Citrate anticoagulation for continuous renal replacement therapy in small children

A Comparison of the Anticoagulation Efficacy and Safety of Epoprostenol to Heparin and Citrate in Children Receiving Continuous Renal Replacement Therapy

INTRODUCTION

Anticoagulants are used in continuous renal replacement therapy (CRRT) to prolong filter life. There are no prior investigations directly comparing epoprostenol to more commonly used forms of anticoagulation in children. Therefore, the primary aim of this study was to assess the efficacy and safety of epoprostenol as compared to heparin and citrate anticoagulation in a pediatric cohort.

METHODS

We performed a retrospective analysis of all patients <18 years of age admitted to an academic quaternary care children's hospital from 2017-2022 who received epoprostenol, heparin, or citrate exclusively for CRRT anticoagulation. Efficacy was evaluated by comparing the hours to the first unintended filter change and the ratio of filters used to CRRT days. Safety was assessed by evaluating changes in platelet count and vasoactive-ionotropic score (VIS).

RESULTS

Of 101 patients, 44 received epoprostenol (43.6%), 38 received heparin (37.6%), and 19 received citrate (18.8%). The first filter change was more commonly planned in patients receiving anticoagulation with epoprostenol (43%) as compared to citrate (11%) or heparin (29%) (p = 0.034). Of those patients where the first filter change was unintended (n = 33), there were greater median hours until the filter was replaced in those receiving epoprostenol (29) when compared to citrate (21) (p = 0.002) or heparin (18) (p = 0.003). There was a smaller median ratio of filters used to days on therapy in the patients that received epoprostenol (0.53) when compared to citrate (1) (p = 0.003) or heparin (0.75) (p = 0.001). For those receiving epoprostenol, there was no significant decrease in platelet count when comparing values prior to CRRT initiation through 7 days of therapy. There was no significant difference in VIS when comparing values prior to CRRT initiation through the first 2 days of CRRT.

CONCLUSIONS

Epoprostenol-based anticoagulation is effective when compared to other anticoagulation strategies used in pediatric CRRT with a favorable side effect profile.

Citrate anticoagulation and systemic heparin anticoagulation during continuous renal replacement therapy among critically-ill children

BAKCGROUND

The aim of this study was to evaluate the efficacy and safety of citrate versus heparin anticoagulation for CRRT in critically-ill children.

METHODS

This retrospective comparative cohort reviewed the clinical records of critically-ill children undergoing CRRT with either RCA or systemic heparin anticoagulation. The primary outcome measure was hemofilter survival time. Secondary outcomes included the comparison of complications and metabolic disorders.

RESULTS

A total of 131 patients (55 RCA and 76 systemic heparin) were included, in which a cumulative number of 280 hemofilters were used (115 in RCA with 5762 h total CRRT time, and 165 in systemic heparin with 6230 h total CRRT time). Hemofilter survival was significantly longer for RCA (51.0 h; IQR: 24-67 h) compared to systemic heparin (29.5 h; IQR, 17-48 h) (p = 0.002). Clotting-related hemofilter failure occurred in 9.6% of the RCA group compared to 19.6% in the systemic heparin group (p = 0.038). Citrate accumulation occurred in 4 (3.5%) of 115 RCA sessions. Hypocalcemia and metabolic alkalosis episodes were significantly more frequent in RCA recipients (35.7% vs 15.2%, p < 0.0001; 33.0% vs 19.4%, p = 0.009).

CONCLUSION

RCA is a safe and effective anticoagulation method for CRRT in critically-ill children and it prolongs hemofilter survival.

IMPACT

RCA is superior to systemic heparin for the prolongation of circuit survival (overall and for clotting-related loss) during CRRT. These data indicate that RCA can be used to maximize the effective delivery of CRRT in critically-ill patients admitted to the PICU. There are potential cost-saving implications from our results owing to benefits such as less circuit downtime and fewer circuit changes.

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.

Evaluation of the efficacy and associated complications of regional citrate anticoagulation in neonates: experience from a fourth level neonatal intensive care unit

Continuous kidney replacement therapy (CKRT) use has increased in recent years, but anticoagulation is a challenge for neonates. Regional citrate anticoagulation (RCA) is rarely preferred in neonates because of citrate accumulation (CA) and metabolic complications. We aimed to demonstrate the efficacy and safety of RCA in neonates. We retrospectively analyzed the medical records of 11 neonates treated with RCA-CKRT between 2018 and 2023. The initial dose of RCA was 2.1-3 mmol/l, and then, its dose was increased according to the level of ionized calcium (iCa+2) in the circuit and patients. The total/iCa+2 ratio after-treatment > 2.5 was indicated as CA. We evaluated to citrate dose, CA, circuit lifespan, and dialysis effectivity. The median gestational age was 39 (36.4-41.5) weeks, the median body weight (BW) was 3200 (2400-4000) grams, and the mean postnatal age was 4 (2-24) days. The most common indication for CKRT was hyperammonemia (73%). All neonates had metabolic acidosis and hypocalcemia during CKRT. Other common metabolic complications were hypophosphatemia (90%), hypokalemia (81%), and hypomagnesemia (63%). High dialysate rates with a median of 5765 ml/h/1.73 m2 allowed for a rapid decrease in ammonia levels to normal. Four patients (36.3%) had CA, and seven (63.7%) did not (non-citrate accumulation, NCA). Mean BW, median postnatal age, biochemical parameters, coagulation tests, and ammonia levels were similar between the CA and NCA groups. Low pH, low HCO3, high lactate, and SNAPPE-II scores could be associated with a higher T/iCa ratio.

CONCLUSION

 RCA was an efficient and safe anticoagulation for neonates requiring CKRT. Metabolic complications may occur, but they could be managed with adequate supplementation.

WHAT IS KNOWN

• Continuous kidney replacement therapy (CKRT) has become popular in recent years due to its successful treatment of fluid overload, electrolyte imbalance, metabolic acidosis, multi-organ failure, and hyperleucinemia/hyperammonemia associated with inborn errors of metabolism. • The need for anticoagulation is the major difficulty in neonatal CKRT. In adult and pediatric patients, regional citrate anticoagulation has been shown to be effective.

WHAT IS NEW

• RCA is an effective and safe anticoagulation method for neonates who require CKRT. • Electrolyte imbalances and metabolic acidosis could be managed with adequate supplementation and appropriate treatment parameters such as citrate dose, blood flow rate, and dialysate flow rate.

Clinical application of regional citrate anticoagulation for membrane-based therapeutic plasma exchange in children with liver failure

Background

Regional citrate anticoagulation (RCA) is being used more commonly in children for continuous renal replacement therapy. Few reports describe the application of membrane-based therapeutic plasma exchange (mTPE) with RCA in children with liver failure (LF).

Aims

To explore the application of RCA-mTPE in children with LF.

Methods

We retrospectively analyzed data from children with LF who underwent RCA-mTPE in the Children's Hospital of Chongqing Medical University's pediatric intensive care unit. We used the total to ionized calcium ratio (T/iCa) > 2.5 as the diagnostic criteria for citrate accumulation (CA). The patients were divided into two groups according to the occureence of CA at the end of RCA-mTPE (CA group: T/iCa > 2.5; NCA group: T/iCa ≤ 2.5). To evaluate the clinical safety and efficacy of RCA-mTPE, the following data from medical records were assessed and compared between groups: clinical characteristics, reasons for LF, RCA-mTPE parameters and duration, laboratory findings, and complications.

Results

In total, 92 RCA-mTPE treatments were administered to 21 children with LF over 3.8 ± 0.9 h. The following mean values were determined: blood flow rate (QB) = 2.8 ml/kg/min, 4% sodium citrate dose/blood flow rate ratio (QCi/QB) = 1.1(QCi,ml/kg/h); plasma dose/body weight ratio(QP/BW) = 18.5 (QP, ml/kg/h); 10% calcium gluconate dose/blood flow rate ratio (QCa/QB) = 0.2(QCa, ml/kg/h). The mean concentration of iCa in vitro was 0.38 ± 0.07 mmol/L. Citrate accumulation was recorded after 34 (37%) treatments. Hypocalcemia occurred in 11 (12%) and 7 (7.6%) treatments, during and after mTPE, respectively. Three hypotensive and one convulsive events, related to hypocalcemia, and two clotting events occurred during RCA-mTPE. After RCA-mTPE, the patients' pH, HCO3- and Na+ levels, and T/iCa were significantly increased and the total bilirubin (TB), conjugated bilirubin (DB), prothrombin time (PT), activated partial thromboplastin time (APTT), alanine aminotransferase (ALT), aspartate aminotransferase (AST),and ammonia levels were significantly decreased. The TB, DB, and lactic acid levels, before RCA-mTPE, were significantly higher in the CA group than in the NCA group, but there were no significance between the two groups in QB/BW, QCi/QB, and QP/BW, mTPE duration, and estimated amount of citrate metabolized.

Conclusions

Children with LF undergoing RCA-mTPE are at risk of hypocalcemia. With proper protocol adjustment, however, RCA-mTPE can be used safely and effectively in these patients.

Novel blood product transfusion regimen to prevent clotting and citrate accumulation during continuous renal replacement therapy with regional citrate anticoagulation in children

Objective

Introduce a novel protocol to prevent clotting and citrate accumulation (CA) from blood product transfusion (BPT) during continuous renal replacement therapy (CRRT) with regional citrate anticoagulation (RCA) in children.

Methods

We prospectively compared fresh frozen plasma (FFP) and platelet transfusions between the two BPT protocols, direct transfusion protocol (DTP) and partial replacement of citrate transfusion protocol (PRCTP), in terms of the risks of clotting, citric accumulation (CA), and hypocalcemia. For DTP, blood products were directly transfused without any adjustment to the original RCA-CRRT regimen. For PRCTP, the blood products were infused into the CRRT circulation near the sodium citrate infusion point, and the dosage of 4% sodium citrate was reduced depending on the dosage of sodium citrate in the blood products. Basic information and clinical data were recorded for all children. Heart rate, blood pressure, ionized calcium (iCa) and various pressure parameters were recorded before, during and after BPT, as well as coagulation indicators, electrolytes, and blood cell counts before and after BPT.

Results

Twenty-six children received 44 PRCTPs and 15 children received 20 DTPs. The two groups had similar in vitro ionized calcium (iCa) concentrations (PRCTP: 0.33 ± 0.06 mmol/L, DTP: 0.31 ± 0.04 mmol/L), total filter lifespan (PRCTP: 49.33 ± 18.58, DTP: 50.65 ± 13.57 h), and filter lifespan after BPT (PRCTP: 25.31 ± 13.87, DTP: 23.39 ± 11.34 h). There was no visible filter clotting during BPT in any of the two groups. The two groups had no significant differences in arterial pressure, venous pressure, and transmembrane pressure before, during, or after BPT. Neither treatment led to significant decreases in WBC, RBC, or hemoglobin. The platelet transfusion group and the FFP group each had no significant decrease in platelets, and no significant increases in PT, APTT, and D-dimer. The most clinically significant changes were in the DTP group, in which the ratio of total calcium to ionized calcium (T/iCa) increased from 2.06 ± 0.19 to 2.52 ± 0.35, the percentage of patients with T/iCa above 2.5 increased from 5.0% to 45%, and the level of in vivo iCa increased from 1.02 ± 0.11 to 1.06 ± 0.09 mmol/L (all p < 0.05). Changes in these three indicators were not significant in the PRCTP group.

Conclusion

Neither protocol was associated with filter clotting during RCA-CRRT. However, PRCTP was superior to DTP because it did not increase the risk of CA and hypocalcemia.

Clinical characteristics and outcomes of continuous renal replacement therapy performed on younger children weighing up to 10 kg

BACKGROUND

This study aimed to investigate the clinical features, modality, complications, and effecting factors on the survival of children weighing up to 10 kg who received continuous renal replacement therapy (CRRT).

METHODS

This study was a retrospective observational study conducted in five pediatric intensive care units in tertiary hospitals in Turkey between January 2015 and December 2019.

RESULTS

One hundred and forty-one children who underwent CRRT were enrolled in the study. The median age was 6 (range, 2-12)months, and 74 (52.5%) were male. The median weight of the patients was 6 (range, 4-8.35) kg and 52 (36.9%) weighed less than 5 kg. The most common indication for CRRT was fluid overload in 75 (53.2%) patients, and sepsis together with multiorgan failure in 62 (44%). The overall mortality was 48.2%.

DISCUSSION

Despite its complexity, CRRT in children weighing less than 10 kg is a beneficial, lifesaving extracorporeal treatment modality.

Regional citrate anticoagulation for continuous renal replacement therapy in newborns

Background

Regional citrate anticoagulant (RCA) is recommended as the preferred anticoagulant regimen for continuous renal replacement therapy (CRRT) in adults; however, it is rarely reported in neonates due to concerns associated with their immature liver. Few studies have reported on the use of RCA to evaluate the safety and efficacy of RCA-CRRT in neonates.

Method

In this retrospective observational study, we reviewed the clinical records of neonates who underwent RCA-CRRT at our pediatric intensive care unit between September 2015 to January 2021.

Results

A total of 23 neonates underwent 57 sessions of RCA-CRRT. Their mean age was 10.1 ± 6.9 days and mean weight was 3.0 ± 0.7 kg (range, 0.95-4 kg). The mean filter life was 31.54 ± 19.58 h (range, 3.3-72.5 h). Compared to pretreatment values, the total-to-ionized calcium ratio (T/iCa) on RCA-CRRT increased (2.00 ± 34 0.36 vs. 2.19 ± 0.40, P = 0.056) as did the incidence of T/iCa levels >2.5 (11.4 vs. 14.3, P = 0.477), albeit not significantly. Using a post-treatment T/iCa threshold of 2.5, we divided all the cases into citrate accumulation (CA) and non-CA (NCA) groups. Compared with the NCA group, the CA group had significantly higher body weight (3.64 ± 0.32 kg vs. 2.95 ± 0.41 kg, P = 0.033) and significantly lower blood flow rate per body weight ml/kg/min (3.08 ± 0.08 vs. 4.07 ± 0.71, P = 0.027); however, there was no significant difference between the two groups in terms of age, corrected gestational age, the PRISM-III score, and biochemical tests.

Conclusion

RCA-CRRT is safe and effective for neonates. After appropriate adjustments of the RCA-CRRT parameters, the incidence of CA was not higher in neonates than in children or adults, and CA was not found to be significantly correlated with age or corrected gestational age.

Continuous Kidney Replacement Therapy Practices in Pediatric Intensive Care Units Across Europe

IMPORTANCE

Continuous kidney replacement therapy (CKRT) is the preferred method of kidney support for children with critical illness in pediatric intensive care units (PICUs). However, there are no data on the current CKRT management practices in European PICUs.

OBJECTIVE

To describe current CKRT practices across European PICUs.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional survey of PICUs in 20 European countries was conducted by the Critical Care Nephrology Section of the European Society of Pediatric and Neonatal Intensive Care from April 1, 2020, to May 31, 2022. Participants included intensivists and nurses working in European PICUs. The survey was developed in English and distributed using SurveyMonkey. One response from each PICU that provided CKRT was included in the analysis. Data were analyzed from June 1 to June 30, 2022.

MAIN OUTCOME AND MEASURES

Demographic characteristics of European PICUs along with organizational and delivery aspects of CKRT (including prescription, liberation from CKRT, and training and education) were assessed.

RESULTS

Of 283 survey responses received, 161 were included in the analysis (response rate, 76%). The attending PICU consultant (70%) and the PICU team (77%) were mainly responsible for CKRT prescription, whereas the PICU nurses were responsible for circuit setup (49%) and bedside machine running (67%). Sixty-one percent of permanent nurses received training to use CKRT, with no need for certification or recertification in 36% of PICUs. Continuous venovenous hemodiafiltration was the preferred dialytic modality (51%). Circuit priming was performed with normal saline (67%) and blood priming in children weighing less than 10 kg (56%). Median (IQR) CKRT dose was 35 (30-50) mL/kg/h in neonates and 30 (30-40) mL/kg/h in children aged 1 month to 18 years. Forty-one percent of PICUs used regional unfractionated heparin infusion, whereas 35% used citrate-based regional anticoagulation. Filters were changed for filter clotting (53%) and increased transmembrane pressure (47%). For routine circuit changes, 72 hours was the cutoff in 62% of PICUs. Some PICUs (34%) monitored fluid removal goals every 4 hours, with variation from 12 hours (17%) to 24 hours (13%). Fluid removal goals ranged from 1 to 3 mL/kg/h. Liberation from CKRT was performed with a diuretic bolus followed by an infusion (32%) or a diuretic bolus alone (19%).

CONCLUSIONS AND RELEVANCE

This survey study found a wide variation in current CKRT practice, including organizational aspects, education and training, prescription, and liberation from CKRT, in European PICUs. This finding calls for concerted efforts on the part of the pediatric critical care and nephrology communities to streamline CKRT education and training, research, and guidelines to reduce variation in practice.

Anticoagulation in patients with acute kidney injury undergoing kidney replacement therapy

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

Semiautomated Regional Citrate Anticoagulation for Continuous Kidney Replacement Therapy: An Observational Study in Young Children

OBJECTIVES

To review use of semiautomated regional citrate anticoagulation (saRCA) for continuous kidney replacement therapy (CKRT) in young children.

DESIGN

Retrospective cohort study.

SETTING

Three independent PICUs.

PATIENTS

All consecutive children weighing less than 11 kg who received CKRT with saRCA from January 2015 to June 2020.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Twenty-one children weighing less than 11 kg underwent CKRT with saRCA. The total duration of the CKRT was 2,014 hours, with a total of 64 CKRT sessions. Citrate intoxication occurred in four of 64 CKRT sessions (6%). Citrate intoxication was consistently observed in the few CKRT sessions where the initial lactate concentration was greater than 4 mmol/L or the ratio of replacement fluid flow to citrate flow less than 50%. The rate of unscheduled interruptions of CKRT sessions was 25% (16/64).

CONCLUSIONS

We have used saRCA for CKRT in children weighing less than 11 kg. A strict protocol and intensive training are required to minimize complications.

Continuous Renal Replacement Therapy in Pediatric Patients With Acute Kidney Injury After Liver Transplantation

Objective

This study aimed to explore the clinical application of continuous renal replacement therapy (CRRT) in pediatric patients with acute kidney injury (AKI) after liver transplantation.

Methods

Pediatric patients who underwent liver transplantation were retrospectively investigated. Those who developed AKI within 1 year after the surgery were included and divided into a CRRT group and a non-CRRT group. The perioperative conditions and postoperative complications of the two groups were compared along with the prognoses of the groups to analyze the high-risk factors of the postoperative CRRT.

Results

189 (36.91%) patients developed AKI within 1 year after the liver transplantation surgery. There were 18 patients in the CRRT group and 171 in the non-CRRT group. The differences in the preoperative conditions were not statistically significant between the two groups. Compared with the non-CRRT group, patients in the CRRT group had significantly longer transplantation times, higher volumes of intraoperative hemorrhage, and increased incidence of postoperative unscheduled surgery, postoperative primary nonfunction of the transplanted liver, secondary liver transplantation, hepatic artery occlusion, and intestinal fistula (P < 0.05). Moreover, the proportion of patients in AKI stage 3 is higher in the CRRT group (83.33%) than that in the non-CRRT group (11.11%), P < 0.001. The median time to initiate CRRT was 10 days postoperatively, the median number of CRRT treatments per patient was 2 times, the average duration of each CRRT treatment was 10.1 h, and the average rate of the decrease in blood creatinine per treatment was 25.6%. Results of multivariate logistic regression analysis showed that AKI stage 3 [OR=40.000, 95%CI (10.598, 150.969), P = 0.016], postoperative unscheduled surgery [OR=6.269, 95%CI (3.051, 26.379), P = 0.007], and hepatic artery occlusion [OR = 17.682, 95%CI (1.707, 40.843), P = 0.001] were recognized as risk factors for postoperative AKI with CRRT therapy. The one- and two-year survival rates were 72.22% and 72.22% in the CRRT group, respectively; and 97.08% and 96.49% in the non-CRRT group, accordingly. There were statistically significant differences in the one- and two-year survival rates between the two groups (P < 0.001).

Conclusion

The incidence of AKI after liver transplantation in pediatric patients was high. Patients with AKI stage 3, hepatic artery occlusion, and underwent unscheduled surgery postoperatively were with a high likelihood of receiving CRRT, which was related to a lower one- and two-year survival rates. CRRT effectively improved the one- and two-year survival rates.

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

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

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.

Clinical application of regional citrate anticoagulation for continuous renal replacement therapy in children with liver injury

BACKGROUND

Regional citrate anticoagulation (RCA) is increasingly used for continuous renal replacement therapy (CRRT) in children, but it is rarely used in children with liver injury, especially liver failure (LF). We analyze this issue through the following research.

METHODS

We retrospectively analyzed 75 children with liver injury who underwent RCA-CRRT in the Pediatric Intensive Care Unit (PICU) of Children's Hospital of Chongqing Medical University. The patients were divided into the LF group and liver dysfunction (LD) group. The two groups were compared to evaluate the clinical safety and efficacy of RCA-CRRT in children with liver injury and to explore RCA-CRRT management strategies, in terms of the following indicators: the incidence of bleeding, clotting, citrate accumulation (CA), acid-base imbalance, and electrolyte disturbance, as well as filter lifespans, changes in biochemical indicators, and CRRT parameters adjustment.

RESULTS

The total incidence of CA (TCA) and persistent CA (PCA) in the LF group were significantly higher than those in the LD group (38.6 vs. 16.2%, p < 0.001; 8.4 vs. 1.5%, p < 0.001); and the CA incidence was significantly reduced after adjustment both in the LF (38.6 vs. 8.4%, p < 0.001) and LD groups (16.2 vs. 1.5%, p < 0.001). The incidence of hypocalcemia was significantly higher in the LF group than in the LD group either before (34.9 vs. 8.8%, p < 0.001) or after treatment (12.0 vs. 0%, p < 0.001). The speed of the blood and citrate pumps after adjustment was lower than the initial setting values in both the LF and LD groups. The dialysis speed plus replacement speed were higher than the initial settings parameters.

CONCLUSION

For children undergoing RCA-CRRT, the risks of CA and hypocalcemia are significantly higher in children with liver failure than those with liver dysfunction, but through the proper adjustment of the protocol, RCA-CRRT can still be safely and effectively approached for children with LD and even LF.

A Meta-Analysis of Extracorporeal Anticoagulants in Pediatric Continuous Kidney Replacement Therapy

OBJECTIVE

Continuous kidney replacement therapy (CKRT) is the primary therapeutic modality utilized in hemodynamically unstable patients with severe acute kidney injury. As the circuit is extracorporeal, it poses an increased risk of blood clotting and circuit loss; frequent circuit losses affect the provider's ability to provide optimal treatment. The objective of this meta-analysis is to evaluate the safety and efficacy of the extracorporeal anticoagulants in the pediatric CKRT population.

DATA SOURCES

We conducted a literature search on PubMed/Medline and Embase for relevant citations.

STUDY SELECTION

Studies were included if they involved patients under the age of 18 years undergoing CKRT, with the use of anticoagulation (heparin, citrate, or prostacyclin) as a part of therapy. Only English articles were included in the study.

DATA EXTRACTION

Initial search yielded 58 articles and a total of 24 articles were included and reviewed. A meta-analysis was performed focusing on the safety and effectiveness of regional citrate anticoagulation (RCA) vs unfractionated heparin (UFH) anticoagulants in children.

DATA SYNTHESIS

RCA had statistically significantly longer circuit life of 50.65 hours vs. UFH of 42.10 hours. Two major adverse effects metabolic alkalosis and electrolyte imbalance seen more commonly in RCA compared to UFH. There was not a significant difference in the risk of systemic bleeding when comparing RCA vs. UFH.

CONCLUSION

RCA is the preferred anticoagulant over UFH due to its significantly longer circuit life, although vigilant circuit monitoring is required due to the increased risk of electrolyte disturbances. Prostacyclin was not included in the meta-analysis due to the lack of data in pediatric patients. Additional studies are needed to strengthen the study results further.

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.

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.

Comparison between citrate and acetate dialysate in chronic online hemodiafiltration: A short-term prospective study in pediatric settings

BACKGROUND

The use of citrate in chronic hemodialysis to acidify dialysis solutions, in replacement of acetate, began in the 2000's. The purpose of the following study is to determine whether this change represents a better alternative regarding short-term tolerance, efficiency and biocompatibility of chronic renal replacement therapy (RRT) in pediatric patients.

METHODS

A monocentric prospective observational study was conducted in the pediatric dialysis department of Nancy (France) between December 1st, 2014 and January 25, 2015 on a cohort of pediatric patients under predilution on-line hemodiafiltration (olHDF). Sessions were analysed during two study periods of 14 days: a first period during which dialysis solutions were acidified using acetate and a second during which solutes were acidified using citrate. These periods were separated by a washout period of 28 days on citrate solution. Each patient served as his own control.

RESULTS

Dialysis clinical tolerance seems better under citrate regimen, with no statistical significance. No benefit was brought out regarding the prevention of coagulation accidents in the extracorporeal circuit under citrate regimen. The efficiency of olHDF sessions was similar between periods, both in terms of uremic toxins clearance and medium-molecular-weight molecules (MMWM) removal. The evolution of several biological parameters seemed favourable over the citrate period: increase in pre-dialysis serum bicarbonate, stability of plasma hemoglobin and decrease in erythropoietin resistance index (ERI). However, differences in the variation of these parameters between the two periods were not significant. No severe and/or symptomatic hypocalcemia occurred.

CONCLUSION

The use of citrate instead of acetate in dialysis and substitution solutions appears in the short term as a safe alternative for chronic online hemodiafiltration in children.

Pediatric Continuous Renal Replacement Therapy (PCRRT) expert committee recommendation on prescribing prolonged intermittent renal replacement therapy (PIRRT) in critically ill children

INTRODUCTION

Recently, prolonged intermittent renal replacement therapies (PIRRT) have emerged as cost-effective alternatives to conventional CRRT and their use in the pediatric population has started to become more prominent. However, there is a lack of consensus guidelines on the use of PIRRT in pediatric patients in an intensive care setting.

METHODS

A literature search was performed on PubMed/Medline, Embase, and Google Scholar in conjunction with medical librarians from both India and the Cleveland Clinic hospital system to find relevant articles. The Pediatric Continuous Renal Replacement Therapy workgroup analyzed all articles for relevancy, proposed recommendations, and graded each recommendation for their strength of evidence.

RESULTS

Of the 60 studies eligible for review, the workgroup considered data from 37 studies to formulate guidelines for the use of PIRRT in children. The guidelines focused on the definition, indications, machines, and prescription of PIRRT.

CONCLUSION

Although the literature on the use of PIRRT in children is limited, the current studies give credence to their benefits and these expert recommendations are a valuable first step in the continued study of PIRRT in the pediatric population.

Regional citrate anticoagulation for continuous renal replacement therapy in newborns and infants: Focus on citrate accumulation

Continuous renal replacement therapy (CRRT) with regional citrate anticoagulation (RCA) in newborns and infants is challenging and accumulation of citrate can occur. There are only a few studies reporting the detailed data on RCA. We aimed to analyze RCA-CRRT at our institution with focus on citrate accumulation. Critically ill newborns and infants up to 11 kg of body weight (BW), treated with RCA-CRRT in the 2011-2016 period were included in this retrospective observational study. Prismaflex(R) and Multifiltrate-CiCa(R) dialysis monitors were used with either automated or manual RCA. Data was collected regarding the circuit lifetime, parameters of RCA, markers of citrate accumulation (total/ionized calcium ratio > 2.5), and metabolic complications. We included 10 children with mean age of 2.6 ± 3.8 months and BW of 4.6 ± 2.7 kg. In-hospital mortality was 60%. RCA-CRRT parameters were: blood flow 46 ± 9 mL/min (12 ± 5 mL/min/kg BW), citrate dose 2.8 ± 0.6 mmol/L of blood resulting in estimated citrate load to the patient of 1.7 ± 0.8 mmol/h/kg BW. In total, 57 dialysis circuits were used with mean filter lifetime of 39 ± 29 h. Citrate accumulation (total/ionized calcium ratio > 2.5) was observed in 7/10 patients and in 14/57 (25%) of circuits; those circuits were performed in children with lower age and BW, had higher relative blood flow and citrate load, while citrate dose was similar. When citrate load to the patient was used to predict citrate accumulation, AUC under the ROC curve was 0.78 and 1.7 mmol/h/kg BW was considered the optimal cutoff value (sensitivity 71% and specificity 72%). CRRT with RCA using equipment, developed for adult population, is feasible in newborns and infants. Signs of citrate accumulation developed relatively often. To prevent it, we suggest avoiding citrate loads above 1.7 mmol/h/kg BW, which can best be achieved by keeping the blood flow below 9 mL/min/kg BW.

Regional citrate anticoagulation with a substitute containing calcium for continuous hemofiltration in children

Regional citrate anticoagulation (RCA) was recommended as the first treatment option for adults by the Kidney Disease Improving Global Outcomes Kidney Foundation in 2012, for the characteristic of sufficient anticoagulation in vitro, but almost no anticoagulation in vivo. Traditionally, the substitute for RCA is calcium-free. This study investigated a simplified protocol of RCA for continuous hemofiltration (CHF) in children using a commercially available substitute containing calcium.An analytical, observational, retrospective study assessed 59 pediatric patients with 106 sessions and 3580 hours of CHF. Values before and after treatment were compared, including Na, ionic calcium (iCa) and HCO3 concentrations, pH, and the ratio of total calcium to iCa (T/iCa). In addition, in vivo and in vitro iCa, treatment time, sessions with continuous transmembrane pressure >200 mm Hg, and sessions with clotting and bleeding were recorded.The average treatment time was 33.8 ± 10.1 hours. In vitro, 88.5% of iCa achieved the target (0.25-0.35 mmol/L), and in vivo, 95.4% of iCa achieved the target (1.0-1.35 mmol/L). There were 8 sessions with a transmembrane pressure >200 mm Hg and 3 sessions with filters clotted. After treatment, there were 2, 1, and 2 sessions with T/iCa > 2.5 (implying citrate accumulation), iCa < 0.9 mmol/L, and iCa > 1.35 mmol/L. No sodium disorders were recorded. There were fewer cases of acidemia and more cases of alkalemia after treatment compared to before.RCA-CHF with a substitute containing calcium and close monitoring could be a safe and effective treatment for children. In addition, the calcium test site in vitro and the adjustment of citrate should be given strict attention.

Is Regional Citrate Anticoagulation the Future of Hemodialysis?

Citrate has many characteristics of the ideal anticoagulant for hemodialysis. In addition to immediate and complete anticoagulation in the dialysis circuit, citrate has important effects beyond anticoagulation, mainly in reducing inflammatory response induced by hemodialysis. Citrate has already become the standard anticoagulant in acute kidney injury requiring continuous renal replacement therapy (CRRT), both for adults and children, with the citrate module being a part of modern CRRT monitors. Although the citrate module is not yet available for intermittent hemodialysis, precise infusion pumps, point-of-care ionometers and high citrate clearance from high flux dialyzers increase safety while reducing the risk of metabolic complications, both in adult and pediatric patients. Slovenia has a long tradition, high volume and expansion of citrate use in hemodialysis, including long-term citrate anticoagulation in selected patients. At the Department of Nephrology, University Medical Centre Ljubljana, more than 10 000 citrate procedures were performed in 2015. We believe that regional citrate anticoagulation may replace heparin as the main anticoagulant for intermittent hemodialysis in the not so distant future.

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.

Regional citrate anticoagulation for continuous renal replacement therapy in children

BACKGROUND

Anticoagulation of the continuous renal replacement therapy (CRRT) circuit is an important technical aspect of this medical procedure. Most studies evaluating the efficacy and safety of citrate use have been carried out in adults, and little evidence is available for the pediatric patient population. The aim of this study was to compare regional citrate anticoagulation versus systemic heparin anticoagulation in terms of the lifetime of hemofilters in a pediatric population receiving CRRT at a pediatric center in Bogota, Colombia.

METHODS

This was an analytical, observational, retrospective cohort study in which we assessed the survival of 150 hemofilters (citrate group 80 hemofilters, heparin group 70 hemofilters) used in a total of 3442 hours of CCRT (citrate group 2248 h, heparin group 1194 h). Hemofilter survival was estimated beginning at placement and continuing until filter replacement due to clotting or high trans-membrane pressures.

RESULTS

Hemofilter survival was higher in the citrate group than in the heparin group (72 vs. 18 h; p <0.0001). Bivariate analysis showed that the hemofilter coagulation risk was significantly increased when heparin was used, regardless of hemofilter size and pump flow (hazard ratio 3.70, standard error 0.82, 95% confidence interval 2.39-5.72; p <0.00001).

CONCLUSIONS

Regional citrate anticoagulation could be more effective than heparin systemic anticoagulation in terms of prolonging the hemofilter lifetime in patients with acute renal injury who require CRRT.

Citrate versus heparin anticoagulation in continuous renal replacement therapy in small children

BACKGROUND

Citrate is preferred over heparin as an anticoagulant in adult continuous renal replacement therapy (CRRT). However, its potential adverse effects and data on use in CRRT in infants and toddlers is limited. We conducted a prospective study on using citrate in CRRT in critically ill small children.

METHODS

Children who underwent CRRT with the smallest filter in our PICU between November 2011 and November 2016 were included. Both heparin and citrate were applied according to a strict protocol. Our primary outcome was circuit survival time. Secondary outcomes were alkalosis, citrate toxicity, and number of red blood cell transfusions.

RESULTS

Heparin was used in six patients (121 circuits, total CRRT time 3723 h). Citrate was used in 14 patients (105 circuits, total CRRT time 4530 h). Median circuit survival time with heparin was 21 h (IQR 14.5-27.5) compared to 45.2 h (IQR 37.5-52.8) with citrate (p < 0.001). Actual administered effluent dose compared to prescribed dose was 85% (IQR 69-98%) with heparin compared to 92% (IQR 88-98%) with citrate (p = 0.31). No patient treated with citrate developed citrate toxicity. No other differences in electrolytes were found between the two CRRT regimes. In the heparin group, a median of 6.5 units of red blood cells (IQR 1.5-23.8) were given during CRRT, compared to three in the citrate group (IQR 2.0-5.0, p = 0.12).

CONCLUSIONS

Use of regional citrate significantly prolongs circuit survival time and thereby should increase CRRT efficiency when compared to heparin. In addition, citrate appears safe for CRRT in critically ill small children.

Circuit Lifetime With Citrate Versus Heparin in Pediatric Continuous Venovenous Hemodialysis

OBJECTIVES

To determine if there is a difference between regional citrate and global heparinized anticoagulation on circuit lifetimes during continuous venovenous hemodialysis in children.

DESIGN

Prospective "cross-over" trial.

SETTING

PICU, Department of Pediatrics, University Hospital Ostrava.

PATIENTS

Children 0-18 years old.

INTERVENTIONS

From 2009 to 2014, 63 eligible children (age, 89.24 ± 62.9 mo; weight, 30.37 ± 20.62 kg) received at least 24 hours of continuous venovenous hemodialysis. Each child received four continuous venovenous hemodialysis circuits with anticoagulants in the following order: heparin, citrate, heparin, citrate. Circuit life ended when transmembrane pressure was greater than or equal to 250 mm Hg for more than 60 minutes.

MEASUREMENTS AND MAIN RESULTS

The total mean circuit lifetime was 39.75 ± 10.73 hours. Citrate had a significantly longer median circuit lifetime (41.0 hr; CI, 37.6-44.4) than heparin (36.0 hr; CI, 35.4-36.6; p = 0.0001). Mortality was 33.33%. Circuit lifetime was significantly correlated to patient age (r = 0.606), weight (r = 0.763), and blood flow rate (r = 0.697). Transfusion rates (units of red cells per circuit of continuous venovenous hemodialysis) were 0.17 (0.0-1.0) with citrate and 0.36 (0.0-2.0) with heparin (p = 0.002).

CONCLUSIONS

We showed in our study that citrate provided significantly longer circuit lifetimes than heparin for continuous venovenous hemodialysis in children. Citrate was superior to heparin for the transfusion requirements. Citrate was feasible and safe in children and 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.

Renal replacement therapy in children

Acute kidney injury (AKI) affects 3.9/1000 at-risk children in the United States, a number that has been increasing as critically ill and injured children have access to improved care and the diagnosis of AKI is being made more accurately. Children with AKI have a higher mortality and hospital length of stay as compared to children without AKI. Renal replacement therapy can improve outcomes in these patients. This article reviews the pathophysiology of AKI and the modalities, indications, and outcomes of renal replacement for children with AKI.