Postnatal renal function in preterm newborns: a role of diseases, drugs and therapeutic interventions

Progression of serum creatinine and glomerular filtration rate in neonatal critical care patients during the first seven days of life

BACKGROUND

Serum creatinine and estimated glomerular filtration rate (GFR) are key indicators of kidney function.

METHODS

This descriptive, retrospective study included neonatal patients admitted to a tertiary hospital's neonatal intensive care unit from January 2013 to December 2016. Data on kidney function were collected from birth to 7 days of life. Patients were stratified into four gestational age groups: below 28 weeks, 28-31 weeks, 32-36 weeks, and term neonates. Qualitative variables were expressed as percentages. Quantitative variables were assessed using the Kruskal-Wallis/Wilcoxon tests. Chi-square analysis was performed for categorical variables. Statistical analysis was conducted using SPSS (Version 22.0), with significance set at p < 0.05.

RESULTS

Among 138 patients, 99 (71.7%) were premature. Term neonates showed a gradual postnatal decline in creatinine, while premature infants exhibited an initial rise followed by a decline, with values inversely proportional to gestational age (at seven days: 0.70 ± 0.19 mg/dL in below 28 weeks vs. 0.39 ± 0.08 mg/dL in term, p < 0.001). Among the clinical-epidemiological variables of the included patients, seven significantly influenced serum creatinine. GFR decreased in premature neonates at 24 h, then increased throughout the study. Term neonates demonstrated a progressive GFR increase, with higher values associated with greater gestational age (at seven days:16.8 ± 5.0 ml/min/1.73m2 in below 28 weeks vs. 41.8 ± 8.0 ml/min/1.73m2 in term, p < 0.001).

CONCLUSIONS

Evaluating kidney function in neonates, based on serum creatinine and GFR, requires special attention during the first days of life, particularly in critically ill neonates due to multiple physiological changes and clinical factors that may influence these parameters.

Long-term kidney outcomes in pediatric continuous-flow ventricular assist device patients

BACKGROUND

Continuous-flow ventricular assist devices (CF-VADs) are used increasingly in pediatric end-stage heart failure (ESHF) patients. Alongside common risk factors like oxidant injury from hemolysis, non-pulsatile flow constitutes a unique circulatory stress on kidneys. Post-implantation recovery after acute kidney injury (AKI) is commonly reported, but long-term kidney outcomes or factors implicated in the evolution of chronic kidney disease (CKD) with prolonged CF-VAD support are unknown.

METHODS

We studied ESHF patients supported > 90 days on CF-VAD from 2008 to 2018. The primary outcome was CKD (per Kidney Disease Improving Global Outcomes (KDIGO) criteria). Secondary outcomes included AKI incidence post-implantation and CKD evolution in the 6-12 months of CF-VAD support.

RESULTS

We enrolled 134 patients; 84/134 (63%) were male, median age was 13 [IQR 9.9, 15.9] years, 72/134 (54%) had preexisting CKD at implantation, and 85/134 (63%) had AKI. At 3 months, of the 91/134 (68%) still on a CF-VAD, 34/91 (37%) never had CKD, 13/91 (14%) developed de novo CKD, while CKD persisted or worsened in 49% (44/91). Etiology of heart failure, extracorporeal membrane oxygenation use, duration of CF-VAD, AKI history, and kidney replacement therapy were not associated with different CKD outcomes. Mortality was higher in those with AKI or preexisting CKD.

CONCLUSIONS

In the first multicenter study to focus on kidney outcomes for pediatric long-term CF-VAD patients, preimplantation CKD and peri-implantation AKI were common. Both de novo CKD and worsening CKD can happen on prolonged CF-VAD support. Proactive kidney function monitoring and targeted follow-up are important to optimize outcomes.

Model-Informed Vancomycin Dosing Optimization to Address Delayed Renal Maturation in Infants and Young Children with Critical Congenital Heart Disease

Ensuring safe and effective drug therapy in infants and young children often requires accounting for growth and organ development; however, data on organ function maturation are scarce for special populations, such as infants with congenital diseases. Children with critical congenital heart disease (CCHD) often require multiple staged surgeries depending on their age and disease severity. Vancomycin (VCM) is used to treat postoperative infections; however, the standard pediatric dose (60-80 mg/kg/day) frequently results in overexposure in children with CCHD. In this study, we characterized the maturation of VCM clearance in pediatric patients with CCHD and determined the appropriate dosing regimen using population pharmacokinetic (PK) modeling and simulations. We analyzed 1,254 VCM serum concentrations from 152 postoperative patients (3 days-13 years old) for population PK analysis. The PK model was developed using a two-compartment model with allometrically scaled body weight, estimated glomerular filtration rate (eGFR), and postmenstrual age as covariates. The observed clearance in patients aged ≤ 1 year and 1-2 years was 33% and 40% lower compared with that of non-CCHD patients, respectively, indicating delayed renal maturation in patients with CCHD. Simulation analyses suggested VCM doses of 25 mg/kg/day (age ≤ 3 months, eGFR 40 mL/min/1.73 m2 ) and 35 mg/kg/day (3 months < age ≤ 3 years, eGFR 60 mL/min/1.73 m2 ). In conclusion, this study revealed delayed renal maturation in children with CCHD, could be due to cyanosis and low cardiac output. Model-informed simulations identified the lower VCM doses for children with CCHD compared with standard pediatric guidelines.

Renal deficit and associated factors in children born with low birth weight

INTRODUCTION

Kidney problems may be due to low birth weight alone or may occur in association with other conditions. The objective this study was to evaluate the association between maternal and birth characteristics, anthropometric measurements, and kidney function deficit in low birth weight infants.

METHODS

Cross-sectional study with children who were born weighing < 2500 grams and were under outpatient follow-up. Maternal factors investigated were prenatal care and presence of hypertension, diabetes, and infection during pregnancy. The children's variables were sex, gestational age, birth weight, Apgar score, use of nephrotoxic medications, age, body weight at the time of evaluation, height, and serum creatinine and cystatin C dosages. The glomerular filtration rate (GFR) was estimated with the combined Zapittelli equation. Multivariate logistic regression model was used for identification of associated factors, with renal function deficit (GFR < 60 mL/min/1.73 m2) as the dependent variable.

RESULTS

Of the 154 children evaluated, 34.42% had kidney function deficit. Most of them had a gestational age > 32 weeks (56.6%), a mean birth weight of 1439.7 grams, and mean estimated GFR of 46.9 ± 9.3 mL/min/1.73 m2. There was a significant association of GFR < 60 mL/min/1.73 m2 with children's current weight and use of nephrotoxic drugs.

DISCUSSION

Children born with low birth weight had a high prevalence of kidney function deficit and current normal weight was a protective factor while the use of nephrotoxic drugs during perinatal period increased the chance of kidney deficit. These findings reinforce the need to evaluate the kidney function in these children, especially those who use nephrotoxic drugs.

Déficit renal e fatores associados em crianças nascidas com baixo peso

RESUMO Introdução: Problemas renais podem ser devido apenas ao baixo peso ao nascer ou podem ocorrer em associação com outras condições. O objetivo deste estudo foi avaliar a associação entre características maternas e de nascimento, medidas antropométricas e déficit da função renal em bebês de baixo peso ao nascer. Métodos: Estudo transversal com crianças que nasceram com peso < 2500 gramas e estavam sob acompanhamento ambulatorial. Os fatores maternos investigados foram cuidados pré-natal e presença de hipertensão, diabetes e infecção durante a gravidez. As variáveis das crianças foram sexo, idade gestacional, peso ao nascer, índice Apgar, uso de medicamentos nefrotóxicos, idade, peso corporal no momento da avaliação, altura e dosagens séricas de creatinina e cistatina C. A taxa de filtração glomerular (TFG) foi estimada com a equação combinada de Zapittelli. Utilizou-se um modelo de regressão logística multivariada para identificação de fatores associados, com déficit da função renal (TFG < 60 mL/min/1,73 m2) como variável dependente. Resultados: Das 154 crianças avaliadas, 34,42% apresentaram déficit da função renal. A maioria tinha idade gestacional > 32 semanas (56,6%), peso médio ao nascer de 1439,7 gramas, e TFG média estimada de 46,9 ± 9,3 mL/min/1,73 m2. Houve uma associação significativa da TFG < 60 mL/min/1,73 m2 com o peso atual das crianças e o uso de medicamentos nefrotóxicos. Discussão: Crianças nascidas com baixo peso apresentaram alta prevalência de déficit da função renal e o peso atual normal foi um fator de proteção, enquanto o uso de medicamentos nefrotóxicos durante o período perinatal aumentou a chance de déficit renal. Estes achados reforçam a necessidade de avaliar a função renal destas crianças, especialmente aquelas que usam medicamentos nefrotóxicos.

Low albumin levels are independently associated with neonatal acute kidney injury: a report from AWAKEN Study Group

BACKGROUND

Data from adult and pediatric literature have shown an association between albumin levels and AKI. Whether hypoalbuminemia and neonatal AKI are associated has not been studied.

METHODS

We evaluated the association of albumin with early (during the first postnatal week) and late (after the first postnatal week) AKI for 531 neonates from the Assessment of Worldwide AKI Epidemiology in Neonates (AWAKEN) database and for 3 gestational age (GA) subgroups: < 29, 29 to < 36, and ≥ 36 weeks GA.

RESULTS

Low albumin levels were associated with increased odds of neonatal AKI; for every 0.1 g/dL decrease in albumin, the odds of late AKI increased by 12% on continuous analysis. After adjustment for potential confounders, neonates with albumin values in the lowest quartiles (< 2.2 g/dL) had an increased odds of early [Adjusted Odd Ratio (AdjOR) 2.5, 95% CI = 1.1-5.3, p < 0.03] and late AKI [AdjOR 13.4, 95% CI = 3.6-49.9, p < 0.0001] compared to those with albumin in the highest quartile (> 3.1 g/dL). This held true for albumin levels 2.3 to 2.6 g/dL for early [AdjOR 2.5, 95% CI = 1.2-5.5, p < 0.02] and late AKI [AdjOR 6.4, 95% CI = 1.9-21.6, p < 0.01]. Albumin quartiles of (2.7 to 3.0 g/dL) were associated with increased odds of late AKI. Albumin levels of 2.6 g/dL and 2.4 g/dL best predicted early (AUC = 0.59) and late AKI (AUC = 0.64), respectively. Analysis of albumin association with AKI by GA is described.

CONCLUSIONS

Low albumin levels are independently associated with early and late neonatal AKI. Albumin could be a potential modifiable risk factor for neonatal AKI.

Serum Cystatin C as a predictor of acute kidney injury in neonates: a meta-analysis

OBJECTIVES

The objective of this meta-analysis is to evaluate the diagnostic value of serum Cystatin C in acute kidney injury (AKI) in neonates.

SOURCES

PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), and WanFang Database were searched to retrieve the literature related to the diagnostic value of Cystatin C for neonatal AKI from inception to May 10, 2021. Subsequently, the quality of included studies was determined using the QUADAS-2 tool. Stata 15.0 statistical software was used to calculate the combined sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR). Additionally, meta-regression analysis and subgroup analysis contributed to explore the sources of heterogeneity.

SUMMARY OF THE FINDINGS

Twelve articles were included. The pooled sensitivity was 0.84 (95%CI: 0.74-0.91), the pooled specificity was 0.81 (95%CI: 0.75-0.86), the pooled PLR was 4.39 (95%CI: 3.23-5.97), the pooled NLR was 0.19 (95%CI: 0.11-0.34), and the DOR was 22.58 (95%CI: 10.44-48.83). The area under the receiver operating characteristic curve (AUC) was 0.88 (95%CI: 0.85-0.90). No significant publication bias was identified (p > 0.05).

CONCLUSIONS

Serum Cystatin C has a good performance in predicting neonatal AKI; therefore, it can be used as a candidate biomarker after the optimal level is determined by large prospective studies.

Long-term follow-up of patients after acute kidney injury in the neonatal period: abnormal ambulatory blood pressure findings

Background

Data on the long-term effects of neonatal acute kidney injury (AKI) are limited.

Methods

We invited 302 children who had neonatal AKI and survived to hospital discharge; out of 95 patients who agreed to participate in the study, 23 cases were excluded due to primary kidney, cardiac, or metabolic diseases. KDIGO definition was used to define AKI. When a newborn had no previous serum creatinine, AKI was defined as serum creatinine above the mean plus two standard deviations (SD) (or above 97.5^th percentile) according to gestational age, weight, and postnatal age. Clinical and laboratory features in the neonatal AKI period were recorded for 72 cases; at long-term evaluation (2–12 years), kidney function tests with glomerular filtration rate (eGFR) by the Schwartz formula, microalbuminuria, office and 24-h ambulatory blood pressure monitoring (ABPM), and kidney ultrasonography were performed.

Results

Forty-two patients (58%) had stage I AKI during the neonatal period. Mean age at long-term evaluation was 6.8 ± 2.9 years (range: 2.3–12.0); mean eGFR was 152.3 ± 26.5 ml/min/1.73 m². Office hypertension (systolic and/or diastolic BP ≥ 95^th percentile), microalbuminuria (> 30 mg/g creatinine), and hyperfiltration (> 187 ml/min/1.73 m²) were present in 13.0%, 12.7%, and 9.7% of patients, respectively. ABPM was performed on 27 patients, 18.5% had hypertension, and 40.7% were non-dippers; 48.1% had abnormal findings. Female sex was associated with microalbuminuria; low birth weight (< 1,500 g) and low gestational age (< 32 weeks) were associated with hypertension by ABPM. Twenty-three patients (33.8%) had at least one sign of microalbuminuria, office hypertension, or hyperfiltration. Among 27 patients who had ABPM, 16 (59.3%) had at least one sign of microalbuminuria, abnormal ABPM (hypertension and/or non-dipping), or hyperfiltration.

Conclusion

Even children who experienced stage 1 and 2 neonatal AKI are at risk for subclinical kidney dysfunction. Non-dipping is seen in four out of 10 children. Long-term follow-up of these patients is necessary.

Fluconazole Population Pharmacokinetics after Fosfluconazole Administration and Dosing Optimization in Extremely Low-Birth-Weight Infants

A prospective single-center study was conducted to characterize the pharmacokinetics (PK) of fluconazole (FLCZ) in extremely low-birth-weight infants (ELBWIs) who received fosfluconazole (F-FLCZ). Intravenous F-FLCZ was administered at a dose of 3 mg/kg of body weight every 72 h during the first 2 weeks of life, every 48 h during the third and fourth weeks of life, and every 24 h after 5 weeks of life. Blood samples from ELBWIs treated with F-FLCZ were collected using scavenged samples. The concentration of FLCZ was determined using liquid chromatography-tandem mass spectrometry. The population pharmacokinetic model was established using Phenix NLME 8.2 software. In total, 18 ELBWIs were included in this analysis. Individual PK parameters were determined by a one-compartment analysis with first-order conversion. Postmenstrual age (PMA), serum creatinine (SCr), and alkaline phosphatase were considered covariates for clearance (CL). The mean population CL and the volume of distribution were 0.011 L/h/kg^0.75 and 0.95 L/kg, respectively. Simulation assessments with the final model revealed that the current regimen (3 mg/kg every 72 h) could achieve the proposed target FLCZ trough concentration (>2 μg/mL) in 43.3% and 72.2% of infants with a PMA of ≥37 and 30 to 36 weeks, respectively, and an SCr level of <0.5 mg/dL. Shortened dosing intervals (every 48 or 24 h) might improve the probability of target attainment. This study was the first to assess the PK of F-FLCZ in ELBWI, as well as the first to provide fundamental information about FLCZ exposure after F-FLCZ administration, with the goal of facilitating dose optimization in the ELBWI population.

IMPORTANCE Invasive fungal infection is an important cause of mortality and morbidity in very preterm or very-low-birth-weight infants. In order to limit the risk of invasive fungal infections in this population, the administration of fluconazole is generally recommended for extremely low-birth-weight infants admitted to a neonatal intensive care unit with a Candida species colonization prevalence rate of >10%, under the guidelines of the Infectious Diseases Society of America. Fosfluconazole can reduce the volume of solution required for intravenous therapy compared to fluconazole because it has increased solubility, which is a major advantage for infants undergoing strict fluid management. To date, no study has demonstrated the fluconazole pharmacokinetics after fosfluconazole administration in neonates and infants, and this needs to be clarified. Here, we characterized the pharmacokinetics of fluconazole in extremely low-birth-weight infants who received F-FLCZ and explored the appropriate dosage in this patient population.

Prediction of glomerular filtration rate maturation across preterm and term neonates and young infants using inulin as marker

Describing glomerular filtration rate (GFR) maturation across the heterogeneous population of preterm and term neonates and infants is important to predict the clearance of renally cleared drugs. This study aims to describe the GFR maturation in (pre)term neonates and young infants (PNA < 90 days) using individual inulin clearance data (CL_inulin). To this end, published GFR maturation models were evaluated by comparing their predicted GFR with CL_inulin retrieved from literature. The best model was subsequently optimized in NONMEM V7.4.3 to better fit the CL_inulin values. Our study evaluated seven models and collected 381 individual CL_inulin values from 333 subjects with median (range) birthweight (BWb) 1880 g (580-4950), gestational age (GA) 34 weeks (25-43), current weight (CW) 1890 g (480-6200), postnatal age (PNA) 3 days (0-75), and CL_inulin 2.20 ml/min (0.43-17.90). The De Cock 2014 model (covariates: BWb and PNA) performed the best in predicting CL_inulin, followed by the Rhodin 2009 model (covariates: CW and postmenstrual age). The final optimized model shows that GFR at birth is determined by BWb, thereafter the maturation rate of GFR is dependent on PNA and GA, with a higher GA showing an overall faster maturation. To conclude, using individual CL_inulin data, we found that a model for neonatal GFR requires a distinction between prenatal maturation quantified by BWb and postnatal maturation. To capture postnatal GFR maturation in (pre)term neonates and young infants, we developed an optimized model in which PNA-related maturation was dependent on GA.

The concomitant use of vancomycin and piperacillin-tazobactam is associated with acute kidney injury (AKI) in extremely low birth weight infants (ELBW)

BACKGROUND

Late-onset sepsis is common in extremely low birth weight (ELBW) infants, and it leads to the use of antibiotics to cover resistant organisms, which can be nephrotoxic. Here we have investigated the role of vancomycin plus piperacillin-tazobactam on the rate of acute kidney injury (AKI).

METHODS

In a retrospective case-control study, medical records of all ELBW infants who were admitted to our Neonatal Intensive Care Unit (NICU) with late onset sepsis who were prescribed vancomycin plus piperacillin-tazobactam were reviewed for demographics, clinical characteristics, use of potential nephrotoxic medications and outcomes.

RESULTS

During the study period, 264 patients were admitted, of whom 28.4%(75/264) received vancomycin plus piperacillin-tazobactam and were matched with 64 controls. There were no differences in gestational age or birth weight between cases and controls [688±160 vs. 689±162 grams (p = 0.99), and 24.7±1.8 vs. 24.7±1.6 weeks (p = 0.99) respectively]. There was no difference in the rate of sepsis between cases and controls [76%(55/72) vs. 64%(41/64) respectively, p = 0.11]. Infants exposed to vancomycin plus piperacillin-tazobactam had a higher percentage of concomitant use of vasopressors and amphotericin. To adjust for confounders, a logistic regression analysis was conducted with AKI as the dependent variable. Use of vasopressors and vancomycin plus piperacillin-tazobactam were the only risk factors associated with AKI with an adjusted OR (95%CI) of 4.08 (1.90-8.74), p <  0.001; and 2.87 (1.26-6.53), p = 0.01 respectively.

CONCLUSION

The use of vancomycin plus piperacillin-tazobactam in ELBW infants is associated with an increased risk for AKI.

Incidence, Risk Factors, and Outcomes of Neonatal Acute Kidney Injury: Protocol of a Multicentric Prospective Cohort Study [The Indian Iconic Neonatal Kidney Educational Registry]

Background: Acute kidney injury (AKI) is a significant problem in neonates, but the evidence is sparse. Neonatal AKI is an independent risk factor for increased mortality and prolonged hospital stay. There are stark differences in the epidemiology of AKI in neonates amongst the developing and the developed world. Increased prevalence of neonatal sepsis, lack of awareness about neonatal AKI and poor access to pediatric nephrologists add to the improper management of neonatal AKI in the developing countries. Methods: This study is a multicentric, national, prospective cohort study [The Indian iconic Neonatal Kidney Educational Registry (TINKER)] conducted in level 2-3 NICUs in 11 centers across India. We have enrolled nearly 2,000 neonates over the study period. Neonates (≤ 28 days) who were admitted in NICU and those who received intravenous (IV) fluids for at least 48 h for hydration and/or nutrition have been included. Data collection included: (1) baseline demographics (2) daily physiologic and laboratory parameters (3) discharge data. KDIGO workgroup AKI definition modified for neonates was used for defining AKI. Data entry was carried out by individual participating centers using a web-based database (akiregistry.org). De-identified data has been maintained and handled by the principal investigator (PI). This collaboration plans to disseminate data through peer-reviewed publications and through presentations at educational conferences. Conclusions: The purpose of this study is to create the first prospective neonatal all-cause AKI data repository and describe the incidence of neonatal AKI in NICUs in the country and determine the risk factors as well as the outcomes of such neonates-both short-term and long-term outcomes. This will eventually spur therapeutic advancements, facilitate decipherment of epidemiological trends, risk factors as well as outcomes and identify disparities in management across the nation.

Low hemoglobin levels are independently associated with neonatal acute kidney injury: a report from the AWAKEN Study Group

BACKGROUND

Studies in adults showed a relationship between low hemoglobin (Hb) and acute kidney injury (AKI). We performed this study to evaluate this association in newborns.

METHODS

We evaluated 1891 newborns from the Assessment of Worldwide AKI Epidemiology in Neonates (AWAKEN) database. We evaluated the associations for the entire cohort and 3 gestational age (GA) groups: <29, 29-<36, and ≥36 weeks' GA.

RESULTS

Minimum Hb in the first postnatal week was significantly lower in neonates with AKI after the first postnatal week (late AKI). After controlling for multiple potential confounders, compared to neonates with a minimum Hb ≥17.0 g/dL, both those with minimum Hb ≤12.6 and 12.7-14.8 g/dL had an adjusted increased odds of late AKI (aOR 3.16, 95% CI 1.44-6.96, p = 0.04) and (aOR 2.03, 95% CI 1.05-3.93; p = 0.04), respectively. This association was no longer evident after controlling for fluid balance. The ability of minimum Hb to predict late AKI was moderate (c-statistic 0.68, 95% CI 0.64-0.72) with a sensitivity of 65.9%, a specificity of 69.7%, and a PPV of 20.8%.

CONCLUSIONS

Lower Hb in the first postnatal week was associated with late AKI, though the association no longer remained after fluid balance was included.

IMPACT

The current study suggests a possible novel association between low serum hemoglobin (Hb) and neonatal acute kidney injury (AKI). The study shows that low serum Hb levels in the first postnatal week are associated with increased risk of AKI after the first postnatal week. This study is the first to show this relationship in neonates. Because this study is retrospective, our observations cannot be considered proof of a causative role but do raise important questions and deserve further investigation. Whether the correction of low Hb levels might confer short- and/or long-term renal benefits in neonates was beyond the scope of this study.

How should we assess renal function in neonates and infants?

AIM

Review of current knowledge on assessing renal function in term and preterm neonates.

METHODS

Literature review and analysis of own data.

RESULTS

Prematurity, genetic, environmental and maternal factors may alter peak nephron endowment and life-long renal function. Nephrogenesis continues until 34-36 weeks of gestation, but it is altered with premature delivery. Variability of nephron endowment has a substantial impact on the clearance of renally excreted drugs. Postnatally, glomerular function rate (GFR) increases daily, doubles by two weeks, and slowly reaches full maturity at 18 months of age. Ideally, renal function biomarkers should be expressed as age-independent z-scores, and evidence suggests indexing these values to post-conceptual age rather than chronological age. Newborn and maternal serum creatinine correlate tightly for more than 72 hours after delivery, rendering this biomarker unsuitable for the assessment of neonatal renal function. Cystatin C does not cross the placenta and may be the preferred biomarker in the neonate. Here, we provide preliminary data on the natural evolution of the cystatin C eGFR in infancy.

CONCLUSION

Cystatin C may be superior for GFR estimation in neonates, but the best approach to drug dosing of renally excreted drugs remains to be established.

The effect of antenatal indomethacin on extremely preterm neonatal kidney function

Introduction/Objective: Indomethacin is an effective tocolytic to prevent extremely preterm birth. Prior studies have associated antenatal indomethacin exposure with adverse preterm neonatal intestinal and neurological outcomes. Indomethacin is a nephrotoxic medication that may also affect preterm neonatal kidneys. We sought to evaluate the effect of antenatal indomethacin on extremely preterm neonatal kidney function and acute kidney injury (AKI) in the first week of age.Methods: A retrospective cohort study was conducted on neonates born < 29 weeks at a level III neonatal intensive care unit (NICU) from January 2018-April 2019. Serum creatinine (sCr) values and urine output (UOP) in the first seven days of age and the neonate's peak serum creatinine within the first 30 days were evaluated. Neonatal AKI was defined by the modified neonatal Kidney Disease Improving Global Outcomes (KDIGO) definition including urine output.Results: 17 of the 55 neonates meeting criteria for this study were exposed to indomethacin. The average gestational age at birth was similar between study groups. Maternal preeclampsia was more common among women who did not receive indomethacin (p = 0.021). Indomethacin exposed neonates received more gentamicin (p = 0.024). Overall, staging of the neonatal AKI did not differ significantly between the study groups, regardless of how it was quantified (sCr or UOP) or the duration of time in which the injury developed (7 days or 30 days). Separate analysis of sCr and UOP in the first seven days also failed to show any statistically significant differences between the two groups.Conclusion: In this small cohort study of extremely preterm neonates, those born to mothers treated with indomethacin did not have an increased incidence of AKI compared to neonates born to unexposed mothers. Although no statistically significant differences in UOP or sCr were found, they deserve further evaluation in adequately powered prospective clinical trials. Future prospective studies with long-term follow-up utilizing advanced biomarkers are needed to determine how antenatal indomethacin affects extremely preterm neonatal kidney function in the NICU, during childhood, and as adults.

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.

Blood urea in preterm infants on routine parenteral nutrition: A multiple linear regression analysis

BACKGROUND

Blood urea is considered a marker of amino acid utilization in preterm infants on routine parenteral nutrition. However, the association between blood urea and intravenous amino acid intake remains debated.

AIMS

To evaluate the association between blood urea and both nutrition and clinical data, in a large cohort of preterm infants.

METHODS

Consecutively admitted preterm infants with a gestational age of less than 32 weeks and a birth weight lower than 1250 g on routine parenteral nutrition from the first hour of life were studied. Clinical and nutrition data collected hourly during the hospitalization were used in multiple linear regression analysis.

RESULTS

We studied 674 patients and 1863 blood urea determinations. Blood urea concentration was positively associated with blood creatinine concentration, intravenous amino acid intake, patent ductus arteriosus and respiratory distress syndrome, and negatively associated with intravenous non-protein energy intakes, daily weight change, gestational age, being small for gestational age, antenatal steroids therapy and reverse flow in the umbilical artery (p < 0.001; R = 0.7).

CONCLUSIONS

From a nutrition perspective, in our large cohort of small preterm infants blood urea was positively correlated with intravenous amino acid intake and negatively correlated with intravenous non-protein energy intake. This is in line with current knowledge in human physiology and suggest that a reduction of intravenous amino acid intake based on blood urea concentrations was justified.

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.

Laboratory Findings After Urinary Tract Infection and Antimicrobial Prophylaxis in Children With Vesicoureteral Reflux

It is a common practice to monitor blood tests in patients receiving long-term trimethoprim-sulfamethoxazole (TMP-SMZ) prophylaxis for recurrent urinary tract infections. This multicenter, randomized, placebo-controlled trial enrolled 607 children aged 2 to 71 months with vesicoureteral reflux diagnosed after symptomatic urinary tract infection. Study participants received TMP-SMZ (n = 302) or placebo (n = 305) and were followed for 2 years. Serum electrolytes (n ≥ 370), creatinine (n = 310), and complete blood counts (n ≥ 206) were measured at study entry and at the 24-month study conclusion. We found no significant electrolyte, renal, or hematologic abnormalities when comparing the treatment and placebo groups. We observed changes in several laboratory parameters in both treatment and placebo groups as would normally be expected with physiologic maturation. Changes were within the normal range for age. Long-term use of TMP-SMX had no treatment effect on complete blood count, serum electrolytes, or creatinine. Our findings do not support routine monitoring of these laboratory tests in children receiving long-term TMP-SMZ prophylaxis.

Incidence and Risk Factors of Early Onset Neonatal AKI

BACKGROUND AND OBJECTIVES

Neonatal AKI is associated with poor short- and long-term outcomes. The objective of this study was to describe the risk factors and outcomes of neonatal AKI in the first postnatal week.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The international retrospective observational cohort study, Assessment of Worldwide AKI Epidemiology in Neonates (AWAKEN), included neonates admitted to a neonatal intensive care unit who received at least 48 hours of intravenous fluids. Early AKI was defined by an increase in serum creatinine >0.3 mg/dl or urine output <1 ml/kg per hour on postnatal days 2-7, the neonatal modification of Kidney Disease: Improving Global Outcomes criteria. We assessed risk factors for AKI and associations of AKI with death and duration of hospitalization.

RESULTS

Twenty-one percent (449 of 2110) experienced early AKI. Early AKI was associated with higher risk of death (adjusted odds ratio, 2.8; 95% confidence interval, 1.7 to 4.7) and longer duration of hospitalization (parameter estimate: 7.3 days 95% confidence interval, 4.7 to 10.0), adjusting for neonatal and maternal factors along with medication exposures. Factors associated with a higher risk of AKI included: outborn delivery; resuscitation with epinephrine; admission diagnosis of hyperbilirubinemia, inborn errors of metabolism, or surgical need; frequent kidney function surveillance; and admission to a children's hospital. Those factors that were associated with a lower risk included multiple gestations, cesarean section, and exposures to antimicrobials, methylxanthines, diuretics, and vasopressors. Risk factors varied by gestational age strata.

CONCLUSIONS

AKI in the first postnatal week is common and associated with death and longer duration of hospitalization. The AWAKEN study demonstrates a number of specific risk factors that should serve as "red flags" for clinicians at the initiation of the neonatal intensive care unit course.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Assessment of Worldwide AKI Epidemiology in Neonates (AWAKEN), NCT02443389.

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.

Natural evolution of ductus arteriosus with noninterventional conservative management in extremely preterm infants born at 23-28 weeks of gestation

This study aimed to determine the natural course of patent ductus arteriosus (PDA) with noninterventional conservative management and whether the presence and/or prolonged duration of hemodynamically significant (HS) PDA increased the risk of mortality and morbidities in extremely preterm (EPT) infants. We retrospectively reviewed the medical records of EPT infants born at 23-28 weeks of gestation (n = 195) from January 2011 to June 2014, when PDA was managed with noninterventional conservative treatment. We stratified infants into three subgroups of 23-24, 25-26, and 27-28 weeks and analyzed the prevalence and natural evolution of HS PDA, defined as ventilator dependency and PDA size ≥2 mm. Multivariate regression analyses determined if the presence and/or prolonged duration of HS PDA increased the risk for mortality and/or morbidities. The overall incidence of HS PDA was 57% (111/195) at the end of the first postnatal week. In subgroup analyses, infants with 23-24 weeks of gestation had the highest incidence (93%, 50/54), with 64% (47/74) for 25-26 weeks and 21% (14/67) for 27-28 weeks. Six (5%) of 111 infants with HS PDA were discharged without ductus closure, 4 had spontaneous PDA closure on follow up, and device closure was performed for 2 infants. In the multivariate analyses, the presence or prolonged duration (per week) of HS PDA was not associated with the risk of mortality and/or morbidities. Spontaneous closure of HS PDA was mostly achieved, even in EPT infants, with a noninterventional conservative approach. In conclusion, our data showed the incidence and natural course of HS PDA in EPT infants and suggested that the presence or prolonged duration of HS PDA might not increase the rate of mortality or morbidities.

Incidence and Risk Factors of Early Onset Neonatal AKI

BACKGROUND AND OBJECTIVES

Neonatal AKI is associated with poor short- and long-term outcomes. The objective of this study was to describe the risk factors and outcomes of neonatal AKI in the first postnatal week.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The international retrospective observational cohort study, Assessment of Worldwide AKI Epidemiology in Neonates (AWAKEN), included neonates admitted to a neonatal intensive care unit who received at least 48 hours of intravenous fluids. Early AKI was defined by an increase in serum creatinine >0.3 mg/dl or urine output <1 ml/kg per hour on postnatal days 2-7, the neonatal modification of Kidney Disease: Improving Global Outcomes criteria. We assessed risk factors for AKI and associations of AKI with death and duration of hospitalization.

RESULTS

Twenty-one percent (449 of 2110) experienced early AKI. Early AKI was associated with higher risk of death (adjusted odds ratio, 2.8; 95% confidence interval, 1.7 to 4.7) and longer duration of hospitalization (parameter estimate: 7.3 days 95% confidence interval, 4.7 to 10.0), adjusting for neonatal and maternal factors along with medication exposures. Factors associated with a higher risk of AKI included: outborn delivery; resuscitation with epinephrine; admission diagnosis of hyperbilirubinemia, inborn errors of metabolism, or surgical need; frequent kidney function surveillance; and admission to a children's hospital. Those factors that were associated with a lower risk included multiple gestations, cesarean section, and exposures to antimicrobials, methylxanthines, diuretics, and vasopressors. Risk factors varied by gestational age strata.

CONCLUSIONS

AKI in the first postnatal week is common and associated with death and longer duration of hospitalization. The AWAKEN study demonstrates a number of specific risk factors that should serve as "red flags" for clinicians at the initiation of the neonatal intensive care unit course.

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.

The dark side of ibuprofen in the treatment of patent ductus arteriosus: could paracetamol be the solution?

INTRODUCTION

Patent ductus arteriosus (PDA) persistence is associated, in prematures, to several complications. The optimal PDA management is still under debate, especially regarding the best therapeutic approach and the time to treat. The available drugs are not exempt from contraindications and side effects; ibuprofen itself, although representing the first-choice therapy, can show nephrotoxicity and other complications. Paracetamol seems a valid alternative to classic nonsteroidal anti-inflammatory Drugs, with a lower toxicity. Areas covered: Through an analysis of the published literature on ibuprofen and paracetamol effects in preterm neonates, this review compares the available treatments for PDA, analyzing the mechanisms underlining ibuprofen-associated nephrotoxicity and the eventual paracetamol-induced hepatic damage, also providing an update of what has been yet demonstrated and a clear description of the still open issues. Expert Opinion: Paracetamol is an acceptable alternative in case of contraindication to ibuprofen; its toxicity, in this setting, is very low. Lower doses may be effective, with even fewer risks. In the future, paracetamol could represent an efficacious first-line therapy, although its safety, optimal dosage, and global impact have to be fully clarified through long-term trials, also in the perspective of an individualized and person-based therapy taking into account the extraordinary individual variability.

[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.

Acute kidney injury in necrotizing enterocolitis predicts mortality

BACKGROUND

Morbidity and mortality with necrotizing enterocolitis (NEC) remains a significant challenge. Acute kidney injury (AKI) has been shown to worsen survival in critically ill neonates. To our knowledge, this study is the first to evaluate the prevalence of AKI and its impact on outcomes in neonatal NEC.

METHODS

We carried out a single-center retrospective chart review of all neonates treated for NEC between 2003 and 2015 (N = 181). AKI is defined as a rise in serum creatinine (SCr) from a previous trough according to neonatal modified KDIGO criteria (stage 1 = SCr rise 0.3 mg/dL or SCr 150 < 200%, stage 2 = SCr rise 200 < 300%, stage 3 = SCr rise ≥300%, SCr 2.5 mg/dL or dialysis). Primary outcome was in-hospital mortality and secondary outcomes were hospital length of stay (LOS) and need for and type of surgery.

RESULTS

Acute kidney injury occurred in 98 neonates (54%), with 39 stage 1 (22%), 31 stage 2 (18%), and 28 stage 3 (16%), including 5 requiring dialysis. Non-AKI and AKI groups were not statistically different in age, weight, Bell's NEC criteria, and medication exposure (vasopressors, vancomycin, gentamicin, or diuretic). Neonates with AKI had higher mortality (44% vs 25.6%, p = 0.008) and a higher chance of death (HR 2.4, CI 1.2-4.8, p = 0.009), but the effect on LOS on survivors did not reach statistical significance (79 days, interquartile range [IQR] 30-104 vs 54 days, IQR 30-92, p = 0.09). Overall, 48 (27.9%) patients required surgical intervention.

CONCLUSIONS

This study shows that AKI not only occurs in over half of patients with NEC, but that it is also associated with more than a two-fold higher mortality, highlighting the importance of early recognition and potentially early intervention for AKI.

Effect of perinatal risk factors on neutrophil gelatinase-associated lipocalin (NGAL) level in umbilical and peripheral blood in neonates

Introduction

Acute kidney injury biomarkers are opening a new era in diagnosing kidney failure. The requirement for a specific and sensitive marker of kidney function is highly desirable in neonates because the diagnostic possibilities in this age group are not sufficient. Recent research show that neutrophil gelatinase-associated lipocalin (NGAL) can have a great potential but there is a wide range of medical conditions, that may influence their expression.

The aim of the study

was to evaluate the impact of perinatal risk factors on NGAL level in neonates.

Material and methods

NGAL was measured in umbilical cord blood and peripheral blood in full term neonates with perinatal risk factors during the first days of life.

Results

We found significantly higher umbilical cord blood NGAL levels in neonates with perinatal risk factors (117.69 ng/ml) compared to the control group (64.37 ng/ml). No significant difference in peripheral blood NGAL level was shown between the two groups. Umbilical cord blood NGAL level correlated positively with peripheral blood NGAL level (r = 0.36, p < 0.01). Umbilical cord blood NGAL level was significantly higher in neonates with fetal distress and infection compared to neonates with other perinatal risk factors. Peripheral blood NGAL level was significantly higher in neonates with infection compared to neonates with other perinatal risk factors. Significantly higher umbilical cord blood NGAL levels were seen in neonates born by operative delivery compared to born by natural delivery.

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.

Fetal anhydramnios following maternal non-steroidal anti-inflammatory drug use in pregnancy

We present a case report of transient fetal anhydramnios following maternal non-steroidal anti-inflammatory drug use in pregnancy. This reduction in liquor volume resolved following cessation of the medication with no obvious ill-effect on neonatal outcome. The case report is followed by a comprehensive summary of the relevant literature.

The Impact of Kidney Development on the Life Course: A Consensus Document for Action

Hypertension and chronic kidney disease (CKD) have a significant impact on global morbidity and mortality. The Low Birth Weight and Nephron Number Working Group has prepared a consensus document aimed to address the relatively neglected issue for the developmental programming of hypertension and CKD. It emerged from a workshop held on April 2, 2016, including eminent internationally recognized experts in the field of obstetrics, neonatology, and nephrology. Through multidisciplinary engagement, the goal of the workshop was to highlight the association between fetal and childhood development and an increased risk of adult diseases, focusing on hypertension and CKD, and to suggest possible practical solutions for the future. The recommendations for action of the consensus workshop are the results of combined clinical experience, shared research expertise, and a review of the literature. They highlight the need to act early to prevent CKD and other related noncommunicable diseases later in life by reducing low birth weight, small for gestational age, prematurity, and low nephron numbers at birth through coordinated interventions. Meeting the current unmet needs would help to define the most cost-effective strategies and to optimize interventions to limit or interrupt the developmental programming cycle of CKD later in life, especially in the poorest part of the world.

Coagulase negative staphylococcal sepsis in neonates: do we need to adapt vancomycin dose or target?

Background

Despite differences in types of infection and causative organisms, pharmacokinetic-pharmacodynamic (PKPD) targets of vancomycin therapy derived from adult studies are suggested for neonates. We aimed to identify doses needed for the attainment of AUC/MIC > 400 and AUC/MIC > 300 in neonates with sepsis and correlate these targets with recommended doses and treatment outcome.

Methods

Neonates who had Vancomycin therapeutic drug monitoring (TDM) performed between January 1, 2010 and December 31, 2012 were studied. Clinical characteristics, episodes of Gram-positive sepsis with outcomes and all neonatal blood culture isolates in hospital were collected from medical records. To estimate probability of target attainment of AUC/MIC >400 and AUC/MIC >300 a 1000-subject Monte Carlo simulation was performed by calculating AUC using Anderson’s (Anderson et al. 2006) and TDM trough concentrations (C_trough) based population PK models.

Results

Final dataset included 76 patients; 57 with confirmed Gram-positive sepsis. TDM was taken after the 1^st to 44^th dose. 84.1% of C_trough were within the range 5–15 mg/L. Currently recommended doses achieved probability of the targets (PTA) of AUC/MIC >400 and AUC/MIC >300 in less than 25% and 40% of cases, respectively. Doses required for 80% PTA of AUC/MIC > 400 for MIC ≥2 mg/L resulted in C_trough values ≥14 mg/L. Mean AUC/MIC values were similar in treatment failure and success groups.

Conclusion

With currently recommended vancomycin dosing the therapeutic target of AUC/MIC > 400 is achieved only by 25% of neonates. Appropriate PKPD targets and respective dosing regimens need to be defined in prospective clinical studies in this population.

Renal outcome in children born preterm with neonatal acute renal failure: IRENEO-a prospective controlled study

OBJECTIVES

Acute kidney injury (AKI) is a severe complication of prematurity, with currently unknown consequences for renal function in childhood. The objective of this study was to search for signs of reduced nephron number in children aged 3-10 years who had been born preterm with neonatal AKI and compare this group to control children.

METHODS

IRENEO was a prospective, controlled study conducted in 2013 in Nantes University Hospital. Children who were born at less than 33 weeks gestational age (GA) and included in the LIFT cohort were eligible for entry. Twenty-five children with AKI (AKI-C) and 49 no-AKI children were matched on a propensity score of neonatal AKI and age. AKI was defined as a serum creatinine level higher than critical values: 1.6 mg/dl (GA 24-27 weeks), 1.1 mg/dl (28-29) and 1 mg/dl (GA 30-32). Renal function was evaluated during childhood.

RESULTS

Mean age of the children at the time of the study was 6.6 years. No difference in microalbuminuria, estimated glomerular filtration rate (GFR) or pulse wave velocity was observed between the two groups. Renal volume was lower in the AKI-C group (57 vs. 68; p = 0.04). In the entire cohort, 10.8 % had a microalbuminuria, and 23 % had a diminished GFR (median 79 ml/min/1.73 m²). The GFR was lower in children with very low birth weight of <1000 g (99 vs. 107 ml/min/1.73 m²; p = 0.04).

CONCLUSION

In children born preterm, neonatal AKI does not seem to influence renal function. However, independent ofAKI, a large proportion of very preterm infants, especially those with very low birth weight, presented with signs of nephron reduction, thus requiring follow-up with a nephrologist.

Change of cystatin C values in preterm infants with asphyxia-From two centers of China

BACKGROUND

To explore the values of cystatin C (Cys-C) in asphyxial preterm babies as an effective endogenous marker of renal function.

METHODS

After birth, preterm infants with 5-minute Apgar score <8 were included into the asphyxia group. Finally, 276 preterm infants born in two neonatal intensive care units were studied (including 78 babies in the asphyxia group and 198 babies in the control group). Blood samples were obtained from peripheral veins on day 1, day 7, and day 28 when routine blood screening tests were performed.

RESULTS

In first day samples, the mean levels of Cys-C were 2.21 (1.49-2.98) mg/L with gestational age (GA) >32, 1.94 (1.37-2.76) mg/L with GA 28-32, and 1.87 (1.49-2.13) mg/L with GA <28 in the asphyxia group. In seventh day samples, the mean levels of Cys-C were 2.35 (1.57-3.26) mg/L with GA>32, 2.07 (1.42-2.90) mg/L with GA 28-32, and 1.69 (1.13-2.04) mg/L with GA <28. In twenty-eighth day samples, the mean levels of Cys-C were 1.92 (1.61-2.13) mg/L with GA>32, 1.79 (1.29-1.84) mg/L with GA 28-32, and 1.66 (1.21-2.10) mg/L GA <28. There were significant differences not only between the asphyxia and control groups, but also between the mild, moderate, and severe asphyxia groups.

CONCLUSION

Cys-C has a good distinguishability in asphyxial neonates in spite of gestational age or birth weight in the Chinese population. Further studies with large numbers of cases are required to assess whether Cys-C could replace creatinine (Cr) and blood urea nitrogen (BUN) as an endogenous marker of renal function.

Non-dialytic management of acute kidney injury in newborns

Treating acute kidney injury (AKI) in newborns is often challenging due to the functional immaturity of the neonatal kidney. Because of this physiological limitation, renal replacement therapy (RRT) in this particular patient population is difficult to execute and may lead to unwanted complications. Although fluid overload and electrolyte abnormalities, as seen in neonatal AKI, are indications for RRT initiation, there is limited evidence that RRT initiated in the first year of life improves long-term outcome. The underlying cause of AKI in a newborn patient should determine the treatment strategies to restore appropriate renal function. However, our understanding of this common clinical condition remains limited, as no standardized, evidence-based definition of neonatal AKI currently exists. Non-dialytic management of AKI in these patients may restore appropriate renal function to these patients without exposure to complications often encountered with RRT.

Screening for secondary hyperparathyroidism in preterm infants

BACKGROUND

The major cause of osteopathy of prematurity is dietary phosphate deficiency, but secondary hyperparathyroidism caused by calcium deficiency or vitamin D deficiency is also important. Because parathyroid hormone (PTH) mobilizes calcium and phosphate from the bone, hyperparathyroidism worsens osteopathy of prematurity. In order to identify useful markers to screen for and diagnose hyperparathyroidism in preterm infants, we measured serum and urinary biochemical markers.

METHODS

Several biomarkers, including serum intact PTH (iPTH), were measured in urine and serum samples obtained from 95 preterm infants, and the relationship between serum iPTH and the other parameters was analyzed.

RESULTS

Mean gestation was 33.2 ± 2.9 weeks, and mean birthweight was 1705 ± 402 g. Samples were collected around postnatal day 17.3 ± 7.4. Fourteen infants (14.7%) had iPTH >65 pg/mL. Cut-offs for serum alkaline phosphatase (ALP) and percent tubular reabsorption rate of phosphate (%TRP) were fixed at 1300 IU/L and 93%, respectively using receiver operating characteristic curves with iPTH cut-off of 65 pg/mL. Serum ALP was proven to be a good marker: ALP had a sensitivity of 78.6% and a specificity of 86.4%, while %TRP itself was not: %TRP had a sensitivity of 64.3% and a specificity of 58.0%. Combined measurement of serum ALP (>1300 IU/L) and %TRP (≤93%), however, had a specificity of 93.8% for detecting elevated iPTH.

CONCLUSION

Measurement of serum ALP (>1300 IU/L) is considered as an effective screening method to detect hyperparathyroidism. In addition, combined assessment of ALP(>1300 IU/L) and %TRP(≤93%) is a good indicator of elevated iPTH in preterm infants.

Development and Evaluation of a Gentamicin Pharmacokinetic Model That Facilitates Opportunistic Gentamicin Therapeutic Drug Monitoring in Neonates and Infants

Trough gentamicin therapeutic drug monitoring (TDM) is time-consuming, disruptive to neonatal clinical care, and a patient safety issue. Bayesian models could allow TDM to be performed opportunistically at the time of routine blood tests. This study aimed to develop and prospectively evaluate a new gentamicin model and a novel Bayesian computer tool (neoGent) for TDM use in neonatal intensive care. We also evaluated model performance for predicting peak concentrations and the area under the concentration-time curve from time 0 h to time t h (AUC0- t). A pharmacokinetic meta-analysis was performed on pooled data from three studies (1,325 concentrations from 205 patients). A 3-compartment model was used with the following covariates: allometric weight scaling, postmenstrual and postnatal age, and serum creatinine concentration. Final parameter estimates (standard errors) were as follows: clearance, 6.2 (0.3) liters/h/70 kg of body weight; central volume (V), 26.5 (0.6) liters/70 kg; intercompartmental disposition (Q), 2.2 (0.3) liters/h/70 kg; peripheral volume V2, 21.2 (1.5) liters/70 kg; intercompartmental disposition (Q2), 0.3 (0.05) liters/h/70 kg; peripheral volume V3, 148 (52.0) liters/70 kg. The model's ability to predict trough concentrations from an opportunistic sample was evaluated in a prospective observational cohort study that included data from 163 patients and 483 concentrations collected in five hospitals. Unbiased trough predictions were obtained; the median (95% confidence interval [CI]) prediction error was 0.0004 (-1.07, 0.84) mg/liter. Results also showed that peaks and AUC0- t values could be predicted (from one randomly selected sample) with little bias but relative imprecision, with median (95% CI) prediction errors being 0.16 (-4.76, 5.01) mg/liter and 10.8 (-24.9, 62.2) mg · h/liter, respectively. neoGent was implemented in R/NONMEM and in the freely available TDMx software.

The spectrum of onset of acute kidney injury in premature infants less than 30 weeks gestation

OBJECTIVE

To determine risk factors for acute kidney injury (AKI) in preterm infants as a function of time of onset.

STUDY DESIGN

In this 5 1/2-year, single-center, retrospective study, incidence and timing of AKI was determined using modified Acute Kidney Injury Network criteria. Characteristics of newborns with and without AKI were compared by chi square and t-tests. Logistic regression was used to examine risk factors for AKI as a function of time of onset and potential confounders.

RESULT

AKI occurred in 30.3% of 357 neonates; 72.2% was stage 1. Gestational ages (GA), initial Cr, maternal magnesium and volume resuscitation were associated with early AKI (days 0 to 1). Volume resuscitation, umbilical arterial line and receipt of non-steroidal anti-inflammatory drug (NSAID) for patent ductus arteriosus were associated with intermediate AKI (days 2 to 5). GA, steroids for early hypotension, necrotizing enterocolitis and sepsis were associated with late AKI (⩾day 6).

CONCLUSION

Stage 1 AKI is a common morbidity in our population. Risk factors for AKI in our population differed with time of onset.

A propensity-matched cohort study of vancomycin-associated nephrotoxicity in neonates

BACKGROUND

The incidence of nephrotoxicity among vancomycin-treated neonates has been reported to range from 2% to 20%. These widely varying estimates have led to confusion and controversy regarding the safety of vancomycin among neonates.

OBJECTIVE

Evaluate the incidence of nephrotoxicity among neonates receiving vancomycin concomitantly with gentamicin.

DESIGN

Retrospective observational cohort study using propensity score matching to provide covariate balance between neonates who did or did not receive vancomycin based on factors known to be related to the development of renal dysfunction.

SETTING

Hospitals (n=22) throughout the Intermountain West, including a quaternary care children's hospital.

PATIENTS

Neonates ≤44 postmenstrual weeks (median gestational age: 31 (IQR 28-36) weeks) receiving intravenous gentamicin with or without exposure to vancomycin from January 2006 to December 2012.

MAIN OUTCOME MEASURES

Nephrotoxicity based on the modified Acute Kidney Injury Network criteria for acute kidney injury (AKI) or serum creatinine concentration ≥1.5 mg/dL persisting for ≥48 h.

RESULTS

The final cohort was comprised of 1066 neonates (533 receiving vancomycin and gentamicin vs 533 receiving gentamicin). In a propensity score-matched cohort that was well balanced across 16 covariates, AKI was not associated with vancomycin use (16 neonates receiving vancomycin vs 7 controls experienced AKI; OR 1.5; 95% CI 0.6 to 4.0). However, the presence of a patent ductus arteriosus, concomitant non-steroidal anti-inflammatory drug use, ≥1 positive blood cultures, low birth weight and higher severity of illness and risk of mortality scores were associated with an increased risk of nephrotoxicity.

CONCLUSIONS

These results corroborate several earlier reports and much anecdotal evidence describing the infrequent occurrence of nephrotoxicity in neonates receiving concomitant vancomycin and gentamicin.

Drug-induced acute kidney injury in neonates

PURPOSE OF REVIEW

Acute kidney injury (AKI) is an independent risk factor for morbidity and mortality in critically ill neonates. Nephrotoxic medication exposure is common in neonates. Nephrotoxicity represents the most potentially avoidable cause of AKI in this population.

RECENT FINDINGS

Recent studies in critically ill children revealed the importance of recognizing AKI and potentially modifiable risk factors for the development of AKI such as nephrotoxic medication exposures. Data from critically ill children who have AKI suggest that survivors are at risk for the development of chronic kidney disease. Premature infants are born with incomplete nephrogenesis and are at risk for chronic kidney disease. The use of nephrotoxic medications in the neonatal intensive care unit is very common; yet the effects of medication nephrotoxicity on the short and long-term outcomes remains highly understudied.

SUMMARY

The neonatal kidney is predisposed to nephrotoxic AKI. Our ability to improve outcomes for this vulnerable group depends on a heightened awareness of this issue. It is important for clinicians to develop methods to minimize and prevent nephrotoxic AKI in neonates through a multidisciplinary approach aiming at earlier recognition and close monitoring of nephrotoxin-induced AKI.

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.

Acute Kidney Injury Recognition and Management: A Review of the Literature and Current Evidence

Acute renal failure is defined as a rapid decrease in the glomerular filtration rate, occurring over a period of hours to days and by the inability of the kidney to regulate fluid and electrolyte homeostasis appropriately. AKI is a catastrophic, life-threatening event in critically ill patients. AKI can be divided into pre-renal injury, intrinsic kidney disease (including vascular insults) and obstructive uropathies. The prognosis of AKI is highly dependent on the underlying cause of the injury. Children who have AKI as a component of multisystem failure have a much higher mortality rate than children with intrinsic renal disease. Treatment of AKI is subjected to risk stratification and ongoing damage control measures, such as patients with sepsis, exposure to nephrotoxic agents, ischemia, bloody diarrhea, or volume loss, could be helped by optimizing the fluid administrations, antibiotics possessing least nephrotoxic potential, blood transfusion where hemoglobin is dangerously low, limiting the use of nephrotoxic agents including radio contrast use, while maximize the nutrition. Acute kidney injury remains a complex disorder with an apparent differentiation in pathology between septic and nonseptic forms of the disease. Although more studies are still required, progress in this area has been steady over the last decade with purposeful international collaboration.

Nutritional support for premature infants in the neonatal intensive care unit

Nutritional support for premature infants in the neonatal intensive care unit setting is complex. Such infants have conditions unique to this period of the lifespan requiring specialized care management, both of which may impede the provision of adequate nutrition to support basal metabolic needs. Premature infants require optimum nutritional intake to support rapid growth during a time when they are not fully capable of tolerating it. This article reviews developmental anatomy, physiology, and the effect of premature delivery by systems; the challenges of providing adequate nutrition; and current evidence-based strategies to provide nutrition for premature infants during hospitalization.

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.

Population pharmacokinetic study of gentamicin in a large cohort of premature and term neonates

AIM

This study aims to investigate the clinical and demographic factors influencing gentamicin pharmacokinetics in a large cohort of unselected premature and term newborns and to evaluate optimal regimens in this population.

METHODS

All gentamicin concentration data, along with clinical and demographic characteristics, were retrieved from medical charts in a Neonatal Intensive Care Unit over 5 years within the frame of a routine therapeutic drug monitoring programme. Data were described using non-linear mixed-effects regression analysis ( nonmem®).

RESULTS

A total of 3039 gentamicin concentrations collected in 994 preterm and 455 term newborns were included in the analysis. A two compartment model best characterized gentamicin disposition. The average parameter estimates, for a median body weight of 2170 g, were clearance (CL) 0.089 l h(-1) (CV 28%), central volume of distribution (Vc ) 0.908 l (CV 18%), intercompartmental clearance (Q) 0.157 l h(-1) and peripheral volume of distribution (Vp ) 0.560 l. Body weight, gestational age and post-natal age positively influenced CL. Dopamine co-administration had a significant negative effect on CL, whereas the influence of indomethacin and furosemide was not significant. Both body weight and gestational age significantly influenced Vc . Model-based simulations confirmed that, compared with term neonates, preterm infants need higher doses, superior to 4 mg kg(-1) , at extended intervals to achieve adequate concentrations.

CONCLUSIONS

This observational study conducted in a large cohort of newborns confirms the importance of body weight and gestational age for dosage adjustment. The model will serve to set up dosing recommendations and elaborate a Bayesian tool for dosage individualization based on concentration monitoring.

Early urinary angiotensinogen excretion in critically ill neonates

INTRODUCTION

Urinary angiotensinogen is considered a reliable biomarker for intrarenal renin-angiotensin system activity. The aims of this study were to assess the urinary angiotensinogen level during the first day of life and to evaluate its correlation with renal function in critically ill neonates.

METHODS

Urinary angiotensinogen concentration during the first 24 hours of life was measured in 98 critically ill neonates. Neonatal renal function was assessed by urinary levels of cystatin-C, albumin and α1-microglobulin and urinary electrolyte excretion.

RESULTS

Urinary angiotensinogen level decreased with increasing gestational age and body weight in critically ill neonates (P<0.001). After adjustment for gestational age, urinary angiotensinogen level correlated with urinary fractional excretion of sodium and urinary levels of cystatin-C and α1-microglobulin. Multivariate linear regression identified a significant impact of urinary cystatin-C on urinary angiotensinogen level (P<0.001). Furthermore, urinary angiotensinogen was significantly increased in neonates with a urinary cystatin-C-to-creatinine ratio ⩾2500 ng/mg, which was the optimal cut-off value to predict acute kidney injury in our previous study.

CONCLUSIONS

The urinary angiotensinogen level correlates with the overall maturity of renal function during the early postnatal period in critically ill neonates and an increased urinary angiotensinogen level might reflect renal injury in immature neonates.