Acute kidney injury in the fetus and neonate

High-sensitive troponinT, interleukin-8, and interleukin-6 link with post-surgery risk in infant heart surgery

BACKGROUND

This study focuses on biomarkers in infants after open heart surgery, and examines the association of high-sensitive troponin T (hs-cTnT), interleukin-6 (IL-6), and interleukin-8 (IL-8) with postoperative acute kidney injury (AKI), ventilatory support time and need of vasoactive drugs.

METHODS

Secondary exploratory study from a double-blinded clinical randomized trial (Mile-1) on 70 infants undergoing open heart surgery with cardiopulmonary bypass (CPB). In this sub-study, the entire study population was examined without considering the study drugs. The biomarkers' peak concentration (highest concentration at 2 or 6 h post-CPB) were used for statistical analyses.

RESULTS

Peak IL-8, hs-cTnT, and IL-6 occurred at 2 h post-CPB for 96%, 79%, and 63% of the patients, respectively. The odds ratio of developing AKI2-3 for IL-6 > 293 pg/mL was 23.4 (95% CI 5.3;104.0), for IL-8 > 100 pg/mL it was 11.5 (3.0;44.2), and for hs-cTnT >5597 pg/mL it was 6.1 (1.5; 24.5). In more than two third of the patients with the highest peak concentrations of IL-8, IL-6, and hs-cTnT, there was a need for ventilatory support for >24 h and use of vasoactive drugs at 24 h post-CPB, while in less than one third of the patients with the lowest peak concentrations of IL-8 and hs-cTnT such requirements were observed.

CONCLUSIONS

The peak biomarker concentrations and CPB-time strongly predicted AKI2-3, with IL-6 and IL-8 emerging as strongest predictors. Furthermore, our findings suggest that measuring hs-cTnT and IL-8 just 2 h post-CPB-weaning may assist in identifying infants suitable for early extubation and highlight those at risk of prolonged ventilation.

Kidney volume-to-birth weight ratio as an estimate of nephron endowment in extremely low birth weight preterm infants

In humans, nephrogenesis is completed by 32-36 weeks gestation, with a highly variable total number of nephrons, ranging from 200,000 to over 2 million. Premature birth disrupts the development and maturation of the kidneys, leading to a reduction in the final number of nephrons. Due to significant genetic variability in the number of nephrons among individuals, it is crucial to identify premature infants with fewer nephrons at birth as early as possible. These infants are more susceptible to developing renal failure with advancing age compared to those with a higher nephron endowment. Bedside ultrasound, an effective and non-invasive tool, is practical for identifying newborns with a lower nephron count. However, renal volume alone cannot reliably indicate the number of nephrons due to substantial variability at birth, influenced by gestational age when nephron maturation is incomplete. This variability in kidney volumes persists as newborns grow. In this observational study we hypothesize that the relationship between renal volume and birth weight may serve as an indicator of nephron endowment in premature infants with birth weight less than 1000 g. This finding could represent the basis for defining appropriate surveillance protocols and developing targeted therapeutic approaches.

EARLY FLUID PLUS NOREPINEPHRINE RESUSCITATION DIMINISHES KIDNEY HYPOPERFUSION AND INFLAMMATION IN SEPTIC NEWBORN PIGS

ABSTRACT

Sepsis is the most frequent risk factor for acute kidney injury (AKI) in critically ill infants. Sepsis-induced dysregulation of kidney microcirculation in newborns is unresolved. The objective of this study was to use the translational swine model to evaluate changes in kidney function during the early phase of sepsis in newborns and the impact of fluid plus norepinephrine resuscitation. Newborn pigs (3-7-day-old) were allocated randomly to three groups: 1) sham, 2) sepsis (cecal ligation and puncture) without subsequent resuscitation, and 3) sepsis with lactated Ringer plus norepinephrine resuscitation. All animals underwent standard anesthesia and mechanical ventilation. Cardiac output and glomerular filtration rate were measured noninvasively. Mean arterial pressure, total renal blood flow, cortical perfusion, medullary perfusion, and medullary tissue oxygen tension (mtPO 2 ) were determined for 12 h. Cecal ligation and puncture decreased mean arterial pressure and cardiac output by more than 50%, with a proportional increase in renal vascular resistance and a 60-80% reduction in renal blood flow, cortical perfusion, medullary perfusion, and mtPO 2 compared to sham. Cecal ligation and puncture also decreased glomerular filtration rate by ~79% and increased AKI biomarkers. Isolated foci of tubular necrosis were observed in the septic piglets. Except for mtPO 2 , changes in all these parameters were ameliorated in resuscitated piglets. Resuscitation also attenuated sepsis-induced increases in the levels of plasma C-reactive protein, proinflammatory cytokines, lactate dehydrogenase, alanine transaminase, aspartate aminotransferase, and renal NLRP3 inflammasome. These data suggest that newborn pigs subjected to cecal ligation and puncture develop hypodynamic septic AKI. Early implementation of resuscitation lessens the degree of inflammation, AKI, and liver injury.

Podocyte involvement in the pathogenesis of preterm-related long-term chronic kidney disease

With the continuous advancement of neonatal intensive care technology, the survival rate of preterm infants is gradually increasing. However, this improvement in survival is accompanied by long-term prognostic implications in various systems. In the field of renal diseases, current epidemiological data indicate that preterm birth is a significant risk factor for the development of long-term chronic kidney disease (CKD). This not only imposes an economic burden on patients families but also severely impacts their quality of life. Understanding the underlying mechanisms involved in this process could offer potential strategies for early prevention and management of CKD. Although the nephron number hypothesis is currently widely accepted as a mechanism, there has been limited exploration regarding podocytes - one of the most important structures within nephrons - in relation to long-term CKD associated with preterm birth. Therefore, this review aims to summarize current knowledge on how prematurity influences CKD development overall, while specifically focusing on our current understanding of podocytes in relation to prematurity.

Renal Oxygen Saturations and Acute Kidney Injury in the Preterm Infant with Patent Ductus Arteriosus

OBJECTIVE

 Decreased near-infrared spectroscopy (NIRS) measures of renal oxygen saturation (Rsat) have identified preterm infants with a hemodynamically significant patent ductus arteriosus (hsPDA). NIRS may further identify infants at risk for acute kidney injury (AKI) in a population with concern for hsPDA.

STUDY DESIGN

 Review of infants ≤29 weeks' gestation undergoing NIRS and echocardiography due to concern for hsPDA. The hsPDA was defined by two of the following: moderate-large size, left to right shunt, aortic flow reversal, left atrial enlargement. AKI was defined by neonatal modified Kidney Disease Improving Global Outcomes (KDIGO). Rsat and cerebral saturation (Csat), averaged over 1 hour, were evaluated for the 24-hour period around echocardiography.

RESULTS

 Among 77 infants, 29 (38%) had AKI by neonatal modified KDIGO criteria. hsPDA was found on echocardiography in 59 (77%). There were no differences in hsPDA in infants with and without AKI (p = 0.1). Rsat was not associated with AKI (p = 0.3). Infants on dopamine had less Rsat variability (p < 0.01).

CONCLUSION

 Rsat prior to echocardiography did not discriminate AKI in this cohort of preterm infants at risk for hsPDA; however, data may not capture optimal timing of Rsat measurement before AKI.

KEY POINTS

· No Rsat value was found to be associated with the development of AKI.. · The optimal timing of Rsat measurement should be evaluated in infants at risk for hsPDA.. · NIRS bedside monitoring of Csat and Rsat measures may be useful in trending perfusion patterns.. · Identification of those at high risk for AKI may allow for more careful kidney function monitoring..

Acute kidney injury surveillance in the high-risk neonatal population following implementation of creatinine screening protocol

AIM

Acute kidney injury (AKI) in neonates is associated with longer hospital stays and higher mortality rates. However, there is significant variability in prevalence rates of AKI and the true burden is incompletely understood. In November 2020, the University of Iowa Stead Family Children's Hospital Neonatal Intensive Care Unit implemented a creatinine screening protocol to enhance kidney function monitoring. We sought to evaluate adherence to the protocol to determine if increased surveillance led to increased detection of AKI events.

METHODS

A retrospective chart review was conducted for neonates born at <30 weeks' gestation admitted between 2015 and 2020. We reviewed 100 charts in both the pre (2015-2016) and post (2020-2021) implementation era of the AKI surveillance protocol. AKI was defined according to neonatal modified KDIGO criteria.

RESULTS

Following implementation of the protocol, neonates were significantly more likely to have creatinine checked (p < 0.001). Serum creatinine was drawn according to protocol guidelines 68% of the time, and 42% of patients (34/82) had an 80% or higher adherence to the protocol. There was a significant increase in detection of AKI in the post-protocol cohort (13/82, incidence of 16%) compared to the pre-protocol cohort (5/83, incidence of 6%), (p = 0.047).

CONCLUSION

The implementation of a serum creatinine screening protocol increased the frequency of creatinine draws and detection of AKI.

Trend analysis and prediction of the incidence and mortality of CKD in China and the US

BACKGROUND

Currently, limited research is available on the comparative analysis of chronic kidney disease (CKD) incidence and mortality rates between China and the United States. This study aimed to explore the trends in CKD incidence and mortality rates in both countries, as well as make some future predictions.

METHODS

The data on CKD incidence and mortality in China and the US from 1990 to 2019 were derived from the 2019 Global Burden of Disease database. A Joinpoint regression model was used to analyze temporal trends in CKD incidence and mortality. An age-period-cohort model was used to assess the effects of age, period, and birth cohort on CKD risk and forecast the age-standardized incidence rate (ASIR) and age-standardized mortality rate (ASMR) of CKD in China and the US over the next 15 years.

RESULTS

CKD incidence in China and the US showed an upward trend. Its mortality rate showed a downward trend in China but an upward one in the US. The relative risk (RR) of CKD incidence and mortality increases with age. The RR of CKD incidence in the 0-5 age group exceeds that in the 5-55 age group, and the RR for mortality surpasses that in the 5-35 age group. Over time, the RR of CKD incidence has gradually increased in China and the US. Individuals born in later birth cohorts had a lower RR of CKD incidence and mortality. The ASIR of CKD may increase in both China and the US, whereas its ASMR may decline over the next 15 years.

CONCLUSION

Screening measures should be strengthened among populations at high risk of CKD; prenatal examinations of pregnant women should be emphasized to reduce CKD incidence in newborns. It is imperative to increase health education and encourage individuals to adopt healthy lifestyles.

Understanding Near-Infrared Spectroscopy: An Update

Near-infrared spectroscopy (NIRS) is a novel technology that uses infrared light to noninvasively and continuously measure regional oxygen extraction in real time at the bedside. Neonatal research using this device supports its use as an adjunct to routine cardiovascular monitoring because NIRS serves as a surrogate marker for end-organ perfusion and can detect minute changes in cerebral, intestinal, and kidney tissue beds. Multiple conditions affecting premature infants are frequently associated with hypoperfusion; therefore, methods to detect early tissue-specific perfusion alterations may substantially improve the clinician's ability to intervene and prevent further deterioration.

Acute renal failure as a key to significant neonatal weight loss

We present a case of a male neonate who experienced a 13.5% weight loss at 96 hours of life, despite receiving adequate calorie intake and exhibiting no feeding difficulties. The pregnancy was uneventful, and maternal serological investigation was normal. A routine ultrasound at 34 weeks of gestational age revealed late oligohydramnios. The neonate was delivered at 35 weeks of gestational age by forceps, weighing 2600 g. Physical examination disclosed bilateral cryptorchidism. Laboratory studies unveiled acute kidney injury (AKI) with hyperkalaemia. Renal ultrasound revealed bilateral hydronephrosis and renal dysplasia with pyelocalyceal dilatation. Despite early recognition and treatment, the newborn developed chronic kidney disease (CKD). AKI is an important and under-recognised cause of significant neonatal weight loss.This case underscores the significance of considering AKI as a potential and under-recognised cause of neonatal weight loss. It emphasises the importance of maintaining a high clinical suspicion for early AKI diagnosis to mitigate the risk of progression to CKD.

The efficacy and safety of continuous blood purification in neonates with septic shock and acute kidney injury: a two-center retrospective study

To investigate the efficacy and safety of continuous blood purification (CBP) in neonates with septic shock and acute kidney injury (AKI). This retrospective study was conducted at two tertiary care children's hospitals between January 2015 and May 2022. A total of 26 neonates with septic shock and AKI were included in this study, with a mortality rate of 50%. Fourteen neonates (53.8%) received continuous veno-venous hemodiafiltration, and 12 (46.2%) received continuous veno-venous hemofiltration. Compared with the indices before CBP, urine output increased 12 h after CBP initiation (P = 0.003) and serum creatinine decreased (P = 0.019). After 24 h of CBP, blood urea nitrogen had decreased (P = 0.006) and mean arterial pressure had increased (P = 0.007). At the end of CBP, the vasoactive-inotropic score and blood lactate were decreased (P = 0.035 and 0.038, respectively) and PH was increased (P = 0.015). Thrombocytopenia was the most common complication of CBP.  Conclusion: CBP can efficiently maintain hemodynamic stability, improve renal function, and has good safety in neonates with septic shock and AKI. However, the mortality rate remains high, and whether CBP improves the prognosis of neonates with septic shock and AKI remains unclear. What is Known: • Over 50% of children with septic shock have severe AKI, of which 21.6% required CBP. • The clinical application of CBP in septic shock has attracted increasing attention. What is New: • CBP can efficiently maintain hemodynamic stability, improve renal function, and has good safety in neonates with septic shock and AKI. • The mortality rate in neonates with septic shock and AKI receiving CBP remains high.

Optimizing Nutrition in Neonates with Kidney Dysfunction

The nutritional management of neonates with kidney disease is complex. There may be significant differences in nutritional needs based on the duration and cause of kidney dysfunction, including acute kidney injury (AKI) and chronic kidney disease (CKD). Furthermore, the treatment modality, including acute (continuous renal replacement therapy and peritoneal dialysis [PD]) and chronic (intermittent hemodialysis and PD) approaches may differentially affect nutritional losses and dietary needs. In this review, we discuss the pathophysiology of compromised nutrition in neonates with AKI and CKD. We also summarize the existing data and consensus recommendations on the provision of nutrition to neonates with AKI and CKD. We highlight the paucity of data on micronutrient losses and the need for future prospective studies to enhance nutritional supplementation to hopefully improve outcomes in these patients.

The Utility of Urinary NGAL as an Alternative for Serum Creatinine to Detect Acute Kidney Injury in Infants Exposed to Nephrotoxic Medications in the Neonatal Intensive Care Unit

INTRODUCTION

Nephrotoxic medication (NTM) exposure is commonly associated with acute kidney injury (AKI) in the neonatal intensive care unit (NICU). Baby Nephrotoxic Injury Negated by Just-in-Time Action (NINJA) is a quality improvement program that assesses for AKI in those exposed to NTM with daily serum creatinine (SCr) levels. However, blood draws for SCr are invasive and have clinical disadvantages. Urinary neutrophil gelatinase-associated lipocalin (uNGAL) is a promising indicator of AKI. We tested the hypothesis that uNGAL could reliably screen for NTM-AKI in the Baby NINJA program.

METHODS

This two-center prospective study screened 174 NICU subjects, of whom 148 met screening criteria from January 29, 2019, to September 18, 2020. Daily SCr and urine samples were obtained for up to 7 days of NTM exposure plus 2 days after exposure ended or end of AKI. AKI was defined by a SCr rise of 50% from baseline. The highest uNGAL obtained was evaluated to determine its relationship to the diagnosis of AKI. Logistic regression models were used to determine optimal uNGAL cutoffs.

RESULTS

The negative predictive value of a uNGAL value ≥250 ng/mL was 96.8% (95% CI = 93.3-100%). Urine NGAL ≥400 ng/mL demonstrated the highest ROC-AUC value of 0.72 with a positive likelihood risk for AKI of 2.76 (1.39-4.13).

DISCUSSION/CONCLUSION

We propose that uNGAL could be used to screen for NTM-AKI and thus replace many blood draws needed in those exposed to NTM. The ideal uNGAL threshold requires further investigation in infants.

Real-life effects, complications, and outcomes in 39 critically ill neonates receiving continuous kidney replacement therapy

BACKGROUND

Continuous kidney replacement therapy (CKRT) has been expanded from simple kidney replacement therapy to the field of critical illness in children. However, CKRT is rarely used in critically ill neonates in the neonatal intensive care unit (NICU). This study aimed to describe patients' clinical characteristics at admission and CKRT initiation, CKRT effects, short-term outcomes, and predictors of death in critically ill neonates.

METHODS

A 7-year single-center retrospective study in a tertiary NICU.

RESULTS

Thirty-nine critically ill neonates received CKRT between May 2015 and April 2022 with a mortality rate of 35.9%. The most common primary diagnosis was neonatal sepsis in 15 cases (38.5%). Continuous veno-venous hemodiafiltration and continuous veno-venous hemofiltration were applied in 43.6% and 56.4% of neonates, respectively. The duration of CKRT was 44 (18, 72) h. Thirty-one patients (79.5%) had complications due to CKRT-related adverse events, and the most common complication was thrombocytopenia. Approximately 12 h after the CKRT initiation, urine volume, mean arterial pressure, and pH were increased, and serum creatinine, blood urea nitrogen, and blood lactate were decreased. In the multivariate logistic regression analysis, neonatal critical illness score [odds ratio 0.886 (0.786 ~ 0.998), P = 0.046] was an independent risk factor for death in critically ill neonates who received CKRT.

CONCLUSIONS

CKRT can be an effective and feasible technique in critically ill neonates, but the overall mortality and CKRT-related complications are relatively high. Furthermore, the probability of death is greater among neonates with greater severity of illness at CKRT initiation. A higher resolution version of the Graphical abstract is available as Supplementary information.

Association of intrauterine growth restriction and low birth weight with acute kidney injury in preterm neonates

BACKGROUND

Preterm birth alters nephrogenesis and reduces the total nephron number. Intrauterine growth restriction (IUGR) seems to worsen nephron loss, but only a few studies have investigated its role in neonatal kidney impairment. We investigated whether IUGR, defined as reduced estimated fetal growth and/or placental flow alterations and low birth weight z-score, increases the risk of developing acute kidney injury (AKI) in very preterm infants.

METHODS

We performed a retrospective study including infants born with a birth weight (BW) ≤ 1500 g and/or gestational age (GA) ≤ 32 weeks admitted to our center between January 2016 and December 2021. Neonatal AKI was defined according to the neonatal KDIGO classification based on the decline of urine output and/or creatinine elevation. We used multivariable linear regressions to verify the association between AKI and GA, BW z-score, IUGR definition, and hemodynamically significant patent ductus arteriosus (PDA).

RESULTS

We included 282 infants in the analysis, with a median (IQR) GA = 29.4 (27.4, 31.3) weeks, BW = 1150 (870, 1360) g, and BW z-score =  - 0.57 (- 1.64, 0.25). AKI was diagnosed in 36 (13%) patients, and 58 (21%) had PDA. AKI was significantly associated with BW z-score (beta (std. error) =  - 0.08 (0.03), p = 0.008) and severe IUGR (beta (std. error) = 0.21 (0.08), p = 0.009), after adjusting for GA and PDA.

CONCLUSIONS

Our data suggest that low BW z-score and IUGR could represent adjunctive risk factors for kidney impairment in preterm babies. A higher resolution version of the Graphical abstract is available as Supplementary information.

Early Fluid and Nutritional Management of Extremely Preterm Newborns During the Fetal-To-Neonatal Transition

During the fetal-to-neonatal transitional period, extremely preterm newborns undergo significant intrabody fluid shifts and resulting weight loss due to increased insensible fluid losses due to immature skin, kidneys, among other factors. These ongoing physiologic changes make fluid and nutritional management complex in the neonatal-to-fetal transitional time period for extremely premature newborns. However, limited literature exists to guide optimal practices for providers caring for this population. Here, we review the evidence on optimal fluid and nutritional management during the fetal-to-neonatal transition of extremely preterm newborns.

Evaluation of an Empiric Vancomycin Dosing Protocol on Goal Troughs and Acute Kidney Injury in a Neonatal Intensive Care Unit

OBJECTIVE

Review the efficacy and safety of an updated empiric vancomycin dosing protocol in a neonatal intensive care unit (NICU).

METHODS

Retrospective chart review including neonates with postmenstrual age (PMA) less than 40 weeks without renal dysfunction who received vancomycin per protocol at a single institution's NICU before and after implementation of an updated dosing protocol. The primary outcome is the proportion of initial therapeutic troughs. Secondary outcomes include average trough, achievement of a therapeutic trough, number of days before attainment of a therapeutic trough, and proportion of acute kidney injury (AKI) during therapy.

RESULTS

The 2 groups were similar in gestational age, race, birth weight, PMA, and weight at time of vancomycin initiation. The post-implementation group had a higher proportion of initial therapeutic troughs (33.0% vs 55.1%) and a lower proportion of a subtherapeutic (58.7% vs 43.8%) and supratherapeutic (8.3% vs 1.1%) initial troughs (p = 0.002). The median trough was not different (9.20 vs 10.50 mg/L; p = 0.092). There was no difference in the proportions of achieving a therapeutic trough throughout therapy (69% vs 76%; p = 0.235); however, the post-implementation group achieved a therapeutic trough 1 day earlier (3 vs 2 days; p < 0.001). There was no difference in proportions of AKI developing between the pre-implementation vs post-implementation groups (10.1% vs 5.6%; p = 0.251).

CONCLUSIONS

Implementation of an updated vancomycin dosing protocol yielded a higher percentage of initial therapeutic vancomycin troughs and patients reached the therapeutic range 1 day earlier without increasing the proportion of AKI.

Detecting Neonatal AKI by Serum Cystatin C

SIGNIFICANCE STATEMENT

Serum creatinine is not a sensitive biomarker for neonatal AKI because it is confounded by maternal creatinine level, gestational age, and neonatal muscle mass. In this multicenter cohort study of 52,333 hospitalized Chinese neonates, the authors proposed serum cystatin C-related criteria (CyNA) for neonatal AKI. They found that cystatin C (Cys-C) is a robust and sensitive biomarker for identifying AKI in neonates who are at an elevated risk of in-hospital mortality and that CyNA detects 6.5 times as many cases as the modified Kidney Disease Improving Global Outcomes creatinine criteria. They also show that AKI can be detected using a single test of Cys-C. These findings suggest that CyNA shows promise as a powerful and easily applicable tool for detecting AKI in neonates.

BACKGROUND

Serum creatinine is not a sensitive biomarker for AKI in neonates. A better biomarker-based criterion for neonatal AKI is needed.

METHODS

In this large multicenter cohort study, we estimated the upper normal limit (UNL) and reference change value (RCV) of serum cystatin C (Cys-C) in neonates and proposed cystatin C-based criteria (CyNA) for detecting neonatal AKI using these values as the cutoffs. We assessed the association of CyNA-detected AKI with the risk of in-hospital death and compared CyNA performance versus performance of modified Kidney Disease Improving Global Outcomes (KDIGO) creatinine criteria.

RESULTS

In this study of 52,333 hospitalized neonates in China, Cys-C level did not vary with gestational age and birth weight and remained relatively stable during the neonatal period. CyNA criteria define AKI by a serum Cys-C of ≥2.2 mg/L (UNL) or an increase in Cys-C of ≥25% (RCV) during the neonatal period. Among 45,839 neonates with measurements of both Cys-C and creatinine, 4513 (9.8%) had AKI detected by CyNA only, 373 (0.8%) by KDIGO only, and 381 (0.8%) by both criteria. Compared with neonates without AKI by both criteria, neonates with AKI detected by CyNA alone had an increased risk of in-hospital mortality (hazard ratio [HR], 2.86; 95% confidence interval [95% CI], 2.02 to 4.04). Neonates with AKI detected by both criteria had an even higher risk of in-hospital mortality (HR, 4.86; 95% CI, 2.84 to 8.29).

CONCLUSIONS

Serum Cys-C is a robust and sensitive biomarker for detecting neonatal AKI. Compared with modified KDIGO creatinine criteria, CyNA is 6.5 times more sensitive in identifying neonates at elevated risk of in-hospital mortality.

Magnitude and associated factors of acute kidney injury among preterm neonates admitted to public hospitals in Bahir Dar city, Ethiopia 2022: cross-sectional study

BACKGROUND

Acute kidney injury is an independent risk factor for morbidity and mortality in critically ill neonates. Although the magnitude of preterm neonates is high and a major risk for acute kidney injury, there is a paucity of information regarding the magnitude and associated factors of acute kidney injury among preterm neonates in the study area. Therefore, the aim of this study was to assess magnitude and associated factors of acute kidney injury among preterm neonates admitted to public hospitals in Bahir Dar city, Ethiopia, 2022.

METHODS

An institutional-based cross-sectional study was conducted among 423 preterm neonates admitted to public hospitals in Bahir Dar city from May 27 to June 27, 2022. Data were entered into Epi Data Version 4.6.0.2 transferred to Statistical Package and Service Solution version 26 for analysis. Descriptive and inferential statistics were employed. A binary logistic regression analysis was done to identify factors associated with acute kidney injury. Model fitness was checked through Hosmer-Lemeshow goodness of fit test. Variables with a p-value < 0.05 were considered as statistically significant in the multiple binary logistic regression analysis.

RESULT

Out of 423 eligible, 416 neonatal charts were reviewed with a response rate of 98.3%.This study revealed that the magnitude of acute kidney injury was 18.27% (95% CI = 15-22). Very low birth weight (AOR = 3.26; 95% CI = 1.18-9.05), perinatal asphyxia (AOR = 2.84; 95%CI = 1.55-5.19), dehydration (AOR = 2.30; 95%CI = 1.29-4.09), chest compression (AOR = 3.79; 95%CI = 1.97-7.13), and pregnancy-induced hypertension (AOR = 2.17; 95%CI = 1.20-3.93) were factors significantly associated with the development of neonatal acute kidney injury.

CONCLUSION

Almost one in five admitted preterm neonates developed acute kidney injury. The odds of acute kidney injury were high among neonates who were very low birth weight, perinataly asphyxiated, dehydrated, recipients of chest compression, and born to pregnancy-induced hypertensive mothers. Therefore, clinicians have to be extremely cautious and actively monitor renal function in those neonatal population in order to detect and treat acute kidney injury as early as possible.

The Potential Use of Near- and Mid-Infrared Spectroscopy in Kidney Diseases

Traditional renal biomarkers such as serum creatinine and albuminuria/proteinuria are rather insensitive since they change later in the course of the disease. In order to determine the extent and type of kidney injury, as well as to administer the proper therapy and enhance patient management, new techniques for the detection of deterioration of the kidney function are urgently needed. Infrared spectroscopy is a label-free and non-destructive technique having the potential to be a vital tool for quick and inexpensive routine clinical diagnosis of kidney disorders. The aim of this review is to provide an overview of near- and mid-infrared spectroscopy applications in patients with acute kidney injury and chronic kidney disease (e.g., diabetic nephropathy and glomerulonephritis).

Colistin use in a carbapenem-resistant Enterobacterales outbreak at a South African neonatal unit

Background

Colistin is increasingly prescribed for neonates with carbapenem-resistant Enterobacterales (CRE) infections.

Objectives

We described patient demographics, infection episodes, treatment and clinical outcomes, colistin related adverse events and relatedness of isolates in neonates with clinically confirmed or clinically suspected CRE infections.

Method

The authors retrospectively reviewed culture-confirmed and clinically suspected culture-negative CRE infections at a South African neonatal unit during a CRE outbreak.

Results

Fifty-three neonates (median gestational age 29 weeks and birth weight 1185 g) were included. Twenty-three of 53 neonates (43%) had culture-confirmed CRE (17 received colistin; 6 died without receiving colistin) and 30 (57%) received colistin for clinically suspected CRE infection but were ultimately culture-negative. Prior respiratory support and surgical conditions were present in 37/53 (70%) and 19/53 (36%) neonates, respectively. Crude mortality was high (20/53; 38%) with no significant difference between culture-confirmed CRE versus clinically suspected culture-negative CRE groups (10/23 [44%] vs 10/30 [33%]; p = 0.45). Hypomagnesaemia (10/38; 26%) and hypokalaemia (15/38; 40%) were frequent; acute kidney injury was rare (1/44; 2%). Three CRE infection clusters were identified by genotypic analysis of 20 available isolates (18 [90%] bla _NDM-1 [New Delhi metallo-beta-lactamase], 2 [10%] bla _OXA [oxacillinase]-48).

Conclusion

Neonates receiving colistin therapy were predominantly preterm, with multiple risk factors for infection. Colistin-associated electrolyte derangement was frequent. Over one-third of neonates died. Bla _NDM-1 was the most frequent carbapenemase gene identified in the outbreak isolates.

Contribution

Colistin was safely used during an Enterobacterales outbreak in predominantly premature and surgical neonates. The mortality was high.

Acute Kidney Injury in Very Low Birth Weight Infants: A Major Morbidity and Mortality Risk Factor

BACKGROUND AND OBJECTIVES

Very low birth weight (VLBW) infants are at high risk of developing acute kidney injury (AKI), presumably secondary to low kidney reserves, stressful postnatal events, and drug exposures. Our study aimed to identify the prevalence, risk factors, and outcomes associated with AKI in VLBW infants.

STUDY DESIGN

Records of all VLBW infants admitted to two medical campuses between January 2019 and June 2020 were retrospectively reviewed. AKI was classified using the modified KDIGO definition to include only serum creatinine. Risk factors and composite outcomes were compared between infants with and without AKI. We evaluated the main predictors of AKI and death with forward stepwise regression analysis.

RESULTS

152 VLBW infants were enrolled. 21% of them developed AKI. Based on the multivariable analysis, the most significant predictors of AKI were the use of vasopressors, patent ductus arteriosus, and bloodstream infection. AKI had a strong and independent association with neonatal mortality.

CONCLUSIONS

AKI is common in VLBW infants and is a significant risk factor for mortality. Efforts to prevent AKI are necessary to prevent its harmful effects.

Early urine output monitoring in very preterm infants to predict in-hospital neonatal outcomes: a bicentric retrospective cohort study

OBJECTIVE

To evaluate whether urine output (UO), rarely assessed in the literature, is associated with relevant neonatal outcomes in very preterm infants, and which UO threshold may be the most clinically relevant.

DESIGN

Retrospective cohort study.

SETTING

Two Level IV neonatal intensive care units.

PATIENTS

Very preterm infants born between 24^0/7 and 29^6/7 weeks of gestation documented with eight UO measurements per day between postnatal day 1 and day 7.

MAIN OUTCOME MEASURES

Composite outcome defined as death before discharge, or moderate to severe bronchopulmonary dysplasia, or severe brain lesions. The association between this outcome and UO was studied using several UO thresholds.

RESULTS

Among 532 infants studied, UO <1.0 mL/kg/hour for at least 24 consecutive hours was measured in 55/532 (10%) infants and the primary outcome was recorded in 25 patients. The association between a UO threshold <1.0 mL/kg/hour and the primary outcome was found marginally significant (crude OR 1.80, 95% CI 1.02 to 3.16, p=0.04). The primary outcome was recorded in 112/242 (46%) patients with a UO <2.0 mL/kg/hour and only 64/290 (22%) patients with a UO ≥2.0 mL/kg/hour (p<0.001). This UO threshold was found significantly associated with the primary outcome (crude OR 3.1, 95% CI 2.1 to 4.7, p<0.001), an association confirmed using a multivariate logistic regression model including baseline covariates (adjusted OR 3.7, 95% CI 2.2 to 6.4, p<0.001).

CONCLUSION

A UO <2 mL/kg/hour over 24 hours between postnatal day 1 and day 7 strongly predicts neonatal mortality or severe morbidities in very preterm infants.

Blood pressure and kidney function in neonates and young infants with intrauterine growth restriction

BACKGROUND

Intrauterine growth restriction (IUGR) has been associated with changes in kidney anatomy, nephrogenesis and the vascular system, resulting in secondary arterial hypertension and kidney damage in adulthood. Here, we compare routine clinical and metabolic parameters between IUGR and non-IUGR study participants in the neonatal and early infant period.

METHODS

A total of 39 IUGR and 60 non-IUGR neonates were included during an 18-month study period. We compared blood pressure, serum creatinine (SCr), urea nitrogen (BUN), urinary albumin, α-1-microglobulin, transferrin, immunoglobulin G and total protein excretion in spontaneous urine normalized by urine creatinine level during the hospital stay.

RESULTS

There were no significant differences in mean values of blood pressure and urinary protein excretion between cases and controls. SCr and BUN levels were lower in the IUGR group compared to the non-IUGR group.

CONCLUSIONS

The lower levels of SCr and BUN may be attributed to lower liver and muscle mass in IUGR neonates and young infants. Biomarkers currently used in routine clinical care do not allow early postnatal prediction of higher blood pressure or worse kidney function due to IUGR, so further studies are needed. A higher resolution version of the Graphical abstract is available as Supplementary information.

Analysis of risk factors for death in 59 cases of critically ill neonates receiving continuous renal replacement therapy: a two-centered retrospective study

To investigate the risk factors for death in critically ill neonates receiving continuous renal replacement therapy (CRRT). This retrospective study analyzed the clinical data of critically ill neonates receiving CRRT at two tertiary hospitals from January 2015 to December 2021. A multi-factor logistic regression analysis was performed, and the predictive value of relevant risk factors on death was verified by receiver operating characteristic (ROC) curve. A total of 59 cases of critically ill neonates were included in this study, with a mortality of 37.3%. The most common primary disease in these cases was neonatal sepsis, followed by neonatal asphyxia, and inborn errors of metabolism (IEM). Univariate analysis showed that the risk factors related to death included primary diseases; the number of organs involved in multiple organ dysfunction syndrome (MODS), neonatal critical illness scores (NCIS), and indications of CRRT; the blood lactate, blood glucose, hemoglobin, and platelet before CRRT initiation; and the incidence of bleeding or thrombosis during CRRT. Multi-factor logistic regression analysis showed that risk factors for death in critically ill neonates receiving CRRT included the occurrence of neonatal sepsis, the number of organs involved in MODS, and the NCIS. ROC curve analysis showed that the number of organs involved in MODS and NCIS had a good predictive value for death in critically ill neonates receiving CRRT, with the areas under the curve (AUC) being 0.700 and 0.810, respectively.

CONCLUSION

Neonatal sepsis, the number of organs involved in MODS, and NCIS were independent risk factors for death in critically ill neonates receiving CRRT. Moreover, the number of organs involved in MODS and NCIS could effectively predict death in critically ill neonates receiving CRRT.

WHAT IS KNOWN

• The population to which CRRT is applicable is gradually expanding from critically ill children to critically ill neonates. • The mortality of critically ill neonates receiving CRRT remains high.

WHAT IS NEW

• The most common primary disease in critically ill neonates receiving CRRT was neonatal sepsis, followed by neonatal asphyxia and inborn errors of metabolism (IEM). • The number of organs involved in MODS and NCIS could effectively predict death in critically ill neonates receiving CRRT.

Renal oxygenation measured by near-infrared spectroscopy in preterm neonates in the first week

OBJECTIVE

To describe renal regional saturation of oxygen (RrSO₂) values during the first week of life for preterm neonates born at <32 weeks gestational age (GA).

METHODS

RrSO₂ values recorded over the first week of life using near-infrared spectroscopy were retrospectively analyzed in this two-center cohort study of preterm infants without known congenital anomalies of the kidney.

RESULTS

A cohort of 109 neonates with a median GA of 26.9 weeks and a median of 120 (IQR: 87-141) hours of continuous RrSO₂ monitoring were included. Separately fitted trends in RrSO₂ did not differ (p = 0.52) between sites and demonstrated a consistent decrease in RrSO₂ by 20 points (95% CI: 9.6-30.1) during the first 60 h of life, followed by a stabilization of RrSO₂ thereafter. RrSO₂ baseline trends increased by 2.1 (95% CI: 0.8-3.3) percentage points for each additional week GA between 24 and 32 weeks GA.

CONCLUSIONS

Despite differences in adjusted RrSO₂ values between sites, profiles over time are consistent, allowing for the determination of RrSO₂ trajectories in preterm infants. This expected pattern of RrSO₂ changes in the first week may help guide future investigations and interventions to identify and reduce kidney injury in the preterm neonate.

IMPACT

Renal regional saturation of oxygen (RrSO₂) slowly decreases during the first 60 h of age in <32-week preterm neonates. While site differences were identified with respect to absolute values, RrSO₂ trends from two different centers were not different. Lower gestational age neonates have lower RrSO₂ levels during the first week.

Development and anatomo-physiological features of kidneys in premature newborns

A premature baby in need of resuscitation after birth is exposed to damaging factors that affect the entire body, including the kidneys. The review considers the stages of development and identifies the main anatomical and physiological features of the kidneys in premature babies. The main risk factor for the development of pathology associated with immaturity of the kidneys in preterm infants is imperfect glomerular and tubular functions of the kidneys, a large capillary surface of the kidneys, high renal blood flow, imperfect regulation of the acid-base balance, and the ability to concentrate, which become untenable under the influence of external loads. Any damaging factor in the antenatal period in premature infants, considering the anatomical and physiological characteristics and the imperfect compensatory response from the kidneys, can permanently change the structure of the kidneys, which will lead to the development of chronic kidney disease in the future. Proper management of premature newborns, considering the anatomical and physiological characteristics of the kidneys, will significantly reduce the risk of severe complications and mortality among premature newborns, and improve the long-term clinical prognosis in such children. 

Renal versus cerebral saturation trajectories: the perinatal transition in preterm neonates

BACKGROUND

The aim of this study was to develop reference renal saturation (rSrO₂) curves in premature infants, depict how they differ from cerebral saturation (rScO₂) curves, and evaluate the effect of blood pressure on these values using near-infrared spectroscopy (NIRS).

METHODS

This is a prospective cohort study of 57 inborn infants <12 h and <30 weeks gestation. rScO₂, rSrO₂, fractional tissue oxygen extraction (FTOE), and mean arterial blood pressure (MAP) were continuously monitored every 30 s for 96 h. Quantile regression was used to establish nomograms, and mean saturation values were evaluated for different MAP ranges.

RESULTS

Median rSrO₂ at the start of monitoring was ~10% higher than rScO₂. rSrO₂ showed a significant decline over time while rScO₂ peaked at 26 h. FTOE demonstrated a similar but inverse trend to their saturation counterparts. rScO₂ declined as MAP increased, while rSrO2 showed a peak and decline as MAP increased.

CONCLUSIONS

We provide rSrO₂ reference curves for the first 4 days of life, which differ in their trajectory from rScO₂ and from what has previously been reported for rSrO₂ in the full-term population. In addition, we observed a peak and decline in renal saturation with increasing MAP, suggesting a renovascular response to blood pressure changes.

IMPACT

This article depicts reference renal saturation curves during the perinatal transition in preterm infants. We show how renal saturation compares to cerebral saturation trends over time. We describe a peak and decline in renal saturation with increasing MAP, suggesting a renovascular response to blood pressure changes.

Early indicators of neonatal-onset hereditary thrombotic thrombocytopenia purpura

Background

Neonatal‐onset hereditary thrombotic thrombocytopenia purpura (hTTP) is often misdiagnosed due to its rarity. It begins with jaundice, similar to infants with ABO incompatibility.

Objective

To explore early indicators of neonatal‐onset hTTP.

Methods

This study was a retrospective case series of newborns with hTTP and ABO incompatibility. We compared the clinical characteristics and laboratory test results in these two groups.

Results

This study included four hTTP patients and 20 ABO‐incompatible newborns. All patients manifested disease during the neonatal period. There were equal numbers of males and females in each group. hTTP newborns showed earlier (median difference, 57.0 h; 95% confidence interval [CI], 24.0–65.0) and more severe hyperbilirubinemia (mean difference, 8.0 mg/dl; 95% CI, 3.8–12.1) than ABO‐incompatible newborns. In hTTP newborns, anemia was more common within 7 days after birth than in ABO‐incompatible newborns (odds ratio, 25.4; 95% CI, 1.2–551.6), and platelet counts were lower than in ABO‐incompatible newborns (17 ± 12 × 10⁹/L vs. 291 ± 76 × 10⁹/L). The levels of serum creatinine (median difference, 51.8 μmol/L; 95% CI, 16.0–109.4) and blood urea nitrogen (median difference, 5.7 mmol/L; 95% CI, 2.8–38.7) were higher in hTTP newborns than in ABO‐incompatible newborns. There were no significant differences in white blood cell counts, C‐reactive protein, alanine aminotransferase, or albumin levels.

Conclusions

Severe jaundice soon after birth, early anemia, and severe thrombocytopenia were more common in newborns with hTTP than ABO incompatibility. These are distinguishing early features of hTTP.

Contribution of Serial Focused High-Resolution Renal Ultrasound in the Management of a Neonate in Acute Renal Failure

Most newborns begin urinating within 24hours of life, and almost always by 48hours. Rarely, some of them are anuric beyond 24hours, thereby causing concern to parents and treating doctors. We report the case of a newborn who presented with anuria till 48hours after birth. High-resolution ultrasound examination, focusing on the renal medulla, demonstrated increased echogenicity at the tip of the pyramids. This was attributed to slow clearance of urinary sediment deposited there, which was causing obstruction to the urinary outflow. On monitoring serially over the next few days, the echogenic sludge was observed being slowly eliminated leading thereby to improvement in the urinary output. High-resolution ultrasound focusing on the renal pyramids played an important role in the observation and management of this transient event unfolding, in the urinary tract.

Urine Output Monitoring for the Diagnosis of Early-Onset Acute Kidney Injury in Very Preterm Infants

BACKGROUND AND OBJECTIVES

The current threshold used for oliguria in the definition of neonatal AKI has been empirically defined as 1 ml/kg per hour. Urine output criteria are generally poorly documented, resulting in uncertainty in the most accurate threshold to identify AKI in very preterm infants with known tubular immaturity.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a bicentric study including 473 very preterm infants (24^0/7-29^6/7 weeks of gestation) born between January 2014 and December 2018 with urine output measurements every 3 hours during the first 7 days of life and two serum creatinine measurements during the first 10 days of life. AKI was defined using the neonatal Kidney Disease Improving Global Outcomes (KDIGO) definition. We tested whether higher urine output thresholds (1.5 or 2 ml/kg per hour) in modified AKI definitions may better discriminate neonatal mortality compared with the current definition.

RESULTS

Early-onset AKI was developed by 101 of 473 (21%) very preterm infants. AKI was diagnosed on the basis of urine output criteria alone (no rise in creatinine) for 27 of 101 (27%) participants. Early-onset AKI was associated with higher risk of death before discharge (adjusted odds ratio, 3.9; 95% confidence interval, 1.9 to 7.8), and the AKI neonatal KDIGO score showed good discriminative performance for neonatal mortality, with an area under the receiver operating characteristic (ROC) curve of 0.68 (95% confidence interval, 0.61 to 0.75). Modified AKI definitions that included higher urine output thresholds showed significantly improved discriminative performance, with areas under the ROC curve of 0.73 (95% confidence interval, 0.66 to 0.80) for the 1.5-ml/kg per hour threshold and 0.75 (95% confidence interval, 0.68 to 0.81) for the 2-ml/kg per hour threshold.

CONCLUSIONS

Early-onset AKI was diagnosed on the basis of urine output exclusively for a quarter of the cases. Furthermore, modified AKI definitions that included higher urine output improved the discriminative performance for predicting mortality.

When the progresses in neonatology lead to severe congenital nephron deficit: is there a pilot in the NICU?

Advances in the care of neonates to the extreme limits of viability have increased the risk of severe comorbidities in surviving preemies. The respiratory and the neurodevelopmental consequences of premature birth and/or intra-uterine growth retardation have been well described. Because of the usual clinical silence of the kidney, the long-term renal consequences of low birth weight have not been as well studied. A case report illustrates the risk factors associated with low birth weight and prematurity and discusses the pathogenesis of the late consequences of the congenital nephron deficit associated with a low birth weight. Practical recommendations are given for a tight follow-up of these newly born preemies.

Impact of nephrotoxic drugs on urinary biomarkers of renal function in very preterm infants

BACKGROUND

Following preterm birth, the immature kidney is exposed to several harmful conditions, with an increased risk of renal impairment. We aimed to assess urinary biomarkers of renal function in very preterm infants during early nephrotoxic treatments.

METHODS

Infants ≤32 weeks' gestation and ≤1500 g were enrolled in this observational prospective study. Urine samples were collected on day 1(T1), 2-4(T2), 5-7(T3), 8-10(T4), 11-13(T5). The following urinary biomarkers were determined: osteopontin (uOPN), epidermal growth factor (uEGF), neutrophil gelatinase-associated lipocalin (uNGAL), cystatin C (uCysC). The infants were grouped according to their exposure to amikacin or ibuprofen during the study period and a between-group comparison of urinary biomarkers at each time point was performed.

RESULTS

Thirty-six infants were included. Urinary CysC, uOPN, and uNGAL rose significantly during ibuprofen or amikacin treatment, while no difference was observed for uEGF. After adjustment for possible influencing factors, amikacin administration was associated with higher uCysC at T1 (p = 0.007) and T2 (p = 0.016), whereas ibuprofen increased uOPN (p = 0.001) and uNGAL concentration (p = 0.009) at T3.

CONCLUSION

Nephrotoxic therapies induce molecule-specific change patterns of renal function biomarkers in treated preterm infants. Serial assessments of these biomarkers may aid to identify neonates at risk of renal impairment and to develop tailored therapeutic approaches.

IMPACT

Despite the wide use of nephrotoxic therapies in neonatal settings, little is known on their effect on renal function biomarkers in preterm infants. This study describes molecule-specific change patterns of urinary biomarkers during ibuprofen and amikacin administration, suggesting underlying pathophysiological effects on renal function. Given their low analytical costs and non-invasive collection, the urinary biomarkers investigated in this study represent a promising strategy for serial monitoring of renal function in at-risk neonates and may aid the early detection of renal function impairment at different kidney levels during nephrotoxic treatments.

Fluid and Electrolyte Management in the Neonate: Sodium and Chloride

Maintenance of electrolyte balance in the neonate is a challenge in the context of illness or prematurity. Neonatal providers' approach to fluid management changes and adapts based on the newborn's age, maintenance needs, deficits, and ongoing losses. Understanding the total body water content of the fetus and newborn is foundational to management of electrolyte disturbances. This article reviews common imbalances of sodium and chloride, identifies causes of imbalances, and discusses current evidence-based treatment options.

Detection of Acute Kidney Injury in Neonates after Cardiopulmonary Bypass

Cardiac surgery-associated acute kidney injury (CS-AKI) in neonates has been associated with poor outcomes. Early detection and intervention of acute kidney injury (AKI) are needed in order to mitigate some of these sequalae. Currently, serum creatinine (SCr) remains the gold standard for AKI diagnosis; however, changes are not seen until days after injury thus delaying the diagnosis. Serum creatinine in neonates varies based on multiple factors such as prematurity, the presence of maternal SCr and renal tubule immaturity. Acute kidney injury biomarkers, such as neutrophil gelatinase-associated lipocalin (NGAL), are useful for early AKI diagnosis. In addition to SCr and AKI biomarkers, a risk-based assessment of neonates at risk for CS-AKI could prove useful for early AKI diagnosis and intervention.

Inadvertent hypothermia and acute kidney injury (AKI) in neonates undergoing gastrointestinal surgeries: a retrospective study

OBJECTIVE

The purpose of our study was to evaluate the association between intraoperative hypothermia and AKI in neonates undergoing gastrointestinal surgeries.

STUDY DESIGN

This retrospective study was conducted for neonates who underwent gastrointestinal surgeries from June 2018 to August 2020. Neonates with a minimum of two documented creatinine values before and after surgical procedures within 48 h were included. According to the mean intraoperative temperature, the eligible neonates were divided into three groups. The primary outcome was the incidence of AKI (as defined by the modified KDIGO criteria). The association between variables and AKI or hospital mortality was also examined.

RESULTS

A total of 295 neonates fulfilled the eligibility criteria. AKI was more common in patients with lower intraoperative temperature compared to the normothermia group. Intraoperative mean temperature was independently associated with AKI. Patients developing AKI had a higher hospital mortality. AKI and gestational age were independently associated with hospital mortality.

CONCLUSIONS

Inadvertent intraoperative hypothermia was associated with developing postoperative AKI.

Why Are Bifidobacteria Important for Infants?

The presence of Bifidobacterium species in the maternal vaginal and fecal microbiota is arguably an evolutionary trait that allows these organisms to be primary colonizers of the newborn intestinal tract. Their ability to utilize human milk oligosaccharides fosters their establishment as core health-promoting organisms throughout life. A reduction in their abundance in infants has been shown to increase the prevalence of obesity, diabetes, metabolic disorder, and all-cause mortality later in life. Probiotic strains have been developed as supplements for premature babies and to counter some of these ailments as well as to confer a range of health benefits. The ability to modulate the immune response and produce short-chain fatty acids, particularly acetate and butyrate, that strengthen the gut barrier and regulate the gut microbiome, makes Bifidobacterium a core component of a healthy infant through adulthood.

Perspectives: Neonatal acute kidney injury (AKI) in low and middle income countries (LMIC)

Neonatal AKI (NAKI) remains a challenge in low- and middle-income countries (LMICs). In this perspective, we address issues of diagnosis and risk factors particular to less well-resourced regions. The conservative management pre-kidney replacement therapy (pre-KRT) is prioritized and challenges of KRT are described with improvised dialysis techniques also included. Special emphasis is placed on ethical and palliation principles.

Urinary beta-2 microglobulin as an early predictive biomarker of acute kidney injury in neonates with perinatal asphyxia

To evaluate the role of urinary beta-2 microglobulin (B2mG) as an early predictive biomarker of acute kidney injury (AKI) in neonates with perinatal asphyxia. In this prospective cohort study, 80 term infants with perinatal asphyxia were included. The neonates were divided into AKI and no-AKI groups. Urinary B2mG levels were measured at 24 h of life. The diagnostic efficacy of the biomarker was determined using receiver operating characteristic (ROC) curves. Compared to infants without AKI, infants with AKI had higher levels of urinary B2mG (mean 6.8 versus 2.6 mg/L, p < 0.001). Area under the receiver operating characteristic curve (ROC curve) was 0.944. The balanced sensitivity/specificity trade-off was found at a cut-off value of 3.8 mg/L (81% sensitive and 81.6% specific).Conclusion Urinary B2mG can be useful to predict AKI early in term neonates with perinatal asphyxia. What is Known: • AKI is seen in 20-40% of neonates with asphyxia. • AKI affects the treatment plan and the prognosis of such neonates. What is New: • Urinary biomarkers are the easiest way to diagnose AKI in asphyxiated neonates. • Beta 2 microglobulin is the cheapest and readily available one such urinary biomarker with good sensitivity and specificity.

Assessment of the diagnostic ability of rifle classification and neutrophil gelatinase-associated lipocalin biomarker in detecting acute kidney injury in newborns at the intensive care unit

Introduction/Objective. This study was designed to demonstrate the association of the RIFLE classification and neutrophil gelatinase-associated lipocalin (NGAL) in predicting of newborns with AKI. Methods. This was a prospective study. We included 100 newborns suspected of having a kidney injury. These newborns were admitted to the Intensive Care Unit (ICU) at the University Clinic of Pediatrics from the period of two years. The severity of the disease was determined by RIFLE classification. The biochemical marker NGAL was included in this study because it is an early biomarker of AKI in newborns. The statistical processing of the material was by methods of descriptive statistics. Results. The prevalence rate of AKI was 6.25%, but according to the RIFLE classification the prevalence was 8.7%. According to RIFLE classification, we reported "risk" in 36%, "injury? in 50% and ?failure" in 14% of newborns with AKI. In newborns with perinatal asphyxia, kidney injury was seen in 34% and 30%, making perinatal asphyxia the most common predisposing factor. The difference in average value from the SNAPPE 2 result in newborns with AKI and the control group without AKI was confirmed to be significant (p < 0.001). Also, there was a significant difference p<0.001 between serum creatinine and urinary NGAL values NGAL, on the day they were admitted to the ICU. Conclusion. In newborns hospitalized in the ICU, acute renal injury is a serious condition. We could identify kidney injury and follow up the progression of the disease by using RIFLE classification. The need for early diagnosis of kidney injury, in a period when the disease is not clinically manifest, in the first hours of its occurrence, is provided by NGAL.

Novel strategy to personalise use of ibuprofen for closure of patent ductus arteriosus in preterm neonates

OBJECTIVE

Exploration of a novel therapeutic drug monitoring (TDM) strategy to personalise use of ibuprofen for closure of patent ductus arteriosus (PDA) in preterm neonates.

DESIGN

Prospective, single-centre, open-label, pharmacokinetics study in preterm neonates.

SETTING

Neonatal intensive care unit at McMaster Children's Hospital.

PATIENTS

Neonates with a gestational age ≤28⁺⁶ weeks treated with oral ibuprofen for closure of a PDA.

METHODS

Population pharmacokinetic parameters, concentration-time profiles and exposure metrics were obtained using pharmacometric modelling and simulation.

MAIN OUTCOME MEASURE

Association between ibuprofen plasma concentrations measured at various sampling time points on the first day of treatment and attainment of the target exposure over the first 3 days of treatment (AUC_0-72h >900 mg·hour/L).

RESULTS

Twenty-three preterm neonates (median birth weight 780 g and gestational age 25.9 weeks) were included, yielding 155 plasma ibuprofen plasma samples. Starting from 8 hours' postdose on the first day, a strong correlation between ibuprofen concentrations and AUC_0-72h was observed. At 8 hours after the first dose, an ibuprofen concentration >20.5 mg/L was associated with a 90% probability of reaching the target exposure.

CONCLUSION

We designed a novel and practical TDM strategy and have shown that the chance of reaching the target exposure (AUC_0-72h >900 mg·hour/L) can be predicted with a single sample collection on the first day of treatment. This newly acquired knowledge can be leveraged to personalise ibuprofen dosing regimens and improve the efficacy of ibuprofen use for pharmacological closure of a PDA.

Neonatal AKI profile using KDIGO guidelines: A cohort study in tertiary care hospital ICU of Lahore, Pakistan

BACKGROUND AND OBJECTIVE

Acute kidney injury (AKI) was observed in sick neonates and was associated with poor outcomes. Our cohort represents the neonatal characteristics of those diagnosed with AKI using Kidney Disease: Improved Global Outcome (KDIGO) guidelines.

METHODOLOGY

A cohort study was conducted in the NICU of FMH from June 2019 to May 2021. Data were collected on a proforma. All continuous variables were not normally distributed and expressed as the median and interquartile range. Categorical variables were analyzed by proportional differences with the Pearson chi-square test or Fisher's exact tests. A multinomial logistic regression model was used to explore the independent risk factors for AKI. Time to the event (death) and the cohort's survival curves were plotted using the Cox proportional hazard model.

RESULTS

AKI occurred in 473 (37.6%) neonates. The risk factors of AKI were outborn birth [adjusted odds ratio (AOR): 3.987, 95% confidence interval (CI): 2.564-6.200, p: 0.000], birth asphyxia (AOR: 3.567, 95% CI: 2.093-6.080, p: 0.000), inotropic agent (AOR: 2.060, 95% CI: 1.436-2.957, p: 0.000), antenatal steroids (AOR: 1.721, 95% CI: 1.213-2.443, p: 0.002), central lines (AOR: 1.630, 95% CI: 1.155-2.298, p: 0.005) and intraventricular hemorrhage (IVH)/intracranial hemorrhage/disseminated intravascular coagulopathy (AOR: 1.580, 95% CI: 1.119-2.231, p: 0.009). AKI significantly increases the duration of stay and mortality rates by 16.5% vs. 3.9% in neonates with normal renal function (p < 0.001).

CONCLUSION

About one-third of critically sick neonates had AKI. Significant risk factors for AKI were outborn birth, asphyxia inotropic agents, necrotizing enterocolitis, antenatal steroids central lines, and IVH. AKI is associated with an increased length of stay and increased mortality.

Management of Acute Kidney Injury in Extremely Low Birth Weight Infants

Acute kidney injury (AKI) is a common problem in the neonatal intensive care unit (NICU). Neonates born at <1,000 g (extremely low birth weight, ELBW) are at an increased risk of secondary associated comorbidities such as intrauterine growth restriction, prematurity, volume restriction, ischaemic injury, among others. Studies estimate up to 50% ELBW infants experience at least one episode of AKI during their NICU stay. Although no curative treatment for AKI currently exists, recognition is vital to reduce potential ongoing injury and mitigate long-term consequences of AKI. However, the definition of AKI is imperfect in this population and presents clinical challenges to correct identification, thus contributing to under recognition and reporting. Additionally, the absence of guidelines for the management of AKI in ELBW infants has led to variations in practice. This review summarizes AKI in the ELBW infant and includes suggestions such as close observation of daily fluid balance, review of medications to reduce nephrotoxic exposure, management of electrolytes, maximizing nutrition, and the use of diuretics and/or dialysis when appropriate.

Prostaglandin signaling in ciliogenesis and development

Prostaglandin (PG) signaling regulates a wide variety of physiological and pathological processes, including body temperature, cardiovascular homeostasis, reproduction, and inflammation. Recent studies have revealed that PGs play pivotal roles in embryo development, ciliogenesis, and organ formation. Prostaglandin E2 (PGE2) and its receptor EP4 modulate ciliogenesis by increasing the anterograde intraflagellar transport. Many G-protein-coupled receptors (GPCRs) including EP4 are localized in cilia for modulating cAMP signaling under various conditions. During development, PGE2 signaling regulates embryogenesis, hepatocyte differentiation, hematopoiesis, and kidney formation. Prostaglandins are also essential for skeletal muscle repair. This review outlines recent advances in understanding the functions and mechanisms of prostaglandin signaling in ciliogenesis, embryo development, and organ formation.

Goose nephritic astrovirus infection increases autophagy, destroys intercellular junctions in renal tubular epithelial cells, and damages podocytes in the kidneys of infected goslings

Goose nephritic astrovirus (GNAstV) has recently been identified, which causes kidney swelling and visceral gout in goslings. However, the pathological changes in kidney tissue due to GNAstV infection have not yet been described. In the study, fifty goslings were orally infected with GNAstV, and fifty goslings received PBS as a control. Kidney tissue was collected at different days following infection (dpi) to assess the injury. GNAstV infection reduced body weight, increased the relative weight of the kidney, and increased serum uric acid and creatinine levels. GNAstV was found within renal epithelial cells, and the viral load in the kidney peaked at 7 dpi. Pale and swollen kidney tissue was observed in infected goslings, especially at 5 and 7 dpi. GNAstV infection caused degeneration and necrosis of renal epithelial cells, structural destruction of the brush border, glycogen deposition in the glomerular mesangium, increased fibrosis, and infiltration of inflammatory cells into the renal interstitium. Moreover, swollen mitochondria, broken mitochondrial ridges, autophagosomes, and autophagolysosomes were observed under ultrahistopathological examination. GNAstV infection increased levels of LC3B, ATG5, and Beclin 1, and decreased p62, and downregulated WT1 mRNA and upregulated desmin mRNA. At early stages, GNAstV infection decreased expression of intercellular junction-related genes, including ZO-1, occludin, claudin-10, and catenin-α2. In conclusion, GNAstV infection causes renal epithelial cell autophagy, destruction of brush border and intercellular junctions, podocyte damage, and increased fibrosis, ultimately resulting in damage to the kidney.

Renal biomarkers of acute kidney injury in response to increasing intermittent hypoxia episodes in the neonatal rat

BACKGROUND

We tested the hypotheses that: 1) early exposure to increasing episodes of clinically relevant intermittent hypoxia (IH) is detrimental to the developing kidneys; and 2) there is a critical number of daily IH episodes which will result in irreparable renal damage that may involve angiotensin (Ang) II and endothelin (ET)-1.

METHODS

At birth (P0), neonatal rat pups were exposed to brief IH episodes from the first day of life (P0) to P7 or from P0-P14. Pups were either euthanized immediately or placed in room air (RA) until P21. RA littermates served as controls. Kidneys were harvested at P7, P14, and P21 for histopathology; angiotensin converting enzyme (ACE), ACE-2, ET-1, big ET-1, and malondialdehyde (MDA) levels; immunoreactivity of ACE, ACE-2, ET-1, ET-2, ET receptors (ETAR, ETBR), and hypoxia inducible factor (HIF)1α; and apoptosis (TUNEL stain).

RESULTS

Histopathology showed increased renal damage with 8-12 IH episodes/day, and was associated with Ang II, ACE, HIF1α, and apoptosis. ACE-2 was not expressed at P7, and minimally increased at P14. However, a robust ACE-2 response was seen during recovery with maximum levels noted in the groups recovering from 8 IH episodes/day. ET-1, big ET-1, ETAR, ETBR, and MDA increased with increasing levels of neonatal IH.

CONCLUSIONS

Chronic neonatal IH causes severe damage to the developing kidney with associated elevations in vasoconstrictors, suggesting hypertension, particularly with 8 neonatal IH episodes. ACE-2 is not activated in early postnatal life, and this may contribute to IH-induced vasoconstriction. Therapeutic targeting of ACE and ET-1 may help decrease the risk for kidney injury in the developing neonate to prevent and/or treat neonatal acute kidney injury and/or chronic kidney disease.

Prediction of risk factors and outcomes of neonatal acute kidney injury

Introduction

Neonatal Acute kidney injury (AKI) is an underestimated morbidity in the neonatal intensive care unit (ICU). However, there is a paucity of information about risk factors, outcomes, and possible preventive measures to limit its occurrence.

Aim

This study aimed to determine the prevalence of neonatal AKI in a neonatal ICU. Data obtained from this study will help to better understand current local practices and investigate possible preventive strategies.

Materials and methods

Charts from January 2011 to December 2018 were reviewed. Neonates less than 2 weeks old who depended on intravenous fluid as a nutrition source for at least two days were included.

Results

Overall, the eight-year prevalence of neonatal AKI in the neonatal ICU was 19.6%, and severity was distributed as follows: stage 1 (46.2%), stage 2 (26.5%), and stage 3 (27.3%). Caffeine administration before 29 weeks’ gestational age significantly decreased the incidence of neonatal AKI. The incidence of neonatal AKI was independently associated with death (odds ratios (OR) = 7.11, P < 0.001) and extended length of hospital stay (OR = 2.47, P < 0.001). In the multivariate regression model, vancomycin (AOR = 1.637, P < 0.004), loop diuretics (AOR = 2.203, P < 0.001), intraventricular hemorrhage (AOR = 2.605, P < 0.001), surgical intervention (AOR = 1.566, P < 0.008), mechanical ventilation (AOR = 1.463, P < 0.015), and dopamine administration (AOR = 2.399, P < 0.001) were independently associated with neonatal AKI.

Conclusion

Neonatal AKI occurred in one-fifth of the study population in a neonatal ICU. Outcomes can be improved by identifying high-risk infants and cautiously monitoring kidney function.

Use of diuretics in the neonatal period

The use of diuretics is extremely frequent in sick neonates, the more so in very premature newborn infants. The use of diuretics in patients whose kidney function is immature necessitates a thorough knowledge of renal developmental physiology and pathophysiology. This review presents the basic aspects of body fluid homeostasis in the neonate, discusses the development of kidney function, and describes the mechanisms involved in electrolyte and water reabsorption along the nephron. Diuretics are then classified according to the site of their action on sodium reabsorption. The use of diuretics in sodium-retaining states, in oliguric states, in electrolyte disorders, and in arterial hypertension, as well as in a few specific disorders, is presented. Common and specific adverse effects are discussed. Recommended dosages for the main diuretics used in the neonatal period are given. New developments in diuretic therapy are briefly mentioned.

Renal Oxygenation (rSO2) Population Parameter Estimates in Premature Infants Routinely Monitored With Near-Infrared Spectroscopy

BACKGROUND

Currently, reference ranges for renal oxygenation measured by near-infrared spectroscopy (NIRS) in preterm infants beyond the first days of life are lacking, especially those born prior to 29 weeks' gestation. Population estimates of renal oxygenation (rSO2) levels among preterm infants over time have yet to be established, leading to reluctance in clinical application.

PURPOSE

To characterize the distribution and estimate population parameters for renal oxygenation measured by NIRS during the first 14 days of life among preterm infants.

METHODS

We prospectively observed rSO2 trends of 37 infants before 34 weeks' gestation and 1800-g or less birth weight for the first 14 days of life. Analyses included distribution fit tests, ordinary least squares (OLS) regression, and t tests.

RESULTS

Average daily rSO2 variation steadily increased with 42% difference through the first 14 days of life. For all infants, renal rSO2 means peaked during the first 3 days of life and plateaued around 7 days. Daily rSO2 slopes were significantly lower among males and infants 29 weeks' or less gestation.

IMPLICATIONS FOR PRACTICE

Renal rSO2 during the first 14 days of life reflects normal extrauterine transition reaching stabilization around 7 days of life. Gestational age, birth weight, and gender may predict the early trajectory of rSO2 patterns. Population estimates provide parameters for renal rSO2 that may indicate early-onset tissue hypoxia when acute or significant drops from baseline occur.

IMPLICATIONS FOR RESEARCH

We present a framework to guide future research using renal NIRS technology in preterm infants to determine deviations from expected trends that may precede renal injury.