Impact of the Magnitude and Timing of Fluid Overload on Outcomes in Critically Ill Children: A Report From the Multicenter International Assessment of Worldwide Acute Kidney Injury, Renal Angina, and Epidemiology (AWARE) Study

Carotid peak flow velocity variation as a surrogate of aortic peak flow velocity variation in a pediatric population

BACKGROUND

Carotid peak velocity variation (ΔVpeakCar) is an alternative to aortic peak velocity variation (ΔVpeakAo) and has been used in the pediatric population. Children's physiology and anatomy are heterogeneous throughout their growth. For this reason, the predictive value of ΔVpeakCar as a surrogate of ΔVpeakAo can vary at different ages. We hypothesize that the ability of ΔVpeakCar as a surrogate of ΔVpeakAo changes throughout childhood.

AIM

Analyze the concordance and the tracking ability of ΔVpeakCar and the ΔVpeakAo at different stages of development.

METHODS

Patients from 0 to 12 years were included. Three groups were defined: under 12 months (G1), between 12 and 60 months (G2), and over 60 months (G3). After anesthesia induction and mechanical ventilation, maximal and minimal aortic and carotid peak flow were measured. ΔVpeakAo and ΔVpeakCar were calculated. Pearson test and simple linear regression were performed. Bland-Altman analysis was performed to determine concordance. 4-quadrant analysis was used, followed by polar analysis of the vectors, to complement the concordance analysis and determine the tracking ability of ΔVpeakCar to surrogate ΔVpeakAo.

RESULTS

Sixty-seven patients were enrolled. 22 (32.4%) patients in G1, 21 (31.3%) in G2 and 24 (35.8%) in G3. The determination coefficient (r) between ΔVpeakAo and ΔVpeakCar in G1 was 0.44 (p < 0.001) with a slope value of 0.61 (SE = 0.11; 95% CI:0.3-0.91). In G2, r2 = 0.56 (p < 0.001) with a slope value of 0.59 (SE = 0.14; 95% CI:0.35-0.82); and in G3, r2 = 0.85 (p < 0.001) with a slope value of 1.11 (SE = 0.10; 95% CI:0.91-1.31). Bland-Altman analysis showed to G1 a mean bias of -0.37 (LOA - 7.87 to 7.53), to G2 -0.07 (LOA - 7.37 to 7.23) and G3 0.55 (-3.81 to 4.91). Concordance rates were 100% in G3, 95% in G2, and 93% in G1.

CONCLUSIONS

ΔVpeakCar showed good correlation and tracking ability with ΔVpeakAo in schoolchildren. In younger children, it was not reliable enough.

Incidence of acute kidney injury-associated mortality in hospitalized children: a systematic review and meta-analysis

BACKGROUND

Acute kidney injury (AKI) is a significant health concern in hospitalized children and is associated with increased mortality. However, the true burden of AKI-associated mortality in pediatric populations remains unclear.

OBJECTIVE

To determine the pooled incidence of mortality independently associated with AKI in hospitalized children globally.

DATA SOURCES

Medline and Embase were searched for studies published by March 2024.

STUDY ELIGIBILITY CRITERIA

The inclusion criteria encompassed observational studies involving hospitalized pediatric patients (< 18 years old) with AKI. Only studies that identified AKI as an independent risk factor for increased mortality in multivariate analysis were considered.

STUDY APPRAISAL AND SYNTHESIS METHODS

Studies with at least 100 AKI patients were included in the meta-analysis. Two authors extracted data on the study and patients' characteristics and mortality across AKI stages and assessed the risk of bias. We used a random-effects meta-analysis to generate pooled estimates of mortality.

RESULTS

Analysis of 60 studies including 133,876 children with AKI revealed a pooled in-hospital mortality rate of 18.27% (95% CI: 14.89, 21.65). Mortality increased with AKI severity; 8.19% in stage 1, 13.44% in stage 2, and 27.78% in stage 3. Subgroup analyses showed no significant differences across geographical regions, income levels, or AKI definition criteria. The pooled post-discharge mortality rate was 6.84% (95% CI: 5.86, 7.82) in a 1-9-year follow-up period.

CONCLUSIONS

This meta-analysis demonstrates a substantial global burden of AKI-associated mortality in hospitalized children, with higher mortality rates in more severe AKI stages. These findings highlight the critical need for early detection and intervention strategies in pediatric AKI management.

CLINICAL TRIAL NUMBER

Not applicable.

Population Pharmacokinetics of Cefepime in Critically Ill Children and Young Adults: Model Development and External Validation for Monte Carlo Simulations and Model-Informed Precision Dosing

BACKGROUND AND OBJECTIVE

This study aimed to develop a population pharmacokinetic model for cefepime in critically ill pediatric and young adult patients to inform dosing recommendations and to evaluate the model's predictive performance for model-informed precision dosing.

METHODS

Patients in the pediatric intensive care unit receiving cefepime were prospectively enrolled for clinical data collection and opportunistic plasma sampling for cefepime concentrations. Nonlinear mixed effects modeling was conducted using NONMEM. Allometric body weight scaling was included as a covariate with fixed exponents. Monte Carlo simulations determined optimal initial dosing regimens against susceptible pathogens. The model's predictions were evaluated with an external dataset.

RESULTS

Data from 510 samples across 100 patients were best fit with a two-compartment model with first-order elimination. Estimated glomerular filtration rate and cumulative percentage of fluid balance were identified as significant covariates on clearance and central volume of distribution, respectively. Internal validation showed no model misspecification. External validation confirmed that bias and precision for both population and individual predictions were within commonly accepted ranges. Monte Carlo simulations suggested that the usual dose of 50 mg/kg may require a 3-h infusion or a 6-h dosing interval to keep concentrations above the Pseudomonas aeruginosa minimum inhibitory concentration (≤ 8 mg/L) throughout the dosing interval for patients with normal or augmented renal clearance.

CONCLUSION

A cefepime population pharmacokinetic model for critically ill pediatric patients was successfully developed, accounting for patient renal function, fluid status, and body size, using real-world data. The model was internally and externally validated for use in optimal dosing simulations and model-informed precision dosing.

FLUID OVERLOAD MODIFIES HEMODYNAMIC IMPACT OF CONTINUOUS RENAL REPLACEMENT THERAPY: EVIDENCE OF A COVERT CARDIORENAL SYNDROME?

ABSTRACT

Background: Fluid overload (FO) in critically ill children correlates with higher morbidity and mortality rates. Continuous renal replacement therapy (CRRT) is commonly employed to manage FO. In adults, both FO and CRRT adversely affect myocardial function. It remains unclear if children experience similar cardiovascular effects. Methods: Observational single-center study on children (<18 years) receiving CRRT at Texas Children's Hospital from 11/2019 to 3/2021. Excluded were those with end-stage renal disease, pacemakers, extracorporeal membrane oxygenation, ventricular assist devices, apheresis, or without an arterial line. Electrocardiometry (ICON Osypka Medical GmbH, Berlin, Germany) which is noninvasive and utilizes bioimpedance, was applied to obtain hemodynamic data over the first 48 h of CRRT. Our aim was to identify how FO >15% affects hemodynamics in children receiving CRRT. Results: Seventeen children, median age 43 months (interquartile range [IQR] 12-124), were included. The median FO at CRRT initiation was 14.4% (2.4%-25.6%), with 9 (53%) patients having FO >15%. Differences were noted in systemic vascular resistance index (1,277 [IQR 1088-1,666] vs. 1,030 [IQR 868-1,181] dynes/s/cm 5 /m 2 , P < 0.01), and cardiac index (3.90 [IQR 3.23-4.75] vs. 5.68 [IQR 4.65-6.32] L/min/m 2 , P < 0.01), with no differences in heart rate or mean arterial pressure between children with and without FO. Conclusion: FO affects the hemodynamic profile of children on CRRT, with those having FO >15% showing higher systemic vascular resistance index and lower cardiac index, despite heart rate and mean arterial pressure remaining unchanged. Our study illustrates the feasibility and utility of electrocardiometry in these patients, suggesting future research employ this technology to further explore the hemodynamic effects of dialysis in children.

Identifying Opportunities for Fluid Balance Optimization in Critically Ill Children

Introduction

Fluid overload (FO), a state of pathologic positive cumulative fluid balance (CFB), is common in Pediatric Intensive Care Units (PICU) and associated with morbidity and mortality. Because different PICUs may have unique needs, barriers, and limitations to accurately report fluid balance (FB) and reduce FO, understanding the drivers of positive FB is needed. We hypothesize CFB >5% and >10% is common within initial days of PICU admission, but that reasons for high %CFB will vary across sites, as will barriers to accurate FB recording and opportunities to improve FB recording and management.

Methods

Concurrent mixed methods study utilizing a retrospective observational cohort design and prospective interview and survey design performed at four tertiary pediatric ICUs. FB data was extracted from the electronic health record. A federated data collection framework allowed for rapid data aggregation. The primary outcome was %CFB on PICU days 1 and 2, defined as total intake minus total output divided by PICU admission weight. Chi-square test and Wilcoxon rank sum tests compared results across and within sites.

Results

Amongst 3,071 PICU encounters, day 2 CFB >5% varied from 39% to 54% (p=0.03) and day 2 CFB >10% varied from 16% to 25% (p=0.04) across sites. Urine occurrence recordings and patients receiving >100% Holliday-Segar fluids on Day 1 differed across sites (p<0.001). Sites discussed overall FB and specific FB goals on rounds with differing frequency (42-73% and 19-39%, respectively), but they reported similar barriers to accurate FB reporting and achievable opportunities to improve FB measurements.

Conclusion

Day 2 CFB >5% and >10% was common among PICU encounters but proportion of patients varied significantly across PICUs. Individual ICUs have different drivers of FO that must be targeted to improve FB management.

Fluid deresuscitation in critically ill children: comparing perspectives of intensivists and nephrologists

Introduction

Fluid accumulation, presently defined as a pathologic state of overhydration/volume overload associated with clinical impact, is common and associated with worse outcomes. At times, deresuscitation, the active removal of fluid via diuretics or ultrafiltration, is necessary. There is no consensus regarding deresuscitation in children admitted to the pediatric intensive care unit. Little is known regarding perceptions and practices among pediatric intensivists and nephrologists regarding fluid provision and deresuscitation.

Methods

Cross-sectional electronic survey of pediatric nephrologists and intensivists from academic societies in the United States designed to better understand fluid management between disciplines. A clinical vignette was used to characterize the perceptions of optimal timing and method of deresuscitation initiation at four timepoints that correspond to different stages of shock.

Results

In total, 179 respondents (140 intensivists, 39 nephrologists) completed the survey. Most 75.4% (135/179) providers believe discussing fluid balance and initiating fluid deresuscitation in pediatric intensive care unit (PICU) patients is "very important". The first clinical vignette time point (corresponding to resuscitation phase of early shock) had the most dissimilarity between intensivists and nephrologists (p = 0.01) with regards to initiation of deresuscitation. However, providers demonstrated increasing agreement in their responses to initiate deresuscitation as the clinical vignette progressed. Compared to intensivists, nephrologists were more likely to choose "dialysis or ultrafiltration" as a deresuscitation method during the optimization [10.3 vs. 2.9% (p = 0.07)], stabilization [18.0% vs. 3.6% (p < 0.01)], and evacuation [48.7% vs. 23.6% (p < 0.01)] phases of shock. Conversely, intensivists were more likely to utilize scheduled diuretics than nephrologists [47.1% vs. 28.2% (p = 0.04)] later on in the patient course.

Discussion

Most physicians believe that discussing fluid balance and deresuscitation is important. Nevertheless, when to initiate deresuscitation and how to accomplish it differed between nephrologist and intensivists. Widely understood and operationalizable definitions, further research, and eventually evidence-based guidelines are needed to help guide care.

Identifying optimal dosing strategies for meropenem in the paediatric intensive care unit through modelling and simulation

BACKGROUND

Meropenem, a β-lactam antibiotic commonly prescribed for severe infections, poses dosing challenges in critically ill patients due to highly variable pharmacokinetics.

OBJECTIVES

We sought to develop a population pharmacokinetic model of meropenem for critically ill paediatric and young adult patients.

PATIENTS AND METHODS

Paediatric intensive care unit patients receiving meropenem 20-40 mg/kg every 8 h as a 30 min infusion were prospectively followed for clinical data collection and scavenged opportunistic plasma sampling. Nonlinear mixed effects modelling was conducted using Monolix®. Monte Carlo simulations were performed to provide dosing recommendations against susceptible pathogens (MIC ≤ 2 mg/L).

RESULTS

Data from 48 patients, aged 1 month to 30 years, with 296 samples, were described using a two-compartment model with first-order elimination. Allometric body weight scaling accounted for body size differences. Creatinine clearance and percentage of fluid balance were identified as covariates on clearance and central volume of distribution, respectively. A maturation function for renal clearance was included. Monte Carlo simulations suggested that for a target of 40% fT > MIC, the most effective dosing regimen is 20 mg/kg every 8 h with a 3 h infusion. If higher PD targets are considered, only continuous infusion regimens ensure target attainment against susceptible pathogens, ranging from 60 mg/kg/day to 120 mg/kg/day.

CONCLUSIONS

We successfully developed a population pharmacokinetic model of meropenem using real-world data from critically ill paediatric and young adult patients with an opportunistic sampling strategy and provided dosing recommendations based on the patients' renal function and fluid status.

Continuous Kidney Replacement Therapy and Survival in Children and Young Adults: Findings From the Multinational WE-ROCK Collaborative

RATIONALE & OBJECTIVE

There are limited studies describing the epidemiology and outcomes in children and young adults receiving continuous kidney replacement therapy (CKRT). We aimed to describe associations between patient characteristics, CKRT prescription, and survival.

STUDY DESIGN

Retrospective multicenter cohort study.

SETTING & PARTICIPANTS

980 patients aged from birth to 25 years who received CKRT between 2015 and 2021 at 1 of 32 centers in 7 countries participating in WE-ROCK (Worldwide Exploration of Renal Replacement Outcomes Collaborative in Kidney Diseases).

EXPOSURE

CKRT for acute kidney injury or volume overload.

OUTCOMES

Death before intensive care unit (ICU) discharge.

ANALYTICAL APPROACH

Descriptive statistics.

RESULTS

Median age was 8.8 years (IQR, 1.6-15.0), and median weight was 26.8 (IQR, 11.6-55.0) kg. CKRT was initiated a median of 2 (IQR, 1-6) days after ICU admission and lasted a median of 6 (IQR, 3-14) days. The most common CKRT modality was continuous venovenous hemodiafiltration. Citrate anticoagulation was used in 62%, and the internal jugular vein was the most common catheter placement location (66%). 629 participants (64.1%) survived at least until ICU discharge. CKRT dose, filter type, and anticoagulation were similar in those who did and did not survive to ICU discharge. There were apparent practice variations by institutional ICU size.

LIMITATIONS

Retrospective design; limited representation from centers outside the United States.

CONCLUSIONS

In this study of children and young adults receiving CKRT, approximately two thirds survived at least until ICU discharge. Although variations in dialysis mode and dose, catheter size and location, and anticoagulation were observed, survival was not detected to be associated with these parameters.

PLAIN-LANGUAGE SUMMARY

In this large contemporary epidemiological study of children and young adults receiving continuous kidney replacement therapy in the intensive care unit, we observed that two thirds of patients survived at least until ICU discharge. However, patients with comorbidities appeared to have worse outcomes. Compared with previously published reports on continuous kidney replacement therapy practice, we observed greater use of continuous venovenous hemodiafiltration with regional citrate anticoagulation.

Fluid bolus resuscitation with hypertonic saline albumin solution in critically ill children: a prospective observational pilot study

To evaluate the hemodynamic effects and the safety profile of fluid bolus resuscitation with hypertonic saline albumin (HSA) in critically ill children, we performed a prospective observational pilot study between October 2018 and May 2021 in the pediatric intensive care unit (PICU) in a tertiary hospital in Madrid, Spain. Sixty-four HSA boluses were analyzed in 23 patients. A mean volume of 5.7 ml/kg (Standard Deviation, SD 2.3 ml/kg) per bolus was infused. Acute hypotension was the main indication. 91% of the patients had a cardiac disease, 56% of them had undergone cardiac surgery in the previous 72 h, and 47.8% associated right ventricular dysfunction. A significant increase in systolic, mean, and diastolic blood pressure and a decrease in the vasoactive index was observed after the infusion of HSA. This effect lasted for twenty-four hours (p < 0.05). Moreover, the amount of fluid requirements decreased significantly in the 6 h following HSA infusion [8.7 ml/kg (SD 9.6) vs. 15.1 ml/kg (SD 13.6) in the previous 6 h (p < 0.05)]. Serum levels of sodium and chloride increased after the infusion, reaching their peak concentration after one hour (143 mEq/L (SD 3.5) and 109.7 mEq/L (SD 6) respectively). HSA-related metabolic acidosis or acute kidney injury were not observed in this study. Hypertonic saline albumin is safe and effective when infused at a dose of 5 ml/kg in critically ill children. However, further research is required to confirm our findings.

High intraoperative fluid load associated with prolonged length of hospital stay and complications after non-cardiac surgery in neonates

Inappropriate perioperative fluid load can lead to postoperative complications and death. This retrospective study was designed to investigate the association between intraoperative fluid load and outcomes in neonates undergoing non-cardiac surgery. From April 2020 to September 2022, 940 neonates who underwent non-cardiac surgery were retrospectively enrolled and their perioperative data were harvested for further analysis. According to recorded intraoperative fluid volumes defined as ml.kg-1 h-1, patients were mandatorily divided into quintile with fluid load as restrictive (quintile 1, Q1), moderately restrictive (Q2), moderate (Q3), moderately liberal (Q4), and liberal (Q5). The primary outcomes were defined as prolonged length of hospital stay (LOS) (postoperative LOS ≥ 14 days), complications beyond prolonged LOS, and 30-day mortality. Secondary outcomes included postoperative complications within 14 days of hospital stay. The intraoperative fluid load was in Q1 of 6.5 (5.3-7.3) (median and IQR); Q2: 9.2 (8.7-9.9); Q3: 12.2 (11.4-13.2); Q4: 16.5 (15.4-18.0); and Q5: 26.5 (22.3-32.2) ml.kg-1 h-1. The odd of prolonged LOS was positively correlated with an increase fluid volume (Q5 quintile: OR 2.602 [95% CI 1.444-4.690], P = 0.001), as well as complications beyond prolonged LOS (Q5: OR 3.322 [95% CI 1.656-6.275], P = 0.001). The overall 30-day mortality rate was increased with high intraoperative fluid load but did not reach to a statistical significance after adjusted with confounders. Furthermore, the highest quintile of fluid load (26.5 ml.kg-1 h-1, IQR [22.3-32.2]) (Q5 quintile) was significantly associated with longer postoperative mechanical ventilation time compared with Q1 (Q5: OR 2.212 [95% CI 1.101-4.445], P = 0.026).    Conclusion: Restrictive intraoperative fluid load had overall better outcomes, whilst high fluid load was significantly associated with prolonged LOS and complications after non-cardiac surgery in neonates.    Trial registration:  Chictr.org.cn Identifier: ChiCTR2200066823 (December 19, 2022). What is Known: • Inappropriate perioperative fluid load can lead to postoperative complications and even death. What is New: • High perioperative fluid load was significantly associated with an increased length of stay after non-cardiac surgery in neonates, whilst low fluid load was consistently related to better postoperative outcomes.

Fluid accumulation in critically ill children: a systematic review and meta-analysis

Background

Fluids are often administered for various purposes, such as resuscitation, replacement, maintenance, nutrition, or drug infusion. However, its use is not without risks. Critically ill patients are highly susceptible to fluid accumulation (FA), which is associated with poor outcomes, including organ dysfunction, prolonged mechanical ventilation, extended hospital stays, and increased mortality. This study aimed to assess the association between FA and poor outcomes in critically ill children.

Methods

In this systematic review and meta-analysis, we searched PubMed, Embase, ClinicalTrials.gov, and Cochrane Library databases from inception to May 2024. Relevant publications were searched using the following terms: child, children, infant, infants, pediatric, pediatrics, critically ill children, critical illness, critical care, intensive care, pediatric intensive care, pediatric intensive care unit, fluid balance, fluid overload, fluid accumulation, fluid therapy, edema, respiratory failure, respiratory insufficiency, pulmonary edema, mechanical ventilation, hemodynamic instability, shock, sepsis, acute renal failure, acute kidney failure, acute kidney injury, renal replacement therapy, dialysis, mortality. Paediatric studies were considered eligible if they assessed the effect of FA on the outcomes of interest. The main outcome was all-cause mortality. Pooled analyses were performed by using random-effects models. This review was registered on PROSPERO (CRD42023432879).

Findings

A total of 120 studies (44,682 children) were included. Thirty-five FA definitions were identified. In general, FA was significantly associated with increased mortality (odds ratio [OR] 4.36; 95% confidence interval [CI] 3.53-5.38), acute kidney injury (OR 1.98; 95% CI 1.60-2.44), prolonged mechanical ventilation (weighted mean difference [WMD] 38.1 h, 95% CI 19.35-56.84), and longer stay in the intensive care unit (WMD 2.29 days; 95% CI 1.19-3.38). The percentage of FA was lower in survivors when compared to non-survivors (WMD -4.95 [95% CI, -6.03 to -3.87]). When considering only studies that controlled for potential confounding variables, the pooled analysis revealed 6% increased odds of mortality associated with each 1% increase in the percentage of FA (adjusted OR = 1.06 [95% CI, 1.04-1.09).

Interpretation

FA is significantly associated with poorer outcomes in critically ill children. Thus, clinicians should closely monitor fluid balance, especially when new-onset or worsening organ dysfunction occurs in oedematous patients, indicating potential FA syndrome. Future research should explore interventions like restrictive fluid therapy or de-resuscitation methods. Meanwhile, preventive measures should be prioritized to mitigate FA until further evidence is available.

Funding

None.

An update on the role of fluid overload in the prediction of outcome in acute kidney injury

Over the past two decades, our understanding of the impact of acute kidney injury, disorders of fluid balance, and their interplay have increased significantly. In recent years, the epidemiology and impact of fluid balance, including the pathologic state of fluid overload on outcomes has been studied extensively across multiple pediatric and neonatal populations. A detailed understating of fluid balance has become increasingly important as it is recognized as a target for intervention to continue to work to improve outcomes in these populations. In this review, we provide an update on the epidemiology and outcomes associated with fluid balance disorders and the development of fluid overload in children with acute kidney injury (AKI). This will include a detailed review of consensus definitions of fluid balance, fluid overload, and the methodologies to define them, impact of fluid balance on the diagnosis of AKI and the concept of fluid corrected serum creatinine. This review will also provide detailed descriptions of future directions and the changing paradigms around fluid balance and AKI in critical care nephrology, including the incorporation of the sequential utilization of risk stratification, novel biomarkers, and functional kidney tests (furosemide stress test) into research and ultimately clinical care. Finally, the review will conclude with novel methods currently under study to assess fluid balance and distribution (point of care ultrasound and bioimpedance).

Evaluating fluid overload in critically ill children

PURPOSE OF REVIEW

To review the evaluation and management of fluid overload in critically ill children.

RECENT FINDINGS

Emerging evidence associates fluid overload, i.e. having a positive cumulative fluid balance, with adverse outcome in critically ill children. This is most likely the result of impaired organ function due to increased extravascular water content. The combination of a number of parameters, including physical, laboratory and radiographic markers, may aid the clinician in monitoring and quantifying fluid status, but all have important limitations, in particular to discriminate between intra- and extravascular water volume. Current guidelines advocate a restrictive fluid management, initiated early during the disease course, but are hampered by the lack of high quality evidence.

SUMMARY

Recent advances in early evaluation of fluid status and (tailored) restrictive fluid management in critically ill children may decrease complications of fluid overload, potentially improving outcome. Further clinical trials are necessary to provide the clinician with solid recommendations.

Persistent acute kidney injury and fluid accumulation with outcomes after the Norwood procedure: report from NEPHRON

BACKGROUND

Cardiac surgery-associated acute kidney injury (CS-AKI) is common, but its impact on clinical outcomes is variable. Parsing AKI into sub-phenotype(s) and integrating pathologic positive cumulative fluid balance (CFB) may better inform prognosis. We sought to determine whether durational sub-phenotyping of CS-AKI with CFB strengthens association with outcomes among neonates undergoing the Norwood procedure.

METHODS

Multicenter, retrospective cohort study from the Neonatal and Pediatric Heart and Renal Outcomes Network. Transient CS-AKI: present only on post-operative day (POD) 1 and/or 2; persistent CS-AKI: continued after POD 2. CFB was evaluated per day and peak CFB during the first 7 postoperative days. Primary and secondary outcomes were mortality, respiratory support-free and hospital-free days (at 28, 60 days, respectively). The primary predictor was persistent CS-AKI, defined by modified neonatal Kidney Disease: Improving Global Outcomes criteria.

RESULTS

CS-AKI occurred in 59% (205/347) neonates: 36.6% (127/347) transient and 22.5% (78/347) persistent; CFB > 10% occurred in 18.7% (65/347). Patients with either persistent CS-AKI or peak CFB > 10% had higher mortality. Combined persistent CS-AKI with peak CFB > 10% (n = 21) associated with increased mortality (aOR: 7.8, 95% CI: 1.4, 45.5; p = 0.02), decreased respiratory support-free (predicted mean 12 vs. 19; p < 0.001) and hospital-free days (17 vs. 29; p = 0.048) compared to those with neither.

CONCLUSIONS

The combination of persistent CS-AKI and peak CFB > 10% after the Norwood procedure is associated with mortality and hospital resource utilization. Prospective studies targeting intra- and postoperative CS-AKI risk factors and reducing CFB have the potential to improve outcomes.

Pattern of Fluid Overload and its Impact on Mortality Among Mechanically Ventilated Children: Secondary Analysis of the ReLiSCh Trial

OBJECTIVES

To assess the pattern of fluid overload (FO) and its impact on mortality among mechanically ventilated children.

METHODS

In this secondary analysis of an open-label randomized controlled trial (ReLiSCh trial, October 2020-September 2021), hemodynamically stable mechanically ventilated children (n = 100) admitted to a tertiary level pediatric intensive care unit (PICU) in North India were enrolled. The primary outcome was pattern of FO (FO% >10% and cumulative FO% from day 1-7); and secondary outcomes were pattern of FO among survivors and non-survivors, and prescription practices of maintenance fluid.

RESULTS

The median (IQR) age was 3.5 (0.85-7.5) y and 57% were males. Common diagnoses were pneumonia (27%), scrub typhus (14%), Landry-Guillain-Barré syndrome (9%), dengue (8%), central nervous system infections (7%) and staphylococcal sepsis (6%). Common organ dysfunction included acute respiratory distress syndrome (ARDS) (41%), shock (38%), and acute kidney injury (AKI) (9%). The duration PICU stay was 11 (7-17) d and mortality was 12%. The FO% >10% was noted in 19% children; and there was significant increase in cumulative FO% from day 1-7 [1.2 (0.2-2.6)% to 8.5 (1.7-14.3)%, (p = 0.000)]. Among non-survivors, higher proportion had FO% >10% (66.7% vs. 12.5%, p 0.0001); and trend towards higher cumulative FO% on first seven days. From day 1-7, the percentage of maintenance fluid received increased from 60 (50-71)% to 70 (60-77)% (p = 0.691).

CONCLUSIONS

One-fifth of mechanically ventilated children had FO% >10% and there was significant increase in cumulative FO% from day 1-7. Non-survivors had significantly higher degree of FO.

Time to Continuous Renal Replacement Therapy Initiation and 90-Day Major Adverse Kidney Events in Children and Young Adults

Importance

In clinical trials, the early or accelerated continuous renal replacement therapy (CRRT) initiation strategy among adults with acute kidney injury or volume overload has not demonstrated a survival benefit. Whether the timing of initiation of CRRT is associated with outcomes among children and young adults is unknown.

Objective

To determine whether timing of CRRT initiation, with and without consideration of volume overload (VO; <10% vs ≥10%), is associated with major adverse kidney events at 90 days (MAKE-90).

Design, Setting, and Participants

This multinational retrospective cohort study was conducted using data from the Worldwide Exploration of Renal Replacement Outcome Collaborative in Kidney Disease (WE-ROCK) registry from 2015 to 2021. Participants included children and young adults (birth to 25 years) receiving CRRT for acute kidney injury or VO at 32 centers across 7 countries. Statistical analysis was performed from February to July 2023.

Exposure

The primary exposure was time to CRRT initiation from intensive care unit admission.

Main Outcomes and measures

The primary outcome was MAKE-90 (death, dialysis dependence, or persistent kidney dysfunction [>25% decline in estimated glomerular filtration rate from baseline]).

Results

Data from 996 patients were entered into the registry. After exclusions (n = 27), 969 patients (440 [45.4%] female; 16 (1.9%) American Indian or Alaska Native, 40 (4.7%) Asian or Pacific Islander, 127 (14.9%) Black, 652 (76.4%) White, 18 (2.1%) more than 1 race; median [IQR] patient age, 8.8 [1.7-15.0] years) with data for the primary outcome (MAKE-90) were included. Median (IQR) time to CRRT initiation was 2 (1-6) days. MAKE-90 occurred in 630 patients (65.0%), of which 368 (58.4%) died. Among the 601 patients who survived, 262 (43.6%) had persistent kidney dysfunction. Of patients with persistent dysfunction, 91 (34.7%) were dependent on dialysis. Time to CRRT initiation was approximately 1 day longer among those with MAKE-90 (median [IQR], 3 [1-8] days vs 2 [1-4] days; P = .002). In the generalized propensity score-weighted regression, there were approximately 3% higher odds of MAKE-90 for each 1-day delay in CRRT initiation (odds ratio, 1.03 [95% CI, 1.02-1.04]).

Conclusions and Relevance

In this cohort study of children and young adults receiving CRRT, longer time to CRRT initiation was associated with greater risk of MAKE-90 outcomes, in particular, mortality. These findings suggest that prospective multicenter studies are needed to further delineate the appropriate time to initiate CRRT and the interaction between CRRT initiation timing and VO to continue to improve survival and reduce morbidity in this population.

Revisiting Post-ICU Admission Fluid Balance Across Pediatric Sepsis Mortality Risk Strata: A Secondary Analysis of a Prospective Observational Cohort Study

OBJECTIVES

Post-ICU admission cumulative positive fluid balance (PFB) is associated with increased mortality among critically ill patients. We sought to test whether this risk varied across biomarker-based risk strata upon adjusting for illness severity, presence of severe acute kidney injury (acute kidney injury), and use of continuous renal replacement therapy (CRRT) in pediatric septic shock.

DESIGN

Ongoing multicenter prospective observational cohort.

SETTING

Thirteen PICUs in the United States (2003-2023).

PATIENTS

Six hundred and eighty-one children with septic shock.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Cumulative percent PFB between days 1 and 7 (days 1-7 %PFB) was determined. Primary outcome of interest was complicated course defined as death or persistence of greater than or equal to two organ dysfunctions by day 7. Pediatric Sepsis Biomarker Risk Model (PERSEVERE)-II biomarkers were used to assign mortality probability and categorize patients into high mortality (n = 91), intermediate mortality (n = 134), and low mortality (n = 456) risk strata. Cox proportional hazard regression models with adjustment for PERSEVERE-II mortality probability, presence of sepsis-associated acute kidney injury on day 3, and use of CRRT, demonstrated that time-dependent variable days 1-7%PFB was independently associated with an increased hazard of complicated course. Risk-stratified analyses revealed that each 10% increase in days 1-7 %PFB was associated with increased hazard of complicated course only among patients with high mortality risk strata (adjusted hazard ratio 1.24 (95% CI, 1.08-1.43), p = 0.003). However, this association was not causally mediated by PERSEVERE-II biomarkers.

CONCLUSIONS

Our data demonstrate the influence of cumulative %PFB on the risk of complicated course in pediatric septic shock. Contrary to our previous report, this risk was largely driven by patients categorized as having a high mortality risk based on PERSEVERE-II biomarkers. Incorporation of such prognostic enrichment tools in randomized trials of restrictive fluid management or early initiation of de-escalation strategies may inform targeted application of such interventions among at-risk patients.

Nonresuscitation Fluid Accumulation and Outcomes After Pediatric Cardiac Surgery: Single-Center Retrospective Cohort Study

OBJECTIVES

Postoperative patients after congenital cardiac surgery are at high risk of fluid overload (FO), which is known to be associated with poor outcomes. "Fluid creep," or nonresuscitation IV fluid in excess of maintenance requirement, is recognized as a modifiable factor associated with FO in the general PICU population, but has not been studied in congenital cardiac surgery patients. Our objective was to characterize fluid administration after congenital cardiac surgery, quantify fluid creep, and the association between fluid creep, FO, and outcome.

DESIGN

Retrospective, observational cohort study.

SETTING

Single-center urban mixed-medical and cardiac PICU.

PATIENTS

Patients admitted to the PICU after cardiac surgery between January 2010 and December 2020.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were 1,459 postoperative encounters with 1,224 unique patients. Total fluid intake was greater than maintenance requirements on 3,103 of 4,661 patient days (67%), with fluid creep present on 2,624 patient days (56%). Total nonresuscitation intake was higher in patients with FO (defined as cumulative fluid balance 10% above body weight) versus those without. Fluid creep was higher among patients with FO than those without for each of the first 5 days postoperatively. Each 10 mL/kg of fluid creep in the first 24 hours postoperatively was associated with 26% greater odds of developing FO (odds ratio [OR] 1.26; 95% CI, 1.17-1.35) and 17% greater odds of mortality (OR 1.17; 95% CI, 1.05-1.30) after adjusting for risk of mortality based on surgical procedure, age, and day 1 resuscitation volume. Increasing fluid creep in the first 24 hours postoperatively was associated with increased postoperative duration of mechanical ventilation and PICU length of stay.

CONCLUSIONS

Fluid creep is present on most postoperative days for pediatric congenital cardiac surgery patients, and fluid creep is associated with higher-risk procedures. Fluid creep early in the postoperative PICU stay is associated with greater odds of FO, mortality, length of mechanical ventilation, and PICU length of stay. Fluid creep may be under-recognized in this population and thus present a modifiable target for intervention.

External validation of the modified sepsis renal angina index for prediction of severe acute kidney injury in children with septic shock

BACKGROUND

Acute kidney injury (AKI) occurs commonly in pediatric septic shock and increases morbidity and mortality. Early identification of high-risk patients can facilitate targeted intervention to improve outcomes. We previously modified the renal angina index (RAI), a validated AKI prediction tool, to improve specificity in this population (sRAI). Here, we prospectively assess sRAI performance in a separate cohort.

METHODS

A secondary analysis of a prospective, multicenter, observational study of children with septic shock admitted to the pediatric intensive care unit from 1/2019 to 12/2022. The primary outcome was severe AKI (≥ KDIGO Stage 2) on Day 3 (D3 severe AKI), and we compared predictive performance of the sRAI (calculated on Day 1) to the original RAI and serum creatinine elevation above baseline (D1 SCr > Baseline +). Original renal angina fulfillment (RAI +) was defined as RAI ≥ 8; sepsis renal angina fulfillment (sRAI +) was defined as RAI ≥ 20 or RAI 8 to < 20 with platelets < 150 × 103/µL.

RESULTS

Among 363 patients, 79 (22%) developed D3 severe AKI. One hundred forty (39%) were sRAI + , 195 (54%) RAI + , and 253 (70%) D1 SCr > Baseline + . Compared to sRAI-, sRAI + had higher risk of D3 severe AKI (RR 8.9, 95%CI 5-16, p < 0.001), kidney replacement therapy (KRT) (RR 18, 95%CI 6.6-49, p < 0.001), and mortality (RR 2.5, 95%CI 1.2-5.5, p = 0.013). sRAI predicted D3 severe AKI with an AUROC of 0.86 (95%CI 0.82-0.90), with greater specificity (74%) than D1 SCr > Baseline (36%) and RAI + (58%). On multivariable regression, sRAI + retained associations with D3 severe AKI (aOR 4.5, 95%CI 2.0-10.2, p < 0.001) and need for KRT (aOR 5.6, 95%CI 1.5-21.5, p = 0.01).

CONCLUSIONS

Prediction of severe AKI in pediatric septic shock is important to improve outcomes, allocate resources, and inform enrollment in clinical trials examining potential disease-modifying therapies. The sRAI affords more accurate and specific prediction than context-free SCr elevation or the original RAI in this population.

Association between fluid overload and mortality in children with sepsis: a systematic review and meta-analysis

BACKGROUND

Sepsis is one of the main causes of morbidity and mortality worldwide. Fluid resuscitation is among the most common interventions and is associated with fluid overload (FO) in some patients. The objective of this systematic review and meta-analysis was to summarise the available evidence on the association between FO and morbimortality in children with sepsis.

METHODS

A systematic search was carried out in PubMed/Medline, Embase, Cochrane and Google Scholar up to December 2022 (PROSPERO 408148), including studies in children with sepsis which reported more than 10% FO 24 hours after admission to intensive care. The risk of bias was assessed using the Newcastle-Ottawa scale. Heterogeneity was assessed using I2, considering it absent if <25% and high if >75%. A sensitivity analysis was run to explore the impact of the methodological quality on the size of the effect. Mantel-Haenszel's model of random effects was used for the analysis. The primary outcome was to determine the risk of mortality associated with FO and the secondary outcomes were the need for mechanical ventilation (MV), multiple organ dysfunction syndrome (MODS) and length of hospital stay associated with FO.

RESULTS

A total of 9 studies (2312 patients) were included, all of which were observational. Children with FO had a higher mortality than patients without overload (46% vs 26%; OR 5.06; 95% CI 1.77 to 14.48; p<0.01). We found no association between %FO and the risk of MODS (OR: 0.97; 95% CI 0.13 to 7.12; p=0.98). Children with FO required MV more often (83% vs 47%; OR: 4.78; 95% CI 2.51 to 9.11; p<0.01) and had a longer hospital stay (8 days (RIQ 6.5-13.2) vs 7 days (RIQ 6.1-11.5); p<0.01).

CONCLUSION

In children with sepsis, more than 10% FO 24 hours after intensive care admission is associated with higher mortality, the need for MV and length of hospital stay.

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.

Revisiting post-ICU admission fluid balance across pediatric sepsis mortality risk strata: A secondary analyses from a prospective observational cohort study

Introduction

Post-ICU admission cumulative positive fluid balance (PFB) is associated with increased mortality among critically ill patients. We sought to test whether this risk varied across biomarker-based risk strata upon adjusting for illness severity, presence of severe acute kidney injury (AKI), and use of renal replacement therapy (CRRT) in pediatric septic shock.

Design

Ongoing multi-center prospective observational cohort.

Setting

Thirteen pediatric ICUs in the United States (2003-2023).

Patients

Six hundred and eighty-one children with septic shock.

Interventions

None.

Measurements and Main Results

Cumulative percent positive fluid balance between day 1-7 (Day 1-7%PFB) was determined. Primary outcome of interest was complicated course defined as death or persistence of ≥ 2 organ dysfunctions by day 7. PERSEVERE-II biomarkers were used to assign mortality probability and categorize patients into high (n = 91), intermediate (n = 134), and low (n = 456) mortality risk strata. Cox proportional hazard regression models with adjustment for PERSEVERE-II mortality probability, presence of sepsis associated acute kidney injury (SA-AKI) on Day 3, and any use of CRRT, demonstrated that time-dependent variable Day 1-7%PFB was independently associated with increased hazard of complicated course in the cohort. Risk stratified analyses revealed that each 10% increase in Day 1-7%PFB was independently associated with increased hazard of complicated course among patients with high mortality risk strata (adj HR of 1.24 (95%CI: 1.08-1.42), p = 0.002), but not among those categorized as intermediate- or low- mortality risk.

Conclusions

Our data demonstrate the independent influence of cumulative %PFB on the risk of complicated course. Contrary to our previous report, this risk was largely driven by patients categorized as having a high-mortality risk based on PERSEVERE-II biomarkers. Further research is necessary to determine whether this subset of patients may benefit from targeted deployment of restrictive fluid management or early initiation of de-escalation therapies upon resolution of shock.