Acute Kidney Injury and Fluid Overload in Pediatric Extracorporeal Cardio-Pulmonary Resuscitation: A Multicenter Retrospective Cohort Study

Outcomes in pediatric extracorporeal cardiopulmonary resuscitation: A single-center retrospective study from 2007 to 2022 in China

OBJECTIVE

We aimed to investigate the prognostic factors of pediatric extracorporeal cardiopulmonary resuscitation (ECPR).

METHODS

The retrospective study included a total of 77 pediatric cases (7 neonates and 70 children) who underwent ECPR after in-hospital and out-of-hospital cardiac arrest between July 2007 and December 2022. Primary endpoints were complications, while secondary endpoints included all-cause in-hospital mortality.

RESULTS

Among the 45 cases experiencing complications, 4 neonates and 41 children had multiple simultaneous complications, primarily neurological issues in 25 cases. Additionally, organ failure occurred in 11 cases, and immunodeficiency was present in two cases. Furthermore, 9 cases experienced bleeding events, and 13 cases showed thrombosis. Patients with complications had lower weight, shorter ECMO durations, and longer CPR durations. Non-survivors had longer CPR durations and shorter durations of ECMO, ICU stay, and mechanical ventilation compared to survivors. Complications were more prevalent in non-survivors, particularly organ failure and bleeding events.

CONCLUSION

Weight, CPR duration, and ECMO duration were associated with complications, suggesting areas for treatment optimization. The higher occurrence of complications in non-survivors underscores the importance of early detection and management to improve survival rates. Our findings suggest clinicians consider these factors in prognostic assessments to enhance the effectiveness of ECPR programs.

Timing of Kidney Replacement Therapy Initiation and Survival During Pediatric Extracorporeal Membrane Oxygenation: An Extracorporeal Life Support Organization Registry Study

To characterize kidney replacement therapy (KRT) and pediatric extracorporeal membrane oxygenation (ECMO) outcomes and to identify the optimal timing of KRT initiation during ECMO associated with increased survival. Observational retrospective cohort study using the Extracorporeal Life Support Organization Registry database in children (0-18 yo) on ECMO from January 1, 2016, to December 31, 2020. Of the 14,318 ECMO runs analyzed, 26% of patients received KRT during ECMO. Patients requiring KRT before ECMO had increased mortality to ECMO decannulation (29% vs. 17%, OR 1.97, P < 0.001) and to hospital discharge (58% vs. 39%, OR 2.16, P < 0.001). Patients requiring KRT during ECMO had an increased mortality to ECMO decannulation (25% vs. 15%, OR 1.85, P < 0.001) and to hospital discharge (56% vs. 34%, OR 2.47, P < 0.001). Multivariable logistic regression demonstrated that the need for KRT during ECMO was an independent predictor for mortality to ECMO decannulation (OR 1.49, P < 0.001) and to hospital discharge (OR 2.02, P < 0.001). Patients initiated on KRT between 24 and 72 hours after cannulation were more likely to survive to ECMO decannulation and showed a trend towards survival to hospital discharge as compared to those initiated before 24 hours and after 72 hours.

The approach to extracorporeal cardiopulmonary resuscitation (ECPR) in children. A narrative review by the paediatric ECPR working group of EuroELSO

Extracorporeal Cardiopulmonary Resuscitation (ECPR) has potential benefits compared to conventional Cardiopulmonary Resuscitation (CCPR) in children. Although no randomised trials for paediatric ECPR have been conducted, there is extensive literature on survival, neurological outcome and risk factors for survival. Based on current literature and guidelines, we suggest recommendations for deployment of paediatric ECPR emphasising the requirement for protocols, training, and timely intervention to enhance patient outcomes. Factors related to outcomes of paediatric ECPR include initial underlying rhythm, CCPR duration, quality of CCPR, medications during CCPR, cannulation site, acidosis and renal dysfunction. Based on current evidence and experience, we provide an approach to patient selection, ECMO initiation and management in ECPR regarding blood and sweep flow settings, unloading of the left ventricle, diagnostics whilst on ECMO, temperature targets, neuromonitoring as well as suggested weaning and decannulation strategies.

Neonatal Extracorporeal Membrane Oxygenation: Associations between Continuous Renal Replacement Therapy, Thrombocytopenia, and Outcomes

INTRODUCTION

The incidence of thrombocytopenia in neonates receiving extracorporeal membrane oxygenation (ECMO) with and without concurrent continuous renal replacement therapy (CRRT) and associated complications have not been well described. The primary aims of the current study were to (1) characterize thrombocytopenia in neonates receiving ECMO (including those treated concurrently with CRRT) and (2) evaluate risk factors (including CRRT utilization) associated with severe thrombocytopenia. In a planned exploratory secondary aim, we explored the association of severe thrombocytopenia with outcomes in neonates receiving ECMO.

METHODS

We conducted a retrospective single-center chart review of neonates who received ECMO 07/01/14-03/01/20 and evaluated associations between CRRT, severe thrombocytopenia (platelet count <50,000/mm3), and outcomes (ECMO duration, length of stay, and survival).

RESULTS

Fifty-two neonates received ECMO; 35 (67%) received concurrent CRRT. Severe thrombocytopenia occurred in 27 (52%) neonates overall and in 21 (60%) neonates who received concurrent CRRT. Underlying diagnosis, ECMO mode, care unit, and moderate/severe hemolysis differed between those who did and did not receive CRRT. CRRT receivers experienced shorter hospital stays than CRRT non-receivers, but ECMO duration, length of intensive care unit (ICU) stay, and survival did not differ between groups. CRRT receipt was associated with severe thrombocytopenia. Exploratory classification and regression tree (CART) analysis suggests CRRT use, birthweight, and ICU location are all predictors of interest for severe thrombocytopenia.

CONCLUSIONS

In our cohort, CRRT use during ECMO was associated with severe thrombocytopenia, and patients who received ECMO with CRRT experienced shorter hospital stays than those who did not receive CRRT. Exploratory CART analysis suggests CRRT use, birthweight, and ICU location are all predictors for severe thrombocytopenia and warrant further investigations in larger studies.

In vivo measurement of pediatric extracorporeal oxygenator insensible losses; a single center pilot study

Introduction

Fluid overload on Extracorporeal Membrane Oxygenation (ECMO) is associated with worse outcomes. Previous in vitro studies have attempted to quantify oxygenator-related insensible losses, as failure to account for this fluid loss may lead to inaccurate fluid balance assessment and potentially harmful clinical management, such as unnecessary exposure to diuretics, slow continuous ultrafiltration (SCUF), or continuous kidney replacement therapy (CKRT). We performed a novel in vivo study to measure insensible fluid losses in pediatric ECMO patients.

Methods

Pediatric ECMO patients were approached over eleven months in the pediatric and cardiac intensive care units. The water content of the oxygenator inflow sweep gas and exhaust gas were calculated by measuring the ambient temperature and relative humidity at frequent intervals and various sweep flow.

Results and discussion

Nine subjects were enrolled, generating 431 data points. The cohort had a median age of 11 years IQR [0.83, 13], weight of 23.2 kg IQR [6.48, 44.28], and body surface area of 0.815 m2 IQR [0.315, 1.3725]. Overall, the cohort had a median sweep of 2.5 L/min [0.9, 4], ECMO flow of 3.975 L/m2/min [0.75, 4.51], and a set ECMO temperature of 37 degrees Celsius [36.6, 37.2]. The calculated net water loss per L/min of sweep was 75.93 ml/day, regardless of oxygenator size or patient weight. There was a significant difference in median documented vs. calculated fluid balance incorporating the insensible fluid loss, irrespective of oxygenator size (pediatric oxygenator: 7.001 ml/kg/day [-12.37, 28.59] vs. -6.11 ml/kg/day [-17.44, 13.01], respectively, p = 0.005 and adult oxygenator: 14.36 ml/kg/day [1.54, 25.77] and 9.204 ml/kg/day [-1.28, 22.05], respectively, p = <0.001). We present this pilot study of measured oxygenator-associated insensible fluid losses on ECMO. Our results are consistent with prior in vitro methods and provide the basis for future studies evaluating the impact of incorporating these fluid losses into patients' daily fluid balance on patient management and outcomes.

Managing the kidney - The role of continuous renal replacement therapy in neonatal and pediatric ECMO

Extracorporeal membrane oxygenation (ECMO) represents a lifesaving therapy utilized in in the most critically ill neonates and children with reversible cardiopulmonary failure. As a result of the severity of their critical illness these patients are among the highest risk populations for developing acute kidney injury (AKI) and disorders of fluid balance including the pathologic state of fluid overload (FO). In multiple studies AKI has been shown to occur commonly in 60-80% children treated with ECMO and is associated with adverse outcomes. In early studies evaluating ECMO in neonatal respiratory populations, the importance of fluid balance and the development of FO was recognized as an important contributor to adverse outcomes. Multiple single center studies and multicenter work have confirmed that FO occurs commonly across ECMO populations and is consistently associated with adverse outcomes. As a result of the high rates of AKI and the high rates of FO, continuous renal replacement therapy (CRRT) is increasingly utilized in neonatal and pediatric ECMO. In this state-of-the-art review, we cover the definitions, pathophysiology, incidence, and impact of AKI and FO in neonates and children supported with ECMO and summarize and appraise the evidence regarding the use of CRRT concurrently with ECMO. This review will cover the appropriate timing of this initiation, the options for providing CRRT with ECMO, overview of CRRT prescription, and the long-term implications of kidney support therapy in this population.

Standard Versus Restrictive Transfusion Strategy for Pediatric Cardiac ECLS Patients: Single Center Retrospective Cohort Study

This retrospective cohort study aimed to compare blood component transfusion before and after the implementation of a restrictive transfusion strategy (RTS) in pediatric cardiac Extracorporeal Life Support (ECLS) patients. The study included children admitted to the pediatric cardiac intensive care unit (PCICU) at the Stollery Children's Hospital who received ECLS between 2012 and 2020. Children on ECLS between 2012 and 2016 were treated with standard transfusion strategy (STS), while those on ECLS between 2016 and 2020 were treated with RTS. During the study, 203 children received ECLS. Daily median (interquartile range [IQR]) packed red blood cell (PRBC) transfusion volume was significantly lower in the RTS group; 26.0 (14.4-41.5) vs. 41.5 (26.6-64.4) ml/kg/day, p value <0.001. The implementation of a RTS led to a median reduction of PRBC transfusion of 14.5 (95% CI: 6.70-21.0) ml/kg/day. Similarly, the RTS group received less platelets: median (IQR) 8.4 (4.50-15.0) vs. 17.5 (9.40-29.0) ml/kg/day, p value <0.001. The implementation of a RTS resulted in a median reduction of platelet transfusion of 9.2 (95% CI: 5.45-13.1) ml/kg/day. The RTS resulted in less median (IQR) fluid accumulation in the first 48 hours: 56.7 (2.30-121.0) vs. 140.4 (33.8-346.2) ml/kg, p value = 0.001. There were no significant differences in mechanical ventilation days, PCICU/hospital days, or survival. The use of RTS resulted in lower blood transfusion volumes, with similar clinical outcomes.

Effect of a standardized fluid management algorithm on acute kidney injury and mortality in pediatric patients on extracorporeal support

Acute kidney injury (AKI), fluid overload (FO), and mortality are common in pediatric patients supported by extracorporeal membrane oxygenation (ECMO). The aim of this study is to evaluate if using a fluid management algorithm reduced AKI and mortality in children supported by ECMO. We performed a retrospective study of pediatric patients aged birth to 25 years requiring ECMO at a quaternary level children's hospital from 2007 to 2019 In October 2017, a fluid management algorithm was implemented for protocolized fluid removal after deriving a daily fluid goal using a combination of diuretics and ultrafiltration. Daily algorithm compliance was defined as ≥ 12 h on the algorithm each day. The primary and secondary outcomes were AKI and mortality, respectively, and were assessed in the entire cohort and the sub-analysis of children from the era in which the algorithm was implemented. Two hundred and ninety-nine (median age 5.3 months; IQR: 0.2, 62.3; 45% male) children required ECMO (venoarterial in 85%). The fluid algorithm was applied in 74 patients. The overall AKI rate during ECMO was 38% (26% severe-stage 2/3). Both AKI incidence and mortality were significantly lower in patients managed on the algorithm (p = 0.02 and p = 0.05). After adjusting for confounders, utilization of the algorithm was associated with lower odds of AKI (aOR: 0.40, 95%CI: 0.21, 0.76; p = 0.005) but was not associated with a reduction in mortality. In the sub-analysis, algorithm compliance of 80-100% was associated with a 54% reduction in mortality (ref: < 60% compliant; aOR:0.46, 95%CI:0.22-1.00; p = 0.05).  Conclusion: Among the entire cohort, the use of a fluid management algorithm reduced the odds of AKI. Better compliance on the algorithm was associated with lower mortality. Multicenter studies that implement systematic fluid removal may represent an opportunity for improving ECMO-related outcomes. What is Known: • Acute kidney injury and fluid overload are associated with morbidity and mortality in children supported by extracorporeal membrane oxygenation. What is New: • A systematic and protocolized approach to fluid removal in children supported by extracorporeal membrane oxygenation reduces acute kidney injury incidence. • Greater adherence to a protocolized fluid removal algorithm is associated with a reduction in mortality.

Fluid balance in pediatric critically ill patients (with and without kidney dysfunction)

PURPOSE OF REVIEW

The issues of fluid balance and fluid overload are currently considered crucial aspects of pediatric critically ill patients' care.

RECENT FINDINGS

This review describes current understanding of fluid management in critically ill children in terms of fluid balance and fluid overload and its effects on patients' outcomes. The review describes current evidence surrounding definitions, monitoring, and treatment of positive fluid balance. In particular, the review focuses on specific patient conditions, including perioperative cardiac surgery, severe acute respiratory failure, and extracorporeal membrane oxygenation therapy, as the ones at highest risk of developing fluid overload and poor clinical outcomes. Gaps in understanding include specific thresholds at which fluid overload occurs in all critically ill children or specific populations and optimal timing of decongestion of positive fluid balance.

SUMMARY

Current evidence on fluid balance in critically ill children is mainly based on retrospective and observational studies, and intense research should be recommended in this important field. In theory, active decongestion of patients with fluid overload could improve mortality and other clinical outcomes, but randomized trials or advanced pragmatic studies are needed to better understand the optimal timing, patient characteristics, and tools to achieve this.