thromboembolism in pediatric continuous renal replacement therapy.

DESIGN

Retrospective cohort study.

SETTING

Tertiary multidisciplinary academic pediatric hospital.

PATIENTS

Patients 0-18 years old with a vascular catheter used for continuous renal replacement therapy.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

In our series of 80 patients, we used 105 vascular catheters. The median age of the patients was 10 months and PICU mortality rate was 21%. Venous thromboembolic events were considered to be catheter related if located in the same vein as the vascular catheter and radiologically verified. Six (5.7%) catheter-related venous thromboembolic events were found. The clinically relevant complications of venous thromboembolism included superior vena cava syndrome and catheter dysfunction. In one patient, severe and life-threatening pulmonary embolism occurred. In comparison with patients without venous thromboembolism, venous thromboembolic events were associated with lower body weight (p = 0.03) and longer durations of continuous renal replacement therapy (p < 0.01), mechanical ventilation (p = 0.03), and PICU stay (p < 0.01). Five out of six venous thromboembolisms appeared in neonates.

CONCLUSIONS

Catheter-related venous thromboembolism is a clinically relevant complication of pediatric continuous renal replacement therapy, with a prevalence of 5.7% in our cohort. Clinicians involved in pediatric continuous renal replacement therapy need to be vigilant for symptoms of venous thromboembolisms and initiate appropriate treatment as soon as possible.

Kidney support therapy in the pediatric patient: Unique considerations for a unique population

The use of kidney support therapy (KST) for use in managing patients with acute kidney injury (AKI) has expanded greatly in the last several decades. The growing use of KST modalities in children, and now in neonates, has been associated with opportunities for education, clinical research, clinical practice improvements, and outcomes research. A multitude of controversies exist in the field of pediatric KST-many of which are shared by adult critical care nephrology practice. Simultaneously, pediatric KST has led the way to a burgeoning exploration of the importance of fluid overload as it relates to KST initiation and management and also with quality improvement. In this review, we will explore and describe the paradigms contained with pediatric KST used to support children with AKI. In addition to the governing principles related to the mechanics of KST, we will describe the novel aspects of newer support machines and ethical considerations of KST provision. Anticoagulation, dose, and modality will be discussed as well as priming procedures for special considerations. The utilization of KST across pediatric populations represents the next frontier of critical care nephrology.

Continuous renal replacement therapy in critically ill children: single-center experience

Background/aim

Continuous renal replacement therapy (CRRT) has significant benefits in the treatment of critically ill children.The objective of this study is to describe the treatment indications, methods, demographics, and outcome of the patients who received CRRT in our pediatric intensive care unit and neonatal care unit, and, according to these results, we also aimto make improvements in our unit-based interventions.

Materials and methods

In this single-centered study, we retrospectively evaluated medical charts of the patients admitted to our intensive care units and received CRRT between February 2010 and November 2015.

Results

Fifty of 60 patients were included in this study. Newborns made up 28% (n = 14) of the patients. The mean body weight was 18.4 kg (2.3-98 kg). CRRT indications were fluid overload (30%), acute kidney injury (40%), metabolic disease (24%), electrolyte impairment (4%), and drug intoxication (2%). The most common method of CRRT was continuous venovenous hemodiafiltration (CVVHDF) (72%). The mean duration of CRRT was 135 hours (1-864) and totally 143 filters, polyarylethersulfon (n = 23.46%) and polyacrylonitrile (n = 27.54%) were used. Overall survival was 42%. The survival rate of newborns was significantly higher (P = 0.046).

Conclusion

CRRT is a lifesaving method that can be applied to critically ill children with acute kidney injury and fluid overload at any age and weight by experienced teams.

Improving the quality of neonatal acute kidney injury care: neonatal-specific response to the 22nd Acute Disease Quality Initiative (ADQI) conference

With the adoption of standardized neonatal acute kidney injury (AKI) definitions over the past decade and the concomitant surge in research studies, the epidemiology of and risk factors for neonatal AKI have become much better understood. Thus, there is now a need to focus on strategies designed to improve AKI care processes with the goal of reducing the morbidity and mortality associated with neonatal AKI. The 22nd Acute Dialysis/Disease Quality Improvement (ADQI) report provides a framework for such quality improvement in adults at risk for AKI and its sequelae. While many of the concepts can be translated to neonates, there are a number of specific nuances which differ in neonatal AKI care. A group of experts in pediatric nephrology and neonatology came together to provide neonatal-specific responses to each of the 22nd ADQI consensus statements.

A Case Series: Continuous Kidney Replacement Therapy in Neonates With Low Body Weight

Emerging data indicate that acute kidney injury (AKI) may contribute to a worse prognosis in the infant population. Kidney replacement therapy (KRT) can be used to treat patients with AKI; however, this technique is challenging in patients in the neonatal intensive care units (NICUs) due to the low body weights and blood volumes in this population. Peritoneal dialysis (PD) is a potential modality since it is technically less challenging. However, PD has been associated with several disadvantages, including poor fluid status control, catheter-associated leakage, and peritonitis. Unfortunately, these complications can cause the temporary cessation of PD. Continuous kidney replacement therapy (CKRT) may represent a suitable alternative for PD. CKRT may be technically feasible in infants; however, little is known about the application of CKRT in neonates with low body weights. In this report, we discuss three cases of CKRT who were treated in the NICU at a tertiary medical center in southern Taiwan. We selected an adequate catheter diameter and achieved vascular access via an internal jugular vein or umbilical vein. The prescription of an appropriate dose of heparin was then used to prolong the circuit life of the CKRT. The maintenance of circuit durability in neonates with low body weight remains problematic. We hope that our experience can assist with the future clinical management of CKRT in neonates with low body weight.

Challenges of long-term vascular access in pediatric hemodialysis: Recommendations for practitioners

Kidney transplantation is the preferred treatment of end-stage renal disease in children. However, time to transplant varies, making a well-functioning long-term vascular access essential for performing hemodialysis efficiently and without disruption until a kidney becomes available. However, establishing long-term vascular access in pediatric patients can present distinct challenges due to this population's unique characteristics, such as smaller body size and lower-diameter blood vessels. There are three main pediatric long-term vascular access options, which include central venous catheters (CVC), arteriovenous fistula (AVF), and arteriovenous graft (AVG). CVC are currently the most widely used modality, although various studies and guidelines recommend AVF or AVG as the preferred option. Although AVF should be used whenever possible, it is crucial that clinicians consider factors such as patient size, physical exam findings, comorbidities, predicted duration of treatment to decide on the most optimal long-term vascular access modality. This article reviews the three long-term vascular access methods in children and the benefits and complications of each.

Continuous kidney replacement therapy in critically ill neonates and infants: a retrospective analysis of clinical results with a dedicated device

BACKGROUND

Providing extracorporeal renal support to neonates and infants involves a number of technical and clinical issues, possibly discouraging early utilization. This report aims to describe a multicenter experience of continuous kidney replacement therapy (CKRT) delivery to small infants using a device specifically designed for this age group.

METHODS

A retrospective cohort analysis of all patients treated with the Carpediem™ machine (Bellco-Medtronic, Mirandola, Italy) in 6 centers between June 2013 and December 2016.

RESULTS

Twenty-six neonates and small infants received 165 CKRT sessions in convective modality. Median age at neonatal intensive care unit admission 1 day (IQR 1-11), median body weight 2.9 kg (IQR 2.2-3.6). Median circuit duration 14 h (IQR 10-22), with delivered/prescribed time ratio of 84%. CKRT was conducted using 4 Fr (27%), 5 Fr (35%), 6.5 Fr (11%), and 7 Fr (3%) vascular access, and with umbilical and peripheral accesses (11% each) allowing overall median blood flow of 4.5 ml/kg/min (IQR 3.4-6) and median effluent flow rate 35 ml/kg/h (IQR 28-42). Circuits were primed with normal saline in 58% of treatments, colloids in 31%, and packed red blood cells in 11%. No serious adverse events directly related to machine application were reported by any center. Twenty-five (96%) patients survived their CKRT course and 13 patients (50%) survived to ICU discharge.

CONCLUSIONS

CKRT in neonates was easy to initiate and conduct when performed with small central vascular accesses coupled with this device. A dedicated technology for infant CKRT delivery enables patients to be safely treated avoiding technical complications. Graphical abstract.

Renal Replacement Therapy in Pediatric Acute Kidney Injury

Acute kidney injury (AKI) is common in critically ill children and affects nearly 30-40% of patients admitted to the pediatric intensive care unit (ICU). Even with technological advances in critical care and dialysis, there is a high mortality rate of 66.8% to 90% in ICU patients. Renal replacement therapy (RRT) is often performed to treat patients with AKI. However, for optimal RRT treatment, it is crucial to consider the indications, modes of access, and prescription of each RRT method. Therefore, this review aims to discuss the various modalities of RRT in pediatric patients, which include peritoneal dialysis (PD), hemodialysis (HD), continuous RRT (CRRT), and sustained low-efficiency dialysis (SLED).

Acute Kidney Injury and Special Considerations during Renal Replacement Therapy in Children with Coronavirus Disease-19: Perspective from the Critical Care Nephrology Section of the European Society of Paediatric and Neonatal Intensive Care

Children seem to be less severely affected by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) as compared to adults. Little is known about the prevalence and pathogenesis of acute kidney injury (AKI) in children affected by SARS-CoV-2. Dehydration seems to be the most common trigger factor, and meticulous attention to fluid status is imperative. The principles of initiation, prescription, and complications related to renal replacement therapy are the same for coronavirus disease (COVID) patients as for non-COVID patients. Continuous renal replacement therapy (CRRT) remains the most common modality of treatment. When to initiate and what modality to use are dependent on the available resources. Though children are less often and less severely affected, diversion of all hospital resources to manage the adult surge might lead to limited CRRT resources. We describe how these shortages might be mitigated. Where machines are limited, one CRRT machine can be used for multiple patients, providing a limited number of hours of CRRT per day. In this case, increased exchange rates can be used to compensate for the decreased duration of CRRT. If consumables are limited, lower doses of CRRT (15-20 mL/kg/h) for 24 h may be feasible. Hypercoagulability leading to frequent filter clotting is an important issue in these children. Increased doses of unfractionated heparin, combination of heparin and regional citrate anticoagulation, or combination of prostacyclin and heparin might be used. If infusion pumps to deliver anticoagulants are limited, the administration of low-molecular-weight heparin might be considered. Alternatively in children, acute peritoneal dialysis can successfully control both fluid and metabolic disturbances. Intermittent hemodialysis can also be used in patients who are hemodynamically stable. The keys to successfully managing pediatric AKI in a pandemic are flexible use of resources, good understanding of dialysis techniques, and teamwork.

The Effect of Patient- and Treatment-Related Factors on Circuit Lifespan During Continuous Renal Replacement Therapy in Critically Ill Children

OBJECTIVES

To examine the effects of patient and treatment variables on circuit lifespan in critically ill children requiring continuous renal replacement therapy.

DESIGN

Retrospective observational study based on a prospective registry.

SETTING

Tertiary referral 30-bed PICU.

PATIENTS

One hundred sixty-one critically ill children undergoing continuous renal replacement therapy during an 8-year period (2007-2014) were included in the study.

INTERVENTIONS

Continuous renal replacement therapy.

MEASUREMENTS AND MAIN RESULTS

During the study period, 161 patients received a total of 22,190 hours of continuous renal replacement therapy, with a median duration of 74.75 hours (interquartile range, 32-169.5) per patient. Of the 572 filter circuits used, 276 (48.3%) were changed due to circuit clotting and 262 (45.8%) were electively changed. Median circuit life was 24.62 hours (interquartile range, 10.6-55.3) for all filters and significantly longer for those electively removed as compared to those prematurely removed because of clotting (35.50 hr [interquartile range, 16.9-67.6] vs 22.00 hr [interquartile range, 13.8-42.5]; p < 0.001). Multivariate regression analyses revealed that admission diagnosis (p < 0.001), anticoagulation type (p < 0.001), access type (p = 0.016), and circuit size (p = 0.027) were associated with prolonged circuit life, as well as, in patients on heparin anticoagulation, with higher doses of heparin (p < 0.001) and a prolonged activated partial thromboplastin time (p < 0.001).

CONCLUSIONS

In this study, circuit lifespan in pediatric continuous renal replacement therapy was low and appeared to depend upon the patient's diagnosis, the type of access and anticoagulation used as well as the size of the circuit used.

Challenges of Vascular Access in the Pediatric Population

The incidence and prevalence of renal replacement therapy has continued to increase in the pediatric population. Recent data have shown that hemodialysis was the most frequently used dialysis modality, especially in pediatric ESRD patients (age 0-21 years). A well-functioning vascular access is required for effective hemodialysis and choosing the best vascular access option for pediatric patients can be difficult. Pediatric vascular options include arteriovenous fistula, arteriovenous graft, and central venous catheters (CVCs). There is a national initiative for fistula first-catheter last approach; however, CVCs have been reported as the most conventionally utilized vascular access option in pediatric patients. The use of CVCs should be minimized or avoided as they are associated with high risk of infections, thrombosis, and other complications. Thus, it is important for practitioners to plan appropriately in advance, practice good clinical judgment, and assure that the best vascular access is placed according to the patient's needs. Therefore, this article reviews the different types of pediatric vascular access and the associated benefits and potential complications of each.

Dialysis modalities for the management of pediatric acute kidney injury

Acute kidney injury (AKI) is an increasingly frequent complication among hospitalized children. It is associated with high morbidity and mortality, especially in neonates and children requiring dialysis. The different renal replacement therapy (RRT) options for AKI have expanded from peritoneal dialysis (PD) and intermittent hemodialysis (HD) to continuous RRT (CRRT) and hybrid modalities. Recent advances in the provision of RRT in children allow a higher standard of care for increasingly ill and young patients. In the absence of evidence indicating better survival with any dialysis method, the most appropriate dialysis choice for children with AKI is based on the patient's characteristics, on dialytic modality performance, and on the institutional resources and local practice. In this review, the available dialysis modalities for pediatric AKI will be discussed, focusing on indications, advantages, and limitations of each of them.

Prescription of CRRT: a pathway to optimize therapy

Severe acute kidney injury (AKI), especially when caused or accompanied by sepsis, is associated with prolonged hospitalization, progression to chronic kidney disease (CKD), financial burden, and high mortality rate. Continuous renal replacement therapy (CRRT) is a predominant form of renal replacement therapy (RRT) in the intensive care unit (ICU) due to its accurate volume control, steady acid-base and electrolyte correction, and achievement of hemodynamic stability. This manuscript reviews the different aspects of CRRT prescription in critically ill patients with severe AKI, sepsis, and multiorgan failure in ICU. These include the choice of CRRT versus Intermittent and extended hemodialysis (HD), life of the filter/dialyzer including assessment of filtration fraction, anticoagulation including regional citrate anticoagulation (RCA), prescribed versus delivered CRRT dose, vascular access management, timing of initiation and termination of CRRT, and prescription in AKI/sepsis including adsorptive methods of removing endotoxins and cytokines.

Dual Carbon Dioxide Capture to Achieve Highly Efficient Ultra-Low Blood Flow Extracorporeal Carbon Dioxide Removal

Extracorporeal CO₂ removal is a highly promising support therapy for patients with hypercapnic respiratory failure but whose clinical implementation and patient benefit is hampered by high cost and highly specialized expertise required for safe use. Current approaches target removal of the gaseous CO₂ dissolved in blood which limits their ease of clinical use as high blood flow rates are required to achieve physiologically significant CO₂ clearance. Here, a novel hybrid approach in which a zero-bicarbonate dialysis is used to target removal of bicarbonate ion coupled to a gas exchange device to clear dissolved CO₂, achieves highly efficiently total CO₂ capture while maintaining systemic acid-base balance. In a porcine model of acute hypercapnic respiratory failure, a CO₂-reduction of 61.4 ± 14.4 mL/min was achieved at a blood flow rate of 248 mL/min using pediatric-scale priming volumes. The dialyzer accounted for 81% of total CO₂ capture with an efficiency of 33% with a minimal pH change across the entire circuit. This study demonstrates the feasibility of a novel hybrid CO₂ capture approach capable of achieving physiologically significant CO₂ removal at ultralow blood flow rates with low priming volumes while leveraging widely available dialysis platforms to enable clinical adoption.

Basics of continuous renal replacement therapy in pediatrics

In the last three decades, significant advances have been made in the care of children requiring renal replacement therapy (RRT). The move from the use of only hemodialysis and peritoneal dialysis to continuous venovenous hemofiltration with or without dialysis (continuous renal replacement therapy, CRRT) has become a mainstay in many intensive care units. The move to CRRT is the result of greater clinical experience as well as advances in equipment, solutions, vascular access, and anticoagulation. CRRT is the mainstay of dialysis in pediatric intensive care unit (PICU) for critically ill children who often have hemodynamic compromise. The advantages of this modality include the ability to promote both solute and fluid clearance in a slow continuous manner. Though data exist suggesting that approximately 25% of children in any PICU may have some degree of renal insufficiency, the true need for RRT is approximately 4% of PICU admissions. This article will review the history as well as the progress being made in the provision of this care in children.

Choice of Catheter Size for Infants in Continuous Renal Replacement Therapy: Bigger Is Not Always Better

OBJECTIVES

Renal replacement therapy in infants and small children is the treatment of choice for severe oligoanuric renal dysfunction, with an increasing consensus that early initiation might contribute to preventing acute kidney injury complications. Safer renal replacement therapy devices specifically designed for neonates may contribute to ameliorating outcomes and increasing chances of survival. One of the crucial factors to achieve an effective renal replacement therapy in small infants is adequate vascular access. The interaction of small size central vascular catheters with renal replacement therapy devices has never been investigated. The aim of this study was to characterize both the operating conditions and performance of three different central vascular catheters sizes (4F, 5F, and 7F) connected to two different extracorporeal blood circulation models (adult and pediatric). The rheologic performance of each vascular access size in combination with the adult and pediatric renal replacement therapy models was described.

DESIGN

Series of experimental extracorporeal circulation circuit tests were conducted with different setups. A two-roller pump was used to simulate a standard adult dialysis machine, whereas a small three-roller pump served as pediatric renal replacement therapy device.

SETTING

A pressure-flow setup aimed to collect pressure and flow values under different test conditions. A second experiment focused on hemolysis estimation induced by the extracorporeal system. Hemolysis exclusively induced by the 4F catheter was also evaluated. Finally, our data were applied to estimate the optimal catheter size theoretically capable of delivering adequate doses basing on anthropometric data (patient weight and cannulation site) in absence of direct ultrasound vessel measurement.

SUBJECTS

In vitro tests conducted on simulated extracorporeal circuit models of continuous pediatric and neonatal renal replacement therapy.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

When 4F and 5F catheters are used, maximal blood flows within safe circuit pressures can be set at the values of 13 and 29 mL/min, respectively, when a small pump is used. Differently, when using adult roller pumps, only maximal flows of 10 and 20 mL/min are reached. However, hemolysis is higher when using a three-roller pump compared with the two-roller. The clinical impact of this increased hemolytic burden is likely not relevant.

CONCLUSIONS

Small size central vascular catheters display optimal rheologic performances in terms of pressures and flows particularly when the renal replacement therapy device is equipped with pumps proportional to central vascular catheters sizes, and even when relatively high blood flows are set. This is achieved at the risk of a higher hemolysis rate.

Process based quality improvement using a continuous renal replacement therapy dashboard

BACKGROUND

The prevalence of continuous renal replacement therapy (CRRT) utilization in critically ill patients with acute kidney is increasing. In comparison to published and on-going trials attempting to answer questions surrounding the optimal timing of CRRT initiation, anticoagulation, and modality, a paucity of literature describes the quality of the therapy delivered.

METHODS

We conducted a single-center process improvement project to determine if a methodology to assess the quality of CRRT delivery could lead to improvement in CRRT delivery outcomes. We developed three broad categories of objective CRRT metrics to assess longitudinally, enabling creation of a CRRT Dashboard. Following the objective categories of "filter", "prescription", and "fluid balance" over time allowed us to perform quarterly analyses, target provider based CRRT education, and address variation from our standard of care. From 2012 to 2017, 184 critically ill patients received CRRT.

RESULTS

We report a mean filter life of 56 + 28.4 h, a 60-h filter life of 62%, and unplanned filter changes of 15%. Compared to a minimum target prescription of 2000 ml/1.73 m2/hour, we report the mean prescribed dose (2300 ml/1.73 m2/hour) and the rate of patients receiving at least the minimum prescription (98%). Finally, using a 10% deviation in the acceptable range of desired daily patient fluid balance, we report 83% CRRT patient days achieving an acceptable stipulated fluid goal.

CONCLUSION

We report the implementation of a quality dashboard and adopting quality improvement strategies provided a platform for measuring adherence to our institutional standards and the delivery of CRRT, specifically on the process of the care.

Pediatric continuous renal replacement therapy: have practice changes changed outcomes? A large single-center ten-year retrospective evaluation

Background

To evaluate changes in population characteristics and outcomes in a large single-center pediatric patient cohort treated with continuous renal replacement therapy (CRRT) over a 10 year course, coincident with multiple institutional practice changes in CRRT delivery.

Methods

A retrospective cohort study with comparative analysis of all patients treated from 2004 to 2013 with CRRT in the neonatal, pediatric, and cardiovascular intensive care units within a free-standing pediatric tertiary care hospital.

Results

Three hundred eleven total patients were identified, 38 of whom received concurrent treatment with extracorporeal membrane oxygenation. 273 patients received CRRT only and were compared in two study eras (2004–2008 n = 129; 2009–2013 n = 144). Across eras, mean patient age decreased (9.2 vs 7.7 years, p = 0.08), and the most common principal diagnosis changed from cardiac to liver disease. There was an increase in patients treated with continuous renal replacement therapy between cohorts for acute kidney injury of multi factorial etiology (44% vs 56%) and a decrease in treated patients with sepsis (21% vs 11%, p = 0.04). There was no significant difference in survival to hospital discharge between eras (47% vs 49%). Improvement in outpatient follow-up after discharge amongst survivors was seen between study eras (33% vs 54%).

Conclusions

Despite multiple institutional practice changes in provision of CRRT, few changes were seen regarding patient demographics, diseases treated, indications for therapy, and survival over 10 years at a single tertiary care. Recognition of need for follow-up nephrology care following CRRT is improving. Ongoing assessment of the patient population in a changing landscape of care for critically ill pediatric patients remains important.

Outcome of continuous renal replacement therapy in critically ill children: a retrospective cohort study

BACKGROUND

Continuous renal replacement therapy (CRRT) has become the preferred mode of dialysis to support critically ill children with acute kidney injury. However, there are limited pediatric data on CRRT use, especially in our region.

OBJECTIVE

Determine the outcome of CRRT among critically ill children.

DESIGN

Retrospective cohort study.

SETTING

Pediatric intensive care unit.

PATIENTS AND METHODS

The study included critically ill children 1-14 years of age who underwent CRRT from July 2009 to June 2015. We report the underlying diagnosis, demographics, indications and modality of CRRT, and associated risk factors. Statistical analyses were used to identify risk factors associated with mortality.

MAIN OUTCOME MEASURES

Mortality and associated risk factors with use of CRRT.

SAMPLE SIZE

96 RESULTS: The mean age was 6.0 (standard deviation, 4.4) years, with a male preponderance in the age group from 1-10 years which comprised almost 60% of the study group. The most common primary diagnoses were malignancies [37.5% (36/96)] followed by primary renal diseases [19.8% (19/96)], and immunodeficiency [16.7% (16/96)]. The most common indication for CRRT was fluid overload [67.2% (65/96)] followed by tumor lysis syndrome [18.8%(18/96)], and metabolic encephalopathy [9.4%(9/96)]. The median length of CRRT was 66 hours (IQR, 35.5-161.4), with a median average circuit life of 30.9 hours (IQR, 16.4-45.0). The most common CRRT catheter site was the internal jugular vein [77.1% (74/96)], followed by the femoral vein [18.8%(18/96)] with continuous venovenous hemodiafiltration [82.3%(79/96)] being the most common CRRT modality used. The mortality rate among critically ill children requiring CRRT was 50% (48/96). There was an increased mortality rate among children with hematological diseases (100%, 10/10), immunodeficiency (86.6%, 13/16) and in children who had undergone stem cell transplantation (90.0%, 27/30), with the least mortality in primary renal disease (15.8% (3/19). We identified septic shock and use of inotropic support as being independently associated with mortality in a multivariate analysis.

CONCLUSION

The overall mortality rate among critically ill children who un.derwent CRRT was 50% with significantly increased mortality among patients with hematological diseases, immunodeficiency, and in children who had undergone stem cell transplantation. Septic shock and use of inotropic support were associated with mortality.

LIMITATIONS

Retrospective and single center data that is not generalizable.

CONFLICT OF INTEREST

None.

Renal Replacement Therapy in the Critically Ill Child

OBJECTIVES

Although renal replacement therapy is widely used in critically ill children, there have been few comprehensive population-based studies of its use. This article describes renal replacement therapy use, and associated outcomes, in critically ill children across the United Kingdom in the largest cohort study of this patient group.

DESIGN

A retrospective observational study using prospectively collected data.

SETTING

Data from the Pediatric Intensive Care Audit Network database which collects data on all children admitted to U.K. PICUs.

PATIENTS

Children (< 16 yr) in PICU who received renal replacement therapy between January 1, 2005, and December 31, 2012, were identified.

INTERVENTIONS

Individual-level data including age, underlying diagnosis, modality (peritoneal dialysis and continuous extracorporeal techniques [continuous renal replacement therapy]), duration of renal replacement therapy, PICU length of stay, and survival were extracted.

MEASUREMENTS AND MAIN RESULTS

Three-thousand eight-hundred twenty-five of 129,809 PICU admissions (2.9%) received renal replacement therapy in 30 of 33 centers. Volumes of renal replacement therapy varied considerably from 0% to 8.6% of PICU admissions per unit, but volume was not associated with patient survival. Overall survival to PICU discharge (73.8%) was higher than previous reports. Mortality risk was related to age, with lower risk in older children compared with neonates (odds ratio, 0.6; 95% CI, 0.5-0.8) although mortality did not increase over the age of 1 year; mode of renal replacement therapy, with lower risk in peritoneal dialysis than continuous renal replacement therapy methodologies (odds ratio, 0.7; 0.5-0.9); duration of renal replacement therapy (odds ratio, 1.02/d; 95% CI, 1.01-1.04); and primary diagnosis, with the lowest survival in liver disease patients (53.9%).

CONCLUSIONS

This study describes current renal replacement therapy use across the United Kingdom and associated outcomes. We describe a number of factors associated with outcome, including age, underlying diagnosis, and renal replacement therapy modality which will need to be factored into future trial design.

A Report of 7-Year Experience on Pediatric Continuous Renal Replacement Therapy

BACKGROUND

Continuous renal replacement therapies (CRRTs) either as continuous venovenous hemofiltration (CVVH) or hemodiafiltration (CVVHD) are used frequently in critically ill children. Many clinical variables and technical issues are known to affect the result. The factors that could be modified to increase the survival of renal replacement are sought. As a contribution, we present the data on 104 patients who underwent CRRT within a 7-year period.

MATERIALS AND METHOD

A total of 104 patients admitted between 2009 and 2016 were included in the study. The demographic information, admittance pediatric risk of mortality (PRISM) scores, indication for CRRT, presence of fluid overload, CRRT modality, durations of CRRT, and pediatric intensive care unit (PICU) stay were compared between survivors and nonsurvivors.

RESULTS

The overall rate of survival was 51%. Patients with fluid overload had significantly increased rate of death, CRRT duration, and PICU stay. Multiorgan dysfunction syndrome as the indication for CRRT was significantly related to decreased survival when compared to acute renal failure and acute attacks of metabolic diseases. The CRRT modality was not different between survivors and nonsurvivors. Standardized mortality ratio of the group was calculated to be 0.8.

CONCLUSION

The CRRT in critically ill patients is successful in achieving fluid removal and correction of metabolic imbalances caused by organ failures or attacks of inborn errors of metabolism. It has a positive effect on expected mortality in high-risk PICU patients. To affect the outcome, follow-up should be focused on starting therapy in early stages of fluid overload. Prospective studies defining relative importance of risk factors causing mortality can assist in building up guidelines to affect the outcome.

CRRTnet: a prospective, multi-national, observational study of continuous renal replacement therapy practices

Background

Continuous renal replacement therapy (CRRT) is the recommended modality of dialysis for critically ill patients with hemodynamic instability. Yet there remains significant variability in how CRRT is prescribed and delivered, and limited evidence-basis to guide practice.

Methods

This is a prospective, multi-center observational study of patients undergoing CRRT. Initial enrollment phase will occur at 4 academic medical centers in North America over 5 years, with a target enrollment of 2000 patients. All adult patients (18–89 years of age) receiving CRRT will be eligible for inclusion; patients who undergo CRRT for less than 24 h will be excluded from analysis. Data collection will include patient characteristics at baseline and at time of CRRT initiation; details of CRRT prescription and delivery, including machine-generated treatment data; and patient outcomes.

Discussion

The goal of this study is to establish a large comprehensive registry of critically ill adults receiving CRRT. Specific aims include describing variations in CRRT prescription and delivery across quality domains; validating quality measures for CRRT care by correlating processes and outcomes; and establishing a large registry for use in quality improvement and benchmarking efforts. For initial analyses, some particular areas of interest are anticoagulation protocols; approach to fluid overload; CRRT-related workload; and patient safety.

Trial registration

Registered on ClinicalTrials.gov 1/10/2014: NCT02034448.

Membrane pressures predict clotting of pediatric continuous renal replacement therapy circuits

BACKGROUND

Clotting of continuous renal replacement therapy (CRRT) circuits leads to inadequate clearance, decreased ultrafiltration, and increased resource use. We identified factors associated with premature clotting of circuits during CRRT in children.

METHODS

In a retrospective cohort of 26 children (median age 11.8 years) receiving 79 CRRT circuits (51 heparin, 22 citrate, 6 using no anticoagulation), we captured hourly pressure, flow, and fluid removal rates along with all activated clotting time (ACT) and circuit ionized calcium measurements. Cox and logistic regression models were used to examine factors associated with premature circuit clotting before the scheduled 3-day circuit change.

RESULTS

Of the 79 circuits, 51 (64.6%) underwent unplanned filter change due to filter clotting (median duration 18.25 h, interquartile range [IQR] 9.25, 33.5 h), and 28 (35.4%) underwent scheduled change (median duration 66 h, IQR 61.00, 69.00 h). Patient age, catheter size and location, blood flow rate, and the percentage of pre-filter replacement fluid were not associated with premature clotting. Heparin circuits were less likely than citrate circuits to clot prematurely. Each 1-mmHg increase in the transmembrane or filter pressure was independently associated with a 1.5% (95% confidence interval [CI] 1.0-2.0%) and 1.5% (95% CI 1.0-2.0%) higher risk of clotting, respectively. Higher ACTs were associated with lower transmembrane (p = 0.03) and filter (p < 0.001) pressures.

CONCLUSIONS

The majority of circuits in our cohort were subject to unplanned filter changes. Elevated transmembrane and filter pressures were associated with clotting. Our results suggest that maintaining higher ACT may decrease the risk of circuit clotting. Larger studies are needed to examine other factors that may prolong the lifespan of the CRRT circuit in this high-risk population.

Continuous Venovenous Hemofiltration in Children Less Than or Equal to 10 kg: A Single-Center Experience

OBJECTIVES

The aim of this study was to review the data from patients with a body weight less than or equal to 10 kg who required continuous venovenous hemofiltration, to assess the feasibility and problems associated with continuous venovenous hemofiltration in this population and compare the results with the current literature.

DESIGN

Retrospective study design.

SETTING

PICU in a single tertiary pediatric referral center.

PATIENTS

Children less than or equal to 10 kg who received continuous venovenous hemofiltration between January 2008 and July 2014 were included in the study.

INTERVENTIONS

Clinical data from these children were analyzed, and the differences between survivors and nonsurvivors were evaluated and compared with results from current literature. In a subgroup analysis of children less than or equal to 5 kg compared with children between 5 and 10 kg, the survival rate, indications for continuous venovenous hemofiltration, and continuous venovenous hemofiltration characteristics were assessed.

MEASUREMENTS AND MAIN RESULTS

In total, 71 continuous renal replacement therapy episodes in 70 children were included in the study. Children in our cohort had a survival rate of 57.7% (41/71). Survivors had less frequent need for vasopressor support prior to continuous venovenous hemofiltration, lower oxygen requirement and percent fluid overload at continuous venovenous hemofiltration initiation. Survival rate was not significantly different in children less than or equal to 5 kg compared with 5-10 kg. However, in children less than or equal to 5 kg, metabolic manipulation was a significantly more frequent indication for continuous venovenous hemofiltration, heparin use was lower and maximal blood flow rate was higher.

CONCLUSIONS

We have shown that continuous venovenous hemofiltration can be performed with good outcomes in children less than or equal to 10 kg using relatively high blood flow rates and with the current equipment available.

Fluid Management: Pharmacologic and Renal Replacement Therapies

OBJECTIVES

Focusing on critically ill children with cardiac disease, we will review common causes of fluid perturbations, clinical recognition, and strategies to minimize and treat fluid-related complications.

DATA SOURCE

MEDLINE and PubMed.

CONCLUSIONS

Meticulous fluid management is vital in critically ill children with cardiac disease. Fluid therapy is important to maintain adequate blood volume and perfusion pressure in order to support cardiac output, tissue perfusion, and oxygen delivery. However, fluid overload and acute kidney injury are common and are associated with increased morbidity and mortality. Understanding the etiologies for disturbances in volume status and the pathophysiology surrounding those conditions is crucial for providing optimal care.

Experience of Circuit Survival in Extracorporeal Continuous Renal Replacement Therapy Using Small-Calibre Venous Cannulae

OBJECTIVES

To describe an experience of circuit survival in extracorporeal continuous renal replacement therapy using small-calibre (< 7 French gauge [F]) venous cannulae.

DESIGN

An observational study.

SETTING

A multidisciplinary, university-affiliated PICU.

SUBJECTS

Case note review of all continuous renal replacement therapy episodes (1998-2010), which used vascular access cannulae of an external diameter less than 7F, was performed.

MEASUREMENTS AND MAIN RESULTS

Forty-nine patients underwent continuous renal replacement therapy treatment during which circuit blood flow was delivered using either 5F or 6.5F double-lumen cannulae. One hundred thirty-nine circuits were employed (median per patient, 2; interquartile range, 1-3) in providing 4,903 hours of therapy (median duration of therapy, 43 hr; interquartile range, 22-86 hr); allowing for censoring, the median circuit survival time was 40 hours (95% CI, 28-66). Eighty-one circuits (58%) failed because of clotting/technical problems, equating to a circuit failure rate of 16.5 (95% CI, 13.3-20.5) per 1,000 hours of continuous renal replacement therapy. The probability of a circuit surviving 40 hours or greater was 50% with 43% (95% CI, 34-53%) expected to survive 60 hours or more. No significant relationship between circuit survival and the calibre of the cannula deployed was identified; however, placement of venous access in an internal jugular vein was associated with improved circuit survival.

CONCLUSIONS

Contrary to previous reports, vascular access cannulae of a caliber less than 7F can support sufficiently prolonged continuous renal replacement therapy to make them a useful means of delivering renal support in neonates and small infants.

Renal replacement therapy in adult and pediatric intensive care : Recommendations by an expert panel from the French Intensive Care Society (SRLF) with the French Society of Anesthesia Intensive Care (SFAR) French Group for Pediatric Intensive Care Emergencies (GFRUP) the French Dialysis Society (SFD)

Acute renal failure (ARF) in critically ill patients is currently very frequent and requires renal replacement therapy (RRT) in many patients. During the last 15 years, several studies have considered important issues regarding the use of RRT in ARF, like the time to initiate the therapy, the dialysis dose, the types of catheter, the choice of technique, and anticoagulation. However, despite an abundant literature, conflicting results do not provide evidence on RRT implementation. We present herein recommendations for the use of RRT in adult and pediatric intensive care developed with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system by an expert group of French Intensive Care Society (SRLF), with the participation of the French Society of Anesthesia and Intensive Care (SFAR), the French Group for Pediatric Intensive Care and Emergencies (GFRUP), and the French Dialysis Society (SFD). The recommendations cover 4 fields: criteria for RRT initiation, technical aspects (access routes, membranes, anticoagulation, reverse osmosis water), practical aspects (choice of the method, peritoneal dialysis, dialysis dose, adjustments), and safety (procedures and training, dialysis catheter management, extracorporeal circuit set-up). These recommendations have been designed on a practical point of view to provide guidance for intensivists in their daily practice.

Renal Replacement Therapy in the Pediatric Critical Care Unit

Renal replacement therapy is becoming more prevalent in the pediatric intensive care units for a large variety of disease states, including multiorgan dysfunction syndrome, fluid overload, and electrolyte imbalance. Three modalities-continuous renal replacement therapy, hemodialysis, and peritoneal dialysis-are commonly used. When deciding among the three therapies, there are several advantages and disadvantages of each modality that must be considered. This manuscript provides an overview of each modality as well as its pros and cons.

Continuous renal replacement therapy in children with multiple organ dysfunction syndrome: a case series

There is a lack of definitive information regarding the precise indications, implementation, and outcomes of continuous renal replacement therapy (CRRT) for the treatment of critically ill children. Six children (three boys, three girls) aged from 3 days to 8 years, all of whom had multiple organ failure, were submitted to bedside CRRT using M60 filter membranes. Modified Port carbonate formula was used and clotting time was maintained between 20 and 30 minutes. Activated partial thromboplastin time was 1.5- to 2-fold normal. One patient discontinued treatment due to family decision. Marked improvements were seen in the remaining five patients, including normalization of blood urea nitrogen and creatinine levels, stabilization of electrolytes, and improvements in markers of organ function. Of note, one patient (a six-year-old male) underwent the treatment for 241 hours. All five patients were subsequently discharged and recovered uneventfully. CRRT is effective for the management of children who are critically ill due to multiple organ failure.

Pediatric continuous renal replacement: 20 years later

INTRODUCTION

More than 20 years have passed since the first clinical application of continuous renal replacement therapy (CRRT) in children. In that revolutionary era, before roller pumps and dialysis monitors for intensive care units were readily available, continuous arteriovenous hemofiltration was the most common treatment for critically ill children.

MAJOR FINDINGS

Those steps were the basis for current knowledge about modern CRRT. Research on circuit rheology and filter materials allowed for the improvement of materials, and the optimization of patency and session life spans. Hemofiltration was coupled with dialysis to increase dialytic dose and system efficiency. Several systems were required to optimize ultrafiltration and manage fluid overload. A quarter of a century later, another revolution is taking place. Acute renal failure has been recognized as a threatening syndrome, independently associated with mortality in critically ill children and characterized by a broad spectrum of clinical phenotypes. For this reason, it has been redefined as acute kidney injury (AKI). This condition is today accurately classified in both adults and children, and has been identified as a primary condition for prevention and aggressive treatment in all pediatric intensive care unit patients. Critically ill neonates and children with multiple organ dysfunction are certainly at higher risk of AKI. Finally, novel technology specifically dedicated to pediatric patients allows feasible and easy application of CRRT to infants and children: a new field of critical care nephrology, dedicated to pediatric patients, has been fully developed.

CONCLUSION

After 20 years, significant developments in critical care nephrology have taken place. Clinical and technical issues have both been addressed, and severe pediatric AKI can currently be managed with accurate and safe dialysis machines that will likely warrant outcome improvements over the following decade.

The prospective pediatric continuous renal replacement therapy (ppCRRT) registry: a critical appraisal

Continuous renal replacement therapy (CRRT), which provides gradual, predictable clearance and fluid removal, is commonly used to manage acute kidney injury (AKI) and fluid overload in critically ill children. The Prospective Pediatric CRRT (ppCRRT) Registry, founded in 2001 and comprising 13 pediatric centers in the United States, represents the largest cohort of children receiving CRRT to date. Data from the ppCRRT has been used to describe pediatric CRRT demographics and epidemiology, improve technical aspects of CRRT provision for children, and identify novel or underappreciated risk factors affecting survival. Whereas the registry has successfully answered many questions, a number of questions remain unanswered and new ones have arisen. This article describes the ppCRRT Registry, including its major findings, the lessons learned, and the limitations inherent in its design. Additionally, using the registry as a framework, areas of future study are identified and potential methodologies examined.

Factors affecting circuit life during continuous renal replacement therapy in children with liver failure

Despite abnormal clotting, circuits clot during continuous renal replacement therapy (CRRT) in children with acute liver failure (ALF). We report our experience. All children with ALF needing CRRT were studied over 2 years. Patient and circuit factors associated with circuit use were evaluated. Thirty-one children in liver failure (median age 7.4 years) underwent CRRT, of which 17 (54.8%) died. A total of 98 filtration episodes were used. The smallest access catheter was 6.5 Fr, while the largest was 13.5 Fr. The most common filter used was HFO7 (63%). Mean duration (SD) of circuit use was 33.13(30.83) hours. Of the 98 filtration episodes, circuits blocked in 25, whereas the access catheter blocked in 25. Fifty-two circuits were changed electively for a variety of reasons. Prostacyclin was the anticoagulant in 62 filtration episodes. The remaining filtration episodes had either no anticoagulation or heparin. The mean (SD) "downtime" was 5.13 (9.15) hours. We found a significant association between fresh frozen plasma (FFP) use with circuit blockade. Neither the duration of CRRT nor the "downtime" influenced mortality. The CRRT circuits blocked in children despite deranged clotting in liver disease. Circuits are changed for a variety of reasons other than clotting. The use of FFP reduces circuit life.

Continuous renal replacement therapy in neonates and small infants: development and first-in-human use of a miniaturised machine (CARPEDIEM)

BACKGROUND

Peritoneal dialysis is the renal replacement therapy of choice for acute kidney injury in neonates, but in some cases is not feasible or effective. Continuous renal replacement therapy (CRRT) machines are used off label in infants smaller than 15 kg and are not designed specifically for small infants. We aimed to design and create a CRRT machine specifically for neonates and small infants.

METHODS

We prospectively planned a 5-year project to conceive, design, and create a miniaturised Cardio-Renal Pediatric Dialysis Emergency Machine (CARPEDIEM), specifically for neonates and small infants. We created the new device and assessed it with in-vitro laboratory tests, completed its development to meet regulatory requirements, and obtained a licence for human use. Once approved, we used the machine to treat a critically ill neonate

FINDINGS

The main characteristics of CARPEDIEM are the low priming volume of the circuit (less than 30 mL), miniaturised roller pumps, and accurate ultrafiltration control via calibrated scales with a precision of 1 g. In-vitro tests confirmed that both hardware and software met the specifications. We treated a 2·9 kg neonate with haemorrhagic shock, multiple organ dysfunction, and severe fluid overload for more than 400 h with the CARPEDIEM, using continuous venovenous haemofiltration, single-pass albumin dialysis, blood exchange, and plasma exchange. The patient's 65% fluid overload, raised creatinine and bilirubin concentrations, and severe acidosis were all managed safely and effectively. Despite the severity of the illness, organ function was restored and the neonate survived and was discharged from hospital with only mild renal insufficiency that did not require renal replacement therapy.

INTERPRETATION

The CARPEDIEM CRRT machine can be used to provide various treatment modalities and support for multiple organ dysfunction in neonates and small infants. The CARPEDIEM could reduce the range of indications for peritoneal dialysis, widen the range of indications for CRRT, make the use of CRRT less traumatic, and expand its use as supportive therapy even when complete renal replacement therapy is not indicated.

FUNDING

Associazione Amici del Rene di Vicenza.

Successful continuous renal replacement therapy using two single-lumen catheters in neonates and infants with cardiac disease

BACKGROUND

Acute kidney injury (AKI) frequently occurs in neonates and infants after cardiopulmonary bypass (CPB) and may require renal replacement therapy (RRT). Peritoneal dialysis (PD) is the RRT modality of choice in neonates with AKI after CPB, but continuous renal replacement therapy (CRRT) may be necessary if PD is ineffective or contraindicated. Vascular access is challenging in this population, in part, due to small central vein size that may preclude placement. The risk of malfunction or morbidity associated with standard dialysis catheters may be excessive in neonates with congenital heart disease. We describe a unique approach to vascular access for CRRT in six small patients with AKI.

CASE-DIAGNOSIS/TREATMENT

This is a retrospective review of six patients with fluid overload and AKI that received CRRT because PD was contraindicated. In all cases, CRRT was performed via two hemostasis valve sheaths placed into separate veins for dialysis access and return. The low-resistance sheaths provided excellent blood flow with normalization of metabolic derangements and significant fluid removal (median negative 167 ml/kg at 72 h). Mean circuit life before the first change was 55.2 ± 30.4 h.

CONCLUSIONS

The use of two small single-lumen catheters in separate veins enables consistent and effective hemodiafiltration in neonates and infants with challenging vascular access.