Usefulness of Urinary Neutrophil Gelatinase-associated Lipocalin as a Predictor of Acute Kidney Injury in Critically Ill Children

Renal resistive index by point of care ultrasound to predict sepsis associated acute kidney injury in critically ill children

BACKGROUND

Sepsis associated acute kidney injury (AKI) is linked with adverse outcomes in the PICU. Doppler-based renal resistive index (RRI) has shown promising results in adults for prediction of AKI. We aimed to explore the performance of RRI in children with sepsis.

METHODS

This prospective observational study (March - November 2022) included children aged 1-12 years with sepsis admitted to the PICU. RRI and urine neutrophil gelatinase associated lipocalin (NGAL) were measured within 12 h of admission. Children were followed up for 3 days. AKI (new and persistent) was defined as any child with KDIGO stage 2 or 3 AKI on day 3.

RESULTS

We enrolled 90 children but included 79 in final analysis. Two thirds (n = 53, 67%) had septic shock. Median (IQR) age was 6.2 years (4.1-9.2). RRI decreased with increasing age. Twenty-six (33%) children had AKI on day 3. Mean (SD) RRI was higher in the AKI group [0.72 (0.08) vs. 0.65 (0.07), p < 0.001].The area under ROC curve for RRI to detect AKI among the 1-4 year old group was 0.75 (95% CI:0.51, 0.98; p = 0.05) and among the 5-12 year old group was 0.76 (0.62, 0.89; p = 0.001). An RRI 0.71 predicted AKI with 100% sensitivity and 46.2% specificity among the 1-4-year-old group and RRI 0.69 predicted it with 70% sensitivity and 77.5% specificity in the 5-12-year-old group. RRI and eGFR at admission were independent predictors of AKI on multivariable analysis. Urine NGAL 94.8 ng/ml predicted AKI with 76.9% sensitivity and 77.4% specificity and AUROC was 0.74 (0.62, 0.86) among the 1-12-year-old group.

CONCLUSIONS

RRI values varied with age. RRI showed good diagnostic accuracy to detect new/persistent AKI on day 3 in children with sepsis; however, it was less precise as an independent predictor.

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.

Predictive value of neutrophil gelatinase-associated lipocalin in children with acute kidney injury: A systematic review and meta-analysis

Purpose

Neutrophil gelatin lipase carrier protein (NGAL) has been used as an early biomarker to predict acute kidney injury (AKI). However, the predictive value of NGAL in urine and blood in children with acute kidney injury in different backgrounds remains unclear. Therefore, we conducted this systematic review and meta-analysis to explore the clinical value of NGAL in predicting AKI in children.

Methods

Computerized databases were searched for relevant the studies published through August 4th, 2022, which included PUBMED, EMBASE, COCHRANE and Web of science. The risk of bias of the original included studies was assessed by using the Quality Assessment of Studies for Diagnostic Accuracy (QUADA-2). At the same time, subgroup analysis of these data was carried out.

Results

Fifty-three studies were included in this meta-analysis, involving 5,049 patients, 1,861 of whom were AKI patients. The sensitivity and specificity of blood NGAL for predicting AKI were 0.79 (95% CI: 0.69-0.86) and 0.85 (95% CI: 0.75-0.91), respectively, and SROC was 0.89 (95% CI: 0.86-0.91). The sensitivity and specificity of urine NGAL for predicting AKI were 0.83 (95% CI: 0.78-0.87) and 0.81 (95% CI: 0.77-0.85), respectively, and SROC was 0.89 (95% CI: 0.86-0.91). Meanwhile, the sensitivity and specificity of overall NGAL (urine and blood NGAL) for predicting AKI in children were 0.82 (95% CI: 0.77-0.86) and 0.82 (95% CI: 0.78-0.86), respectively, and SROC was 0.89 (95% CI: 0.86-0.91).

Conclusion

NGAL is a valuable predictor for AKI in children under different backgrounds. There is no significant difference in the prediction accuracy between urine NGAL and blood NGAL, and there is also no significant difference in different measurement methods of NGAL. Hence, NGAL is a non-invasive option in clinical practice. Based on the current evidence, the accuracy of NGAL measurement is the best at 2 h after cardiopulmonary bypass (CPB) and 24 h after birth in asphyxiated newborns.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022360157.

Time for Precision Medicine in the Diagnosis of Acute Kidney Injury

How to cite this article: Ali U. Time for Precision Medicine in the Diagnosis of Acute Kidney Injury. Indian J Crit Care Med 2022;26(5):547-548.