Fluid balance in critically ill children with acute lung injury

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.

A Standardized Approach to Reduce Fluid Overload in Critically Ill Children

Introduction

Fluid overload, the pathologic state of positive fluid balance, is common in the pediatric intensive care unit (PICU) and is independently associated with poor outcomes. Quality improvement-based processes to measure and assess fluid balance in critically ill children are lacking.

Methods

The primary aim was to develop and implement a fluid management strategy that includes the standardized measurement and assessment of fluid balance, which is adhered to in at least 50% of all PICU patients. The 4 components of the strategy include (1) creating a fluid balance dashboard that tracks percent cumulative fluid balance over time, (2) documentation of daily weights, (3) fluid balance reporting and discussion incorporated into standardized rounds, and (4) active total intravenous (IV) fluid order.

Results

We reviewed 280 patient encounters between May 2023 and April 2024 and achieved the primary aim of at least 50% compliance with the fluid management strategy and maintained this success over time. Achieving the primary aim coincides with implementing daily weights and total IV fluid orders into PICU admission order sets.

Conclusions

In this quality improvement project, we develop, implement, and maintain compliance with a fluid management strategy. Future work will involve daily utilization of the fluid balance dashboard and monitoring compliance with total IV fluid orders. Implementing a quality improvement-based fluid management strategy may lead to improved awareness of the fluid status of patients and the prescription of fluid therapy to mitigate the harmful effects of fluid overload.

Relationship between fluid overload and mortality and morbidity in pediatric intensive care unit

OBJECTIVE

The relationship between fluid overload and clinical outcomes was investigated.

DESIGN

This study is an observational and analytic study of a retrospective cohort.

SETTINGS

Pediatric intensive care units.

PATIENTS OR PARTICIPANTS

Between 2019 and 2021 children who needed intensive care were included in the study.

INTERVENTIONS

No intervention.

MAIN VARIABLE OF INTEREST

Early, peak and cumulative fluid overload were evaluated.

RESULTS

The mortality rate was 11.7% (68/513). When fluid overloads were examined in terms of mortality, the percentage of early fluid overload was 1.86 and 3.35, the percent of peak fluid overload was 2.87 and 5.54, and the percent of cumulative fluid overload was 3.40 and 8.16, respectively, in the survivor and the non-survivor groups. After adjustment for age, severity of illness, and other potential confounders, peak (aOR = 1.15; 95%CI 1.05-1.26; p: 0.002) and cumulative (aOR = 1.10; 95%CI 1.04-1.16; p < 0.001) fluid overloads were determined as independent risk factors associated with mortality. When the cumulative fluid overload is 10% or more, a 3.9-fold increase mortality rate was calculated. It is found that the peak and cumulative fluid overload, had significant negative correlation with intensive care unit free days and ventilator free days.

CONCLUSIONS

It is found that peak and cumulative fluid overload in critically ill children were independently associated with intensive care unit mortality and morbidity.

Restricted versus Usual/Liberal Maintenance Fluid Strategy in Mechanically Ventilated Children: An Open-Label Randomized Trial (ReLiSCh Trial)

OBJECTIVES

To assess the impact of restricted vs. usual/liberal maintenance fluid strategy on fluid overload (FO) among mechanically ventilated children.

METHODS

This open-label randomized controlled trial was conducted over a period of 1 y (October 2020-September 2021) in a Pediatric intensive care unit (PICU) in North India. Hemodynamically stable mechanically ventilated children were randomized to 40% (restricted group, n = 50) and 70-80% (usual/liberal group, n = 50) of maintenance fluids. The primary outcome was cumulative fluid overload percentage (FO%) on day 7. Secondary outcomes were FO% >10%; vasoactive inotropic score, sequential organ failure assessment score, pediatric logistic organ dysfunction score and oxygenation index from day 1-7; ventilation free days (VFDs) and PICU free days (PFDs) through day 28; and mortality.

RESULTS

The restricted group had statistically non-significant trend towards lower cumulative FO% at day 7 [7.6 vs. 9.5, p = 0.40]; and proportion of children with FO% >10% (12% vs. 26%, p = 0.21) as compared to usual/liberal group. The increase in FO% from day 1-7 was significant in usual/liberal group as compared to restricted group (p <0.001 and p = 0.134, respectively). Restricted group received significantly lower amount of fluid in the first 5 d; had significantly higher VFDs (23 vs. 17 d, p = 0.008) and PFDs (19 vs. 15 d, p = 0.007); and trend towards lower mortality (8% vs. 16%, p = 0.21).

CONCLUSIONS

Restricted as compared to usual/liberal maintenance fluid strategy among mechanically ventilated children was associated with a trend towards lower rate and severity of FO and mortality; and significantly lower fluid volume received, and higher VFDs and PFDs.

Fluid Overload in Pediatric Acute Respiratory Distress Syndrome after Allogeneic Hematopoietic Cell Transplantation

The aim of the study is to examine the relationship between fluid overload (FO) and severity of respiratory dysfunction in children posthematopoietic cell transplantation (HCT) with pediatric acute respiratory distress syndrome (PARDS). This investigation was a secondary analysis of a multicenter retrospective cohort of children (1month to 21 years) postallogeneic HCT with PARDS receiving invasive mechanical ventilation (IMV) from 2009 to 2014. Daily FO % (FO%) and daily oxygenation index (OI) were calculated for each patient up to the first week of IMV (day 0 = intubation). Linear mixed-effect regression was employed to examine whether FO% and OI were associated on any day during the study period. In total, 158 patients were included. Severe PARDS represented 63% of the cohort and had higher mortality (78 vs. 42%, p <0.001), fewer ventilator free days at 28 (0 [IQR: 0-0] vs. 14 [IQR: 0-23], p <0.001), and 60 days (0 [IQR: 0-27] v. 45 [IQR: 0-55], p <0.001) relative to nonsevere PARDS. Increasing FO% was strongly associated with higher OI ( p <0.001). For children with 10% FO, OI was higher by nearly 5 points (adjusted β , 4.6, 95% CI: [2.9, 6.3]). In subgroup analyses, the association between FO% and OI was strongest among severe PARDS ( p <0.001) and during the first 3 days elapsed from intubation ( p <0.001). FO% was associated with lower PaO 2 /FiO 2 (adjusted β , -1.92, 95% CI: [-3.11, -0.73], p  = 0.002), but not mean airway pressure ( p  = 0.746). In a multicenter cohort of children post-HCT with PARDS, FO was independently associated with oxygenation impairment. The associations were strongest among children with severe PARDS and early in the course of IMV.

Endothelial Glycocalyx Degradation Patterns in Sepsis-Associated Pediatric Acute Respiratory Distress Syndrome: A Single Center Retrospective Observational Study

BACKGROUND

Sepsis-associated destruction of the pulmonary microvascular endothelial glycocalyx (EGCX) creates a vulnerable endothelial surface, contributing to the development of acute respiratory distress syndrome (ARDS). Constituents of the EGCX shed into circulation, glycosaminoglycans and proteoglycans, may serve as biomarkers of endothelial dysfunction. We sought to define the patterns of plasma EGCX degradation products in children with sepsis-associated pediatric ARDS (PARDS), and test their association with clinical outcomes.

METHODS

We retrospectively analyzed a prospective cohort (2018-2020) of children (≥1 month to <18 years of age) receiving invasive mechanical ventilation for acute respiratory failure for ≥72 h. Children with and without sepsis-associated PARDS were selected from the parent cohort and compared. Blood was collected at time of enrollment. Plasma glycosaminoglycan disaccharide class (heparan sulfate, chondroitin sulfate, and hyaluronan) and sulfation subtypes (heparan sulfate and chondroitin sulfate) were quantified using liquid chromatography tandem mass spectrometry. Plasma proteoglycans (syndecan-1) were measured through an immunoassay.

RESULTS

Among the 39 mechanically ventilated children (29 with and 10 without sepsis-associated PARDS), sepsis-associated PARDS patients demonstrated higher levels of heparan sulfate (median 639 ng/mL [interquartile range, IQR 421-902] vs 311 [IQR 228-461]) and syndecan-1 (median 146 ng/mL [IQR 32-315] vs 8 [IQR 8-50]), both p = 0.01. Heparan sulfate subtype analysis demonstrated greater proportions of N-sulfated disaccharide levels among children with sepsis-associated PARDS (p = 0.01). Increasing N-sulfated disaccharide levels by quartile were associated with severe PARDS (n = 9/29) with the highest quartile including >60% of the severe PARDS patients (test for trend, p = 0.04). Higher total heparan sulfate and N-sulfated disaccharide levels were independently associated with fewer 28-day ventilator-free days in children with sepsis-associated PARDS (all p < 0.05).

CONCLUSIONS

Children with sepsis-associated PARDS exhibited higher plasma levels of heparan sulfate disaccharides and syndecan-1, suggesting that EGCX degradation biomarkers may provide insights into endothelial dysfunction and PARDS pathobiology.

Association of Fluid Overload with Escalation of Respiratory Support and Endotracheal Intubation in Acute Bronchiolitis Patients

Fluid overload has been associated with increased oxygen requirement, prolonged duration of mechanical ventilation, and longer length of hospital stay in children hospitalized with pulmonary diseases. Critically ill infants with bronchiolitis admitted to the pediatric intensive care unit (PICU) also tend to develop fluid overload and there is limited information of its role on noninvasive respiratory support. Thus, our primary objective was to study the association of fluid overload in patients with bronchiolitis admitted to the PICU with respiratory support escalation (RSE) and need for endotracheal intubation (ETI). Infants ≤24 months of age with bronchiolitis and admitted to the PICU between 9/2009 and 6/2015 were retrospectively studied. Demographic variables, clinical characteristics including type of respiratory support and need for ETI were evaluated. Fluid overload as assessed by net fluid intake and output (net fluid balance), cumulative fluid balance (CFB) (mL/kg), and percentage fluid overload (FO%), was compared between patients requiring and not requiring RSE and among patients requiring ETI and not requiring ETI at 0 (PICU admission), 12, 24, 36, 48, 72, 96, and 120 hours. One-hundred sixty four of 283 patients with bronchiolitis admitted to the PICU qualified for our study. Thirty-four of 164 (21%) patients required escalation of respiratory support within 5 days of PICU admission and of these 34 patients, 11 patients required ETI. Univariate analysis by Kruskal-Wallis test of fluid overload as assessed by net fluid balance, CFB, and FO% between 34 patients requiring and 130 patients not requiring RSE and among 11 patients requiring ETI and 153 patients not requiring ETI, at 0, 12, 24, 36, 48, 72, 96 and 120 hours did not reveal any significant difference ( p >0.05) at any time interval. Multivariable logistic regression analysis revealed higher PRISM score (odds ratio [OR]: 4.95, 95% confidence interval [95% CI]: 1.79-13.66; p  = 0.002), longer hours on high flow nasal cannula (OR: 4.86, 95% CI: 1.68-14.03; p  = 0.003) and longer hours on noninvasive ventilation (OR: 11.16, 95% CI: 3.36-36.98; p  < 0.001) were associated with RSE. Fluid overload as assessed by net fluid balance, CFB, and FO% was not associated with RSE or need for ETI in critically ill bronchiolitis patients admitted to the PICU. Further prospective studies involving larger number of patients with bronchiolitis are needed to corroborate our findings.

Fluid assessment, fluid balance, and fluid overload in sick children: a report from the Pediatric Acute Disease Quality Initiative (ADQI) conference

BACKGROUND

The impact of disorders of fluid balance, including the pathologic state of fluid overload in sick children has become increasingly apparent. With this understanding, there has been a shift from application of absolute thresholds of fluid accumulation to an appreciation of the intricacies of fluid balance, including the impact of timing, trajectory, and disease pathophysiology.

METHODS

The 26th Acute Disease Quality Initiative was the first to be exclusively dedicated to pediatric and neonatal acute kidney injury (pADQI). As part of the consensus panel, a multidisciplinary working group dedicated to fluid balance, fluid accumulation, and fluid overload was created. Through a search, review, and appraisal of the literature, summative consensus statements, along with identification of knowledge gaps and recommendations for clinical practice and research were developed.

CONCLUSIONS

The 26th pADQI conference proposed harmonized terminology for fluid balance and for describing a pathologic state of fluid overload for clinical practice and research. Recommendations include that the terms daily fluid balance, cumulative fluid balance, and percent cumulative fluid balance be utilized to describe the fluid status of sick children. The term fluid overload is to be preserved for describing a pathologic state of positive fluid balance associated with adverse events. Several recommendations for research were proposed including focused validation of the definition of fluid balance, fluid overload, and proposed methodologic approaches and endpoints for clinical trials.

Furosemide in pediatric intensive care: a retrospective cohort analysis

Introduction

Furosemide is the most commonly used medication in pediatric intensive care. Growing data indicates improved hemodynamic stability and efficacy of furosemide infusions compared to intermittent injections, thereby suggesting furosemide infusions might be considered as first line therapy in critically ill, paediatric patients. The objective of this study is to examine furosemide treatment as either continuous infusions or intermittent injections and subsequent patient outcomes.

Methods

This is a retrospective cohort analysis of patients treated in a pediatric intensive care unit (ICU) over a nine year period (July 31st 2006 and July 31, 2015). Eligible patients were admitted to either the general pediatric or cardiac specific ICU for a duration of at least 6 hours and who received intravenous furosemide treatment.

Results

A total of 7,478 patients were identified who received a total of 118,438 furosemide administrations for a total of 113,951 (96%) intermittent doses and 4,487 (4%) infusions running for a total of 1,588,750 hours. A total of 5,996 (80%) patients received exclusively furosemide injections and 1,482 (20%) patients received at least one furosemide infusion. A total of 193 patients died during ICU admission, amounting to 87 (6%) of the 1,482 patients who received an infusion and 106 (2%) of the 5,996 who received intermittent injections. Multivariable regression analysis showed no statistically significant decrease in adjusted mortality for patients who received furosemide injections compared to furosemide infusions (aOR 1.20, CI 0.76-1.89).

Discussion

This retrospective study observed similar mortality for patients who received furosemide infusions compared to furosemide injections. More research on furosemide in the ICU could provide insights on fluid management, drug effectiveness, and pharmacologic stewardship for critically ill children.

REstrictive versus StandarD FlUid Management in Mechanically Ventilated ChildrEn Admitted to PICU: study protocol for a pilot randomised controlled trial (REDUCE-1)

INTRODUCTION

Intravenous fluid therapy is the most common intervention in critically ill children. There is an increasing body of evidence questioning the safety of high-volume intravenous fluid administration in these patients. To date, the optimal fluid management strategy remains unclear. We aimed to test the feasibility of a pragmatic randomised controlled trial comparing a restrictive with a standard (liberal) fluid management strategy in critically ill children.

METHODS AND ANALYSIS

Multicentre, binational pilot, randomised, controlled, open-label, pragmatic trial. Patients <18 years admitted to paediatric intensive care unit and mechanically ventilated at the time of screening are eligible. Patients with tumour lysis syndrome, diabetic ketoacidosis or postorgan transplant are excluded.

INTERVENTIONS

1:1 random assignment of 154 individual patients into two groups-restrictive versus standard, liberal, fluid strategy-stratified by primary diagnosis (cardiac/non-cardiac). The intervention consists of a restrictive fluid bundle, including lower maintenance fluid allowance, limiting fluid boluses, reducing volumes of drug delivery and initiating diuretics or peritoneal dialysis earlier. The intervention is applied for 48 hours postrandomisation or until discharge (whichever is earlier).

ENDPOINTS

The number of patients recruited per month and proportion of recruited to eligible patients are feasibility endpoints. New-onset acute kidney injury and the incidence of clinically relevant central venous thrombosis are safety endpoints. Fluid balance at 48 hours after randomisation is the efficacy endpoint. Survival free of paediatric intensive care censored at 28 days is the clinical endpoint.

ETHICS AND DISSEMINATION

Ethics approval was gained from the Children's Health Queensland Human Research Ethics Committee (HREC/21/QCHQ/77514, date: 1 September 2021), and University of Zurich (2021-02447, date: 17 March 2023). The trial is registered with the Australia New Zealand Clinical Trials Registry (ACTRN12621001311842). Open-access publication in high impact peer-reviewed journals will be sought. Modern information dissemination strategies will also be used including social media to disseminate the outcomes of the study.

TRIAL REGISTRATION NUMBER

ACTRN12621001311842.

PROTOCOL VERSION/DATE

V5/23 May 2023.

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.

Fluid Overload Precedes and Masks Cryptic Kidney Injury in Pediatric Acute Respiratory Distress Syndrome

OBJECTIVES

Given the complex interrelatedness of fluid overload (FO), creatinine, acute kidney injury (AKI), and clinical outcomes, the association of AKI with poor outcomes in critically ill children may be underestimated due to definitions used. We aimed to disentangle these temporal relationships in a large cohort of children with acute respiratory distress syndrome (ARDS).

DESIGN

Retrospective cohort study.

SETTING

Quaternary care PICU.

PATIENTS

Seven hundred twenty intubated children with ARDS between 2011 and 2019.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Daily fluid balance, urine output (UOP), and creatinine for days 1-7 of ARDS were retrospectively abstracted. A subset of patients had angiopoietin 2 (ANGPT2) quantified on days 1, 3, and 7. Patients were classified as AKI by Kidney Disease Improving Global Outcomes (KDIGO) stage 2/3 then grouped by timing of AKI onset (early if days 1-3 of ARDS, late if days 4-7 of ARDS, persistent if both) for comparison of PICU mortality and ventilator-free days (VFDs). A final category of "Cryptic AKI" was used to identify subjects who met KDIGO stage 2/3 criteria only when creatinine was adjusted for FO. Outcomes were compared between those who had Cryptic AKI identified by FO-adjusted creatinine versus those who had no AKI. Conventionally defined AKI occurred in 26% of patients (early 10%, late 3%, persistent 13%). AKI was associated with higher mortality and fewer VFDs, with no differences according to timing of onset. The Cryptic AKI group (6% of those labeled no AKI) had higher mortality and fewer VFDs than patients who did not meet AKI with FO-adjusted creatinine. FO, FO-adjusted creatinine, and ANGPT2 increased 1 day prior to meeting AKI criteria in the late AKI group.

CONCLUSIONS

AKI was associated with higher mortality and fewer VFDs in pediatric ARDS, irrespective of timing. FO-adjusted creatinine captures a group of patients with Cryptic AKI with outcomes approaching those who meet AKI by traditional criteria. Increases in FO, FO-adjusted creatinine, and ANGPT2 occur prior to meeting conventional AKI criteria.

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

OBJECTIVES

With the recognition that fluid overload (FO) has a detrimental impact on critically ill children, the critical care nephrology community has focused on identifying clinically meaningful targets for intervention. The current study aims to evaluate the epidemiology and outcomes associated with FO in an international multicenter cohort of critically ill children. The current study also aims to evaluate the association of FO at predetermined clinically relevant thresholds and time points (FO ≥ 5% and FO ≥ 10% at the end of ICU days 1 and 2) with outcomes.

DESIGN

Prospective cohort study.

SETTING

Multicenter, international collaborative of 32 pediatric ICUs.

PATIENTS

A total of 5,079 children and young adults admitted consecutively to pediatric ICUs as part of the Assessment of the Worldwide Acute Kidney Injury, Renal Angina and Epidemiology Study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The FO thresholds at the time points of interest occurred commonly in the cohort (FO ≥ 5%Day1 in 38.1% [ n = 1753], FO ≥ 10%Day1 in 11.7% [ n = 537], FO ≥ 5%Day2 in 53.3% [ n = 1,539], FO ≥ 10%Day2 in 25.1% [ n = 724]). On Day1, multivariable modeling demonstrated that FO ≥ 5% was associated with fewer ICU-free days, and FO ≥ 10% was associated with higher mortality and fewer ICU and ventilator-free days. On multivariable modeling, FO-peak, Day2 FO ≥ 5%, and Day2 FO ≥ 10% were associated with higher mortality and fewer ICU and ventilator-free days.

CONCLUSIONS

This study found that mild-to-moderate FO as early as at the end of ICU Day1 is associated with adverse outcomes. The current study fills an important void in the literature by identifying critical combinations of FO timing and quantity associated with adverse outcomes (FO ≥ 5%Day1, FO ≥10%Day1, FO ≥ 5%Day2, and FO ≥ 10%Day2). Those novel findings will help guide the development of interventional strategies and trials targeting the treatment and prevention of clinically relevant FO.

Fluid balance in critically ill children with lower respiratory tract viral infection: a cohort study

BACKGROUND

Increasing evidence has associated positive fluid balance of critically ill patients with poor outcomes. The aim of this study was to explore the pattern of daily fluid balances and their association with outcomes in critically ill children with lower respiratory tract viral infection.

METHODS

A retrospective single-center study was conducted, in children supported with high-flow nasal cannula, non-invasive ventilation, or invasive ventilation. Median (interquartile range) daily fluid balances, cumulative fluid overload (FO) and peak FO variation, indexed as the % of admission body weight, over the first week of Pediatric Intensive Care Unit admission, and their association with the duration of respiratory support were assessed.

RESULTS

Overall, 94 patients with a median age of 6.9 (1.9-18) months, and a respiratory support duration of 4 (2-7) days, showed a median (interquartile range) daily fluid balance of 18 (4.5-19.5) ml/kg at day 1, which decreased up to day 3 to 5.9 (- 14 to 24.9) ml/kg and increased to 13 (- 11 to 29.9) ml/kg at day 7 (p = 0.001). Median cumulative FO% was 4.6 (- 0.8 to 11) and peak FO% was 5.7 (1.9-12.4). Daily fluid balances, once patients were stratified according to the respiratory support, were significantly lower in those requiring mechanical ventilation (p = 0.003). No correlation was found between all examined fluid balances and respiratory support duration or oxygen saturation, even after subgroup analysis of patients with invasive mechanical ventilation, or respiratory comorbidities, or bacterial coinfection, or of patients under 1 year old.

CONCLUSIONS

In a cohort of children with bronchiolitis, fluid balance was not associated with duration of respiratory support or other parameters of pulmonary function.

Fluid management of the critically Ill child

PURPOSE OF REVIEW

This review summarizes current literature pertaining to fluid management for critically ill children. It includes an overview on crystalloid fluid used throughout the critical illness course, management of fluid output and complications with fluid overload.

RECENT FINDINGS

Observational paediatric studies and adult randomized trials show mixed results regarding risk of mortality and kidney injury with 0.9% saline and crystalloid fluid. A recent adult randomized trial suggests that a fluid restrictive strategy may be well tolerated in critically ill adults with septic shock, but further randomized trials are needed in paediatrics. Fluid overload has been associated with increased morbidity and mortality. Trials exploring ways to decrease fluid accumulation must be done in paediatrics.

SUMMARY

Additional high-quality studies are needed to precisely define the type, timing and rate of intravenous fluid critically ill children should receive throughout their clinical illness course.

Nonpulmonary Treatments for Pediatric Acute Respiratory Distress Syndrome: From the Second Pediatric Acute Lung Injury Consensus Conference

OBJECTIVES

To provide an updated review of the literature on nonpulmonary treatments for pediatric acute respiratory distress syndrome (PARDS) from the Second Pediatric Acute Lung Injury Consensus Conference.

DATA SOURCES

MEDLINE (Ovid), Embase (Elsevier), and CINAHL Complete (EBSCOhost).

STUDY SELECTION

Searches were limited to children with PARDS or hypoxic respiratory failure focused on nonpulmonary adjunctive therapies (sedation, delirium management, neuromuscular blockade, nutrition, fluid management, transfusion, sleep management, and rehabilitation).

DATA EXTRACTION

Title/abstract review, full-text review, and data extraction using a standardized data collection form.

DATA SYNTHESIS

The Grading of Recommendations Assessment, Development, and Evaluation approach was used to identify and summarize evidence and develop recommendations. Twenty-five studies were identified for full-text extraction. Five clinical practice recommendations were generated, related to neuromuscular blockade, nutrition, fluid management, and transfusion. Thirteen good practice statements were generated on the use of sedation, iatrogenic withdrawal syndrome, delirium, sleep management, rehabilitation, and additional information on neuromuscular blockade and nutrition. Three research statements were generated to promote further investigation in nonpulmonary therapies for PARDS.

CONCLUSIONS

These recommendations and statements about nonpulmonary treatments in PARDS are intended to promote optimization and consistency of care for patients with PARDS and identify areas of uncertainty requiring further investigation.

Monitoring in Pediatric Acute Respiratory Distress Syndrome: From the Second Pediatric Acute Lung Injury Consensus Conference

OBJECTIVES

Monitoring is essential to assess changes in the lung condition, to identify heart-lung interactions, and to personalize and improve respiratory support and adjuvant therapies in pediatric acute respiratory distress syndrome (PARDS). The objective of this article is to report the rationale of the revised recommendations/statements on monitoring from the Second Pediatric Acute Lung Injury Consensus Conference (PALICC-2).

DATA SOURCES

MEDLINE (Ovid), Embase (Elsevier), and CINAHL Complete (EBSCOhost).

STUDY SELECTION

We included studies focused on respiratory or cardiovascular monitoring of children less than 18 years old with a diagnosis of PARDS. We excluded studies focused on neonates.

DATA EXTRACTION

Title/abstract review, full-text review, and data extraction using a standardized data collection form.

DATA SYNTHESIS

The Grading of Recommendations Assessment, Development and Evaluation approach was used to identify and summarize evidence and develop recommendations. We identified 342 studies for full-text review. Seventeen good practice statements were generated related to respiratory and cardiovascular monitoring. Four research statements were generated related to respiratory mechanics and imaging monitoring, hemodynamics monitoring, and extubation readiness monitoring.

CONCLUSIONS

PALICC-2 monitoring good practice and research statements were developed to improve the care of patients with PARDS and were based on new knowledge generated in recent years in patients with PARDS, specifically in topics of general monitoring, respiratory system mechanics, gas exchange, weaning considerations, lung imaging, and hemodynamic monitoring.

The diuretic effect of adding aminophylline or theophylline to furosemide in pediatric populations: a systematic review

The diuretic effect of the combined furosemide and aminophylline/theophylline among pediatric patients remains unclear. The primary aim of this systematic review was to examine the clinical diuretic effects (urine output and fluid balance) of co-administration of furosemide and aminophylline/theophylline as compared to furosemide alone in pediatric population. Ovid MEDLINE, CENTRAL, and EMBASE were searched from its inception until March 2022 for observational studies and randomized controlled trials (RCTs) comparing the administration of furosemide versus furosemide and aminophylline/theophylline in pediatric population. Case reports, case series, commentaries, letters to editors, systematic reviews, and meta-analyses were excluded. Five articles with a total sample population of 187 patients were included in this systematic review. As compared to the furosemide alone, our pooled data demonstrated that co-administration of furosemide and aminophylline/theophylline was associated with higher urine output (mean difference: 2.91 [90% CI 1.54 to 4.27], p < 0.0001, I² = 90%) and a more negative fluid balance (mean difference - 28.27 [95% CI: - 46.21 to - 10.33], p = 0.002, I² = 56%) than those who received furosemide alone.

CONCLUSION

This is the first paper summarizing the evidence of combined use of furosemide with aminophylline/theophylline in pediatric population. Our systematic review demonstrated that the co-administration of furosemide and aminophylline/theophylline could potentially yield better diuretic effects of urine output and negative fluid balance than furosemide alone in pediatric patients with fluid overload. Given the substantial degree of heterogeneity and low level of evidence, future adequately powered trials are warranted to provide evidence regarding the combined use of aminophylline/theophylline and furosemide as diuretic in the pediatric population.

WHAT IS KNOWN

• Fluid overload is associated with poor prognosis for children in the intensive care unit. • The ineffective result of furosemide alone, even at high dose, as diuretic agent for children with diuretic resistant fluid overload in the intensive care unit.

WHAT IS NEW

• This is the first systematic review that compares furosemide alone and co-administration of furosemide and aminophylline/theophylline. • This paper showed potential benefit of co-administration of furosemide and aminophylline/theophylline promoting urine output and negative fluid balance compared to furosemide alone.

Fluid Accumulation in Mechanically Ventilated, Critically Ill Children: Retrospective Cohort Study of Prevalence and Outcome

OBJECTIVES

To describe the prevalence, patterns, explanatory variables, and outcomes associated with fluid accumulation (FA) in mechanically ventilated children.

DESIGN

Retrospective cohort study.

SETTING

Tertiary PICU.

PATIENTS

Children mechanically ventilated for greater than or equal to 24 hours.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Between July 2016 and July 2021, 1,636 children met eligibility criteria. Median age was 5.5 months (interquartile range [IQR], 0.7-46.5 mo), and congenital heart disease was the most common diagnosis. Overall, by day 7 of admission, the median maximum cumulative FA, as a percentage of estimated admission weight, was 7.5% (IQR, 3.3-15.1) occurring at a median of 4 days after admission. Overall, higher FA was associated with greater duration of mechanical ventilation (MV) (mean difference, 1.17 [95% CI, 1.13-1.22]; p < 0.001]), longer intensive care length of stay (LOS) (mean difference, 1.16 [95% CI, 1.12-1.21]; p < 0.001]), longer hospital LOS (mean difference, 1.19 [95% CI, 1.13-1.26]; p < 0.001]), and increased mortality (odds ratio, 1.31 [95% CI, 1.08-1.59]; p = 0.005). However, these associations depended on the effects of children with extreme values, and there was no increase in risk up to 20% FA, overall, in children following cardiopulmonary bypass and in children in the general ICU. When excluding children with maximum FA of >10%, there was no association with duration of MV (mean difference, 0.99 [95% CI, 0.94-1.04]; p = 0.64) and intensive care or hospital LOS (mean difference, 1.01 [95% CI, 0.96-1.06]; p = 0.70 and 1.01 [95% CI, 0.95-1.08]; 0.79, respectively) but an association with reduced mortality 0.71 (95% CI, 0.53-0.97; p = 0.03).

CONCLUSIONS

In mechanically ventilated critically ill children, greater maximum FA was associated with longer duration of MV, intensive care LOS, hospital LOS, and mortality. However, these findings were driven by extreme values of FA of greater than 20%, and up to 10%, there was reduced mortality and no signal of harm.

Derivation and Validation of Vasoactive Inotrope Score Trajectory Groups in Critically Ill Children With Shock

OBJECTIVES

To determine whether there are clinically relevant and reproducible Vasoactive Inotrope Score (VIS) trajectories in children with shock during the acute phase of critical illness.

DESIGN

Retrospective, observational cohort study.

SETTING

Two tertiary, academic PICUs.

PATIENTS

Children (< 18 yr old) who required vasoactive infusions within 24 hours of admission to the PICU. Those admitted post cardiac surgery were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

An hourly VIS was calculated for the first 72 hours after initiation of vasoactives. Group-based trajectory modeling (GBTM) was applied to a derivation set (75% of encounters) and compared with the trajectories in a validation set (25% of encounters) using the same variables. The primary outcome was in-hospital mortality, and the secondary outcome was multiple organ dysfunction syndrome (MODS) on day 7. A total of 1,828 patients met inclusion criteria, and 309 (16.9%) died. GBTM identified four subgroups that were reproducible in the validation set: "Mild, fast resolving shock" ( n = 853 [47%]; mortality 9%), "Moderate, slow resolving shock" ( n = 422 [23%]; mortality 15%), "Moderate, prolonged shock" ( n = 312 [17%]; mortality 21%), and "Severe, prolonged shock" ( n = 241 [13%]; mortality 40%). There was a significant difference in mortality, MODS on day 7, and suspected infection ( p < 0.001) across groups. The "Mild, fast resolving shock" and "Severe, prolonged shock" groups were identifiable within the first 24 hours. The "Moderate, slow resolving" and "Moderate, prolonged shock" groups were indistinguishable in the first 24 hours after initiation of vasoactives but differed in in-hospital mortality and MODS on day 7. Hydrocortisone administration was independently associated with poor outcomes in the "Mild, fast resolving shock" group.

CONCLUSIONS

We uncovered four distinct and reproducible VIS trajectory groups that were associated with different risk factors, response to therapy, and outcomes in children with shock. Characterizing VIS trajectory groups in the acute phase of critical illness may enable better prognostication and more targeted management.

Variability in Clinician Awareness of Intravenous Fluid Administration in Critical Illness: A Prospective Cohort Study

Intravenous (IV) fluids are commonly administered to critically ill children, but clinicians lack effective guidance for the correct dose and duration of therapy resulting in variation of prescribing habits which harm children. It is unknown if clinicians recognize the amount of IV fluid that patients receive. We aimed to determine clinician's accuracy in the identification of the volume of IV fluids patients will receive over the next 24 hours. Prospective cohort study enrolled all patients admitted to the pediatric intensive care unit (PICU) from May to August 2021 at the University of Michigan's C.S. Mott Children's Hospital PICU. For each patient, clinicians estimated the volume of IV fluid that patients will receive in the next 24 hours. The primary outcome was accuracy of the estimation defined as predicted volume of IV fluids versus actual volume administered within 10 mL/kg or 500 mL depending on patient's weight. We tested for differences in accuracy by clinician type using chi-square tests. There were 259 patients for whom 2,295 surveys were completed by 177 clinicians. Clinicians' estimates were accurate 48.8% of the time with a median difference of 10 (1–26) mL/kg. We found that accuracy varied between clinician type: bedside nurses were most accurate at 64.3%, and attendings were least accurate at 30.5%. PICU clinicians have poor recognition of the amount of IV fluids their patients will receive in the subsequent 24-hour period. Estimate accuracy varied by clinician's role and improved over time, which may suggest opportunities for improvement.

Consensus-Based Recommendations on Priority Activities to Address Acute Kidney Injury in Children: A Modified Delphi Consensus Statement

IMPORTANCE

Increasing evidence indicates that acute kidney injury (AKI) occurs frequently in children and young adults and is associated with poor short-term and long-term outcomes. Guidance is required to focus efforts related to expansion of pediatric AKI knowledge.

OBJECTIVE

To develop expert-driven pediatric specific recommendations on needed AKI research, education, practice, and advocacy.

EVIDENCE REVIEW

At the 26th Acute Disease Quality Initiative meeting conducted in November 2021 by 47 multiprofessional international experts in general pediatrics, nephrology, and critical care, the panel focused on 6 areas: (1) epidemiology; (2) diagnostics; (3) fluid overload; (4) kidney support therapies; (5) biology, pharmacology, and nutrition; and (6) education and advocacy. An objective scientific review and distillation of literature through September 2021 was performed of (1) epidemiology, (2) risk assessment and diagnosis, (3) fluid assessment, (4) kidney support and extracorporeal therapies, (5) pathobiology, nutrition, and pharmacology, and (6) education and advocacy. Using an established modified Delphi process based on existing data, workgroups derived consensus statements with recommendations.

FINDINGS

The meeting developed 12 consensus statements and 29 research recommendations. Principal suggestions were to address gaps of knowledge by including data from varying socioeconomic groups, broadening definition of AKI phenotypes, adjudicating fluid balance by disease severity, integrating biopathology of child growth and development, and partnering with families and communities in AKI advocacy.

CONCLUSIONS AND RELEVANCE

Existing evidence across observational study supports further efforts to increase knowledge related to AKI in childhood. Significant gaps of knowledge may be addressed by focused efforts.

Early Restrictive Fluid Strategy Impairs the Diaphragm Force in Lambs with Acute Respiratory Distress Syndrome

BACKGROUND

The effect of fluid management strategies in critical illness-associated diaphragm weakness are unknown. This study hypothesized that a liberal fluid strategy induces diaphragm muscle fiber edema, leading to reduction in diaphragmatic force generation in the early phase of experimental pediatric acute respiratory distress syndrome in lambs.

METHODS

Nineteen mechanically ventilated female lambs (2 to 6 weeks old) with experimental pediatric acute respiratory distress syndrome were randomized to either a strict restrictive fluid strategy with norepinephrine or a liberal fluid strategy. The fluid strategies were maintained throughout a 6-h period of mechanical ventilation. Transdiaphragmatic pressure was measured under different levels of positive end-expiratory pressure (between 5 and 20 cm H2O). Furthermore, diaphragmatic microcirculation, histology, inflammation, and oxidative stress were studied.

RESULTS

Transdiaphragmatic pressures decreased more in the restrictive group (-9.6 cm H2O [95% CI, -14.4 to -4.8]) compared to the liberal group (-0.8 cm H2O [95% CI, -5.8 to 4.3]) during the application of 5 cm H2O positive end-expiratory pressure (P = 0.016) and during the application of 10 cm H2O positive end-expiratory pressure (-10.3 cm H2O [95% CI, -15.2 to -5.4] vs. -2.8 cm H2O [95% CI, -8.0 to 2.3]; P = 0.041). In addition, diaphragmatic microvessel density was decreased in the restrictive group compared to the liberal group (34.0 crossings [25th to 75th percentile, 22.0 to 42.0] vs. 46.0 [25th to 75th percentile, 43.5 to 54.0]; P = 0.015). The application of positive end-expiratory pressure itself decreased the diaphragmatic force generation in a dose-related way; increasing positive end-expiratory pressure from 5 to 20 cm H2O reduced transdiaphragmatic pressures with 27.3% (17.3 cm H2O [95% CI, 14.0 to 20.5] at positive end-expiratory pressure 5 cm H2O vs. 12.6 cm H2O [95% CI, 9.2 to 15.9] at positive end-expiratory pressure 20 cm H2O; P < 0.0001). The diaphragmatic histology, markers for inflammation, and oxidative stress were similar between the groups.

CONCLUSIONS

Early fluid restriction decreases the force-generating capacity of the diaphragm and diaphragmatic microcirculation in the acute phase of pediatric acute respiratory distress syndrome. In addition, the application of positive end-expiratory pressure decreases the force-generating capacity of the diaphragm in a dose-related way. These observations provide new insights into the mechanisms of critical illness-associated diaphragm weakness.

EDITOR’S PERSPECTIVE

Analysis of Fluid Balance as Predictor of Length of Assisted Mechanical Ventilation in Children Admitted to Pediatric Intensive Care Unit (PICU)

Background

Ventilator-associated lung injury (VALI) is a devastating complication of assisted mechanical ventilation (AMV) and is one of the root causes of prolonged AMV. Many strategies were made to decrease the effect of the same. This study is conducted to determine the association of prolonged AMV with fluid balance and pediatric index of mortality 2 (PIM2) score.

Methods

This prospective observational study was carried out in a PICU of a tertiary care centre over a period of 12 months. Patient's fluid balance was calculated by tabulating fluid input-output over initial 48 hours of AMV. The PIM2 score on admission was documented. The association between qualitative variables was assessed by a chi-square test. Comparison of quantitative data measured between cases with duration of AMV ≥ 7 days and <7 days was done using the Mann–Whitney U test. Correlation between quantitative data was done by using the Pearson product moment correlation.

Results

Out of 40 patients, 27 patients who had ≥15% positive fluid balance required prolonged mechanical ventilation. Similarly, 27 patients with PIM2 score ≥ 5 required prolonged AMV. On applying the Pearson chi-square test, we found a significant association between positive fluid balance and prolonged mechanical ventilation (P value = 2.25 × 10⁻⁷ (<0.05)). Likewise, a statistically significant association was found between PIM2 score and prolonged ventilation (P value = 1.19 × 10⁻⁵ (<0.05)).

Conclusion

There is a significant association of prolonged AMV with positive fluid balance (>15%) and PIM2 score (>5). By strict maintenance of fluid balance with appropriate intervention, the length of AMV and PICU stay can be decreased.

Initial Fluid Balance Associated Outcomes in Children With Severe Sepsis and Septic Shock

INTRODUCTION

Net fluid balance and its role in sepsis-related mortality is not clear; studies suggest that aggressive fluid resuscitation can help in treatment, whereas others consider it is associated with poor outcomes. This study aimed to clarify the possible association of initial 24 hours' fluid balance with poor outcomes in pediatric patients with sepsis.

METHODS

Retrospective data analysis included pediatric patients admitted with suspected or proven sepsis or septic shock to pediatric intensive care unit (PICU) of a tertiary care teaching hospital in Saudi Arabia.

RESULTS

The study included 47 patients; 13 (28%) died, and mortality rate was significant in children with neurologic failure (P < 0.02), mechanical ventilation within 24 hours of admission (P < 0.03), leukopenia (P < 0.02), abnormal international normalized ratio (P < 0.02), initial blood lactate levels higher than 5 mmol/L (P < 0.02), or positive fluid balance at 24 hours of admission to the PICU (P < 0.001).

CONCLUSION

Among children with sepsis and/or septic shock, there is significant association between mortality and initial high blood lactate levels and positive fluid balance at 24 hours from admission to the PICU.

Fluid overload in children with pediatric acute respiratory distress syndrome: A retrospective cohort study

OBJECTIVES

To assess the association of cumulative fluid overload (FO) up to 14 days from the diagnosis of pediatric acute respiratory syndrome (PARDS) with pediatric intensive care unit (PICU) mortality, 28-day mechanical ventilation free days (VFD), and 28-day intensive care unit free days (IFD). We hypothesized that fluid overload, even beyond the acute period, would be associated with increased morbidity and mortality.

METHODS

We conducted a retrospective cohort study of PARDS patients admitted to PICU from 2009 to 2015. For repeated admissions, we considered the admission with the highest oxygenation index (OI). Daily FO (%) was calculated as (intake - output)/weight at PICU admission × 100. Peak cumulative FO (CFO) was the highest CFO from the diagnosis of PARDS to Day 14 or to PICU discharge or mortality, whichever was earliest. Rate to peak CFO was the peak CFO divided by the number of days to reach that highest CFO. The association of FO with mortality, VFD and IFD were analyzed with logistic and linear regression models, with the following covariates: Pediatric Index of Mortality 2 score, PARDS severity, and the presence of acute kidney injury (AKI).

RESULTS

There were 165 patients included in this study, with a mortality rate of 45.5% (75/165), median age 3.2 years (interquartile range [IQR] 0.7-9.9) and OI 15.8 (IQR 9.5-27.9). Seventy-three (44.2%) patients had severe PARDS and 64 (38.8%) had AKI. AKI (aOR [adjusted odds ratio] 3.19, 95% CI [confidence interval] 1.43-7.09, p = 0.004) and rate to peak cumulative FO (aOR 1.23, 95% CI 1.07-1.42, p = 0.004) were associated with mortality. AKI and peak cumulative FO were associated with decreased VFD and IFD.

CONCLUSION

The rate to peak CFO over the first 14 days of PARDS was associated with mortality and peak CFO was associated with decreased VFD and IFD.

Renal Dysfunction Criteria in Critically Ill Children: The PODIUM Consensus Conference

CONTEXT

Renal dysfunction is associated with poor outcomes in critically ill children.

OBJECTIVE

To evaluate the current evidence for criteria defining renal dysfunction in critically ill children and association with adverse outcomes. To develop contemporary consensus criteria for renal dysfunction in critically ill children.

DATA SOURCES

PubMed and Embase were searched from January 1992 to January 2020.

STUDY SELECTION

Included studies evaluated critically ill children with renal dysfunction, performance characteristics of assessment tools for renal dysfunction, and outcomes related to mortality, functional status, or organ-specific or other patient-centered outcomes. Studies with adults or premature infants (≤36 weeks' gestational age), animal studies, reviews, case series, and studies not published in English with inability to determine eligibility criteria were excluded.

DATA EXTRACTION

Data were extracted from included studies into a standard data extraction form by task force members.

RESULTS

The systematic review supported the following criteria for renal dysfunction: (1) urine output <0.5 mL/kg per hour for ≥6 hours and serum creatinine increase of 1.5 to 1.9 times baseline or ≥0.3 mg/dL, or (2) urine output <0.5 mL/kg per hour for ≥12 hours, or (3) serum creatinine increase ≥2 times baseline, or (4) estimated glomerular filtration rate <35 mL/minute/1.73 m2, or (5) initiation of renal replacement therapy, or (6) fluid overload ≥20%. Data also support criteria for persistent renal dysfunction and for high risk of renal dysfunction.

LIMITATIONS

All included studies were observational and many were retrospective.

CONCLUSIONS

We present consensus criteria for renal dysfunction in critically ill children.

Current Practice of Fluid Maintenance and Replacement Therapy in Mechanically Ventilated Critically Ill Children: A European Survey

Appropriate fluid management in mechanically ventilated critically ill children remains an important challenge and topic of active discussion in pediatric intensive care medicine. An increasing number of studies show an association between a positive fluid balance or fluid overload and adverse outcomes. However, to date, no international consensus regarding fluid management or removal strategies exists. The aim of this study was to obtain more insight into the current clinical practice of fluid therapy in mechanically ventilated critically ill children. On behalf of the section of cardiovascular dynamics of the European Society of Pediatric and Neonatal Intensive Care (ESPNIC) we conducted an anonymous survey among pediatric intensive care unit (PICU) specialists in Europe regarding fluid overload and management. A total of 107 study participants responded to the survey. The vast majority of respondents considers fluid overload to be a common phenomenon in mechanically ventilated children and believes this complication is associated with adverse outcomes, such as mortality and duration of respiratory support. Yet, only 75% of the respondents administers a lower volume of fluids (reduction of 20% of normal intake) to mechanically ventilated critically ill children on admission. During PICU stay, a cumulative fluid balance of more than 5% is considered to be an indication to reduce fluid intake and start diuretic treatment in most respondents. Next to fluid balance calculation, the occurrence of peripheral and/or pulmonary edema (as assessed including by chest radiograph and lung ultrasound) was considered an important clinical sign of fluid overload entailing further therapeutic action. In conclusion, fluid overload in mechanically ventilated critically ill children is considered an important problem among PICU specialists, but there is great heterogeneity in the current clinical practice to avoid this complication. We identify a great need for further prospective and randomized investigation of the effects of (restrictive) fluid strategies in the PICU.

Non-resuscitation fluid in excess of hydration requirements is associated with higher mortality in critically ill children

BACKGROUND

Large volumes of non-resuscitation fluids are often administered to critically ill children. We hypothesize that excess maintenance fluid is a significant contributor to non-resuscitation fluid and that non-resuscitation fluid administered beyond hydration requirements is associated with worse clinical outcomes in critically ill children.

METHODS

We evaluated all patients admitted to two large urban pediatric intensive care units (PICU) between January 2010-August 2016 and January 2010-August 2018, respectively, who survived and remained in the hospital for at least 3 days following PICU admission. The primary outcome was in-hospital mortality. Association of excess fluid with outcomes was adjusted for confounders (age, Pediatric Risk of Mortality III score, study site, day 3 acute kidney injury, PICU era, resuscitation volume, and volume output) using multivariable regression.

RESULTS

We evaluated 14,483 patients; 52% received non-resuscitation fluid in excess of hydration requirements. Non-resuscitation fluid in excess of hydration requirements was associated with higher in-hospital mortality after adjustment for confounders (adjusted odds ratio 1.01 per 10 mL/kg in excess fluid, 95% confidence interval: 1.002-1.02).

CONCLUSIONS

Non-resuscitation fluid in excess of hydration requirements is associated with increased mortality in critically ill children. Excess maintenance fluid is a modifiable contributor to this fluid volume. Strategies to reduce excess maintenance fluids warrant further study.

IMPACT

Critically ill children frequently receive non-resuscitation fluid in excess of their estimated hydration requirements. Non-resuscitation fluid volume in excess of estimated hydration requirements is associated with higher morbidity and mortality in critically ill children. Critically ill children receive a large volume burden from maintenance fluid. Maintenance fluid represents a modifiable contributor of non-resuscitation fluid in excess of hydration requirements. Strategies focused on limitation of maintenance fluid warrant further study.

The Use of Diuretic in Mechanically Ventilated Children with Viral Bronchiolitis: a Cohort Study

Introduction

Viral bronchiolitis is a leading cause of admissions to pediatric intensive care unit (PICU). A literature review indicates that there is limited information on fluid overload and the use of diuretics in mechanically ventilated children with viral bronchiolitis. This study was conducted to understand diuretic use concerning fluid overload in this population.

Material and methods

A retrospective cohort study performed at a quaternary children’s hospital. The study population consisted of mechanically ventilated children with bronchiolitis, with a confirmed viral diagnosis on polymerase chain reaction (PCR) testing. Children with co-morbidities were excluded. Data collected included demographics, fluid status, diuretic use, morbidity and outcomes. The data were compared between groups that received or did not receive diuretics.

Result

Of the 224 mechanically ventilated children with confirmed bronchiolitis, 179 (79%) received furosemide on Day 2 of invasive ventilation. Out of these, 72% of the patients received intermittent intravenous furosemide, whereas 28% received continuous infusion. It was used more commonly in patients who had a higher fluid overload. Initial fluid overload was associated with longer duration of mechanical ventilation (median days 6 vs 4, p<0.001) and length of stay (median days 10 vs 6, p<0.001) even with the use of furosemide. Superimposed bacterial pneumonia was seen in 60% of cases and was associated with a higher per cent fluid overload at 24 hours (9.1 vs 6.3, p = 0.003).

Conclusion

Diuretics are frequently used in mechanically ventilated children with bronchiolitis and fluid overload, with intermittent dosing of furosemide being the commonest treatment. There is a potential benefit of improved oxygenation in these children, though further research is needed to quantify this benefit and any potential harm. Due to potential harm with fluid overload, restrictive fluid strategies may have a potential benefit.

Advances in Neonatal Acute Kidney Injury

In this state-of-the-art review, we highlight the major advances over the last 5 years in neonatal acute kidney injury (AKI). Large multicenter studies reveal that neonatal AKI is common and independently associated with increased morbidity and mortality. The natural course of neonatal AKI, along with the risk factors, mitigation strategies, and the role of AKI on short- and long-term outcomes, is becoming clearer. Specific progress has been made in identifying potential preventive strategies for AKI, such as the use of caffeine in premature neonates, theophylline in neonates with hypoxic-ischemic encephalopathy, and nephrotoxic medication monitoring programs. New evidence highlights the importance of the kidney in "crosstalk" between other organs and how AKI likely plays a critical role in other organ development and injury, such as intraventricular hemorrhage and lung disease. New technology has resulted in advancement in prevention and improvements in the current management in neonates with severe AKI. With specific continuous renal replacement therapy machines designed for neonates, this therapy is now available and is being used with increasing frequency in NICUs. Moving forward, biomarkers, such as urinary neutrophil gelatinase-associated lipocalin, and other new technologies, such as monitoring of renal tissue oxygenation and nephron counting, will likely play an increased role in identification of AKI and those most vulnerable for chronic kidney disease. Future research needs to be focused on determining the optimal follow-up strategy for neonates with a history of AKI to detect chronic kidney disease.

Association between early fluid overload and mortality in critically-ill mechanically ventilated children: a single-center retrospective cohort study

Background

Positive fluid overload (FO) may cause adverse effect. This study retrospectively analyzed the relationship between early FO and in-hospital mortality in children with mechanical ventilation (MV) in pediatric intensive care unit (PICU).

Methods

This study retrospectively enrolled 309 children (ages 28 days to 16 years) receiving invasive MV admitted to the PICU of Xinhua Hospital from March 2014 to March 2019. Children receiving MV for less than 48 h were excluded. The FO in the first 3 days of MV was considered to the early FO. Patients were divided into groups according to early FO and survival to evaluate the associations of early FO, percentage FO(%FO) > 10%, and %FO > 20% with in-hospital mortality.

Results

A total of 309 patients were included. The mean early FO was 8.83 ± 8.81%, and the mortality in hospital was 26.2% (81/309). There were no significant differences in mortality among different FO groups (P = 0.053) or in early FO between survivors and non-survivors (P = 0.992). Regression analysis demonstrated that use of more vasoactive drugs, the presence of multiple organ dysfunction syndrome, longer duration of MV, and a non-operative reason for PICU admission were related to increased mortality (P < 0.05). Although early FO and %FO > 10% were not associated with in-hospital mortality (β = 0.030, P = 0.090, 95% CI = 0.995–1.067; β = 0.479, P = 0.153, 95% CI = 0.837–3.117), %FO > 20% was positively correlated with mortality (β = 1.057, OR = 2.878, P = 0.029, 95% CI = 1.116–7.418).

Conclusions

The correlation between early FO and mortality was affected by interventions and the severity of the disease, but %FO > 20% was an independent risk factor for in-hospital mortality in critically ill MV-treated children.

Renal angina index predicts fluid overload in critically ill children: an observational cohort study

Background

Fluid overload and acute kidney injury are common and associated with poor outcomes among critically ill children. The prodrome of renal angina stratifies patients by risk for severe acute kidney injury, but the predictive discrimination for fluid overload is unknown.

Methods

Post-hoc analysis of patients admitted to a tertiary care pediatric intensive care unit (PICU). The primary outcome was the performance of renal angina fulfillment on day of ICU admission to predict fluid overload ≥15% on Day 3.

Results

77/139 children (55%) fulfilled renal angina (RA+). After adjusting for covariates, RA+ was associated with increased odds of fluid overload on Day 3 (adjusted odds ratio (aOR) 5.1, 95% CI 1.23–21.2, p = 0.025, versus RA-). RA- resulted in a 90% negative predictive value for fluid overload on Day 3. Median fluid overload was significantly higher in RA+ patients with severe acute kidney injury compared to RA+ patients without severe acute kidney injury (% fluid overload on Day 3: 8.8% vs. 0.73%, p = 0.002).

Conclusion

Among critically ill children, fulfillment of renal angina was associated with increased odds of fluid overload versus the absence of renal angina and a higher fluid overload among patients who developed acute kidney injury. Renal angina directed risk classification may identify patients at highest risk for fluid accumulation. Expanded study in larger populations is warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02540-6.

Timing and Clinical Significance of Fluid Overload in Pediatric Acute Respiratory Distress Syndrome

OBJECTIVES

Fluid overload is associated with worse outcomes in adult and pediatric acute respiratory distress syndrome. However, the time-course of fluid overload and its relationship to outcome has not been described. We aimed to determine the relationship between the timing of fluid overload and outcomes over the first 7 days after acute respiratory distress syndrome onset in children.

DESIGN

Retrospective cohort study.

SETTING

Single tertiary care PICU.

PATIENTS

Intubated children with acute respiratory distress syndrome between 2011 and 2019.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Daily and cumulative total fluid intake, total output, urine output, and fluid balance were collected for each 24-hour period from days 1 to 7 after acute respiratory distress syndrome onset. We tested the association between daily cumulative fluid metrics with PICU mortality and probability of extubation by 28 days using multivariable logistic and competing risk regression, respectively. In a subset of children, plasma was collected on day 1 and day 3 of acute respiratory distress syndrome and angiopoietin-2 quantified. Of 723 children with acute respiratory distress syndrome, 132 died (18%). In unadjusted analysis, nonsurvivors had higher cumulative fluid balance starting on day 3. In multivariable analysis, a positive cumulative fluid balance on days 5 through 7 was associated with increased mortality. Higher cumulative fluid balance on days 4 to 7 was associated with lower probability of extubation. Elevated angiopoietin-2 on day 1 predicted early (within 3 d) fluid overload greater than or equal to 10%, and elevated angiopoietin-2 on day 3 predicted late (between days 4 and 7) fluid overload.

CONCLUSIONS

Fluid overload after day 4 of acute respiratory distress syndrome, but not before, was associated with worse outcomes. Higher angiopoietin-2 predicted subsequent fluid overload. Our results suggest that future interventions aimed at managing fluid overload may have differential efficacy depending on when in the time-course of acute respiratory distress syndrome they are initiated.

Early Cumulative Fluid Balance and Outcomes in Pediatric Allogeneic Hematopoietic Cell Transplant Recipients With Acute Respiratory Failure: A Multicenter Study

OBJECTIVES

To evaluate the associations between early cumulative fluid balance (CFB) and outcomes among critically ill pediatric allogeneic hematopoietic cell transplant (HCT) recipients with acute respiratory failure, and determine if these associations vary by treatment with renal replacement therapy (RRT).

METHODS

We performed a secondary analysis of a multicenter retrospective cohort of patients (1mo - 21yrs) post-allogeneic HCT with acute respiratory failure treated with invasive mechanical ventilation (IMV) from 2009 to 2014. Fluid intake and output were measured daily for the first week of IMV (day 0 = day of intubation). The exposure, day 3 CFB (CFB from day 0 through day 3 of IMV), was calculated using the equation [Fluid in - Fluid out] (liters)/[PICU admission weight](kg)*100. We measured the association between day 3 CFB and PICU mortality with logistic regression, and the rate of extubation at 28 and 60 days with competing risk regression (PICU mortality = competing risk).

RESULTS

198 patients were included in the study. Mean % CFB for the cohort was positive on day 0 of IMV, and increased further on days 1-7 of IMV. For each 1% increase in day 3 CFB, the odds of PICU mortality were 3% higher (adjusted odds ratio (aOR) 1.03, 95% CI 1.00-1.07), and the rate of extubation was 3% lower at 28 days (adjusted subdistribution hazard ratio (aSHR) 0.97, 95% CI 0.95-0.98) and 3% lower at 60 days (aSHR 0.97, 95% CI 0.95-0.98). When day 3 CFB was dichotomized, 161 (81%) had positive and 37 (19%) had negative day 3 CFB. Positive day 3 CFB was associated with higher PICU mortality (aOR 3.42, 95% CI 1.48-7.87) and a lower rate of extubation at 28 days (aSHR 0.30, 95% CI 0.18-0.48) and 60 days (aSHR 0.30, 95% 0.19-0.48). On stratified analysis, the association between positive day 3 CFB and PICU mortality was significantly stronger in those not treated with RRT (no RRT: aOR 9.11, 95% CI 2.29-36.22; RRT: aOR 1.40, 95% CI 0.42-4.74).

CONCLUSIONS

Among critically ill pediatric allogeneic HCT recipients with acute respiratory failure, positive and increasing early CFB were independently associated with adverse outcomes.

Early restrictive fluid resuscitation has no clinical advantage in experimental severe pediatric acute respiratory distress syndrome

Intravenous fluids are widely used to treat circulatory deterioration in pediatric acute respiratory distress syndrome (PARDS). However, the accumulation of fluids in the first days of PARDS is associated with adverse outcome. As such, early fluid restriction may prove beneficial, yet the effects of such a fluid strategy on the cardiopulmonary physiology in PARDS are unclear. In this study, we compared the effect of a restrictive with a liberal fluid strategy on a hemodynamic response and the formation of pulmonary edema in an animal model of PARDS. Sixteen mechanically ventilated lambs (2-6 wk) received oleic acid infusion to induce PARDS and were randomized to a restrictive or liberal fluid strategy during a 6-h period of mechanical ventilation. Transpulmonary thermodilution determined extravascular lung water (EVLW) and cardiac output (CO). Postmortem lung wet-to-dry weight ratios were obtained by gravimetry. Restricting fluids significantly reduced fluid intake but increased the use of vasopressors among animals with PARDS. Arterial blood pressure was similar between groups, yet CO declined significantly in animals receiving restrictive fluids (P = 0.005). There was no difference in EVLW over time (P = 0.111) and lung wet-to-dry weight ratio [6.1, interquartile range (IQR) = 6.0-7.3 vs. 7.1, IQR = 6.6-9.4, restrictive vs. liberal, P = 0.725] between fluid strategies. Both fluid strategies stabilized blood pressure in this model, yet early fluid restriction abated CO. Early fluid restriction did not limit the formation of pulmonary edema; therefore, this study suggests that in the early phase of PARDS, a restrictive fluid strategy is not beneficial in terms of immediate cardiopulmonary effects.

Impact of CRRT in Patients with PARDS Treated with VV-ECMO

The high mortality of pediatric acute respiratory distress syndrome (PARDS) is partly related to fluid overload. Extracorporeal membrane oxygenation (ECMO) is used to treat pediatric patients with severe PARDS, but can result in acute kidney injury (AKI) and worsening fluid overload. The objective of this study was to determine whether the addition of CRRT to ECMO in patients with PARDS is associated with increased mortality.

METHODS

We conducted a retrospective 7-year study of patients with PARDS requiring ECMO and divided them into those requiring CRRT and those not requiring CRRT. We calculated severity of illness scores, the amount of blood products administered to both groups, and determined the impact of CRRT on mortality and morbidity.

RESULTS

We found no significant difference in severity of illness scores except the vasoactive inotropic score (VIS, 45 ± 71 vs. 139 ± 251, p = 0.042), which was significantly elevated during the initiation and the first three days of ECMO. CRRT was associated with an increase in the use of blood products and noradrenaline (p < 0.01) without changing ECMO duration, length of PICU stay or mortality.

CONCLUSION

The addition of CRRT to ECMO is associated with a greater consumption of blood products but no increase in mortality.

Integrating Focused Cardiac Ultrasound Into Pediatric Septic Shock Assessment

OBJECTIVES

To assess focused cardiac ultrasound impact on clinician hemodynamic characterization of patients with suspected septic shock as well as expert-generated focused cardiac ultrasound algorithm performance.

DESIGN

Retrospective, observational study.

SETTING

Single-center, noncardiac PICU.

PATIENTS

Less than 18 years old receiving focused cardiac ultrasound study within 72 hours of sepsis pathway initiation from January 2014 to December 2016.

INTERVENTIONS

Hemodynamics of patients with suspected septic shock were characterized as fluid responsive, myocardial dysfunction, obstructive physiology, and/or reduced systemic vascular resistance by a bedside clinician before and immediately following focused cardiac ultrasound performance. The clinician's post-focused cardiac ultrasound hemodynamic assessments were compared with an expert-derived focused cardiac ultrasound algorithmic hemodynamic interpretation. Subsequent clinical management was assessed for alignment with focused cardiac ultrasound characterization and association with patient outcomes.

MEASUREMENTS AND MAIN RESULTS

Seventy-one patients with suspected septic shock (median, 4.7 yr; interquartile range, 1.6-8.1) received clinician performed focused cardiac ultrasound study within 72 hours of sepsis pathway initiation (median, 2.1 hr; interquartile range, -1.5 to 11.8 hr). Two patients did not have pre-focused cardiac ultrasound and 23 patients did not have post-focused cardiac ultrasound hemodynamic characterization by clinicians resulting in exclusion from related analyses. Post-focused cardiac ultrasound clinician hemodynamic characterization differed from pre-focused cardiac ultrasound characterization in 67% of patients (31/46). There was substantial concordance between clinician's post-focused cardiac ultrasound and algorithm hemodynamic characterization (33/48; κ = 0.66; CI, 0.51-0.80). Fluid responsive (κ = 0.62; CI, 0.40-0.84), obstructive physiology (к = 0.87; CI, 0.64-1.00), and myocardial dysfunction (1.00; CI, 1.00-1.00) demonstrated substantial to perfect concordance. Management within 4 hours of focused cardiac ultrasound aligned with algorithm characterization in 53 of 71 patients (75%). Patients with aligned management were less likely to have a complicated course (14/52, 27%) compared with misaligned management (8/19, 42%; p = 0.25).

CONCLUSIONS

Incorporation of focused cardiac ultrasound in the evaluation of patients with suspected septic shock frequently changed a clinician's characterization of hemodynamics. An expert-developed algorithm had substantial concordance with a clinician's post-focused cardiac ultrasound hemodynamic characterization. Management aligned with algorithm characterization may improve outcomes in children with suspected septic shock.

Ventilator Liberation in the Pediatric ICU

Despite the accepted importance of minimizing time on mechanical ventilation, only limited guidance on weaning and extubation is available from the pediatric literature. A significant proportion of patients being evaluated for weaning are actually ready for extubation, suggesting that weaning is often not considered early enough in the course of ventilation. Indications for extubation are often not clear, although a trial of spontaneous breathing on CPAP without pressure support seems an appropriate prerequisite in many cases. Several indexes have been developed to predict weaning and extubation success, but the available literature suggests they offer little or no improvement over clinical judgment. New techniques for assessing readiness for weaning and predicting extubation success are being developed but are far from general acceptance in pediatric practice. While there have been some excellent physiologic, observational, and even randomized controlled trials on aspects of pediatric ventilator liberation, robust research data are lacking. Given the lack of data in many areas, a determined approach that combines systematic review with consensus opinion of international experts could generate high-quality recommendations and terminology definitions to guide clinical practice and highlight important areas for future research in weaning, extubation readiness, and liberation from mechanical ventilation following pediatric respiratory failure.

Association of Fluid Balance and Survival of Pediatric Patients Treated With Extracorporeal Membrane Oxygenation

The effect of positive fluid balance (FB) on extracorporeal membrane oxygenation (ECMO) outcomes in pediatric patients remains unknown. We sought to evaluate if positive FB in pediatric intensive care unit (PICU) patients with respiratory and/or cardiac failure necessitating ECMO was associated with increased morbidity or mortality. This was a multicenter retrospective cohort study of data from the deidentified PEDiatric ECMO Outcomes Registry (PEDECOR). Patients entered into the database from 2014 to 2017, who received ECMO support, were included. A total of 168 subjects met the study criteria. Univariate analysis showed no significant difference in total FB on ECMO days 1-5 between survivors and non-survivors [median 90 ml/kg (IQR 18-208.5) for survivors vs. median 139.7 ml/kg (IQR 11.2-300.6) for non-survivors, p = 0.334]. There was also no difference in total FB on ECMO days 1-5 in patients with no change in functional outcome as reflected by the Pediatric Outcome Performance Category (POPC) score vs. those who had worsening in POPC score ≥2 at hospital discharge [median 98 ml/kg (IQR 18-267) vs. median 130 ml/kg (IQR 13-252), p = 0.91]. Subjects that required 50 ml/kg or more of blood products over the initial 5 days of ECMO support had an increased rate of mortality with an odds ratio of 5.8 (95% confidence interval of 2.7-12.3; p = 0.048). Our study showed no association of the noted FB with survival after ECMO cannulation. This FB trend was also not associated with POPC at hospital discharge, MV duration, or ECMO duration. The amount of blood product administered was found to be a significant predictor of mortality.

Timing of Fluid Overload and Association With Patient Outcome

OBJECTIVES

To determine if the timing of excess fluid accumulation (fluid overload) is associated with adverse patient outcomes.

DESIGN

Secondary analysis of a prospectively collected dataset.

SETTING

PICU of a tertiary care hospital.

PATIENTS

Children 3 months to 25 years old admitted to the PICU with expected length of stay greater than or equal to 48 hours.

INTERVENTIONS

Patients were dichotomized by time of peak overload: peak fluid overload from ICU admission (Day0) to 48 hours (Day3-7) and peak fluid overload value after 48 hours of ICU admission, as well as time of first-time negative daily fluid balance: net fluid out greater than net fluid in for that 24-hour period.

MEASUREMENTS AND MAIN RESULTS

There were 177 patients who met inclusion criteria, 92 (52%) male, with an overall mortality rate of 7% (n = 12). There were no differences in severity of illness scores or fluid overload on Day0 between peak fluid overload from ICU admission (Day0) to 48 hours (Day3-7) (n = 97; 55%) and peak fluid overload value after 48 hours of ICU admission (n = 80; 45%) groups. Peak fluid overload value after 48 hours of ICU admission was associated with a longer median ICU course (8 [4-15] vs 4 d [3-8 d]; p ≤ 0.001], hospital length of stay (18 [10-38) vs 12 [8-24]; p = 0.01], and increased risk of mortality (n = 10 [13%] vs 2 [2%]; χ2 = 7.6; p = 0.006]. ICU length of stay was also longer in the peak fluid overload value after 48 hours of ICU admission group when only patients with at least 7 days of ICU stay were analyzed (p = 0.02). Timing of negative fluid balance was also correlated with outcome. Compared with Day0-2, a negative daily fluid balance on Day3-7 was associated with increased length of mechanical ventilation (3 [1-7] vs 1 d [2-10 d]; p ≤ 0.001) and increased hospital (17 [10-35] vs 11 d [7-26 d]; p = 0.006) and ICU (7 [4-13] vs 4 d [3-7 d]; p ≤ 0.001) length of stay compared with a negative fluid balance between Day0-2.

CONCLUSIONS

Our results show timing of fluid accumulation not just peak percentage accumulated is associated with patient outcome. Further exploration of the association between time and fluid accumulation is warranted.

Profile of Fluid Exposure and Recognition of Fluid Overload in Critically Ill Children

OBJECTIVES

Fluid overload is common in the PICU and has been associated with increased morbidity and mortality. It remains unclear whether fluid overload is a surrogate marker for severity of illness and need for increased support, an iatrogenic modifiable risk factor, or a sign of oliguria. The proportions of various fluid intake contributing to fluid overload and its recognition have not been adequately examined. We aimed to: 1) describe the types and amounts of fluid exposure in the PICU and 2) identify the clinicians' recognition of fluid overload.

SETTING

Noncardiac PICU in a quaternary care hospital.

PATIENTS

Pediatric patients admitted for more than 24 hours.

DESIGN

Prospective observational study over 28 days.

INTERVENTIONS

Data were collected on the amount and type of fluid exposure-resuscitative boluses, blood products, enteral intake, parenteral nutrition (total parenteral nutrition), or modifiable fluids (IV fluids and medications) indexed to the patients' admission body surface area on days 1 and 3. Charts of patients admitted for 3 days who developed 15% fluid overload were reviewed to assess clinicians' recognition of fluid overload.

MEASUREMENTS AND MAIN RESULTS

One hundred two patients were included. Day 1 median fluid exposure was 2,318 mL/m (1,831-3,037 mL/m; 1,646 mL/m [1,296-2,086 mL/m] modifiable fluids). Forty-seven patients (46%) received fluid boluses, and 16 (16%) received blood products. Day 3 median fluid exposure was 2,233 mL/m (1,904-2,556 mL/m; 750 mL/m [375-1,816 mL/m] modifiable fluids). Of the 54 patients, one patient (1.9%) received a fluid bolus and two (3.7%) received blood products. In our cohort, 47 of 54 (87%) had fluid exposure greater than 1,600 mL/m on day 3. Fluid overload was not recognized by the clinicians in 30% of the patients who developed more than 15% fluid overload.

CONCLUSIONS

Although resuscitation fluids contributed more to fluid exposure on day 1 compared with day 3, fluid exposure frequently exceeded maintenance requirements on day 3. Fluid overload was not always recognized by PICU practitioners. Further studies to correlate modifiable fluid exposure to fluid overload and explore modifiable practice improvement opportunities are needed.

Point-of-Care Ultrasound Assessment of the Inferior Vena Cava in Mechanically Ventilated Critically Ill Children

OBJECTIVES

The objective of this study was to compare the ultrasound-measured inferior vena cava distensibility index (IVCdi), inferior vena cava distensibility variability (IVCdv), and inferior vena cava-to-aorta ratio (IVC/Ao) to other common methods to assess fluid status in mechanically ventilated pediatric critically ill patients. These methods include central venous pressure (CVP), percent fluid overload by weight (%FOw), and percent fluid overload by volume (%FOv).

METHODS

This was a prospective observational study of a convenience sample of 50 mechanically ventilated pediatric patients. Ultrasound measurements of the inferior vena cava and aorta were obtained, and the IVCdi, IVCdv, and IVC/Ao were calculated and compared to CVP, %FOw, and %FOv.

RESULTS

The median %FOw was 5%, and the median %FOv was 10%. The mean CVP ± SD was 8.6 ± 4 mm Hg. The CVP had no significant correlation with %FOw or %FOv. There was no significant correlation of the IVCdi with CVP (r = -0.145; P = .325) or %FOv (r = 0.119; P = .420); however, the IVCdi had a significant correlation with %FOw (P = .012). There was also no significant relationship of the IVCdv with CVP (r = -0.135; P = .36) or %FOv (r = 0.128; P = .385); however, there was a significant correlation between the IVCdv and %FOw (P = .012). There was no relationship between the IVC/Ao and any other measures of fluid status.

CONCLUSIONS

In this cohort of mechanically ventilated pediatric intensive care unit patients, many commonly used markers of fluid status showed weak correlations with each other. The IVCdi and IVCdv significantly correlated with %FOw and may have potential as markers for fluid overload in this patient population.

Assessment of the Independent and Synergistic Effects of Fluid Overload and Acute Kidney Injury on Outcomes of Critically Ill Children

OBJECTIVES

Evaluate the independent and synergistic associations of fluid overload and acute kidney injury with outcome in critically ill pediatric patients.

DESIGN

Secondary analysis of the Acute Kidney Injury in Children Expected by Renal Angina and Urinary Biomarkers (NCT01735162) prospective observational study.

SETTING

Single-center quaternary level PICU.

PATIENTS

One-hundred forty-nine children 3 months to 25 years old with predicted PICU length of stay greater than 48 hours, and an indwelling urinary catheter enrolled (September 2012 to March 2014). Acute kidney injury (defined by creatinine or urine output on day 3) and fluid overload (≥ 20% on day 3) were used as outcome variables and risk factors for ICU endpoints assessed at 28 days.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Acute kidney injury and fluid overload occurred in 19.4% and 24.2% respectively. Both acute kidney injury and fluid overload were associated with longer ICU length of stay but neither maintained significance after multivariate regression. Delineation into unique fluid overload/acute kidney injury classifications demonstrated that fluid overload patients experienced a longer ICU and hospital length of stay and higher rate of mortality compared with fluid overload patients, regardless of acute kidney injury status. Fluid overload/acute kidney injury patients had increased odds of death (p = 0.013). After correction for severity of illness, ICU length of stay remained significantly longer in fluid overload/acute kidney injury patients compared with patients without both classifications (17.4; 95% CI, 11.0-23.7 vs 8.8; 95% CI, 7.3-10.9; p = 0.05). Correction of acute kidney injury classification for net fluid balance led to acute kidney injury class switching in 29 patients and strengthened the association with increased mechanical ventilation and ICU length of stay on bivariate analysis, but reduced the increased risk conferred by fluid overload for mortality.

CONCLUSIONS

The current study suggests the effects of significant fluid accumulation may be delineable from the effects of acute kidney injury. Concurrent fluid overload and acute kidney injury significantly worsen outcome. Correction of acute kidney injury assessment for net fluid balance may refine diagnosis and unmask acute kidney injury associated with deleterious downstream sequelae. The unique effects of fluid overload and acute kidney injury on outcome in critically ill patients warrant further study.