Acute kidney injury in preterm infants admitted to a neonatal intensive care unit

Risk factors for acute kidney injury in preterm neonates after noncardiac surgery: a single-center retrospective cohort study

Postoperative acute kidney injury (AKI) is a common complication that is associated with chronic kidney disease, early postsurgical mortality, and prolonged hospital stays. Preterm neonates who undergo surgery are at risk factors for AKI due to underdeveloped kidneys. To date, little is known about the incidence and perioperative risk factors for AKI in preterm neonates undergoing noncardiac surgery. Preterm neonates who underwent noncardiac surgery between January May 1, 2020, and February 28, 2023, were enrolled in the trial according to the inclusion criteria. Both multivariable and logistic regression analyses were used to analyze the associations between characteristic data and AKI. In total, 106 preterm neonates met the inclusion criteria, and 25 preterm neonates (23.6%) developed postoperative AKI. Multivariate analysis revealed that the factors associated with AKI were gestational age < 32 weeks [OR: 4.88; 95% CI (1.23-19.42)], preoperative sepsis [OR: 3.98; 95% CI (1.29-12.28)], and intraoperative hypotension [OR: 3.75; 95% CI (1.26-11.15)]. Preterm neonates who developed AKI were more likely to have longer hospital length of stays (38 [18,69] days vs. 21[12,46]) and higher medical costs (93,181.6 [620450.0,173,219.0] ￥ vs. 58,134.6 [31015.1,97,224,1) ￥ than neonates who did not develop AKI. Preterm neonates who underwent noncardiac surgery had a high incidence of AKI. Independent risk factors for AKI in preterm neonates who underwent noncardiac surgery were low gestational age, preoperative sepsis, and intraoperative hypotension. Preterm neonates who developed AKI were more likely to have longer hospital stays and higher medical costs.

Incidence and predictors of acute kidney injury among asphyxiated neonates in comprehensive specialized hospitals, northwest Ethiopia, 2023

Acute kidney injury (AKI) is characterized by a sudden decline in the kidneys' abilities to remove waste products and maintain water and electrolyte homeostasis. This study aims to determine the incidence and predictors of acute kidney injury among neonates with perinatal asphyxia admitted at the neonatal intensive care unit of West Amhara Comprehensive Specialized Hospital, Northwest Ethiopia, 2023. Multicentred institution-based retrospective follow-up study was conducted from October 1, 2021, to September 30, 2023, among 421 perinatal asphyxia neonates. A simple random sampling technique was used. The data were collected using a data extraction checklist from the medical registry of neonates. The collected data were entered into EPI-DATA V.4.6.0.0. and analyzed using STATA V.14. The Kaplan-Meier failure curve and log-rank test were employed. Bivariable and multivariable Cox regression was carried out to identify predictors of Acute kidney injury. Statistical significance was declared at a p ≤ 0.05. The overall incidence of AKI was 54 (95% CI 47.07-62.51) per 100 neonate days. C/S delivery (AHR = 0.64; (95% CI 0.43-0.94), prolonged labor (AHR = 1.43; 95% CI 1.03-1.99) low-birth weight times (AHR = 1.49; (95% CI 1.01-2.20), stage three HIE(AHR: 1.68; (95% CI (1.02-2.77), No ANC follow up (AHR = 1.43; 95% CI 1.9 (1.07-3.43) and Hyperkalemia (AHR = 1.56; 95% CI 1.56 (1.05-2.29); 95% CI) were significant predictors. The incidence rate of acute kidney injury was higher than in other studies conducted on other groups of neonates. Cesarean section delivery, prolonged low birthweight, no Anc follow-up, stage 3 HIE, and neonatal hyperkalemia were predictors of acute kidney injury. However, it needs further prospective study. Therefore, the concerned stakeholders should give due attention and appropriate intervention to these predictors.

Insulin-like growth factor-1 effects on kidney development in preterm piglets

BACKGROUND

Preterm birth disrupts fetal kidney development, potentially leading to postnatal acute kidney injury. Preterm infants are deficient in insulin-like growth factor 1 (IGF-1), a growth factor that stimulates organ development. By utilizing a preterm pig model, this study investigated whether IGF-1 supplementation enhances preterm kidney maturation.

METHODS

Cesarean-delivered preterm pigs were treated systemically IGF-1 or vehicle control for 5, 9 or 19 days after birth. Blood, urine, and kidney tissue were collected for biochemical, histological and gene expression analyses. Age-matched term-born pigs were sacrificed at similar postnatal ages and served as the reference group.

RESULTS

Compared with term pigs, preterm pigs exhibited impaired kidney maturation, as indicated by analyses of renal morphology, histopathology, and inflammatory and injury markers. Supplementation with IGF-1 reduced signs of kidney immaturity, particularly in the first week of life, as indicated by improved morphology, upregulated expression of key developmental genes, reduced severity and incidence of microscopic lesions, and decreased levels of inflammatory and injury markers. No association was seen between the symptoms of necrotizing enterocolitis and kidney defects.

CONCLUSION

Preterm birth in pigs impairs kidney maturation and exogenous IGF-1 treatment partially reverses this impairment. Early IGF-1 supplementation could support the development of preterm kidneys.

IMPACT

Preterm birth may disrupt kidney development in newborns, potentially leading to morphological changes, injury, and inflammation. Preterm pigs have previously been used as models for preterm infants, but not for kidney development. IGF-1 supplementation promotes kidney maturation and alleviates renal impairments in the first week of life in preterm pigs. IGF-1 may hold potential as a supportive therapy for preterm infants sensitive to acute kidney injury.

Chronic kidney disease in children: an update

Chronic kidney disease (CKD) is a major healthcare issue worldwide. However, the prevalence of pediatric CKD has never been systematically assessed and consistent information is lacking in this population. The current definition of CKD is based on glomerular filtration rate (GFR) and the extent of albuminuria. Given the physiological age-related modification of GFR in the first years of life, the definition of CKD is challenging per se in the pediatric population, resulting in high risk of underdiagnosis in this population, treatment delays and untailored clinical management. The advent and spreading of massive-parallel sequencing technology has prompted a profound revision of the epidemiology and the causes of CKD in children, supporting the hypothesis that CKD is much more frequent than currently reported in children and adolescents. This acquired knowledge will eventually converge in the identification of the molecular pathways and cellular response to damage, with new specific therapeutic targets to control disease progression and clinical features of children with CKD. In this review, we will focus on recent innovations in the field of pediatric CKD and in particular those where advances in knowledge have become available in the last years, with the aim of providing a new perspective on CKD in children and adolescents.

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.

Early Mortality in Infants Born with Neonatally Operated Congenital Heart Defects and Low or Very-Low Birthweight: A Systematic Review and Meta-Analysis

Mortality outcomes of children with isolated neonatally operated congenital heart defects (CHDs) born with a low (LBW), moderately low (MLBW) or very-low birthweight (VLBW) remain ambiguous. We searched Medline and Embase (inception until October 2021) and included studies that evaluated early mortality. The risk of bias was assessed using the Critical Appraisal Skills Program cohort checklist. Meta-analysis involved random-effects models. We explored variability in mortality across birthweight subgroups, CHD types, and study designs. From 2035 reports, we included 23 studies in qualitative synthesis, and the meta-analysis included 11 studies (1658 CHD cases), divided into 30 subcohorts. The risk of bias was low in 4/11 studies included in the meta-analysis. Summary mortality before discharge or within one month after surgery was 37% (95%CI 27-47). Early mortality varied by birthweight (VLBW 56%, MLBW 15%, LBW 16%; p = 0.003) and CHD types (hypoplastic left heart syndrome (HLHS) 50%, total anomalous pulmonary venous return (TAPVR) 47%, transposition of the great arteries (TGA) 34%, coarctation of the aorta (CoA) 16%; p = 0.13). Mortality was higher in population-based studies (49% vs. 10%; p = 0.006). One-third of infants born with neonatally operated isolated CHDs and LBW, MLBW, or VLBW died within 30 days after surgery. Mortality varied across infant and study characteristics. These results may help clinicians assess neonatal prognosis. PROSPERO registration CRD42020170289.

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.

Risk factors and outcomes of neonates with acute kidney injury needing peritoneal dialysis: Results from the prospective TINKER (The Indian PCRRT-ICONIC Neonatal Kidney Educational Registry) study

BACKGROUND

Acute kidney injury (AKI) is common in neonates admitted to neonatal intensive care units (NICUs). There is a need to have prospective data on the risk factors and outcomes of acute peritoneal dialysis (PD) in neonates. The use of kidney replacement therapy in this population compared to older populations has been associated with worse outcomes (mortality rates 17-24%) along with a longer stay in the NICU and/or hospital.

METHODS

The following multicentre, prospective study was derived from the TINKER (The Indian PCRRT-ICONIC Neonatal Kidney Educational Registry) database, assessing all admitted neonates ≤28 days who received intravenous fluids for at least 48 h. The following neonates were excluded: death within 48 h, presence of any lethal chromosomal anomaly, requirement of congenital heart surgery within the first 7 days of life and those receiving only routine care in nursery. Demographic data (maternal and neonatal) and daily clinical and laboratory parameters were recorded. AKI was defined according to the Neonatal Kidney Disease: Improving Global Outcomes criteria.

RESULTS

Of the included 1600 neonates, a total of 491 (30.7%) had AKI. Of these 491 neonates with AKI, 44 (9%) required PD. Among neonates with AKI, the odds of needing PD was significantly higher among those with significant cardiac disease (odds ratio (95% confidence interval): 4.95 (2.39-10.27); p < 0.001), inotropes usage (4.77 (1.98-11.51); p < 0.001), severe peripartum event (4.37 (1.31-14.57); p = 0.02), requirement of respiratory support in NICU (4.17 (1.00-17.59); p = 0.04), necrotising enterocolitis (3.96 (1.21-13.02); p = 0.03), any grade of intraventricular haemorrhage (3.71 (1.63-8.45); p = 0.001), evidence of fluid overload during the first 12 h in NICU (3.69 (1.27-10.70); p = 0.02) and requirement of resuscitation in the delivery room (2.72 (1.45-5.12); p = 0.001). AKI neonates with PD as compared to those without PD had a significantly lower median (interquartile range) duration of stay in NICU (7 (4-14) vs. 11 (6-21) days; p = 0.004), but significantly higher mortality (31 (70.5%) vs. 50 (3.2%); p < 0.001). This discrepancy is likely attributable to the critical state of the neonates with AKI.

CONCLUSIONS

This is the largest prospective, multicentre study specifically looking at neonatal AKI and need for dialysis in neonates. AKI was seen in 30.7% of neonates (with the need for acute PD in 9% of the AKI group). The odds of needing acute PD were significantly higher among those with significant cardiac disease, inotropes usage, severe peripartum event, requirement of respiratory support in NICU, necrotising enterocolitis, any grade of intraventricular haemorrhage, evidence of fluid overload more than 10% during the first 12 h in NICU and requirement of resuscitation in the delivery room. AKI neonates with PD as compared to AKI neonates without PD had a significantly higher mortality. There is a need to keep a vigilant watch in neonates with risk factors for the development of AKI and need for PD.

Accuracy of diagnosing acute kidney injury by assessing urine output within the first week of life in extremely preterm infants

BACKGROUND

Neonatal acute kidney injury (AKI) is associated with increased mortality and is often assessed with the neonatal modified Kidney Disease: improving Global Outcomes (KDIGO) classification, which uses changes in serum creatinine levels. However, because this classification has many drawbacks, a novel method, the neonatal Risk, Injury, Failure, Loss, and End-Stage Kidney Disease (nRIFLE) classification for diagnosing neonatal AKI according to urine output (UO), was recently proposed. To date, no data on the incidence of AKI according to nRIFLE are available for extremely preterm infants (born at gestational age less than 28 weeks). This study was conducted to clarify the association between incidence of AKI and in-hospital mortality in extremely preterm infants.

METHODS

Of 171 extremely preterm infants hospitalized from 2006 to 2020, 84 in whom indwelling bladder catheters were placed for UO measurements within 24 h of life were included. The incidence of AKI was assessed using the nRIFLE classification. In-hospital mortality was compared between patients with AKI and those without it.

RESULTS

The incidence of AKI during the first week of life was 56% and that of in-hospital mortality was significantly higher in patients with AKI (25.5%) than in those without it (2.8%). The odds ratio was 12.3 with 95% confidence interval ranging from 1.5 to 100.0.

CONCLUSION

The incidence of AKI according to nRIFLE was higher than reported in most previous studies using the neonatal modified KDIGO classification, suggesting that assessment by nRIFLE criteria using UO may improve diagnostic accuracy of AKI in extremely preterm infants.

Mortality Risk Factors among Infants Receiving Dialysis in the Neonatal Intensive Care Unit

OBJECTIVES

To identify risk factors associated with mortality for infants receiving dialysis in the neonatal intensive care unit (NICU).

STUDY DESIGN

In this retrospective cohort study, we extracted data from the Pediatrix Clinical Data Warehouse on all infants who received dialysis in the NICU from 1999 to 2018. Using a Cox proportional hazards model with robust SEs we estimated the mortality hazard ratios associated with demographics, birth details, medical complications, and treatment exposures.

RESULTS

We identified 273 infants who received dialysis. Median gestational age at birth was 35 weeks (interquartile values 33-37), median birth weight was 2570 g (2000-3084), 8% were small for gestational age, 41% white, and 72% male. Over one-half of the infants (59%) had a kidney anomaly; 71 (26%) infants died before NICU hospital discharge. Factors associated with increased risk of dying after dialysis initiation included lack of kidney anomalies, Black race, gestational age of <32 weeks, necrotizing enterocolitis, dialysis within 7 days of life, and receipt of paralytics or vasopressors (all P < .05).

CONCLUSION

In this cohort of infants who received dialysis in the NICU over 2 decades, more than 70% of infants survived. The probability of death was greater among infants without a history of a kidney anomaly and those with risk factors consistent with greater severity of illness at dialysis initiation.

Acute kidney injury in premature and low birth weight neonates: a systematic review and meta-analysis

BACKGROUND

Acute kidney injury (AKI) is common and it is associated with poor clinical outcomes in premature and low birth weight neonates. This systematic review and meta-analysis was performed to summarize the literature and evaluate the prevalence, risk factors, and mortality of premature and low birth weight neonates with AKI.

METHODS

A systematic search in PubMed, Embase, and the Cochrane Library was performed. Studies on the prevalence, risk factors, diagnosis, and outcomes of acute kidney injury in preterm neonates and neonates with low birth weight were included and analyzed.

RESULTS

Fifty articles of 10,744 patients were included in this study. The overall rate of AKI from the pooled results of all patients was 25% (95% CI 20-30%) with heterogeneity among studies (I² = 97%; P < 0.01). Patients with AKI had significantly higher rate of mortality than patients without AKI (odds ratio (OR) = 7.13; 95% CI 5.91-8.60; P < 0.01).

CONCLUSIONS

AKI was prevalent and was associated with high mortality rate among preterm and low birth weight neonates.

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.

Vancomycin Use in Children and Neonates across Three Decades: A Bibliometric Analysis of the Top-Cited Articles

Vancomycin is frequently prescribed in pediatrics, especially in intensive care unit settings, to treat Gram-positive bacterial infections. This work aims to collect the top-cited articles of pediatric and infectious diseases areas to gather the current evidence and gaps of knowledge on the use of vancomycin in these populations. The most relevant journals reported in the "pediatrics" and "infectious diseases" categories of the 2019 edition of Journal Citation Reports were browsed. Articles with more than 30 citations and published over the last three decades were collected. A bibliometric analysis was performed and 115 articles were retrieved. They were published in 21 journals, with a median impact factor of 4.6 (IQR 2.9-5.4). Sixty-eight of them (59.1%) belonged to "infectious diseases" journals. The most relevant topic was "bloodstream/complicated/invasive infections", followed by "antibiotic resistance/MRSA treatment". As for population distribution, 27 articles were on children only and 27 on neonates, most of which were from intensive care unit (ICU) settings. The current literature mainly deals with vancomycin as a treatment for severe infections and antibiotic resistance, especially in neonatal ICU settings. Lately, attention to new dosing strategies in the neonatal and pediatric population has become a sensible topic.

Longitudinal Changes in Serum Creatinine Levels and Urinary Biomarkers in Late Preterm Infants during the First Postnatal Week: Association with Acute Kidney Injury and Treatment with Aminoglycoside

We aimed to determine the incidence of acute kidney injury (AKI) and longitudinal changes in SCr levels and urinary biomarkers associated with AKI and aminoglycoside (AG) medication during the first week of life of late preterm infants. Urine biomarkers and SCr were measured in thirty late preterm infants on days one, two, five, and seven postnatal. Urine biomarkers included neutrophil gelatinase-associated lipocalin (NGAL), monocyte chemotactic protein-1 (MCP-1), epidermal growth factor (EGF), Tamm-Horsfall glycoprotein (THP), and liver fatty-acid-binding protein (L-FABP). Gestational age was positively correlated with SCr levels at birth, but inversely correlated with SCr levels at day five and day seven. Eighteen (60%) infants had stage 1 AKI, and twenty (67%) infants were treated with AGs. Infants with AKI had lower gestational age and lower birth weight than those without AKI. Urinary biomarkers adjusted according to uCr levels in infants with AKI were not statistically different from those in infants without AKI. There were no significant differences in incidence of AKI, and SCr levels during and after cessation of AG treatment. The uMCP-1/Cr ratio at days five and seven was higher in infants treated with AG than in non-treated infants.

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.

Neonatal Acute Kidney Injury: Understanding of the Impact on the Smallest Patients

The study of neonatal acute kidney injury (AKI) has transitioned from small, single-center studies to the development of a large, multicenter cohort. The scope of research has expanded from assessment of incidence and mortality to analysis of more specific risk factors, novel urinary biomarkers, interplay between AKI and other organ systems, impact of fluid overload, and quality improvement efforts. The intensification has occurred through collaboration between the neonatology and nephrology communities. This review discusses 2 case scenarios to illustrate the clinical presentation of neonatal AKI, important risk factors, and approaches to minimize AKI events and adverse long-term outcomes.

Non-invasive continuous renal tissue oxygenation monitoring to identify preterm neonates at risk for acute kidney injury

BACKGROUND

Near-infrared spectroscopy (NIRS) is an emerging tool to identify signs of inadequate tissue oxygenation in preterm neonates with acute kidney injury (AKI). Previous studies have shown a correlation between low renal tissue oxygenation (RrSO₂) in the first 24 hours of age and the later development of AKI. In this prospective clinical trial, NIRS monitoring was used to identify changes in RrSO₂ in comparison to traditional AKI markers, serum creatinine (SCr), and urine output (UOP).

METHODS

We enrolled 35 preterm neonates born less than 32 weeks' gestation and applied neonatal NIRS sensors at less than 48 hours of age. Neonates underwent 7 days of continuous monitoring. Renal and demographic information were collected for the first 7 days of age. AKI was determined by the modified neonatal Kidney Disease: Improving Global Outcomes (KDIGO) definition including UOP.

RESULTS

Three patients experienced AKI, all based on both SCr and UOP criteria. Each neonate with AKI had decreases in RrSO₂ over 48 hours prior to changes in SCr and UOP. Patients with AKI had lower median RrSO₂ values compared to patients without AKI over the first week of age, (32.4% vs. 60%, p < 0.001).

CONCLUSION

RrSO₂ monitoring identified preterm neonates at risk for AKI. NIRS detected a decline in RrSO₂ prior to changes in SCr and UOP and was significantly lower in patients with AKI compared to those without AKI. Further studies are needed to evaluate the ability of RrSO₂ monitoring to detect signs of kidney stress prior to the diagnosis of AKI. Graphical abstract.

Determination of vancomycin exposure target and individualised dosing recommendations for neonates: model-informed precision dosing

INTRODUCTION

Few studies incorporating population pharmacokinetic/pharmacodynamic (Pop-PK/PD) modelling have been conducted to quantify the exposure target of vancomycin in neonates. A retrospective observational cohort study was undertaken in neonates to determine this target and dosing recommendations (chictr.org.cn, ChiCTR1900027919).

METHODS

A Pop-PK model was developed to estimate PK parameters. Causalities between acute kidney injury (AKI) occurrence and vancomycin use were verified using Naranjo criteria. Thresholds of vancomycin exposure in predicting AKI or efficacy were identified via classification and regression tree analysis. Associations between exposure thresholds and clinical outcomes, including AKI and efficacy, were analysed by logistic regression. Dosing recommendations were designed using Monte Carlo simulations based on the optimised exposure target.

RESULTS

Pop-PK modelling included 182 neonates with 411 observations. On covariate analysis, neonatal physiological maturation, renal function and concomitant use of vasoactive agents (VAS) significantly affected vancomycin PK. Seven cases of vancomycin-induced AKI were detected. Area under the concentration-time curve from 0-24 hours (AUC_0-24) ≥ 485 mg•h/L was an independent risk factor for AKI after adjusting for VAS co-administration. The clinical efficacy of vancomycin was analysed in 42 patients with blood culture-proven staphylococcal sepsis. AUC_0-24 to minimum inhibitory concentration (AUC_0-24/MIC) ≥ 234 was the only significant predictor of clinical effectiveness. Monte Carlo simulations indicated that regimens in Neonatal Formulary 7 and Red Book (2018) were unsuitable for all neonates.

CONCLUSION

An AUC_0-24 of 240-480 (assuming MIC = 1 mg/L) is a recommended exposure target of vancomycin in neonates. Model-informed dosing regimens are valuable in clinical practice.

Sex-Specific Survival, Growth, Immunity and Organ Development in Preterm Pigs as Models for Immature Newborns

Background: After very preterm birth, male infants show higher mortality than females, with higher incidence of lung immaturity, neurological deficits, infections, and growth failure. In modern pig production, piglets dying in the perinatal period (up to 20%) often show signs of immature organs, but sex-specific effects are not clear. Using preterm pigs as model for immature infants and piglets, we hypothesized that neonatal survival and initial growth and immune development depend on sex. Methods: Using data from a series of previous intervention trials with similar delivery and rearing procedures, we established three cohorts of preterm pigs (90% gestation), reared for 5, 9, or 19 days before sample collection (total n = 1,938 piglets from 109 litters). Partly overlapping endpoints among experiments allowed for multiple comparisons between males and females for data on mortality, body and organ growth, gut, immunity, and brain function. Results: Within the first 2 days, males showed higher mortality than females (18 vs. 8%, P < 0.001), but less severe immune response to gram-positive infection. No effect of sex was observed for thermoregulation or plasma cortisol. Later, infection resistance did not differ between sexes, but growth rate was reduced for body (up to -40%) and kidneys (-6%) in males, with higher leucocyte counts (+15%) and lower CD4 T cell fraction (-5%) on day 9 and lower monocyte counts (-18%, day 19, all P < 0.05). Gut structure, function and necrotizing enterocolitis (NEC) incidence were similar between groups, but intestinal weight (-3%) and brush-border enzyme activities were reduced at day 5 (lactase, DPP IV, -8%) in males. Remaining values for blood biochemistry, hematology, bone density, regional brain weights, and visual memory (tested in a T maze) were similar. Conclusion: Following preterm birth, male pigs show higher mortality and slower growth than females, despite limited differences in organ growth, gut, immune, and brain functions. Neonatal intensive care procedures may be particularly important for compromised newborns of the male sex. Preterm pigs can serve as good models to study the interactions of sex- and maturation-specific survival and physiological adaptation in mammals.

Cystic dysplasia of the kidneys in extremely preterm infants following acute kidney injury

BACKGROUND

Various perinatal morbidities may adversely affect postnatal nephrogenesis in preterm infants. Kidney ultrasonographic findings following acute kidney injury (AKI) have not been well described in preterm infants. Herein, we describe three cases of extremely preterm infants who showed abnormal kidney ultrasonographic findings resembling dysplasia of the kidneys following AKI.

CASE-DIAGNOSIS/TREATMENT

Their median gestational age and birth weight were 25⁺⁶ (range 23⁺³-26⁺⁶) weeks and 620 (480-840) g, respectively. All infants suffered severe AKI during their third to seventh week of life. Their kidney function recovered with conventional management. Kidney ultrasonographies performed after AKI revealed increased kidney echogenicity, loss of corticomedullary differentiation, and multiple cortical cysts, which were similar to cystic dysplasia of the kidneys and were absent in previous kidney imaging. Three infants eventually developed at least one of the long-term kidney sequelae following AKI, including proteinuria, hypertension, and elevated levels of serum creatinine or cystatin C as determined during the last follow-up at the corrected age of 9-18 months.

CONCLUSIONS

Based on these cases, we can infer that AKI occurring during the early postnatal period may result in dysplasia of the kidneys with cortical cysts in extremely preterm infants, which may lead to chronic kidney disease in their later life. It is useful to follow up not only laboratory parameters but also kidney ultrasonographic findings in extremely preterm infants who suffered AKI during their early postnatal periods.

Urine biomarkers for monitoring acute kidney injury in premature infants

Background

Premature infants are at high risk for acute kidney injury (AKI). Serum creatinine (Cr) has limitations for evaluating kidney function in premature infants. We evaluated whether urine biomarkers could be used to monitor AKI in premature infants.

Methods

A prospective cohort study was conducted among infants born at < 37 weeks. Urine biomarkers and serum Cr were measured on postnatal days 1, 3, 5, 7, 10, and 14. Infants were divided into 3 groups according to gestational age (GA); < 28, 28 to < 32 and 32 to < 37 weeks.

Results

AKI occurred in 17 of 83 (20.5%) recruited infants at a median age of 7 (interquartile range 5–10) days. While the most common cause of AKI was hemodynamically significant patent ductus arteriosus (53.8%) in infants of GA < 28 weeks, necrotizing enterocolitis was the leading cause (50.0%) in infants of GA 28 to < 32 weeks. Urinary levels of neutrophil-gelatinase-associated lipocalin/Cr were higher and epidermal growth factor/Cr were lower in AKI group before the onset of AKI in infants of GA < 28 weeks. In infants of GA 28 to < 32 weeks, urinary interleukin-8/Cr levels were higher in AKI group at approximately the time of AKI onset.

Conclusion

Several urine biomarkers were significantly different between AKI and no AKI groups, and some had changed before the onset of AKI. These groups were distinct according to causative factors of AKI and GA. Urine biomarkers could be useful for monitoring the development of AKI in premature infants.

Prevalence of acute kidney injury (AKI) in extremely low gestational age neonates (ELGAN)

BACKGROUND

To determine the prevalence and severity of acute kidney injury (AKI) at different time frames in relation to gestational age (GA) and birthweight (BW) in extremely low gestational age neonates (ELGAN). Our hypothesis is that ELGAN with lower GA and lower BW have higher AKI rates.

METHODS

A total of 923 ELGAN enrolled in the Preterm Erythropoietin Neuroprotection Trial were evaluated from birth until death or hospital discharge. AKI was defined according to kidney disease: improving global outcomes (KDIGO) definition from clinically-derived serum creatinine (SCr) measurements. Severe AKI was defined as stage 2 or higher.

RESULTS

For the entire cohort, 351/923 (38.0%, CI = 34.8-41.3%) had at least one episode of stage 1 or higher AKI and 168/923 (18.2%, CI = 15.7-20.7%) had at least one episode of severe (stage 2 or higher) AKI. The prevalence of AKI stage 1 or higher for the entire cohort during the early (days 3-7), middle (days 8-14), and late follow-up period (after day 14) was 112/923 (12.1%, CI = 10.0-14.3%), 142/891 (15.9%, CI = 13.5-18.4%), and 249/875 (28.5%, CI = 25.4-31.5%), respectively. The rates of severe AKI during the hospital course were 27.8%, 21.9%, 13.6%, and 9.4% for the 24-, 25-, 26-, and 27-week GA groups, respectively. AKI rates were significantly higher with decreasing GA and decreasing BW for stated time trends (all p < 0.01 using tests for trend).

CONCLUSIONS

AKI is relatively common in ELGAN during their initial hospital course and is associated with lower GA and BW.

Incidence, risk factors, and outcomes of acute kidney injury in neonates after surgical procedures

BACKGROUND

Acute kidney injury (AKI) is common and associated with poor outcomes in critically ill neonates. The objective of this study was to study the incidence, risk factors, and clinical outcomes of AKI in neonates receiving non-cardiac surgery.

METHODS

We performed a single-center retrospective study between January 2017 and December 2018 of neonates who had received abdominal and thoracic surgical procedures. AKI was defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Patient information, clinical data, and outcomes were collected and analyzed. Logistic regression was used to analyze risk factors of AKI and association between AKI and mortality.

RESULTS

Fifty-four (33.8%) of 160 patients developed AKI after surgical procedures. Compared with neonates without AKI, neonates with AKI had higher mortality rate (18.5% VS 5.7%, p = 0.022), lower gestational age (30.5 weeks, interquartile range [IQR] 28-33.5, VS 34.5 weeks, IQR 33-37.5, p = 0.035), higher rates of very low birth weight (33.3% VS 17.0%, p = 0.019), longer duration of mechanical ventilation (0.5 days, IQR 0-1.5, VS 0 days, IQR 0-1, p = 0.043) and higher rates of sepsis (35.2% VS 19.8%, p = 0.034). Risk factors of AKI included gestational age under 32 weeks (OR 4.8, 95% CI 1.8-12.6; p = 0.001), sepsis (OR 4.3, 95% CI 1.7-11.3; p = 0.003), operation time longer than 120 min (OR 2.7, 95% CI 1.1-6.6; p = 0.024), and diagnosis of necrotizing enterocolitis (OR 3.5, 95% CI 1.3-9.1; p = 0.011). AKI after surgery was significantly associated with mortality (OR 4.3, 95% CI 1.1-16.9; p = 0.036).

CONCLUSIONS

AKI is common and associated with poor outcomes in surgical neonates. Early recognition and intervention of AKI in these patients are important.

Acute kidney injury in sick neonates: a comparative study of diagnostic criteria, assessment of risk factors and outcomes

Introduction: Neonatal acute kidney injury (nAKI) poses unique challenges with diagnostic criteria specific to neonates evolving over time. Urine output (UOP) criterion has a special place in the diagnosis of nAKI although significant clarity on the ideal diagnostic threshold for UOP is not established. Risk factors peculiar to the tropical region for acute kidney injury (AKI) in neonates needs attention. It would be interesting to assess for kidney function in neonates who survived AKI during the dynamic phase of infancy.Objectives: To compare criteria of modified kidney disease improving global outcome (mKDIGO) and neonatal risk, injury, failure, loss, and end-stage criteria (nRIFLE) in diagnosing AKI in sick neonates; to study the risk factors for AKI and clinical outcomes at the end of neonatal ICU stay and during infancy.Methods: This prospective study was conducted at a tertiary neonatal ICU that screened and staged sick neonates by applying mKDIGO and nRIFLE criteria. Risk factors were assessed and glomerular filtration rate was calculated by cystatin C in survivors of nAKI for 12 months post conception age.Results: nAKI was observed in 30% (49/163) of sick neonates. The mKDIGO (94%) detected a higher number of neonates with AKI compared to nRIFLE (49%). Based on only UOP, nRIFLE diagnosed a higher proportion of neonates with mild AKI compared to mKDIGO (29% versus 16%), respectively. Besides known risk factors, hypernatremic dehydration (18%) was an important risk factor for AKI. With 20% mortality, the risk of developing AKI was comparable using either mKDIGO or nRIFLE diagnostic criteria. At the end of infancy, mean cystatin C eGFR of neonates was 101.3 ± 29.2 ml/1.73 m²/min.Conclusion: In sick neonates, mKDIGO criteria performed better than nRIFLE in detecting AKI. However, the risk of mortality was comparable using either diagnostic criterion. Hypernatremic dehydration was an important risk factor for AKI and renal function of neonates following complete recovery of AKI was normal at the end of infancy.

Changes in Serum Creatinine Levels and Natural Evolution of Acute Kidney Injury with Conservative Management of Hemodynamically Significant Patent Ductus Arteriosus in Extremely Preterm Infants at 23-26 Weeks of Gestation

Changes in kidney function in extremely preterm infants (EPT) with conservatively managed hemodynamically significant (HS) patent ductus arteriosus (PDA) are not known well. We aimed to present the postnatal course in serum creatinine levels (sCr), prevalence of acute kidney injury (AKI), then relevance between AKI and adverse outcomes in EPT with conservatively managed HS PDA. By review of medical records, we analyzed the postnatal course of sCr and prevalence of stage 3 AKI defined by the modified Kidney Disease Improving Global Outcome (KDIGO) in EPT at gestational age of 23 to 26 weeks with conservatively treated HS PDA. We investigated if the presence and/or prolonged duration of stage 3 AKI elevated the risk of adverse outcomes. The results showed that, neither factor was associated with adverse outcomes. While the average PDA closure date was at postnatal day (P) 41 and 53, sCr peaked at P 10 and 14 and the cumulative prevalence of stage 3 AKI was 57% and 72% in the EPT of 25–26 and 23–24 weeks’ gestation, respectively. The high prevalence of stage 3 AKI without adverse outcomes in EPT with conservatively managed HS PDA suggests that it might reflect renal immaturity rather than pathologic conditions.

Peritoneal Dialysis in Very Low Birth Weight Neonates

Background

The aim of this retrospective study is to evaluate clinical characteristics and outcomes of very low birth weight (VLBW) neonates with acute kidney injury (AKI) treated with peritoneal dialysis (PD).

Methods

This retrospective study included 10 VLBW neonates treated with PD. Intravenous (IV) cannula and umbilical venous catheter were used for the peritoneal access.

Results

Mean age at the moment of starting PD was 14.9 ± 9.3 days. Mean body weight (BW) was 825 ± 215 g. The average gestational age was 26.3 ± 1.1 weeks. The average duration of dialysis was 20.5 ± 14.7 h. The average ultrafiltration was 7.7 ± 4.2 mL/kg/h. At the moment of starting PD, the average BW was 302 ± 317g (22 ± 13%), higher than at birth (in patients who had PD started in first 2 weeks of their lives) or higher than the BW before AKI was diagnosed (patients who had PD started when they were older than 2 weeks). The main cause of AKI was sepsis ( n = 8/10). Dialysate leak was registered in 2 patients, 1 patient had peritonitis and the other had a blocked PD catheter. Six patients died during PD (severe sepsis), 1 died due to hypoxic encephalopathy and coma, and 2 patients survived. One patient (with hypoxic encephalopathy and coma) died 10 days after PD was stopped due to sepsis. The overall mortality was 80%.

Conclusion

Acute PD is still an appropriate treatment choice for VLBW neonates with AKI. In VLBW neonates, PD can be performed with an improvised PD system and catheters.

AWAKEN-Ing a New Frontier in Neonatal Nephrology

In 2013, literature about the epidemiology of neonatal acute kidney injury (AKI) was limited to primarily retrospective, single center studies that suggested that AKI was common and that those with AKI had higher rates of mortality. We developed a 24-center retrospective cohort of neonates admitted to the NICU between January 1 and March 31, 2014. Analysis of the Assessment of Worldwide Acute Kidney Epidemiology in Neonates (AWAKEN) cohort, has allowed us to describe the prevalence, risk factors and impact of neonatal AKI for different gestational age cohorts. The ample sample size allows us to provide convincing data to show that those with AKI have an increase independent higher odds of death and prolonged hospitalization time (1). This data mirrors similar studies in pediatric (2) and adult (3) critically ill populations which collectively suggest that patients do not just die with AKI, but instead, AKI is directly linked to hard clinical outcomes. This study has allowed us to answer multiple other questions in the field which has expanded our understanding of the risk factors, complications, impact of fluid overload, the definition of neonatal AKI and suggests interventions for improving outcomes. Furthermore, this project brought together neonatologist and nephrologist within and across centers. Finally, the AWAKEN project has enabled us to build relationships and infrastructure that has launched the Neonatal Kidney Collaborative http://babykidney.org/ on its way to accomplish its stated mission to improve the health of newborns with or at risk for kidney disease through multidisciplinary collaborative research, advocacy, and education.

Renal Function Profiles in Preterm Neonates With Birth Asphyxia Within the First 24 H of Life

The characteristics of early renal function in preterm neonates of different gestational ages (GAs) with birth asphyxia (BA) remain unclear. Kidneys are sensitive to oxygen deprivation, and renal insufficiency may occur within 24 h of BA. We aimed to elucidate the renal function profiles within the first 24 h after the development of BA among vulnerable preterm neonates of different GAs. The medical records of 128 preterm neonates born to mothers with normal renal function were retrospectively analyzed. Data regarding the serum creatinine (SCr) and urea nitrogen (BUN) levels in venous blood, estimated creatinine clearance (eCCI) within the first hours after birth, and urinary output (UOP) in the first 24 h after birth were compared between the preterm with BA population and GA-matched population without BA (n = 64 and n = 64, respectively). Significantly higher SCr levels and lower eCCI were observed in mid-late preterm neonates with BA than in preterm neonates without BA (84.05 versus [vs.] 64.20 μmol/L, z = 4.41, p < 0.001; 15.02 vs. 21.30 mL/min/1.73 m², z = 3.57, p < 0.001, respectively). Very preterm neonates showed a higher UOP (2.01 vs. 1.66 mL/kg/h, z = 2.01, p = 0.045) after the development of BA than before. In preterm neonates with BA, the incidence of SCr > 133 μmol/L, CCI < 16 mL/min/1.73 m² and UOP < 1.0 ml/kg/h, was 10.94%, 62.50%, and 20.31%, respectively. Within 24 h after birth, BA was associated with eCCI < 16 mL/min/1.73 m² (p = 0.016, odds ratio = 2.83, 95% confidence interval: 1.210-6.613) in preterm neonates. Different renal function profiles were observed in preterm neonates of different GAs within the first 24 h of life after the development of BA. Candidate therapies based on different renal function statuses will bring these vulnerable patient populations of different GAs closer to receiving precision medicine.

Preoperative metabolic acidosis and acute kidney injury after open laparotomy in the neonatal intensive care unit

BACKGROUND

This study evaluated potential risk factors associated with acute kidney injury (AKI) in infants undergoing bedside open laparotomy in the neonatal intensive care unit (NICU), and analyzed the association between postoperative AKI and outcomes.

METHODS

Retrospective data, including neonatal characteristics, perioperative findings (i.e. vital signs and fluid status), postoperative AKI incidence, and postoperative mortality rate of infants who underwent bedside open laparotomy in the NICU between May 2013 and May 2018 were collected and analyzed.

RESULTS

A total of 53 cases (26 in AKI group vs 27 in non-AKI group) were analyzed. On univariable analysis, transfusion, pre- and postoperative blood gas analysis and number of inotropic agents, cumulative postoperative percentage fluid overload (48 h), and preoperative hourly urine output were associated with the development of postoperative AKI. On multivariable logistic regression analysis, preoperative acidosis (pH <7.15 or base deficit >10; P = 0.002; OR, 11.067; 95%CI: 2.499-49.017) and preoperative urine output (P = 0.035; OR, 0.548; 95%CI: 0.314-0.959) were significant factors associated with postoperative AKI. Postoperative mortality rate 30 days after surgery was higher in the AKI group, but the difference was not significant.

CONCLUSIONS

Preoperative metabolic acidosis and urine output are important factors potentially associated with the development of postoperative AKI in neonates undergoing bedside open laparotomy. Strategies such as alkali therapy, which protect the kidney from further injury, should be validated in future studies. A decreasing urine output may suggest deteriorating kidney function prior to surgery, potentially amplifying the risk of postoperative AKI.

Maternal and environmental risk factors for neonatal AKI and its long-term consequences

Acute kidney injury (AKI) is a common and life-threatening complication in critically ill neonates. Gestational risk factors for AKI include premature birth, intrauterine growth restriction and low birthweight, which are associated with poor nephron development and are often the consequence of pre-gestational and gestational factors, such as poor nutritional status. Our understanding of how to best optimize renal development and prevent AKI is in its infancy; however, the identification of pre-gestational and gestational factors that increase the risk of adverse neonatal outcomes and the implementation of interventions, such as improving nutritional status early in pregnancy, have the potential to optimize fetal growth and reduce the risk of preterm birth, thereby improving kidney health. The overall risk of AKI among critically ill and premature neonates is exacerbated postnatally as these infants are often exposed to dehydration, septic shock and potentially nephrotoxic medications. Strategies to improve outcomes - for example, through careful evaluation of nephrotoxic drugs - may reduce the incidence of AKI and its consequences among this population. Management strategies and updated technology that will support neonates with AKI are greatly needed. Extremely premature infants and those who survive an episode of AKI should be screened for chronic kidney disease until early adulthood. Here, we provide an overview of our current understanding of neonatal AKI, focusing on its relationship to preterm birth and growth restriction. We describe factors that prevent optimal nephrogenesis during pregnancy and provide a framework for future explorations designed to maximize outcomes in this vulnerable population.

Patent ductus arteriosus is associated with acute kidney injury in the preterm infant

BACKGROUND

This study aimed to test the hypothesis that a patent ductus arteriosus (PDA) is independently associated with acute kidney injury (AKI) in neonates ≤ 28 weeks gestation.

METHODS

Preterm infants with echocardiographic diagnosis of moderate-large PDA at age ≤ 30 days were studied retrospectively. AKI, the primary outcome, was defined and staged according to serum creatinine using Kidney Disease Improving Global Outcomes (KDIGO) neonatal criteria. Its association with the timing and duration of PDA, non-steroidal anti-inflammatory drugs (NSAIDs) and other nephrotoxic exposures, gestational age, and other covariates was evaluated using mixed-effects logistic regression models.

RESULTS

Acute Kidney Injury occurred in 49% (101/206) of infants. Moderate-to-large PDA was associated with any-stage AKI (OR 5.31, 95% CI 3.75 to 7.53), stage 1 (mild) AKI (OR 4.86, 95% CI 3.12 to 7.56), and stages 2-3 (severe) AKI (OR 10.9, 95% CI 5.70 to 20.8). NSAID treatment added additional risk for mild AKI (OR 2.45, 95% CI 1.61 to 3.71). Severe AKI was less likely when NSAID treatment was effective (OR 0.45, 95% CI 0.21 to 0.97) but not when ineffective (OR 1.63, 95% CI 0.76 to 3.50).

CONCLUSIONS

Moderate-to-large PDA was strongly associated with all stages of AKI in preterm infants ≤ 28 weeks of gestational age. Effective NSAID treatment decreased the risk of severe but not mild AKI. These differential effects reflect the balance between the renal benefits of PDA closure and the risk of NSAID toxicity.

Optimizing the AKI definition during first postnatal week using Assessment of Worldwide Acute Kidney Injury Epidemiology in Neonates (AWAKEN) cohort

BACKGROUND

Neonates with serum creatinine (SCr) rise ≥0.3 mg/dL and/or ≥50% SCr rise are more likely to die, even when controlling for confounders. These thresholds have not been tested in newborns. We hypothesized that different gestational age (GA) groups require different SCr thresholds.

METHODS

Neonates in Assessment of Worldwide Acute Kidney Epidemiology in Neonates (AWAKEN) with ≥1 SCr on postnatal days 1-2 and ≥1 SCr on postnatal days 3-8 were assessed. We compared the mortality predictability of SCr absolute (≥0.3 mg/dL) vs percent (≥50%) rise. Next, we determine usefulness of combining absolute with percent rise. Finally, we determined the optimal absolute, percent, and maximum SCr thresholds that provide the highest mortality area under curve (AUC) and specificity for different GA groups.

RESULTS

The ≥0.3 mg/dL rise outperformed ≥50% SCr rise. Addition of percent rise did not improve mortality predictability. The optimal SCr thresholds to predict AUC and specificity were ≥0.3 and ≥0.6 mg/dL for ≤29 weeks GA, and ≥0.1 and ≥0.3 mg/dL for >29 week GA. The maximum SCr value provides great specificity.

CONCLUSION

Unique SCr rise cutoffs for different GA improves outcome prediction. Percent SCr rise does not add value to the neonatal AKI definition.

Incidence, risk factors, and outcome of neonatal acute kidney injury: a prospective cohort study

BACKGROUND

Acute kidney injury (AKI) is common in neonates admitted to the neonatal intensive care unit (NICU). AKI is associated with increased morbidity and mortality and a greater long-term risk of chronic kidney disease.

OBJECTIVES

To study the incidence and outcome of neonatal AKI in a single Saudi Arabian center, level 2\3 NICU.

METHODS

This single-center prospective cohort study included all infants who received level II or III NICU care during 2015 (January to December). We excluded infants who survived less than 48 h after admission, had evidence of congenital renal anomalies, or had insufficient data. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Both AKI and non-AKI neonates were prospectively followed up until NICU discharge. Outcomes studied included mortality and length of NICU stay. The results of adjusted risk analyses were expressed as relative risk (RR) with 95% confidence interval (95% CI).

RESULTS

The incidence of AKI (modified neonatal KDIGO stages) was 56% (120/214 patients). Compared with neonates without AKI, those with AKI had a lower birth weight (2202 ± 816 vs. 1570 ± 776 g; p < 0.001) and a lower gestational age (35 ± 3 vs. 32 ± 4 weeks; p < 0.001). After adjustment for potential confounders, only gestational age (RR, 4.8; 95% CI, 3-9) and perinatal depression (RR, 10; 95% CI, 2-46) were significantly associated with an increased risk of AKI. For infants with gestational age < 32 weeks, only the Clinical Risk Index for Babies (CRIB II) score was associated with an increased risk of AKI (RR, 1.9; 95% CI, 1-3). After adjustment for gestational age, AKI was significantly associated with mortality (RR, 5.4; 95% CI, 2-14), but not with the length of hospital stay (LOS) (p = 0.133). However, the AKI group had a significantly longer LOS (mean difference: 14 days; 95% CI, 5.5-23 days), and 33 patients (27.5%) with AKI were discharged with abnormally high serum creatinine levels (> 65 μmol/L).

CONCLUSION

AKI occurred in more than half of all NICU admissions, was associated with an increased risk of mortality, and had a higher incidence among smaller and sicker infants. Therefore, close monitoring of renal function during hospitalization and after discharge is warranted in such infants.

Serum cystatin C as an early predictor of acute kidney injury in preterm neonates with respiratory distress syndrome

Preterm neonates with respiratory distress syndrome (RDS) are at increased risk of acute kidney injury (AKI). Our study aimed at determining whether serum cystatin C (sCysC) on day 3 of life (D3) can early predict AKI in preterm neonates with RDS. This prospective study was conducted on 75 preterm neonates; 50 with RDS and 25 without RDS. On D3, sCysC, serum creatinine (sCr) and blood urea nitrogen (BUN) were measured and estimated glomerular filtration rate (eGFR) was calculated. sCr and BUN levels were measured again on days 5 and 7. Neonates were evaluated for development of AKI during first week of life according to the modified pediatric RIFLE (pRIFLE) criteria. Thirteen neonates with RDS developed AKI (26%).There was no significant difference between RDS and control groups with respect to sCysC. RDS neonates with AKI had significantly higher sCysC than those without AKI (1.62 ± 0.12 versus 1.16 ± 0.09 mg/l; p < .001). RDS grade III-IV neonates had significantly higher sCysC than RDS grade I-II. There was a significant positive correlation between D3 sCysC and (D5 and D7 sCr and BUN). Receiver operating characteristic (ROC) curve showed that D3 sCysC can predict AKI in preterm neonates with RDS at a cutoff point of >1.3 mg/l with sensitivity of 92.30% and specificity of 96%. We conclude that neonates with RDS are at increased risk of AKI. sCysC on day 3 of life can predict AKI earlier than Cr and eGFR.

The effect of hemodynamically significant patent ductus arteriosus on acute kidney injury and systemic hypertension in extremely low gestational age newborns

Background: Acute kidney injury (AKI) in preterm neonates is becoming an increasingly recognized morbidity in the neonatal intensive care unit neonatal intensive care unit (NICU), yet its epidemiology, delineation and relation to numerous toxic exposures and common morbidities such as systemic hypertension is just evolving. With a frequency of the patent ductus arteriosus (PDA) as high as 70% in preterm infants born before 28-week gestation, the role of the hemodynamically significant PDA (hs-PDA) remains unclear. Objective: To determine if AKI and systemic hypertension is more common in extremely low gestational age newborns (ELGAN) with hs PDA compared to ELGAN with no or non-hs PDA using modified AKIN and Neonatal Risk, Injury, Failure, Loss of Kidney Function, and End-stage (N-RIFLE) scoring systems. Methods: This was a retrospective cohort study of infants ≤28 weeks gestational age born between 2010 and 2016 who had echocardiographic PDA evaluation completed for hemodynamical significance as well as serial serum creatinine and urine output measurement documented, needed for the two AKI scoring systems: modified AKIN (based on serial serum creatinine) and N-RIFLE (using urine output data). Blood pressure measurements and therapy were evaluated during the hospitalization and on the day of NICU discharge. Baseline characteristics and outcome variables were compared between the hs-PDA and no or non-hs PDA using unpaired t-tests for continuous variables and chi square tests for categorical data. Results: One hundred fifty-one infants were eligible of which 110 had hs-PDA. Infants with hs-PDA were smaller (777 versus 867 g, p = .026), less mature (25.8 versus 26.4 weeks, p = .023) and had greater exposure to nephrotoxic drugs (14 versus 9.4 days, p = .001). Other clinical and demographic variables were similar between the two groups. The overall incidence of AKI was not different between the hs-PDA and no PDA or non-hs PDA groups when evaluated by the acute kidney injury network (AKIN) or N-RIFLE staging; however, preterm newborns with hs-PDA demonstrated a trend towards increased risk of AKI injury (12.7 versus 0.02%, p = .06). The N-RIFLE and AKIN scoring systems demonstrated very poor degree of agreement (kappa = 0.00853) in our study. There was no difference in the rates of hypertension during the hospitalization as well as on the day of NICU discharge. Conclusion: Preterm neonates with hs-PDA had similar rates of AKI and hypertension as neonates with no or non-hs PDA.

[Monitoring of kidney injury in preterm infants]

Acute kidney injury (AKI) is a common complication in the neonatal intensive care unit that causes a high mortality of preterm infants and various chronic kidney diseases in adulthood. Preterm infants have immature development of the kidneys at birth. The kidneys continue to develop within a specific time window after birth. However, due to various factors during pregnancy and after birth, preterm infants tend to develop AKI. At present, serum creatinine and urine volume are used for the assessment of kidney injury, and their early sensitivity and specificity have attracted increasing attention. In recent years, various new biomarkers have been identified for early recognition of AKI. This article reviews the features, risk factors, renal function assessment, and prevention/treatment of AKI of preterm infants, in order to provide a reference for improving early diagnosis and treatment of AKI in preterm infants and long-term quality of life.

Risk factors and mortality rate in premature babies with acute kidney injury

BACKGROUND

Acute kidney injury (AKI) is a common morbidity in neonatal intensive care units and associated with poor outcome. This study aimed to determine the prevalence of AKI and provide a demographic data and risk factors associated with the mortality and morbidity.

METHODS

This is a retrospective study included 105 premature babies. Diagnosis of AKI was based on neonatal KDIGO classification criteria. The babies were stratified into two groups according to AKI status during the hospitalization. Clinical and laboratory characteristics of the AKI group were compared to non-AKI group.

RESULTS

AKI occurred in 21 (20.0%) of 105 premature babies, and mortality rate in these babies was 61.9%. Lower gestational weeks, lower Apgar scores at 5 minutes, lower systolic blood pressures, and inotropic supports were independent risk factors for the development of AKI in preterm babies (P < .05, for each). Oliguria, preeclampsia/eclampsia, resuscitation at birth, lower diastolic blood pressure, patent ductus arteriosus (PDA), inotropic support, and furosemide treatment were associated with the mortality (P < .05, for each).

CONCLUSIONS

Prenatal risk factors and medical interventions are associated with AKI, and AKI is associated with increased morbidity and mortality. Therefore, identification of AKI is very important in this vulnerable population and it should be performed as quickly as possible in all babies who are at high risk for developing of AKI.

Incidence and outcomes of acute kidney injury in extremely-low-birth-weight infants

Background

Acute kidney injury (AKI) is a common event in the neonatal intensive care unit (NICU), especially in extremely-low-birth-weight (ELBW) infants. This cohort study investigated the incidence of and risk factors for AKI in ELBW infants and their overall survival at the postmenstrual age (PMA) of 36 weeks.

Methods

All ELBW infants admitted to our NICU between January 2010 and December 2013 were enrolled. Those who died prior to 72 hours of life, had congenital renal abnormality, or had only one datum of the serum creatinine (SCr) level after the first 24 hours of life were excluded. The criteria used for the diagnosis of AKI was set according to the modified neonatal KDIGO AKI definition.

Results

AKI occurred in 56% of 276 infants. Specifically, stage 1, stage 2, and stage 3 AKI occurred in 30%, 17%, and 9% of ELBW infants, respectively. High-frequency ventilation support (adjusted odds ratio [OR]: 3.4, 95% confidence interval [CI]: 1.78–6.67, p< 0.001), the presence of patent ductus arteriosus (adjusted OR: 4.3, 95% CI: 2.25–8.07, p < 0.001), lower gestational age (adjusted OR for gestational age: 0.7, 95% CI: 0.58–0.83, < 0.001), and inotropic agent use (adjusted OR: 2.6, 95% CI: 1.31–5.21, p = 0.006) were independently associated with AKI. Maternal pre-eclampsia was a protective factor (adjusted OR: 0.4, 95% CI: 0.14–0.97, p = 0.044). Infants with AKI had higher mortality before the PMA of 36 weeks with an adjusted hazard ratio (HR) of 5.34 (95% CI: 1.21–23.53, p = 0.027). Additionally, infants with stage 3 AKI had a highest HR of 10.60, 95% CI: 2.09–53.67, p = 0.004).

Conclusion

AKI was a very common event (56%) in ELBW infants and was associated with a lower GA, high-frequency ventilation support, the presence of PDA, and inotropic agent use. AKI reduced survival of ELBW infants before the PMA of 36 weeks.

Incidence and outcomes of neonatal acute kidney injury (AWAKEN): a multicentre, multinational, observational cohort study

Background

Single-center studies suggest that neonatal acute kidney injury (AKI) is associated with poor outcomes. However, inferences regarding the association between AKI, mortality, and hospital length of stay are limited due to the small sample size of those studies. In order to determine whether neonatal AKI is independently associated with increased mortality and longer hospital stay, we analyzed the Assessment of Worldwide Acute Kidney Epidemiology in Neonates (AWAKEN) database.

Methods

All neonates admitted to 24 participating neonatal intensive care units from four countries (Australia, Canada, India, United States) between January 1 and March 31, 2014, were screened. Of 4273 neonates screened, 2022 (47·3%) met study criteria. Exclusion criteria included: no intravenous fluids ≥48 hours, admission ≥14 days of life, congenital heart disease requiring surgical repair at <7 days of life, lethal chromosomal anomaly, death within 48 hours, inability to determine AKI status or severe congenital kidney abnormalities. AKI was defined using a standardized definition —i.e., serum creatinine rise of ≥0.3 mg/dL (26.5 mcmol/L) or ≥50% from previous lowest value, and/or if urine output was <1 mL/kg/h on postnatal days 2 to 7.

Findings

Incidence of AKI was 605/2022 (29·9%). Rates varied by gestational age groups (i.e., ≥22 to <29 weeks =47·9%; ≥29 to <36 weeks =18·3%; and ≥36 weeks =36·7%). Even after adjusting for multiple potential confounding factors, infants with AKI had higher mortality compared to those without AKI [(59/605 (9·7%) vs. 20/1417 (1·4%); p< 0.001; adjusted OR=4·6 (95% CI=2·5–8·3); p=<0·0001], and longer hospital stay [adjusted parameter estimate 8·8 days (95% CI=6·1–11·5); p<0·0001].

Interpretation

Neonatal AKI is a common and independent risk factor for mortality and longer hospital stay. These data suggest that neonates may be impacted by AKI in a manner similar to pediatric and adult patients.

Funding

US National Institutes of Health, University of Alabama at Birmingham, Cincinnati Children’s, University of New Mexico.

Risk of nonsteroidal anti-inflammatory drug-associated renal dysfunction among neonates diagnosed with patent ductus arteriosus and treated with gentamicin

OBJECTIVE

To evaluate the risk of nonsteroidal anti-inflammatory drug (NSAID) therapy-associated acute kidney injury (AKI) among neonates diagnosed with patent ductus arteriosus (PDA) who are treated with gentamicin.

STUDY DESIGN

Multicenter retrospective observational study of patients ⩽44 postmenstrual weeks of age diagnosed with PDA who received gentamicin during hospitalization between January 2006 and December 2014. Patients with and without NSAID exposure were matched on covariates associated with AKI and NSAID therapy. The primary end point, AKI, was defined according to Kidney Disease Improving Global Outcomes neonatal criteria.

RESULTS

The rate of AKI for the entire cohort (n=594) was 12% (n=71). Among neonates receiving NSAIDS, 14.8% (n=44) experienced an AKI as compared to 9.1% (n=27) for those who were not exposed (relative risk, 1.6; 95% confidence interval, 1.0 to 2.6). Therefore, the attributable risk of NSAID use was 5.7% (95% confidence interval, 0.5 to 11.0).

CONCLUSION

Among neonates with PDA and receiving gentamicin, NSAID therapy increases the risk of AKI by about 6%.

Prevalence and outcome of acute kidney injury, as defined by the new Kidney Disease Improving Global Outcomes guideline, in very low birth weight infants

AIM

To evaluate the prevalence, risk factors and outcome of acute kidney injury (AKI) in very low birth weight (VLBW) infants.

METHODS

In this retrospective study of VLBW infants, we analyzed the prevalence of AKI, as defined by changes in serum creatinine and urine output, associated risk factors and outcomes.

RESULTS

A total of 293 VLBW infants (mean gestational age 28.7 wk) were included, of whom 109 weighed less than 1000 g at birth. The overall prevalence of AKI was 11.6% (22% in infants with a birth weight under 1000 g and 5.4% those heavier). A total of 19 (55%) affected infants died, with a mortality rate of 58% in infant less than 1000 g and 50% in those heavier. After adjusting for confounding variables, only necrotizing enterocolitis (NEC) remained associated with AKI, with odds ratio of 4.9 (95%CI: 1.9-18.6). Blood pressure and glomerular filtration rate (GFR) were not different between affected infants and the others upon discharge from hospital. A normal GFR was documented in all affected infants at one year of age.

CONCLUSION

Using Kidney Disease Improving Global Outcomes definition of AKI, it occurred in over 10% of VLBW infants, more commonly in infants with lower birth weight. NEC was an independent associated risk factor. Renal function, as defined by GFR, was normal in all surviving affected infants 10 to 12 mo later.

Increased urinary neutrophil gelatinase-associated lipocalin in very-low-birth-weight infants with oliguria and normal serum creatinine

BACKGROUND

In infants, oliguria is defined as a urine output of <1.5 mL/kg/h. The aim of our study was to assess the impact of oliguria on urinary neutrophil gelatinase-associated lipocalin (NGAL) and serum cystatin C (CysC) levels in very-low-birth-weight infants (VLBWIs) with a normal serum creatinine (Cr) level.

METHODS

Fifty-seven VLBWIs were enrolled in the study. Urinary NGAL, serum CysC and Cr levels and urinary NGAL/Cr ratios were measured. Infants with Apgar scores of >5 at 5 min and/or a serum Cr level of >1.5 mg/dL or those treated for patent ductus arteriosus were excluded. In case of antibiotic treatment, blood and urine samples were collected at ≥48 h after discontinuation of antibiotic treatment.

RESULTS

There was a significant difference in gestational age between infants with oliguric episodes during hospitalization and those without, but not in birth weight, perinatal or postnatal factors. Gestational age was negatively correlated with urinary NGAL and serum CysC levels and urinary NGAL/Cr ratio (p < 0.05), whereas postnatal age was negatively correlated with serum Cr level and urinary NGAL/Cr ratio (p < 0.05). Of the 117 urine and blood samples collected, 25 (21.4%) were obtained from neonates with oliguric episodes. After adjusting for gestational age and postnatal age, comparison of samples collected in infants with and without oliguric episodes revealed significant differences in the mean level of urinary NGAL and in the urinary NGAL/Cr ratio, but not in mean serum CysC or serum Cr levels. The urinary NGAL level [area under the curve (AUC) 0.886, 95% confidence interval (CI) 0.814-0.937] and urinary NGAL/Cr ratio (AUC 0.853, 95% CI 0.775-0.911) showed significantly greater discrimination for oliguria than serum CysC (AUC 0.610, 95% CI: 0.515-0.699) or serum Cr (AUC 0.747, 95%CI 0.659-0.823) levels.

CONCLUSIONS

Urinary NGAL level and urinary NGAL/Cr ratio were more sensitive markers for the presence of oliguria in VLBWIs with normal serum Cr levels than serum CysC level.

Outcome of extremely low birth weight infants with a history of neonatal acute kidney injury

OBJECTIVE

To study the outcome of extremely low birth weight (ELBW) infants with a history of acute kidney injury (AKI).

METHOD

In a retrospective, case control study, medical records of all ELBW infants admitted to the neonatal intensive care unit (NICU) between Jan 2002 and Dec 2011 were reviewed. Medical records were reviewed for infants' demographics, blood pressure (BP) at NICU discharge and at ≥3 years, and estimated glomerular filtration rate (eGFR) at ≥2 years.

RESULTS

During the study period, 222 patients met the inclusion criteria, of whom 10% (23 out of 222) had AKI stage 2 and 3, 39% (87 out of 222) had AKI stage 1, and the rest did not have AKI. At NICU discharge, there was a difference in diastolic BP (DBP) among infants who had AKI stages 2 and 3, those who had stage 1, and those who did not have AKI (53 ± 12 vs 46 ± 9 vs 46 ± 11 mmHg respectively; p = 0.007), and 11% (23 out of 209) had hypertension (HTN). Although there was a significant correlation between the rise in SCr and DBP at NICU discharge in infants with AKI (R = 0.304; p = 0.004), there was no difference in HTN between infants with and those without AKI. At ≥2 years of age, 4% (5 out of 120) across all groups had an eGFR < 90 ml/min/1.73m² or chronic kidney disease (CKD). At ≥3 years of age, 5% (11 out of 222) had HTN.

CONCLUSION

At NICU discharge, infants with AKI stages 2 and 3 have a higher DBP than infants with stage 1 AKI and those who did not have AKI. However, there is no difference in the rate of HTN between the two groups. At ≥2 years ELBW infants are at risk for CKD independently of whether or not they develop neonatal AKI.

The amikacin research program: a stepwise approach to validate dosing regimens in neonates

INTRODUCTION

For safe and effective use of antibacterial agents in neonates, specific knowledge on the pharmacokinetics (PK) and its covariates is needed. This necessitates a stepwise approach, including prospective validation. Areas covered: We describe our approach throughout almost two decades to improve amikacin exposure in neonates. A dosing regimen has been developed and validated using pharmacometrics, considering current weight, postnatal age, perinatal asphyxia, and ibuprofen use. This regimen has been developed based on clinical and therapeutic drug monitoring (TDM) data collected during routine care, and subsequently underwent prospective validation. A similar approach has been scheduled to quantify the impact of hypothermia. Besides plasma observations, datasets on deep compartment PK were also collected. Finally, the available literature on developmental toxicology (hearing, renal) of amikacin is summarized. Expert opinion: The amikacin model reflects a semi-physiological function for glomerular filtration. Consequently, this model can be used to develop dosing regimens for other aminoglycosides or to validate physiology-based pharmacokinetic models. Future studies should explore safety with incorporation of covariates like pharmacogenetics, biomarkers, and long-term outcomes. This includes a search for mechanisms of developmental toxicity. Following knowledge generation and grading the level of evidence in support of data, dissemination and implementation initiatives are needed.

Urinary kidney injury molecule-1 rapid test predicts acute kidney injury in extremely low-birth-weight neonates

BACKGROUND

The new urinary and serum biomarkers are discovered and are being investigated. With them we can diagnose acute kidney injury (AKI) faster and more precisely and they also have a significant role in the outcome prediction.

METHODS

The study included 22 extremely low-birth-weight neonates who were hospitalized in the neonatal intensive care units. They were divided into two groups based on serum creatinine (SCr) level-with and without AKI. Detection and quantification of urinary kidney injury molecule-1 (uKIM-1) was done on the third day of life, using commercially available KIM-1 rapid test. Subsequently, measurements were repeated only in subjects who were diagnosed with AKI, at different values of SCr.

RESULTS

Logistic regression analysis showed that AKI is an independent risk factor for mortality. In a group of neonates with AKI, 50% of neonates administered the KIM-1 rapid test showed positive findings. KIM-1 rapid test was positive in patients with a wide range of SCr levels (range of 78.73-385 µmol/l), but all subjects had oliguria and died in the next 24 h.

CONCLUSION

KIM-1 is a significant predictor of death. On the other hand, our study failed to prove that KIM-1 rapid test has any significance for early prediction of AKI.

Neonatal Acute Kidney Injury

In recent years, there have been significant advancements in our understanding of acute kidney injury (AKI) and its impact on outcomes across medicine. Research based on single-center cohorts suggests that neonatal AKI is very common and associated with poor outcomes. In this state-of-the-art review on neonatal AKI, we highlight the unique aspects of neonatal renal physiology, definition, risk factors, epidemiology, outcomes, evaluation, and management of AKI in neonates. The changes in renal function with gestational and chronologic age are described. We put forth and describe the neonatal modified Kidney Diseases: Improving Global Outcomes AKI criteria and provide the rationale for its use as the standardized definition of neonatal AKI. We discuss risk factors for neonatal AKI and suggest which patient populations may warrant closer surveillance, including neonates <1500 g, infants who experience perinatal asphyxia, near term/ term infants with low Apgar scores, those treated with extracorporeal membrane oxygenation, and those requiring cardiac surgery. We provide recommendations for the evaluation and treatment of these patients, including medications and renal replacement therapies. We discuss the need for long-term follow-up of neonates with AKI to identify those children who will go on to develop chronic kidney disease. This review highlights the deficits in our understanding of neonatal AKI that require further investigation. In an effort to begin to address these needs, the Neonatal Kidney Collaborative was formed in 2014 with the goal of better understanding neonatal AKI, beginning to answer critical questions, and improving outcomes in these vulnerable populations.