Association Between Progression and Improvement of Acute Kidney Injury and Mortality in Critically Ill Children

Pediatric acute kidney injury and adverse health outcomes: using a foundational framework to evaluate a causal link

Acute kidney injury (AKI) is a major global health problem, expensive to manage, and its associations with negative pediatric health outcomes have been clearly demonstrated. One of the most fundamental questions to consider as we use previous epidemiological information to advance research and care paradigms is the strength of the causal link between pediatric AKI and health outcomes. In this review, we apply the foundational framework of the Bradford Hill criteria to evaluate the extent to which a causal link exists between AKI and the associated adverse outcomes in children. Available data in children support a causal link between AKI and short-term outcomes including mortality, length of stay, and ventilation time. Clarifying the causal nature of longer term associations requires further high-quality observational studies in children, careful consideration of what defines the most meaningful and measurable longer term outcomes after pediatric AKI, and integration of evolving biological data related to mechanisms of disease. Preventing or mitigating AKI should lead to improved outcomes. Demonstrating such reversibility will solidify confidence in the causal relationship, improve child health, and highlight an aspect which is highly relevant to clinicians, scientists, and policy makers.

Acute kidney injury requiring dialysis in children: a multicentric, emerging country perspective

BACKGROUND

Acute kidney injury (AKI) is a life-threatening condition, especially in extreme age groups and when kidney replacement therapy (KRT) is necessary. Studies worldwide report mortality rates of 10-63% in pediatric patients undergoing KRT.

METHODS

Over 13 years, this multicenter study analyzed data from 693 patients with AKI, all receiving KRT, across 74 hospitals and medical facilities in Rio de Janeiro, Brazil.

RESULTS

The majority were male (59.5%), under one year old (55.6%), and treated in private hospitals (76.5%). Sixty-six percent had comorbidities. Pneumonia and congenital heart disease were the most common admission diagnoses (21.5% and 20.2%, respectively). The mortality rate was 65.2%, with lower rates in patients over 12 years (50%). Older age was protective (HR: 2.35, IQR [1.52-3.62] for neonates), and primary kidney disease had a three-fold lower mortality rate. ICU team experience (HR: 0.74, IQR [0.60-0.91]) correlated with lower mortality, particularly in hospitals treating 20 or more patients. Among the deceased, 40% died within 48 h of KRT initiation, suggesting possible late referral or treatment futility.

CONCLUSIONS

This study confirms the high mortality in pediatric dialytic AKI in middle-income countries, underlining early mortality and offering critical insights for improving outcomes.

Furosemide stress test to predict acute kidney injury progression in critically ill children

BACKGROUND

Furosemide stress test (FST) is a novel functional biomarker for predicting severe acute kidney injury (AKI); however, pediatric studies are limited.

METHODS

Children 3 months to 18 years of age admitted to the intensive care unit (ICU) of a tertiary care hospital from Nov 2019 to July 2021 were screened and those who developed AKI stage 1 or 2 within 7 days of admission underwent FST (intravenous furosemide 1 mg/kg). Urine output was measured hourly for the next 6 h; a value > 2 ml/kg within the first 2 h was deemed furosemide responsive. Other biomarkers like plasma neutrophil gelatinase-associated lipocalin (NGAL) and proenkephalin (PENK) were also evaluated.

RESULTS

Of the 480 admitted patients, 51 developed AKI stage 1 or 2 within 7 days of admission and underwent FST. Nine of these patients were furosemide non-responsive. Thirteen (25.5%) patients (eight of nine from FST non-responsive group) developed stage 3 AKI within 7 days of FST, nine (17.6%) of whom (seven from non-responsive group) required kidney support therapy (KST). FST emerged as a good biomarker for predicting stage 3 AKI and need for KST with area-under-the-curve (AUC) being 0.93 ± 0.05 (95% CI 0.84-1.0) and 0.96 ± 0.03 (95% CI 0.9-1.0), respectively. FST outperformed NGAL and PENK in predicting AKI stage 3 and KST; however, the combination did not improve the diagnostic accuracy.

CONCLUSIONS

Furosemide stress test is a simple, inexpensive, and robust biomarker for predicting stage 3 AKI and KST need in critically ill children. Further research is required to identify the best FST cut-off in children.

Epidemiology of acute kidney injury in children: a report from the 26th Acute Disease Quality Initiative (ADQI) consensus conference

The nephrology and critical care communities have seen an increase in studies exploring acute kidney injury (AKI) epidemiology in children. As a result, we now know that AKI is highly prevalent in critically ill neonates, children, and young adults. Furthermore, children who develop AKI experience greater morbidity and higher mortality. Yet knowledge gaps still exist that suggest a more comprehensive understanding of AKI will form the foundation for future efforts designed to improve outcomes. In particular, the areas of community acquired AKI, AKI in non-critically ill children, and cohorts from low-middle income countries have not been well studied. Longer-term functional outcomes and patient-centric metrics including social determinants of health, quality of life, and healthcare utilization should be the foci of the next phase of scholarship. Current definitions identify AKI-based upon evidence of dysfunction which serves as a proxy for injury; biomarkers capable of identifying injury as it occurs are likely to more accurately define populations with AKI. Despite the strength of the association, the causal and mechanistic relationships between AKI and poorer outcomes remain inadequately examined. A more robust understanding of the relationship represents a potential to identify therapeutic targets. Once established, a more comprehensive understanding of AKI epidemiology in children will allow investigation of preventive, therapeutic, and quality improvement interventions more effectively.

Real-Time Acute Kidney Injury Risk Stratification-Biomarker Directed Fluid Management Improves Outcomes in Critically Ill Children and Young Adults

Introduction

Critically ill admitted patients are at high risk of acute kidney injury (AKI). The renal angina index (RAI) and urinary biomarker neutrophil gelatinase-associated lipocalin (uNGAL) can aid in AKI risk assessment. We implemented the Trial in AKI using NGAL and Fluid Overload to optimize CRRT Use (TAKING FOCUS 2; TF2) to personalize fluid management and continuous renal replacement therapy (CRRT) initiation based on AKI risk and patient fluid accumulation. We compared outcomes pre-TF2 and post-TF2 initiation.

Methods

Patients admitted from July 2017 were followed-up prospectively with the following: (i) an automated RAI result at 12 hours of admission, (ii) a conditional uNGAL order for RAI ≥8, and (iii) a CRRT initiation goal at 10% to 15% weight-based fluid accumulation.

Results

A total of 286 patients comprised 304 intensive care unit (ICU) RAI+ admissions; 178 patients received CRRT over the observation period (2014-2021). Median time from ICU admission to CRRT initiation was 2 days shorter (P < 0.002), and ≥15% pre-CRRT fluid accumulation rate was lower in the TF2 era (P < 0.02). TF2 ICU length of stay (LOS) after CRRT discontinuation and total ICU LOS were 6 and 11 days shorter for CRRT survivors (both P < 0.02). Survival rates to ICU discharge after CRRT discontinuation were higher in the TF2 era (P = 0.001). These associations persisted in each TF2 year; we estimate a conservative $12,500 health care cost savings per CRRT patient treated after TF2 implementation.

Conclusion

We suggest that automated clinical decision support (CDS) combining risk stratification and AKI biomarker assessment can produce durable reductions in pediatric CRRT patient morbidity.

Multiple Electrolytes Solution Versus Saline as Bolus Fluid for Resuscitation in Pediatric Septic Shock: A Multicenter Randomized Clinical Trial

OBJECTIVE

To determine if initial fluid resuscitation with balanced crystalloid (e.g., multiple electrolytes solution [MES]) or 0.9% saline adversely affects kidney function in children with septic shock.

DESIGN

Parallel-group, blinded multicenter trial.

SETTING

PICUs of four tertiary care centers in India from 2017 to 2020.

PATIENTS

Children up to 15 years of age with septic shock.

METHODS

Children were randomized to receive fluid boluses of either MES (PlasmaLyte A) or 0.9% saline at the time of identification of shock. All children were managed as per standard protocols and monitored until discharge/death. The primary outcome was new and/or progressive acute kidney injury (AKI), at any time within the first 7 days of fluid resuscitation. Key secondary outcomes included hyperchloremia, any adverse event (AE), at 24, 48, and 72 hours, and all-cause ICU mortality.

INTERVENTIONS

MES solution ( n = 351) versus 0.9% saline ( n = 357) for bolus fluid resuscitation during the first 7 days.

MEASUREMENTS AND MAIN RESULTS

The median age was 5 years (interquartile range, 1.3-9); 302 (43%) were girls. The relative risk (RR) for meeting the criteria for new and/or progressive AKI was 0.62 (95% CI, 0.49-0.80; p < 0.001), favoring the MES (21%) versus the saline (33%) group. The proportions of children with hyperchloremia were lower in the MES versus the saline group at 24, 48, and 72 hours. There was no difference in the ICU mortality (33% in the MES vs 34% in the saline group). There was no difference with regard to infusion-related AEs such as fever, thrombophlebitis, or fluid overload between the groups.

CONCLUSIONS

Among children presenting with septic shock, fluid resuscitation with MES (balanced crystalloid) as compared with 0.9% saline resulted in a significantly lower incidence of new and/or progressive AKI during the first 7 days of hospitalization.

Prognostic factors for multi-organ dysfunction in pediatric oncology patients admitted to the pediatric intensive care unit

Background

Pediatric oncology patients who require admission to the pediatric intensive care unit (PICU) have worse outcomes compared to their non-cancer peers. Although multi-organ dysfunction (MOD) plays a pivotal role in PICU mortality and morbidity, risk factors for MOD have not yet been identified. We aimed to identify risk factors at PICU admission for new or progressive MOD (NPMOD) during the first week of PICU stay.

Methods

This retrospective cohort study included all pediatric oncology patients aged 0 to 18 years admitted to the PICU between June 2018 and June 2021. We used the recently published PODIUM criteria for defining multi-organ dysfunction and estimated the association between covariates at PICU baseline and the outcome NPMOD using a multivariable logistic regression model, with PICU admission as unit of study. To study the predictive performance, the model was internally validated by using bootstrap.

Results

A total of 761 PICU admissions of 571 patients were included. NPMOD was present in 154 PICU admissions (20%). Patients with NPMOD had a high mortality compared to patients without NPMOD, 14% and 1.0% respectively. Hemato-oncological diagnosis, number of failing organs and unplanned admission were independent risk factors for NPMOD. The prognostic model had an overall good discrimination and calibration.

Conclusion

The risk factors at PICU admission for NPMOD may help to identify patients who may benefit from closer monitoring and early interventions. When applying the PODIUM criteria, we found some opportunities for fine-tuning these criteria for pediatric oncology patients, that need to be validated in future studies.

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.

Fluid Removal in Children on Continuous Renal Replacement Therapy Improves Organ Dysfunction Score

The objective is to assess impact of fluid removal on improvement in organ function in children who received continuous renal replacement therapy (CRRT) for management of acute kidney injury and/or fluid overload (FO). A retrospective review of eligible patients admitted to a tertiary level intensive care unit over a 3-year period was performed. Improvement in nonrenal organ function, the primary outcome, was defined as decrease in nonrenal component of Pediatric Logistic Organ Dysfunction (PELOD) score on day 3 of CRRT. The cohort was categorized into Group 1 (improvement) and Group 2 (no improvement or worsening) in nonrenal PELOD score. Multivariable logistic regression analysis was performed to identify independent predictors. A higher PELOD score at CRRT initiation (odds ratio [OR]: 1.11, 95% confidence interval [CI]: 1.05, 1.18, p < 0.001), belonging to infant-age group (OR: 4.53, 95% CI: 4.40, 5.13, p = 0.02) and greater fluid removal during initial 3 days of CRRT (OR: 1.05, 95% CI: 1.01, 1.10, p = 0.01) were associated with an improvement in nonrenal PELOD score at day 3 of CRRT. FO at CRRT initiation (OR: 0.66, 95% CI: 0.46, 0.93, p = 0.02) and having an underlying oncologic diagnosis (OR: 0.28, 95% CI: 0.09, 0.85, p = 0.03) were associated with worsening of nonrenal PELOD score at day 3 of CRRT. Careful consideration of certain modifiable patient and/or fluid removal kinetic factors may have an impact on outcomes.

Evaluation of the Performance of Vasoactive Ventilation Renal Score in Predicting the Duration of Mechanical Ventilation and Intensive Care Hospitalization After Pediatric Cardiac Surgery

Various methods have been used to evaluate the predictivity of some markers during the recovery process after cardiac surgery in children. The aim herein was to evaluate the vasoactive ventilation renal (VVR) score in predicting the clinical outcomes of children who underwent congenital cardiac surgery within the early period in the pediatric intensive care unit (PICU). Patients who underwent congenital heart surgery (CHS) between November 2016 and March 2020 were enrolled and evaluated prospectively. The VVR score was calculated as follows: vasoactive inotrope score (VIS) + ventilation index + (change in serum creatinine level based on the baseline value × 10). The relationship between the duration of mechanical ventilation and the length of stay (LOS) in the PICU was evaluated via receiver operating characteristic (ROC) curve analysis and the cut-off values were calculated. At all of the time points identified in the study, the VVR score had a higher area under the ROC curve (AUC) when compared to the VIS and serum lactate levels, and the 48-h VVR score had the highest AUC (AUC 0.851, 95% confidence interval (CI) 0.761-0.942/LOS in the PICU; AUC 0.946, 95% CI 0.885-1.000/duration of mechanical ventilation). The 48-h VVR score for the LOS in the PICU was 6.7 (sensitivity 70%, specificity 92%) and that for the duration of mechanical ventilation was 9.1 (sensitivity 87%, specificity 97%). As a result, in our study, it was found that the VVR score is a new and effective predictor of the duration of mechanical ventilation and LOS in the PICU in postoperative CHS patients.

Pediatric Reference Change Value Optimized for Acute Kidney Injury: Multicenter Retrospective Study in China

OBJECTIVES

The standard definition of pediatric acute kidney injury (AKI) is evolving, especially for critically ill in the PICU. We sought to validate the application of the Pediatric Reference Change Value Optimized for Acute Kidney Injury in Children (pROCK) criteria in critically ill children.

DESIGN

Multicenter retrospective study.

SETTING

Six PICUs in mainland China.

PATIENTS

One thousand six hundred seventy-eight hospitalized children admitted to the PICU with at least two creatinine values within 7 days.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

AKI was diagnosed and staged according to the Pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease (pRIFLE), the Kidney Disease Improving Global Outcomes (KDIGO), and the pROCK criteria. Multiple clinical parameters were assessed and analyzed along with 90-day follow-up outcomes. According to the definitions of pRIFLE, KDIGO, and pROCK, the prevalence of AKI in our cohort of 1,678 cases was 52.8% (886), 39.0% (655), and 19.0% (318), respectively. The presence of AKI, as defined by pROCK, was associated with increased number of injured organs, occurrence of sepsis, use of mechanical ventilation, use of continuous renal replace therapy ( p < 0.05), higher Pediatric Risk of Mortality III score, and higher Pediatric Logistic Organ Dysfunction-2 score ( p < 0.001). The survival curve of 90-day outcomes showed that pROCK was associated with shorter survival time (LogRank p < 0.001), and pROCK definition was associated with better separation of the different stages of AKI from non-AKI ( p < 0.001).

CONCLUSIONS

In this retrospective analysis of AKI criteria in PICU admissions in China, pROCK is better correlated with severity and outcome of AKI. Hence, the pROCK criteria for AKI may have better utility in critically ill children.

Derivation and evaluation of baseline creatinine equations for hospitalized children and adolescents: the AKI baseline creatinine equation

BACKGROUND

Acute kidney injury (AKI) definitions incorporate baseline creatinine (Cr_b) values, but Cr_b are frequently unknown in pediatrics. Our primary aim was to derive and validate a novel AKI Baseline Creatinine (ABC) estimation equation and compare it to existing methods of estimating Cr_b values.

METHODS

We conducted a single-center retrospective analysis of pediatric patients (0-25 years) admitted from 2012 to 2019. Included patients required at least one outpatient Cr_b prior to hospitalization (gold standard). Novel equations were developed with demographic and initial creatinine data. Existing methods included back-calculating Cr_b based on Schwartz, Full Age Spectrum (FAS), and CKiD-under-25 (U25) equations. To determine an optimal equation, we compared novel and existing equations to the gold standard.

RESULTS

The optimal simplified equation (ABC) included only age and had R² = 59.9% and 73.2% of values within 30% of true Cr_b. The precision increased significantly when the equation included age and minimum creatinine within initial 72 h (ABC-cr): R² = 75.4% and 86.5% of values within 30% of true Cr_b. The best performing existing equation was the age-based FAS, which had R² = 61.0% and 78.0% of values within 30% of true Cr_b. All other existing equations performed worse, some methods as low as 52.6% within 30% of true Cr_b.

CONCLUSIONS

The newly derived ABC equation is simple, and the ABC-cr equation can more accurately estimate Cr_b by ≥ 25% compared to previous methods. The potential applicability of these equations is vast, including faster recognition of AKI on initial patient contact and improved standardization of pediatric AKI definitions, enhancing health services research. A higher resolution version of the Graphical abstract is available as Supplementary information.

Major adverse kidney events after acute kidney injury in the pediatric intensive care unit: a propensity score-matched cohort study

BACKGROUND

Acute kidney injury (AKI) in patients admitted to the pediatric intensive care unit (PICU) is associated with poor short-term and long-term outcomes. Greater awareness of long-term AKI-associated outcomes is needed to optimally plan follow-up and management after ICU discharge. We used propensity score methods to study associations between pediatric AKI and major adverse kidney outcomes, including mortality.

METHODS

We included all children 6 months-18 years admitted to PICU at Seattle Children's Hospital from 7/1/2009 to 12/31/2018. Our primary outcome measure was Major Adverse Kidney Events at 30 days (MAKE30): creatinine > 200% of baseline, eGFR < 60 mL/min/1.73 m², dialysis dependence, or mortality. Propensity scores for AKI development in PICU were generated using demographic, medical history, admission, and PICU hospitalization variables. Patients with AKI were matched to control patients without AKI. Logistic regression was used to test association between AKI status and MAKE30.

RESULTS

In the unmatched cohort (n = 878), patients with AKI had lower platelet count (160 vs. 222) and higher PRISM III score (11 vs. 3.5). After propensity score matching, those with AKI vs. no AKI had similar PRISM III scores (9 vs. 10) and platelet count (163 vs. 159). AKI was significantly associated with MAKE30 after propensity score matching (OR: 2.97; 95% CI 1.82-4.84).

CONCLUSIONS

Propensity score matching significantly reduced imbalance in baseline characteristics between those with and without AKI. After matching, AKI remained significantly associated with MAKE30. Patients who developed AKI were more likely to have abnormal kidney function at 30 and 90 days after ICU admission and may be at high risk for developing CKD in the future. A higher resolution version of the Graphical abstract is available as Supplementary information.

Integration of the Renal Angina Index and Urine Neutrophil Gelatinase Associated Lipocalin Improves Severe AKI Prediction in Critically Ill Children and Young Adults

Introduction

Acute kidney injury (AKI) occurs in one-fourth of children and young adults admitted to pediatric intensive care unit (PICU). Severe AKI (sAKI; Kidney Disease: Improving Global Outcomes stage 2 or 3) is associated with morbidity and mortality. An AKI risk stratification system, the Renal Angina Index (RAI) calculated at 12 hours of admission, exhibits excellent performance to rule out sAKI at 72 hours of admission. We found that integration of urine neutrophil gelatinase-associated lipocalin (NGAL) with RAI improves prediction of sAKI. We now report the first-year results after implementation of our prospective automated RAI-NGAL clinical decision support (CDS) program.

Methods

Patients 3 months to 25 years of age were eligible. Admission order sets have a conditional order for urine NGAL released when a 12-hour RAI ≥8. The primary outcome was sAKI any time at days 2 to 4 of admission. We assessed performance of the RAI and RAI+/NGAL to predict the primary outcome.

Results

A total of 1427 unique patients accounted for 1575 admissions. In 147 admissions, RAI was ≥8. RAI <8 had negative predictive value (NPV) of 0.98 (95% CI 0.97–0.99); RAI ≥ 8 had positive predictive value (PPV) of 0.37 (95% CI 0.30–0.46) to predict days 2 to 4 sAKI (area under the receiver operating characteristic curve [AUC-ROC] 0.88 [95% CI 0.84–0.92]). Of 147 RAI+ patients, 89 had NGAL available. RAI/NGAL combination improved PPV (0.64, 95% CI 0.50–0.79) without decrement in NPV (0.98, 95% CI 0.97–0.98).

Conclusion

AKI biomarker assessment directed by risk stratification improves prediction of sAKI in critically ill children and young adults. This CDS process has potential to enrich the population for interventional study, although improvement to adherence to CDS is needed.

Acute kidney injury and kidney recovery after cardiopulmonary bypass in children

BACKGROUND

Acute kidney injury (AKI) that improves in the pediatric intensive care unit (PICU) is associated with better outcomes compared to AKI that persists, but no study has investigated whether this also occurs in children undergoing cardiopulmonary bypass (CPB).

METHODS

A retrospective study of children ≤18 years who underwent CPB in three children's hospitals was conducted. Patients were classified into groups by kidney recovery after AKI according to Acute Disease Quality Initiative (ADQI) guidelines. Adjusted regression models evaluated associations between kidney recovery group and hospital outcomes.

RESULTS

Among 3620 children, AKI developed in 701 (19.4%): 610 transient AKI, 47 persistent AKI, and 44 acute kidney disease (AKD). Mortality increased with severity of kidney recovery group: 4.5% in the never developed AKI group, 8.9% in the transient AKI group, 25.5% in the persistent AKI group, and 31.8% in the AKD group (p <0.0001). In adjusted analysis, transient AKI (HR 1.4, CI 1.02, 2), persistent AKI (HR 22.4, CI 10.2, 49.2), and AKD (HR 3.7, CI 1.7, 7.9) had a greater hazard of mortality when compared to the never developed AKI group. Patients with transient AKI had a longer length of PICU stay than those with never developed AKI (HR 5.1, CI 2.9, 7.3).

CONCLUSIONS

Patterns of kidney recovery after AKI were associated with worse PICU outcomes in children after CPB compared to those who did not develop AKI, even after rapid AKI recovery. Identification of factors that increase risk for these AKI patterns is necessary for prevention of AKI during CPB in children. A higher resolution version of the Graphical abstract is available as Supplementary information.

Early and late acute kidney injury: temporal profile in the critically ill pediatric patient

Background

Increasing AKI diagnosis precision to refine the understanding of associated epidemiology and outcomes is a focus of recent critical care nephrology research. Timing of onset of acute kidney injury (AKI) during pediatric critical illness and impact on outcomes has not been fully explored.

Methods

This was a secondary analysis of the Assessment of Worldwide Acute Kidney Injury, Renal Angina and Epidemiology (AWARE) database. AKI was defined as per Kidney Disease: Improving Global Outcomes criteria. Early AKI was defined as diagnosed at ≤48 h after intensive care unit (ICU) admission, with any diagnosis >48 h denoted as late AKI. Transient AKI was defined as return to baseline serum creatinine ≤48 h of onset, and those without recovery fell into the persistent category. A second incidence of AKI ≥48 h after recovery was denoted as recurrent. Patients were subsequently sorted into distinct phenotypes as early-transient, late-transient, early-persistent, late-persistent and recurrent. Primary outcome was major adverse kidney events (MAKE) at 28 days (MAKE28) or at study exit, with secondary outcomes including AKI-free days, ICU length of stay and inpatient renal replacement therapy.

Results

A total of 1262 patients had AKI and were included. Overall mortality rate was 6.4% (n = 81), with 34.2% (n = 432) fulfilling at least one MAKE28 criteria. The majority of patients fell in the early-transient cohort (n = 704, 55.8%). The early-persistent phenotype had the highest odds of MAKE28 (odds ratio 7.84, 95% confidence interval 5.45–11.3), and the highest mortality rate (18.8%). Oncologic and nephrologic/urologic comorbidities at AKI diagnosis were associated with MAKE28.

Conclusion

Temporal nature and trajectory of AKI during a critical care course are significantly associated with patient outcomes, with several subtypes at higher risk for poorer outcomes. Stratification of pediatric critical care-associated AKI into distinct phenotypes is possible and may become an important prognostic tool.

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.

Advances in pediatric acute kidney injury

The objective of this study was to inform the pediatric nephrologists of recent advances in acute kidney injury (AKI) epidemiology, pathophysiology, novel biomarkers, diagnostic tools, and management modalities. Studies were identified from PubMed, EMBASE, and Google Scholar for topics relevant to AKI. The bibliographies of relevant studies were also reviewed for potential articles. Pediatric (0-18 years) articles from 2000 to May 2020 in the English language were included. For epidemiological outcomes analysis, a meta-analysis on data regarding AKI incidence, mortality, and proportion of kidney replacement therapy was performed and an overall pooled estimate was calculated using the random-effects model. Other sections were created highlighting pathophysiology, novel biomarkers, changing definitions of AKI, evolving tools for AKI diagnosis, and various management modalities. AKI is a common condition seen in hospitalized children and the diagnosis and management have shown to be quite a challenge. However, new standardized definitions, advancements in diagnostic tools, and the development of novel management modalities have led to increased survival benefits in children with AKI. IMPACT: This review highlights the recent innovations in the field of AKI, especially in regard to epidemiology, pathophysiology, novel biomarkers, diagnostic tools, and management modalities.

Clinical value of pediatric sepsis-induced coagulopathy score in diagnosis of sepsis-induced coagulopathy and prognosis in children

BACKGROUND

In adults, sepsis-induced coagulopathy (SIC) is diagnosed by the SIC score, known as sepsis-3. There is no pediatric SIC (pSIC) score at present.

OBJECTIVES

We proposed a pSIC scoring method and evaluated the diagnostic efficacy of the score in the diagnosis of SIC in children.

PATIENTS/METHODS

Patient data were retrospectively analyzed from Shanghai Children's Medical Center between February 2014 and January 2015. The pSIC score was modified from the SIC score. The area under ROC curve (AU-ROC) was used to compare the prognostic values of pSIC with other scores for pediatric sepsis-induced disseminated intravascular coagulation (DIC) to arrive at a 28-day outcome.

RESULTS AND CONCLUSIONS

There were 54 patients in the pSIC group and 37 in the non-pSIC group. The Kaplan-Meier survival curve analysis showed that the 28-day prognosis was better in the non-pSIC than in the pSIC group (p < .001). The AU-ROC of the pSIC score in predicting 28-day mortality in sepsis was 0.716, with the optimal cutoff value of >3 inferior to that of pediatric sequential organ failure (0.716 vs. 0.921, p < .001). The AU-ROC of pSIC in predicting nonovert DIC was 0.845 and the optimal cutoff value was >3. The AU-ROC of pSIC in predicting overt DIC was 0.901, with the best optimal cutoff value of >4. The pSIC score can be used to diagnose SIC in children, screen potential nonovert DIC, and assess the severity of sepsis, organ dysfunction, and 28-day outcome in children.

Incidence and Outcome of Community-Acquired Acute Kidney Injury in Pediatric Patients Seen at an Emergency Department: A Retrospective Cohort Study

OBJECTIVES

Acute kidney injury (AKI) has significant morbidity and mortality rates among young patients. This study aimed to determine the incidence and outcome of community-acquired AKI among pediatric patients seen in the emergency department of King Abdulaziz University Hospital for more than 3 years.

METHODS

This retrospective study reviewed electronic medical records for all pediatric patients aged 1 month to 18 years who visited the emergency department of King Abdulaziz University Hospital from January 1, 2015, until December 31, 2017. Acute kidney injury was diagnosed and classified according to the Kidney Disease: Improving Global Outcomes criteria.

RESULTS

Of 6038 patients, 1581 were included. Acute kidney injury occurred in 135 patients (8.5%), of which 77 (57%) were in stage 1, 42 (31.1%) were in stage 2, and 16 (11.9%) were in stage 3. Mortality was higher in the AKI group (4.4%) than in the non-AKI group (0.2%; P < 0.01). On long-term observation, 14.8% did not return for follow-up, 58.5% of survivors recovered completely, and 22.2% progressed to chronic kidney disease. The most affected age group was 1 month to 2 years (26%). Common admission causes were chemotherapy-induced AKI (31.9%) and pneumonia (10.4%). There was a significant inverse relationship between AKI and age group (P < 0.001) and a positive association between AKI and death (P < 0.001). However, no association was found between AKI stages and outcomes.

CONCLUSIONS

Community-acquired AKI remains a common condition affecting the pediatric population. It is associated with a higher mortality rate. Infants were more susceptible to AKI, and a significant number of patients with AKI progressed to chronic kidney disease.

Machine learning model for early prediction of acute kidney injury (AKI) in pediatric critical care

BACKGROUND

Acute kidney injury (AKI) in pediatric critical care patients is diagnosed using elevated serum creatinine, which occurs only after kidney impairment. There are no treatments other than supportive care for AKI once it has developed, so it is important to identify patients at risk to prevent injury. This study develops a machine learning model to learn pre-disease patterns of physiological measurements and predict pediatric AKI up to 48 h earlier than the currently established diagnostic guidelines.

METHODS

EHR data from 16,863 pediatric critical care patients between 1 month to 21 years of age from three independent institutions were used to develop a single machine learning model for early prediction of creatinine-based AKI using intelligently engineered predictors, such as creatinine rate of change, to automatically assess real-time AKI risk. The primary outcome is prediction of moderate to severe AKI (Stage 2/3), and secondary outcomes are prediction of any AKI (Stage 1/2/3) and requirement of renal replacement therapy (RRT). Predictions generate alerts allowing fast assessment and reduction of AKI risk, such as: "patient has 90% risk of developing AKI in the next 48 h" along with contextual information and suggested response such as "patient on aminoglycosides, suggest check level and review dose and indication".

RESULTS

The model was successful in predicting Stage 2/3 AKI prior to detection by conventional criteria with a median lead-time of 30 h at AUROC of 0.89. The model predicted 70% of subsequent RRT episodes, 58% of Stage 2/3 episodes, and 41% of any AKI episodes. The ratio of false to true alerts of any AKI episodes was approximately one-to-one (PPV 47%). Among patients predicted, 79% received potentially nephrotoxic medication after being identified by the model but before development of AKI.

CONCLUSIONS

As the first multi-center validated AKI prediction model for all pediatric critical care patients, the machine learning model described in this study accurately predicts moderate to severe AKI up to 48 h in advance of AKI onset. The model may improve outcome of pediatric AKI by providing early alerting and actionable feedback, potentially preventing or reducing AKI by implementing early measures such as medication adjustment.

Association Between Acute Kidney Injury Duration and Outcomes in Critically Ill Children

OBJECTIVES

Acute kidney injury occurs frequently in children during critical illness and is associated with increased morbidity, mortality, and health resource utilization. We aimed to examine the association between acute kidney injury duration and these outcomes.

DESIGN

Retrospective cohort study.

SETTINGS

PICUs in Alberta, Canada.

PATIENTS

All children admitted to PICUs in Alberta, Canada between January 1, 2015, and December 31, 2015.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

In total, 1,017 children were included, and 308 (30.3%) developed acute kidney injury during PICU stay. Acute kidney injury was categorized based on duration to transient (48 hr or less) or persistent (more than 48 hr). Transient acute kidney injury occurred in 240 children (77.9%), whereas 68 children (22.1%) had persistent acute kidney injury. Persistent acute kidney injury had a higher proportion of stage 2 and stage 3 acute kidney injury compared with transient acute kidney injury and was more likely to start within 24 hours from PICU admission. Persistent acute kidney injury occurred more frequently in those with higher illness severity and in those admitted with shock, sepsis, or with a history of transplant. Mortality varied significantly according to acute kidney injury status: 1.8% of children with no acute kidney injury, 5.4% with transient acute kidney injury, and 17.6% with persistent acute kidney injury died during hospital stay (p < 0.001). On multivariable analysis adjusting for illness and acute kidney injury severity, transient and persistent acute kidney injury were both associated with fewer ventilation-free days at 28 days (-1.28 d; 95% CI, -2.29 to -0.26 and -4.85 d; 95% CI, -6.82 to -2.88), vasoactive support-free days (-1.07 d; 95% CI, -2.00 to -0.15 and -4.24 d; 95% CI, -6.03 to -2.45), and hospital-free days (-1.93 d; 95% CI, -3.36 to -0.49 and -5.25 d; 95% CI, -8.03 to -2.47), respectively.

CONCLUSIONS

In critically ill children, persistent and transient acute kidney injury have different clinical characteristics and association with outcomes. Acute kidney injury, even when its duration is short, carries significant association with worse outcomes. This risk increases further if acute kidney injury persists longer independent of the degree of its severity.

Machine Learning for Early Warning of Septic Shock in Children With Hematological Malignancies Accompanied by Fever or Neutropenia: A Single Center Retrospective Study

OBJECTIVES

The purpose of this article was to establish and validate clinically applicable septic shock early warning model (SSEW model) that can identify septic shock in hospitalized children with onco-hematological malignancies accompanied with fever or neutropenia.

METHODS

Data from EMRs were collected from hospitalized pediatric patients with hematological and oncological disease at Shanghai Children's Medical Center. Medical records of patients (>30 days and <19 years old) with fever (≥38°C) or absolute neutrophil count (ANC) below 1.0 × 109/L hospitalized with hematological or oncological disease between January 1, 2017 and August 1, 2019 were considered. Patients in whom septic shock was diagnosed during the observation period formed the septic shock group, whereas non-septic-shock group was the control group. In the septic shock group, the time points at 4, 8, 12, and 24 hours prior to septic shock were taken as observation points, and corresponding observation points were obtained in the control group after matching. We employed machine learning artificial intelligence (AI) to filter features and used XGBoost algorithm to build SSEW model. Area under the ROC curve (AU-ROC) was used to compare the effectiveness among the SSEW Model, logistic regression model, and pediatric sequential organ failure score (pSOFA) for early warning of septic shock.

MAIN RESULTS

A total of 64 observation periods in the septic shock group and 2191 in the control group were included. AU-ROC of the SSEW model had higher predictive value for septic shock compared with the pSOFA score (0.93 vs. 0.76, Z = -2.73, P = 0.006). Further analysis showed that the AU-ROC of the SSEW model was superior to the pSOFA score at the observation points 4, 8, 12, and 24 h before septic shock. At the 24 h observation point, the SSEW model incorporated 14 module root features and 23 derived features.

CONCLUSION

The SSEW model for hematological or oncological pediatric patients could help clinicians to predict the risk of septic shock in patients with fever or neutropenia 24 h in advance. Further prospective studies on clinical application scenarios are needed to determine the clinical utility of this AI model.

Evaluation of the Accuracy of Standard Renal Function Equations in Critically Ill Patients with Subarachnoid Hemorrhage

BACKGROUND

Obtaining an accurate estimation of renal function is germane to optimizing care in critically ill patients. However, there is no consensus on the most accurate renal function assessment to utilize in this patient population, particularly in aneurysmal subarachnoid hemorrhage (aSAH) patients. Thus, the objective of this observational study was to determine the comparability of renal function equations to body surface area (BSA)-adjusted 8-h creatinine clearance (CrCl) in aSAH patients.

METHODS

A PubMed search investigated the applicability of various renal function equations in critically ill patient populations. A subset of these equations was compared to BSA-adjusted 8-h CrCl from a previous study with aSAH patients with no evidence of renal dysfunction (admission serum creatinine < 1.5 mg/dL) and no history of chronic kidney disease. Area-under-the-curve (AUC) calculations were completed using serial laboratory measurements to validate preliminary findings.

RESULTS

A total of 14 renal function equations were identified with seven carried forward for further analysis based upon a priori criteria. Seven equations were excluded for various reasons, including lack of available clinical data, redundancy with other equations, and dissimilar patient populations to this study. When directly compared to the BSA-adjusted 8-h CrCl, only the Cockcroft-Gault and BSA-adjusted Cockcroft-Gault equations were not statistically significantly different (P = 0.0886 and P = 0.4805, respectively); all other equations were statistically significantly different (P < 0.0001). Additionally, only 52% and 44% of patients had average values within 20% of the BSA-adjusted 8-h CrCl using the Cockcroft-Gault and BSA-adjusted Cockcroft-Gault equations, respectively. Finally, the AUC calculations corroborated the preliminary findings with similar results in statistical testing for the Cockcroft-Gault and BSA-adjusted Cockcroft-Gault (P = 0.6300 and P = 0.1513, respectively).

CONCLUSIONS

The Cockcroft-Gault equation may be the best renal function equation to assess in critically ill patients diagnosed with aSAH. However, accuracy and consistency in assessing renal function when compared to the BSA-adjusted 8-h CrCl were lacking. Thus, this study suggests the BSA-adjusted 8-h CrCl may be the most appropriate assessment of renal function in patients with aSAH.

Fluid management in patients with acute kidney injury - A post-hoc analysis of the FINNAKI study

PURPOSE

Whether positive fluid balance among patients with acute kidney injury (AKI) stems from decreased urine output, overzealous fluid administration, or both is poorly characterized.

MATERIALS AND METHODS

This was a post hoc analysis of the prospective multicenter observational Finnish Acute Kidney Injury study including 824 AKI and 1162 non-AKI critically ill patients.

RESULTS

We matched 616 AKI (diagnosed during the three first intensive care unit (ICU) days) and non-AKI patients using propensity score. During the three first ICU days, AKI patients received median [IQR] of 11.4 L [8.0-15.2]L fluids and non-AKI patients 10.2 L [7.5-13.7]L, p < 0.001 while the fluid output among AKI patients was 4.7 L [3.0-7.2]L and among non-AKI patients 5.8 L [4.1-8.0]L, p < 0.001. In AKI patients, the median [IQR] cumulative fluid balance was 2.5 L [-0.2-6.0]L compared to 0.9 L [-1.4-3.6]L among non-AKI patients, p < 0.001. Among the 824 AKI patients, smaller volumes of fluid input with a multivariable OR of 0.90 (0.88-0.93) and better fluid output (multivariable OR 1.12 (1.07-1.18)) associated with enhanced change of resolution of AKI.

CONCLUSIONS

AKI patients received more fluids albeit having lower fluid output compared to matched critically ill non-AKI patients. Smaller volumes of fluid input and higher fluid output were associated with better AKI recovery.

Acute Kidney Injury in Critically Ill Children Is Not all Acute: Lessons Over the Last 5 Years

Acute kidney injury (AKI) in the pediatric intensive care unit (PICU) is an important risk factor for increased morbidity and mortality during hospitalization. Over the past decade, accumulated data on children and young people indicates that acute episodes of kidney dysfunction can have lasting consequences on multiple organ systems and health outcomes. To date, there are no guidelines for follow-up of surviving children that may be at risk of long-term sequelae following AKI in the PICU. This narrative review aims to describe literature from the last 5 years on the risk of medium and long-term kidney and non-kidney outcomes after AKI in the PICU. More specifically, we will focus on outcomes in children and young people following AKI in the general PICU population and children undergoing cardiac surgery. These outcomes include mortality, hypertension, proteinuria, chronic kidney disease, and healthcare utilization. We also aim to highlight current gaps in knowledge in medium and long-term outcomes in this pediatric population. We suggest a framework for future research to develop evidence-based guidelines for follow-up of children surviving an episode of critical illness and AKI.

Pediatric acute kidney injury: new advances in the last decade

Pediatric acute kidney injury (AKI) is a frequently missed complication. AKI has a significant impact on both short- and long-term outcomes in children. Within the last decade, there have been major landmark developments in this field of critical care pediatric nephrology. The topic was searched by two independent researchers using Google Scholar and PubMed and related studies published in the last 10 years. The terms used for the search were 'pediatric acute kidney injury,' 'pediatric acute renal failure,' 'pediatric dialysis,' 'biomarkers,' 'nephrotoxins,' 'nephrotoxicity in children,' and 'pediatric critical care nephrology.' We found that AKI is common in critically ill neonates and children. Among the various definitions, the Kidney Disease: Improving Global Outcomes (KDIGO) definition is most commonly used. In addition, it is imperative to risk stratify sick children at admission in the hospital to predict AKI and worse outcomes as this aids in early management. There are now major landmark trials that describe the epidemiology, prevention, and management guidelines in this field and health care professionals need to be aware they should diagnose AKI early. Overall, this review highlights the landmark studies in the last decade and shows that early diagnosis and management of AKI in 'at risk' children can improve outcomes.

Association of early hypotension in pediatric sepsis with development of new or persistent acute kidney injury

OBJECTIVE

To determine how hypotension in the first 48 h of sepsis management impacts acute kidney injury (AKI) development and persistence.

STUDY DESIGN

Retrospective study of patients > 1 month to < 20 years old with sepsis in a pediatric ICU between November 2012 and January 2015 (n = 217). All systolic blood pressure (SBP) data documented within 48 h after sepsis recognition were collected and converted to percentiles for age, sex, and height. Time below SBP percentiles and below pediatric advanced life support (PALS) targets was calculated by summing elapsed time under SBP thresholds during the first 48 h. The primary outcome was new or persistent AKI, defined as stage 2 or 3 AKI present between sepsis day 3-7 using Kidney Disease: Improving Global Outcomes creatinine definitions. Secondary outcomes included AKI-free days (days alive and free of AKI) and time to kidney recovery.

RESULTS

Fifty of 217 sepsis patients (23%) had new or persistent AKI. Patients with AKI spent a median of 35 min under the first SBP percentile, versus 4 min in those without AKI. After adjustment for potential confounders, the odds of AKI increased by 9% with each doubling of minutes spent under this threshold (p = 0.03). Time under the first SBP percentile was also associated with fewer AKI-free days (p = 0.02). Time spent under PALS targets was not associated with AKI.

CONCLUSIONS

The duration of severe systolic hypotension in the first 48 h of pediatric sepsis management is associated with AKI incidence and duration when defined by age, sex, and height norms, but not by PALS definitions. Graphical abstract.

Modification of Pediatric Sequential Organ Failure Assessment Score Using Acute Kidney Injury Diagnostic Criteria

OBJECTIVES

To develop a modified pediatric Sequential Organ Failure Assessment score using the acute kidney injury diagnostic criteria and evaluate its performance in predicting mortality.

DESIGN

A single-center retrospective study.

SETTING

Fourteen-bed PICU in a tertiary care academic children's hospital.

PATIENTS

Critically ill children admitted to the PICU between January 2017 and September 2019 with at least more than two serum creatinine measurements-one for baseline and the other within the first 48 hours of PICU admission.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 755 patients were included. Overall, 265 patients were diagnosed with acute kidney injury using the current acute kidney injury diagnostic criteria. The overall PICU mortality was 5.8%. Patients with acute kidney injury required more vasoactive-inotropic drugs and showed higher illness severity scores, including the Pediatric Risk of Mortality III, Pediatric Logistic Organ Dysfunction 2, pediatric Sequential Organ Failure Assessment, and modified pediatric Sequential Organ Failure Assessment scores, as well as higher PICU mortality than patients without acute kidney injury (p < 0.001). As acute kidney injury stages increase, PICU mortality also increased (p < 0.001). Based on multivariable logistic regression analysis adjusted for age and sex, the modified pediatric Sequential Organ Failure Assessment score was an independent prognostic factor of PICU mortality. The modified pediatric Sequential Organ Failure Assessment score showed better performance in predicting PICU mortality (area under the receiver operating characteristic curve, 0.821; 95% CI, 0.759-0.882) than other severity scores (area under the receiver operating characteristic curve [95% CI] of Pediatric Risk of Mortality III, Pediatric Logistic Organ Dysfunction 2, and pediatric Sequential Organ Failure Assessment scores: 0.788 [0.723-0.853], 0.735 [0.663-0.807], and 0.785 [0.718-0.853], respectively).

CONCLUSIONS

Acute kidney injury is prevalent and associated with poor clinical outcomes in critically ill children. The modified pediatric Sequential Organ Failure Assessment score, based on the acute kidney injury diagnostic criteria, showed improved performance in predicting PICU mortality. The modified pediatric Sequential Organ Failure Assessment score could be a promising prognostic factor for critically ill children.

Community-Based Epidemiology of Hospitalized Acute Kidney Injury

BACKGROUND

Acute kidney injury (AKI) may lead to short- and long-term consequences in children, but its epidemiology has not been well described at a population level and outside of ICU settings.

METHODS

In a large, diverse pediatric population receiving care within an integrated health care delivery system between 2008 and 2016, we calculated age- and sex-adjusted incidences of hospitalized AKI using consensus serum creatinine (SCr)-based diagnostic criteria. We also investigated the proportion of AKI detected in non-ICU settings and the rates of follow-up outpatient SCr testing after AKI hospitalization.

RESULTS

Among 1 500 546 children, the mean age was 9.8 years, 49.0% were female, and 33.1% were minorities. Age- and sex-adjusted incidence of hospitalized AKI among the entire pediatric population did not change significantly across the study period, averaging 0.70 (95% confidence interval: 0.68-0.73) cases per 1000 person-years. Among the subset of hospitalized children, the adjusted incidence of AKI increased from 6.0% of hospitalizations in 2008 to 8.8% in 2016. Approximately 66.7% of AKI episodes were not associated with an ICU stay, and 54.3% of confirmed, unresolved Stage 2 or 3 AKI episodes did not have outpatient follow-up SCr testing within 30 days postdischarge.

CONCLUSIONS

Community-based pediatric AKI incidence was ∼1 per 1000 per year, with two-thirds of cases not associated with an ICU stay and more than one-half not receiving early outpatient follow-up kidney function testing. Further efforts are needed to increase the systematic recognition of AKI in all inpatient settings with appropriate, targeted postdischarge kidney function monitoring and associated management.

Acute kidney injury without previous renal disease in critical care unit

BACKGROUND

Acute kidney injury (AKI) is common in hospitalized and critically ill children. Apart from primary kidney disease, etiologies of AKI are usually related to systemic disease and nephrotoxic insult. This study examines the incidence, characteristics, and mortality risks of AKI in critically ill children without primary renal disease or previously known chronic kidney disease.

METHODS

A retrospective cohort study was conducted of patients aged 1-18 years, diagnosed with AKI (excluding severe glomerulonephritis and previously known chronic kidney disease) in pediatric intensive care units between 2013 and 2016. Acute kidney injury was defined according to the Kidney Disease Improving Global Outcomes classifications. Cox proportional hazards regression analysis was employed to assess the relationship between the risk factors and mortality.

RESULTS

Of 1,377 pediatric intensive care unit patients, 253 (18.4%) developed AKI and only 169 (12.3%) who did not have previously known renal disease were included. Of these 169 AKI patients, the mean age was 8.1 ± 4.7 years; 88 (52.1%) patients were male; and 60 (35.5%) patients had AKI stage 3. The most common etiologies of AKI were sepsis (76.9%) and shock (64.5%). Fifty-three (31.4%) of those patients died during admission. The risk factors for death were the need for mechanical ventilation (adjusted hazard ratio, 17.82; 95% CI, 2.41-132.06) and AKI stage 3 (adjusted hazard ratio, 2.32; 95% CI, 1.07-5.00).

CONCLUSIONS

Acute kidney injury in critically ill children without previously known renal disease was approximately two-thirds of the overall incidence. The risk factors of in-hospital death were the use of mechanical ventilation, and AKI stage 3.

Population-Based Epidemiology and Outcomes of Acute Kidney Injury in Critically Ill Children

OBJECTIVES

We describe the epidemiology, characteristics, risk factors, and incremental risks associated with acute kidney injury in critically ill children at a population-level.

DESIGN

Population-based retrospective cohort study.

SETTING

PICUs in Alberta, Canada.

PATIENTS

All children admitted to PICUs in Alberta, Canada between January 1, 2015, and December 31, 2015.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 1,017 patients were included. Acute kidney injury developed in 308 patients (30.3%; 95% CI, 28.1-33.8%) and severe acute kidney injury (Kidney Disease: Improving Global Outcomes stage 2 and 3) developed in 124 patients (12.2%; 95% CI, 10.3-14.4%). Incidence rates for critical illness-associated acute kidney injury and severe acute kidney injury were 34 (95% CI, 30.3-38.0) and 14 (95% CI, 11.38-16.38) per 100,000 children-year, respectively. Severe acute kidney injury incidence rates were greater in males (incidence rate ratio, 1.55; 95% CI, 1.08-2.33) and infants younger than 1 year old (incidence rate ratio, 14.77; 95% CI, 10.36-21.07). Thirty-two patients (3.1%) did not survive to PICU discharge. The acute kidney injury-associated PICU mortality rate was 2.3 (95% CI, 1.4-3.5) per 100,000 children-year. In multivariate analysis, severe acute kidney injury was associated with greater PICU mortality (odds ratio, 11.93; 95% CI, 4.68-30.42) and 1-year mortality (odds ratio, 5.50; 95% CI, 2.76-10.96). Severe acute kidney injury was further associated with greater duration of mechanical ventilation, duration of vasoactive support, and lengths of PICU and hospital stay.

CONCLUSIONS

The population-level burden of acute kidney injury and its attributable risks are considerable among critically ill children. These findings emphasize the need for enhanced surveillance for acute kidney injury, identification of modifiable risks, and evaluation of interventional strategies.

Incidence and Risk Factors of Acute Kidney Injury after Kasai Operation for Biliary Atresia: A Retrospective Study

Background: Biliary atresia is a progressive, inflammatory, and destructive pathology of the bile ducts. Patients who undergo surgery for correction of biliary atresia (Kasai operation) are at risk of acute kidney injury (AKI) because of their young age at the time of surgery, long operation time, and liver fibrosis or failure as complication of biliary atresia. Conversely, AKI is associated with poor outcomes after surgery. This study therefore aimed to evaluate the incidence, risk factors, and outcomes of AKI after Kasai operation. Methods: All consecutive patients who underwent Kasai operation between March 2006 and December 2015 in a single tertiary-care university hospital were enrolled. AKI was defined based on the Acute Kidney Injury Network criteria. Multivariate logistic regression models were used to assess risk factors for AKI. Results: One hundred sixty-six patients received Kasai operation during study period. Of these, AKI occurred in 37 of 166 patients (22.3%). In multivariate logistic regression analysis, age older than 30 days, higher preoperative estimated glomerular filtration rate, and preoperative contrast use within 7 days were associated with the development of AKI. Perioperative packed red blood cells transfusion was related to reduced occurrence of AKI. AKI was associated with longer ICU stay (OR = 1.015, p = 0.016). More patients with AKI were also found to receive additional surgery except liver transplantation within 1 year compared to those without AKI (10.8 % vs. 2.3 %, p = 0.045). Conclusions: Increased age is strongly associated with the development of AKI after Kasai operation. These findings indicate a rational basis for early corrective surgery for biliary atresia, early screening for AKI, and intervention to improve the results of Kasai operation.

Long-term Mortality After Acute Kidney Injury in the Pediatric ICU

OBJECTIVES

(1) To evaluate the association between acute kidney injury (AKI) in the PICU and long-term mortality and (2) to determine the extent to which adding the urine output (UO)-defined AKI alters the association.

METHODS

A 2-center retrospective cohort study of children (≤18 years old) admitted to the PICU between 2003 and 2005 for noncardiac surgery, with follow-up until 2010. Patients with end stage renal disease, no provincial health insurance number, who died during hospitalization, or could not be linked to administrative data were excluded. One hospitalization per patient was included. AKI was defined by using serum creatinine criteria and/or UO criteria. Mortality was ascertained by using administrative data. Cox regression analysis was performed to evaluate the association between AKI and long-term mortality.

RESULTS

The study population included 2041 patients (55.7% male, mean admission age 6.5 ± 5.8 years). Of 2041 hospital survivors, 9 (0.4%) died within 30 days, 51 (2.5%) died within 1 year, and 118 (5.8%) died within 5 to 7 years postdischarge. AKI was independently associated with 5- to 7-year mortality (adjusted hazard ratio [95% confidence interval]: 3.10 [1.46-6.57] and 3.38 [1.63-7.02], respectively). Including UO did not strengthen the association.

CONCLUSIONS

AKI is associated with 5- to 7-year mortality. Because this is an observational study we cannot determine if AKI is causative of mortality or of the pathophysiology. However, patients with AKI represent a high-risk group. It is reasonable that these patients be considered for targeted follow-up until future researchers better elucidate these relationships.

Global epidemiology and outcomes of acute kidney injury

Acute kidney injury (AKI) is a commonly encountered syndrome associated with various aetiologies and pathophysiological processes leading to decreased kidney function. In addition to retention of waste products, impaired electrolyte homeostasis and altered drug concentrations, AKI induces a generalized inflammatory response that affects distant organs. Full recovery of kidney function is uncommon, which leaves these patients at risk of long-term morbidity and death. Estimates of AKI prevalence range from <1% to 66%. These variations can be explained by not only population differences but also inconsistent use of standardized AKI classification criteria. The aetiology and incidence of AKI also differ between high-income and low-to-middle-income countries. High-income countries show a lower incidence of AKI than do low-to-middle-income countries, where contaminated water and endemic diseases such as malaria contribute to a high burden of AKI. Outcomes of AKI are similar to or more severe than those of patients in high-income countries. In all resource settings, suboptimal early recognition and care of patients with AKI impede their recovery and lead to high mortality, which highlights unmet needs for improved detection and diagnosis of AKI and for efforts to improve care for these patients.

A Pilot Evaluation of a Capacitance-Based Automatic Urinometer in a Pediatric Intensive Care Setting

OBJECTIVES

To compare a modified capacitance-based automatic urinometer to a manual urinometer, with regard to precision of measurement and to evaluate the staff's opinion regarding the automatic urinometer.

DESIGN

Prospective observational cohort study.

SETTING

PICU at Astrid Lindgren's Children Hospital in Solna, Sweden.

PATIENTS

Twelve children weighing up to 10 kg with an indwelling urinary catheter in place before enrollment.

INTERVENTIONS

Measurement of hourly diuresis using either an automatic urinometer or manual urinometer.

MEASUREMENTS AND MAIN RESULTS

Hourly diuresis was measured with an automatic urinometer (n = 127; Sippi; Observe Medical Nordic AB, Gothenburg, Sweden) or an manual urinometer (n = 83; Unometer Safeti Plus; Convatec, Lejre, Denmark) and thereafter validated with a measuring cylinder. The absolute mean bias was -1.1 mL for the automatic urinometer (CI, -0.6 to -1.5) and -0.6 mL (CI, ± 0.0 to -1.2) for the manual urinometer (p = 0.21). The SDs were 2.6 and 2.8 mL, respectively. User evaluation comparing the automatic urinometer with the manual urinometer concerning the ease of use was made with a questionnaire (n = 18). The majority of staff preferred the automatic urinometer to the manual urinometer in terms of ease of use, learning, and handling.

CONCLUSIONS

The two urinometers were comparable in performance for children weighing up to 10 kg. Taking into account the overwhelming staff satisfaction with the automatic urinometer and benefits in less well-staffed wards as well as lack of temporal deviation, the modified automatic urinometer may be considered for clinical use in the PICU.

Infections with Carbapenem-Resistant Gram-Negative Bacteria are a Serious Problem Among Critically Ill Children: A Single-Centre Retrospective Study

Children in paediatric intensive care units (PICUs) are vulnerable to infections because invasive devices are frequently used during their admission. We aimed to determine the prevalence, associated factors, and prognosis of infections in our PICU. This retrospective study evaluated culture results from 477 paediatric patients who were treated in the PICU between January 2014 and March 2019. Ninety patients (18.9%) had bacterial infections, with gram-negative bacteria being the predominant infectious agents. Culture-positive patients were younger than culture-negative patients, and age was related to mortality and various clinical factors. Culture-positive bacterial infections in the PICU were associated with increased use of invasive mechanical ventilation (odds ratio(OR); 2.254), red blood cell (RBC) transfusions (OR:2.624), and inotropic drugs (OR:2.262). Carbapenem resistance was found in approximately one-third of gram-negative bacteria, and was most common in tracheal aspirate specimens and cases involving Klebsiella spp. Total parenteral nutrition was a significant risk factor (OR:5.870). Positive blood culture results were associated with poorer patient survival than other culture results. These findings indicate that infections, especially those involving carbapenem-resistant bacteria, are an important issue when treating critically ill children.

Oliguria and Acute Kidney Injury in Critically Ill Children: Implications for Diagnosis and Outcomes

OBJECTIVES

Consensus definitions for acute kidney injury are based on changes in serum creatinine and urine output. Although the creatinine criteria have been widely applied, the contribution of the urine output criteria remains poorly understood. We evaluated these criteria individually and collectively to determine their impact on the diagnosis and outcome of severe acute kidney injury.

DESIGN AND SETTING

Post hoc analysis of Assessment of Worldwide Acute Kidney Injury, Renal Angina, and Epidemiology study-a prospective international observational multicenter study.

PATIENTS

Critically ill children enrolled in Assessment of Worldwide Acute Kidney Injury, Renal Angina and, Epidemiology database.

MEASUREMENT

To assess the differential impact of creatinine and urine output criteria on severe acute kidney injury (Kidney Disease: Improving Global Outcomes stage ≥ 2). Patients were divided into four cohorts: no-severe acute kidney injury, severe acute kidney injury by creatinine criteria only, severe acute kidney injury by urine output criteria only, and severe acute kidney injury by both creatinine and urine output criteria.

RESULTS

Severe acute kidney injury occurred in 496 of 3,318 children (14.9%); 343 (69.2%) were creatinine criteria only, 90 (18.1%) were urine output criteria only, and 63 (12.7%) were both creatinine and urine output criteria. Twenty-eight-day mortality for creatinine criteria only and urine output criteria only patients was similar (6.7% vs 7.8%) and higher than those without severe acute kidney injury (2.9%; p < 0.01). Both creatinine and urine output criteria patients had higher mortality than creatinine criteria only and urine output criteria only patients (38.1%; p < 0.001). Compared with patients without severe acute kidney injury, the relative risk of receiving dialysis increased from 9.1 (95% CI, 3.9-21.2) in creatinine criteria only, to 28.2 (95% CI, 11.8-67.7) in urine output criteria only, to 165.7 (95% CI, 86.3-318.2) in both creatinine and urine output criteria (p < 0.01).

CONCLUSIONS

Nearly one in five critically ill children with acute kidney injury do not experience increase in serum creatinine. These acute kidney injury events, which are only identified by urine output criteria, are associated with comparably poor outcomes as those diagnosed by changes in creatinine. Children meeting both criteria had worse outcomes than those meeting only one. We suggest oliguria represents a risk factor for poorer outcomes among children who develop acute kidney injury. Application of both the creatinine and urine output criteria leads to a more comprehensive epidemiologic assessment of acute kidney injury and identifies a subset of children with acute kidney injury who are at higher risk for morbidity and mortality.

Short-term outcome associated with disease severity and electrolyte abnormalities among critically ill children with acute kidney injury

Background

Acute kidney injury (AKI) in critically ill children is associated with increased mortality and morbidity. In this study we evaluated the effect of AKI severity on the incidence of short-term mortality and morbidity.

Methods

Multicenter prospective cohort study was conducted over two years period. We used the Kidney Disease Improving Global Outcomes (KDIGO) to diagnose and stage AKI.

Results

A total of 511 out of 1367 included children (37.4%; 95% CI: 34.8–40.0) were diagnosed with AKI. They were categorized into three KDIGO stages: stage I (mild) in 47.5% (95% CI: 43.2–52.0), stage II (moderate) in 32.8% (95% CI: 28.8–37.1) and stage III (severe) in 19.7% (95% CI: 16.4–23.5). Stage II and III AKI had higher risk of mortality and longer length of stay (LOS) in hospital.

Children with stage III AKI were more likely to require mechanical ventilation, referral to pediatric nephrology and discharge with abnormal creatinine level (above 100 uml\L).

Hypervolemia, hypocalcemia, anemia, and acidosis were found to be independent risk factors of mortality.

Conclusion

The extent of severity of AKI is directly associated with increased mortality, LOS and short-term morbidity.

Procalcitonin Value Is an Early Prognostic Factor Related to Mortality in Admission to Pediatric Intensive Care Unit

Introduction

Procalcitonin (PCT) and C-reactive protein (CRP) are already known predictive markers in serious bacterial infections, and it is emphasized that these biomarkers can be used as a marker of increased mortality in critically ill patients. Herein, we aimed to evaluate the initial serum PCT and CRP levels on the outcome of patients in pediatric intensive care units (PICUs) and find out if these biomarkers can be used to predict mortality.

Materials and Methods

The relationship between the initial serum PCT and CRP levels and invasive mechanical ventilation (IMV) and noninvasive mechanical ventilation (NIV) support, inotropic drug need, acute renal kidney injury (AKI), continuous renal replacement therapy (CRRT), mortality, and hospitalization period was investigated retrospectively.

Results

In total, 418 suitable patients (226 males and 192 females) were included in the study. Age distributions of patients ranged from 1 month to 17 years. There was a statistically significant relationship between PCT levels in the first biochemical analysis performed during admission and MV support, inotropic drug use, mortality, ARF, hospitalization in the intensive care unit, CRRT and blood component transfusion. There was a statistically significant relationship between CRP levels and MV support, NIV, inotropic drug use, mortality, AKI, hospitalization in the intensive care unit, CRRT, and blood component transfusion.

Conclusion

We suggest that the initial PCT and CRP levels during admission can be used to predict the outcome of patients in PICU.

Acute Kidney Injury among Hospitalized Children in China

BACKGROUND AND OBJECTIVES

High-quality epidemiologic data on AKI in children are particularly lacking in developing countries. This study aimed to assess the epidemiology and clinical correlates of AKI among hospitalized children in China.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed a multicenter study, in a cohort of hospitalized children aged 1 month to 18 years, from 25 general and children's hospitals in China during 2013-2015. We obtained patient-level data from the electronic hospitalization information system and laboratory databases of all children who had at least two serum creatinine tests within any 7-day window during their first 30 days of hospitalization. We identified AKI events according to the creatinine criteria of Kidney Disease Improving Global Outcomes. The in-hospital outcomes of AKI, including mortality, kidney recovery, and length of stay, were assessed. We estimated the corresponding hazard ratios using a Cox proportional hazard model, with adjustment for age, sex, comorbidities, and clinical procedures.

RESULTS

A total of 19,908 (20%) patients with AKI were identified among 101,836 pediatric inpatients, of which 7220 (7%) were community acquired and 12,688 (13%) were hospital acquired. Up to 96% of these AKI events were not diagnosed on the discharge records. The cumulative incidence of AKI in infants (28%) was twice that in adolescents (12%). The profiles of risk factors differed between community-acquired and hospital-acquired AKI and varied with age. Diarrhea and sepsis were the top risk factors for community-acquired AKI, each contributing 6% of the risk. Congenital heart disease/cardiac surgery was the major risk factor for hospital-acquired AKI, contributing to 19% of cases. Exposure to nephrotoxic drugs, mostly nonsteroidal anti-inflammatory drugs and proton pump inhibitors, was common in hospitalized children and was associated with a higher risk of AKI. Death occurred in 842 out of 19,908 patients (4%) with AKI versus 450 out of 81,478 children (0.5%) without AKI. The risk of in-hospital death was higher among children with severe AKI, shock, and respiratory failure. Pediatric AKI was associated with longer hospital stay and higher daily cost, even after adjustment for covariates.

CONCLUSIONS

Pediatric AKI is common and is substantially underdiagnosed in China.

Acute Kidney Injury Epidemiology in pediatrics

We performed a search in the MEDLINE database using the MeSH term: "Acute Kidney Injury", selecting the subtopic "Epidemiology", and applying age and year of publication filters. We also searched for the terms: "acute renal failure" and "epidemiology" "acute tubular necrosis" and "epidemiology" in the title and summary fields with the same filters. In a second search, we searched in the LILACS database, with the terms: "acute renal injury", or "acute renal failure" or "acute kidney injury" and the age filter. All abstracts were evaluated by the authors and the articles considered most relevant, were examined in their entirety. Acute Kidney Injury (AKI) -related mortality ranged from 3-63% in the studies included in this review. AKI etiology has marked regional differences, with sepsis being the main cause in developed countries. In developing countries, primary renal diseases and hypovolemia are still a common cause of AKI.

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

Background

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

Methods

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

Results

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

Conclusions

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

Risk factors and inpatient outcomes associated with acute kidney injury at pediatric severe sepsis presentation

BACKGROUND

Little data exist on acute kidney injury (AKI) risk factors in pediatric sepsis. We identified risk factors and inpatient outcomes associated with AKI at sepsis recognition in children with severe sepsis.

METHODS

Retrospective, cross-sectional study with inpatient outcome description of 315 patients > 1 month to < 20 years old with severe sepsis in a pediatric intensive care unit over 3 years. Exposures included demographics, vitals, and laboratory data. The primary outcome was kidney disease: Improving Global Outcomes creatinine-defined AKI within 24 h of sepsis recognition. Factors associated with AKI and AKI severity were identified using multivariable Poisson and multinomial logistic regression, respectively.

RESULTS

AKI was present in 42% (133/315) of severe sepsis patients, and 26% (83/315) had severe (stage 2/3) AKI. In multivariable-adjusted analysis, hematologic/immunologic comorbidities, malignancies, chronic kidney disease (CKD), abdominal infection, admission illness severity, and minimum systolic blood pressure (SBP) ≤ 5th percentile for age and sex within 24 h of sepsis recognition were associated with AKI. Factors associated with mild AKI were CKD and abdominal infection, while factors associated with severe AKI were younger age, hematologic/immunologic comorbidities, malignancy, abdominal infection, and minimum SBP ≤ 5th percentile. Patients with AKI had increased hospital mortality (17 vs. 8%, P = 0.02) and length of stay [median 20 (IQR 10-47) vs. 16 days (IQR 7-37), P = 0.03].

CONCLUSIONS

In pediatric severe sepsis, AKI is associated with age, comorbidities, infection characteristics, and hypotension. Future evaluation of risk factors for AKI progression during sepsis is warranted to minimize AKI progression in this high-risk population.

Community-acquired Acute Kidney Injury Among Children Seen in the Pediatric Emergency Department

OBJECTIVES

Acute kidney injury (AKI) is a significant risk factor for morbidity and mortality in children. Little is known about community-acquired AKI (CA-AKI) in the pediatric emergency department (PED). Early recognition of AKI allows for nephroprotective measures. The goal of this investigation was to determine the incidence of CA-AKI and the frequency of clinician identified CA-AKI to better inform future nephroprotective interventions.

METHODS

This was a retrospective cross-sectional study in the PED of a children's hospital. Children 1 month to 18 years of age seen in the PED from January 1 to December 31, 2015, and in whom at least one creatinine level was obtained were included. Patients with chronic kidney disease or end-stage renal disease or who died in the PED were excluded. Patients had CA-AKI based on modified Kidney Disease-Improving Global Outcomes criteria using the creatinine obtained in the PED compared to age-specific norms. Patients were considered identified if the PED clinician diagnosed AKI. The primary outcome was the incidence of CA-AKI. Secondary outcomes included frequency of AKI identification, nephrotoxic medication use, hospital length of stay, renal replacement therapy, and death. Fisher exact test or Pearson's chi-square test was used to calculate odds ratio (OR) with 95% confidence intervals (CIs); multivariable analyses were performed using logistic regression.

RESULTS

In 2015 there were 119,151 PED visits; 15,486 met inclusion criteria. CA-AKI was present in 239 of 15,486 (1.5%) encounters. AKI was identified by PED clinicians in 46 of 239 (19%) of encounters and by the inpatient team in 123 of 199 (62%) of the encounters admitted. AKI was never recognized by a PED or inpatient clinician in 74 of 199 (37%) encounters. Encounters with AKI correctly diagnosed were older (13 years old vs. 10 years old, p = 0.0114), had more severe (stage 2 or 3) AKI (OR = 5.5, 95% CI = 2.6-11.8), and were more likely to be admitted (OR = 10.3, 95% CI = 1.38-77.4) than encounters with missed AKI.

CONCLUSIONS

CA-AKI remains an underrecognized entity in the PED. Better tools for early recognition of AKI in the busy PED environment are needed.

Serum and urine FGF23 and IGFBP-7 for the prediction of acute kidney injury in critically ill children

Background

Fibroblast growth factor 23 (FGF23) and insulin-like growth factor binding protein 7 (IGFBP-7) are suggested to be biomarkers for predicting acute kidney injury (AKI). We compared them with proposed AKI biomarker of cystatin C (CysC), and aimed (1) to examine whether concentrations of these biomarkers vary with age, body weight, illness severity assessed by pediatric risk of mortality III score, and kidney function assessed by estimated glomerular filtration rate (eGFR), (2) to determine the association between these biomarkers and AKI, and (3) to evaluate whether these biomarkers could serve as early independent predictors of AKI in critically ill children.

Methods

This prospective single center study included 144 critically ill patients admitted to the pediatric intensive care unit (PICU) regardless of diagnosis. Serum and spot urine samples were collected during the first 24 h after PICU admission. AKI was diagnosed based on the AKI network (AKIN) criteria.

Results

Twenty-one patients developed AKI within 120 h of sample collection, including 11 with severe AKI defined as AKIN stages 2 and 3. Serum FGF23 levels were independently associated with eGFR after adjustment in a multivariate linear analysis (P < 0.001). Urinary IGFBP-7 (Adjusted OR = 2.94 per 1000 ng/mg increase, P = 0.035), serum CysC (Adjusted OR = 5.28, P = 0.005), and urinary CysC (Adjusted OR = 1.13 per 1000 ng/mg increase, P = 0.022) remained significantly associated with severe AKI after adjustment for body weight and illness severity, respectively. Urinary IGFBP-7 level was predictive of severe AKI and achieved the AUC of 0.79 (P = 0.001), but was not better than serum (AUC = 0.89, P < 0.001) and urinary (AUC = 0.88, P < 0.001) CysC in predicting severe AKI.

Conclusions

Serum FGF23 levels were inversely related to measures of eGFR. In contrast to serum and urinary FGF23 which are not associated with AKI in a general and heterogeneous PICU population, an increased urinary IGFBP-7 level was independently associated with the increased risk of severe AKI diagnosed within the next 5 days after sampling, but not superior to serum or urinary CysC in predicting severe AKI in critically ill children.

M, Mehta L. R. Recognition and management of acute kidney injury in children: The ISN 0by25 Global Snapshot study

BACKGROUND

In low and middle-income countries, reliable data on the epidemiology of childhood acute kidney injury (AKI) is lacking. The Global Snapshot, conducted by the ISN "0by25" AKI initiative, was a world-wide cross-sectional, observational study to evaluate AKI in hospitalized patients. Here we report the pediatric results of this study.

PATIENTS AND METHODS

We prospectively collected data on children who met the Kidney Disease Improving Global Outcomes AKI criteria during a 10-week window in late 2014. AKI risk factors, etiological factors, management and outcomes were recorded using standardized forms and protocols. Countries were classified according to their 2014 gross national income (GNI) per person into high-income countries (HIC), upper-middle income countries (UMIC) and low and low-middle income countries (LLMIC). Need for renal replacement therapy, mortality, and renal recovery were assessed 7 days after AKI diagnosis or at hospital discharge, whichever came first.

RESULTS

92 centers from 41 countries collected data on 354 pediatric AKI patients; 53% of the children developed AKI while hospitalized and 47% in the community. The most common etiological factors for AKI differed across GNI categories as well as between patients with community-acquired vs. hospital-acquired AKI. Children from HIC were younger, and larger proportion of AKI in this group were due to post-surgical complications vs. other etiologies when compared to other income categories. In patients with hypotension as the cause of AKI, the adjusted risk of death was almost 10-fold higher compared to patients without hypotension as an etiological factor for AKI development. Mortality was similar within AKI stages in HIC and UMIC. In LLMIC, patients with the highest AKI level of severity had higher mortality than patients in higher income categories. Patients from LLMIC and UMIC had a 57-fold and 11 fold higher adjusted risk of death, respectively, compared to patients from HIC.

CONCLUSION

In resource-limited countries, pediatric AKI-associated mortality is disproportionately higher when compared to high-resource areas, especially among patients with more severe AKI.