Diagnostic accuracy of renal angina index alone or in combination with biomarkers for predicting acute kidney injury in children

Dialysis for paediatric acute kidney injury in Cape Town, South Africa

BACKGROUND

Dialysis is lifesaving for acute kidney injury (AKI), but access is poor in less resourced settings. A "peritoneal dialysis (PD) first" policy for paediatric AKI is more feasible than haemodialysis in low-resource settings.

METHODS

Retrospective review of modalities and outcomes of children dialysed acutely at Red Cross War Memorial Children's Hospital between 1998 and 2020.

RESULTS

Of the 593 children with AKI who received dialysis, 463 (78.1%) received PD first. Median age was 9.0 (range 0.03-219.3; IQR 13.0-69.6) months; 57.6% were < 1 year old. Weights ranged from 0.9 to 2.0 kg (median 7.0 kg, IQR 3.0-16.0 kg); 38.6% were < 5 kg. PD was used more in younger children compared to extracorporeal dialysis (ECD), with median ages 6.4 (IQR 0.9-30.4) vs. 73.9 (IQR 17.5-113.9) months, respectively (p = 0.001). PD was performed with Seldinger soft catheters (n = 480/578, 83%), predominantly inserted by paediatricians at the bedside (n = 412/490, 84.1%). Complications occurred in 127/560 (22.7%) children receiving PD. Overall, 314/542 (57.8%) children survived. Survival was significantly lower in neonates (< 1 month old, 47.5%) and infants (1-12 months old, 49.2%) compared with older children (> 1 year old, 70.4%, p < 0.0001). Survival was superior in the ECD (75.4%) than in the PD group (55.6%, p = 0.002).

CONCLUSIONS

"PD First for Paediatric AKI" is a valuable therapeutic approach for children with AKI. It is feasible in low-resourced settings where bedside PD catheter insertion can be safely taught and is an acceptable dialysis modality, especially in settings where children with AKI would otherwise not survive.

Evaluation of the Renal Angina Index to Predict the Development of Acute Kidney Injury in Children With Sepsis Who Live in Middle-Income Countries

OBJECTIVE

The renal angina index (RAI) provides a clinically feasible and applicable tool to identify critically ill children at risk of severe acute kidney injury (AKI) in high-income countries. Our objective was to evaluate the performance of the RAI as a predictor of the development of AKI in children with sepsis in a middle-income country and its association with unfavorable outcomes.

METHODS

This is a retrospective cohort study in children with sepsis hospitalized in the pediatric intensive care unit (PICU) between January 2016 and January 2020. The RAI was calculated 12 hours after admission to predict the development of AKI and at 72 hours to explore its association with mortality, the need for renal support therapy, and PICU stay.

RESULTS

We included 209 PICU patients with sepsis with a median age of 23 months (interquartile range, 7-60). We found that 41.1% of the cases (86/209) developed de novo AKI on the third day of admission (KDIGO 1, 24.9%; KDIGO 2, 12.9%; and KDIGO 3, 3.3%).Overall mortality was 8.1% (17/209), higher in patients with AKI (7.7% vs 0.5%, P < 0.01). The RAI on admission was able to predict the presence of AKI on day 3 (area under the curve (AUC), 0.87; sensitivity, 94.2%; specificity, 100%; P < 0.01), with a negative predictive value greater than 95%. An RAI greater than 8 at 72 hours was associated with a greater risk of mortality (adjusted odds ratio [aOR], 2.6; 95% confidence interval [CI], 2.0-3.2; P < 0.01), a need for renal support therapy (aOR, 2.9; 95% CI, 2.3-3.6; P < 0.01), and a PICU stay of more than 10 days (aOR, 1.54; 95% CI, 1.1-2.1; P < 0.01).

CONCLUSIONS

The RAI on the day of admission is a reliable and accurate tool for predicting the risk of developing AKI on day 3, in critically ill children with sepsis in a limited resource context. A score greater than eight 72 hours after admission is associated with a higher risk of death, the need for renal support therapy, and PICU stay.

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.

Integration of Urinary Neutrophil Gelatinase-associated Lipocalin with the Renal Angina Index to Predict Subsequent Severe Acute Kidney Injury in Critically Ill Children: A Diagnostic Accuracy Study

The primary objective of this study was to determine the performance of the renal angina index (RAI) in predicting subsequent severe acute kidney injury (AKI) on day 3 of admission and whether integrating urinary neutrophil gelatinase-associated lipocalin (NGAL) with RAI would lead to improved prediction of AKI. This was a prospective observational study conducted in the pediatric intensive care unit (PICU) of a tertiary care hospital involving 170 children meeting the inclusion criteria. The RAI was assessed within 24 h of admission to the PICU. Positivity for renal angina was considered RAI ≥8. Urine samples were collected for all enrolled patients within the first 24 h and on day 3 of the PICU stay. NGAL was assayed using human-specific enzyme-linked immunosorbent assay. The overall incidence of AKI was 18.2%. Out of 170 children, 31 (18.2%) were RAI-positive on day 0. A higher proportion of patients in the RAI-positive group developed AKI on day 3 compared with the RAI-negative group (83.9% vs. 3.6%, P <0.001). Those who were RAI-positive on day 0 had a sensitivity, specificity, positive predictive value (PPV), and negative predictive value of 83.8%, 96.4%, 83.8%, and 96.4%, respectively, for predicting severe AKI on day 3. Incorporating urinary NGAL improved the specificity and PPV to 97.8% and 85.7%, respectively. Assessing the RAI is simple and useful for predicting severe AKI in critically ill children. The addition of urinary NGAL to the RAI optimizes its use for identifying patients at risk of subsequent severe AKI.

Biomarkers for prediction of acute kidney injury in pediatric patients: a systematic review and meta-analysis of diagnostic test accuracy studies

BACKGROUND

Severity of acute kidney injury (AKI) confers higher odds of mortality. Timely recognition and early initiation of preventive measures may help mitigate the injury further. Novel biomarkers may aid in the early detection of AKI. The utility of these biomarkers across various clinical settings in children has not been evaluated systematically.

OBJECTIVE

To synthesize the currently available evidence on different novel biomarkers for the early diagnosis of AKI in pediatric patients.

DATA SOURCES

We searched four electronic databases (PubMed, Web of Science, Embase, and Cochrane Library) for studies published between 2004 and May 2022.

STUDY ELIGIBILITY CRITERIA

Cohort and cross-sectional studies evaluating the diagnostic performance of biomarkers in predicting AKI in children were included.

PARTICIPANTS AND INTERVENTIONS

Participants in the study included children (aged less than 18 years) at risk of AKI.

STUDY APPRAISAL AND SYNTHESIS METHODS

We used the QUADAS-2 tool for the quality assessment of the included studies. The area under the receiver operating characteristics (AUROC) was meta-analyzed using the random-effect inverse-variance method. Pooled sensitivity and specificity were generated using the hierarchical summary receiver operating characteristic (HSROC) model.

RESULTS

We included 92 studies evaluating 13,097 participants. Urinary NGAL and serum cystatin C were the two most studied biomarkers, with summary AUROC of 0.82 (0.77-0.86) and 0.80 (0.76-0.85), respectively. Among others, urine TIMP-2*IGFBP7, L-FABP, and IL-18 showed fair to good predicting ability for AKI. We observed good diagnostic performance for predicting severe AKI by urine L-FABP, NGAL, and serum cystatin C.

LIMITATIONS

Limitations were significant heterogeneity and lack of well-defined cutoff value for various biomarkers.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

Urine NGAL, L-FABP, TIMP-2*IGFBP7, and cystatin C showed satisfactory diagnostic accuracy in the early prediction of AKI. To further improve the performance of biomarkers, they need to be integrated with other risk stratification models.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (CRD42021222698). A higher resolution version of the Graphical abstract is available as "Supplementary information".

Early recognition and prevention of acute kidney injury in hospitalised children

Acute kidney injury is common in hospitalised children and is associated with poor patient outcomes. Once acute kidney injury occurs, effective therapies to improve patient outcomes or kidney recovery are scarce. Early identification of children at risk of acute kidney injury or at an early injury stage is essential to prevent progression and mitigate complications. Paediatric acute kidney injury is under-recognised by clinicians, which is a barrier to optimisation of inpatient care and follow-up. Acute kidney injury definitions rely on functional biomarkers (ie, serum creatinine and urine output) that are inadequate, since they do not account for biological variability, analytical issues, or physiological responses to volume depletion. Improved predictive tools and diagnostic biomarkers of kidney injury are needed for earlier detection. Novel strategies, including biomarker-guided care algorithms, machine-learning methods, and electronic alerts tied to clinical decision support tools, could improve paediatric acute kidney injury care. Clinical prediction models should be studied in different paediatric populations and acute kidney injury phenotypes. Research is needed to develop and test prevention strategies for acute kidney injury in hospitalised children, including care bundles and therapeutics.

Management of Acute Kidney Injury in Critically Ill Children

Acute kidney injury (AKI) is common in critically ill patients, affecting almost one in four critically ill children and one in three neonates. Higher stages of AKI portend worse outcomes. Identifying AKI timely and instituting appropriate measures to prevent and manage severe AKI is important, since it is independently associated with mortality. Methods to predict severe AKI should be applied to all critically ill patients. Assessment of volume status to prevent the development of fluid overload is useful to prevent adverse outcomes. Patients with metabolic or clinical complications of AKI need prompt kidney replacement therapy (KRT). Various modes of KRT are available, and the choice of modality depends most on the technical competence of the center, patient size, and hemodynamic stability. Given the significant risk of chronic kidney disease, patients with AKI require long-term follow-up. It is important to focus on improving awareness about AKI, incorporate AKI prevention as a quality initiative, and improve detection, prevention, and management of AKI with the aim of reducing acute and long-term morbidity and mortality.

Febrile Urinary Tract Infections in Children: The Role of High Mobility Group Box-1

BACKGROUND

Differentiating between febrile lower urinary tract infection (LUTI) and acute pyelonephritis (APN) is crucial for prompt clinical management. We investigated whether the high mobility group box-1 (HMGB1) could be a useful biomarker in differentiating between LUTI or APN.

METHODS

We enrolled seventy-four pediatric patients with suspected LUTI/APN, according to the positive or negative renal scintigraphy (DMSA) scan. If the first DMSA findings were abnormal, a second DMSA was performed after six months. Voiding cystourethrography ruled out vesicoureteral reflux (VUR).

RESULTS

Higher serum (s) HMGB1 levels characterized the APN group when compared to LUTI patients (13.3 (11.8-14.3) versus 5.9 (5.2-6.8) ng/mL, p: 0.02), whereas there were no differences according to urine (u) HMGB1 values. sHMGB1 correlated with C-reactive protein (CRP) levels (β = 0.47; p: 0.02). Receiver operating characteristic curves identified the best diagnostic profile for detecting APN. sHMGB1 area under the curve was different from CRP (p: 0.01) and white blood cells (p: 0.003). After multivariate analyses, VUR (HR:4.81) and sHMGB1 (HR 1.16; p: 0.006) were independently associated with the risk of renal scarring development.

CONCLUSIONS

sHMGB1 could represent a marker to differentiate APN from LUTI. Measurement of sHMGB1 could select children for early intervention or long-term follow-up.

Interventions for preventing and treating acute kidney injury in children

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

This review aims to look at the benefits and harms of all pharmacological interventions except dialysis for the prevention and treatment of AKI.