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

Impact of preterm birth on kidney health and development

Preterm birth, defined as birth before the gestational age of 37 weeks, affects 11% of the newborns worldwide. While extensive research has focused on the immediate complications associated with prematurity, emerging evidence suggests a link between prematurity and the development of kidney disease later in life. It has been demonstrated that the normal course of kidney development is interrupted in infants born prematurely, causing an overall decrease in functional nephrons. Yet, the pathogenesis leading to the alterations in kidney development and the subsequent pathophysiological consequences causing kidney disease on the long-term are incompletely understood. In the present review, we discuss the current knowledge on nephrogenesis and how this process is affected in prematurity. We further discuss the epidemiological evidence and experimental data demonstrating the increased risk of kidney disease in these individuals and highlight important knowledge gaps. Importantly, understanding the intricate interplay between prematurity, abnormal kidney development, and the long-term risk of kidney disease is crucial for implementing effective preventive and therapeutic strategies.

Results of Aortic Coarctation Repair in Low- and Normal Birth-Weight Neonates: A Propensity Score-Matched Analysis

INTRODUCTION

Surgical treatment of aortic coarctation in low-birth-weight (LBW) neonates is associated with risks of higher hospital mortality rates and recoarctation development in the long-term. The goal of our study was to compare the results of surgical treatment of aortic coarctation in LBW neonates and normal-weight patients, to identify predictors of recoarctation in the long-term among LBW patients.

MATERIALS AND METHODS

A retrospective study was performed to analyse the patients who had undergone resection of isolated aortic coarctation between 2005 and 2022. Overall analysis included 521 patients under the age of 30 days, 89 LBW patients and 432 patients with normal body weight. Propensity score matching (PSM) was performed at a ratio of 1:1 for the statistical adjustment of original patients' data in both groups.

RESULTS

All patients underwent standard resection of aortic coarctation with extended end-to-end anastomosis. Hospital mortality among LBW patients was 8% and in patients with normal weight the mortality amounted to 1% (p = 0.030). LBW patients were transferred to other hospitals more often than normal-weight patients who were more often discharged (p < 0.001). In the long-term, period mortality was not statistically significantly different (p = 0.801). The freedom from reoperation in the group of normal-weight children was 87%, whereas in the LBW patients the rate was 63% (log rank test, p = 0.104). In the multivariate regression model, the most significant risk factors for reoperation were as follows: preoperative inotropes administration (OR (95% CI) 4.369 (1.316-14.51)) and pressure gradient across aortic arch before discharge (OR (95% CI) 1.081 (1.014-1.153)).

CONCLUSIONS

Hospital mortality was higher among LBW patients (p = 0.030). There was a statistical trend of differences in reoperation rates: in the long-term among LBW patients, a higher reintervention probability remains. Moreover, the LBW group initially had more severe clinical condition in terms of cardiac failure and impaired renal function. Factors associated with the risk of recoarctation were preoperative inotropes infusion and pressure gradient across aortic before discharge.

Gut microbiota and neonatal acute kidney injury biomarkers

One of the most frequent issues in newborns is acute kidney injury (AKI), which can lengthen their hospital stay or potentially raise their chance of dying. The gut-kidney axis establishes a bidirectional interplay between gut microbiota and kidney illness, particularly AKI, and demonstrates the importance of gut microbiota to host health. Since the ability to predict neonatal AKI using blood creatinine and urine output as evaluation parameters is somewhat constrained, a number of interesting biomarkers have been developed. There are few in-depth studies on the relationships between these neonatal AKI indicators and gut microbiota. In order to gain fresh insights into the gut-kidney axis of neonatal AKI, this review is based on the gut-kidney axis and describes relationships between gut microbiota and neonatal AKI biomarkers.

Burden and Risk Factors of Contrast-Associated Acute Kidney Injury in Hospitalized Zambian Children: A Prospective Cohort Study at the University Teaching Hospitals

Background

Contrast-associated acute kidney injury (CAAKI) is defined as acute kidney injury (AKI) occurring within 72 hours of administration of contrast media (CM) and is linked to adverse outcomes including longer hospital stay, increased hospital mortality, and a higher risk of chronic kidney disease in later life. Risk factors for the development of CAAKI in the Zambian pediatric population have not been well studied.

Objectives

The objective of this study was to assess the burden of CAAKI, ascertain its risk factors, and describe short-term outcomes in hospitalized children at the University Teaching Hospitals (UTH) undergoing contrast-enhanced radiological investigations.

Methods

This was a prospective observational study of in-patients undergoing contrast-enhanced radiological procedures, between September 2020 and September 2021. The participants were recruited from the Children's Hospital, the Cancer Diseases Hospital, and the Pediatric Surgical Ward at the University Teaching Hospital in Lusaka, Zambia. The primary outcome variable was occurrence of AKI at 48 hours post CM administration. We used 2 criteria to define CAAKI in our study-the European Society of Urogenital Radiology (ESUR) and the Kidney Disease Improving Global Outcomes (KDIGO) 2012 criteria. Multivariable logistic regression models were formulated to assess for risk factors of CAAKI.

Results

Of the 201 enrolled participants, 123 (61.2%) were male and the median age of the participants was 5 years (interquartile range [IQR] = 3-10). The mean hemoglobin was 103 g/L (standard deviation [SD] = 26), median creatinine was 30.9 µmol/l (IQR = 22.6-43), and the glomerular filtration rate (GFR) was 102.5 mL/min/1.73 m2 (IQR = 76.2-129.4). Forty-six (22.9%) developed CAAKI using the ESUR compared with 4.5% (9/201) using the KDIGO criteria. Independent risk factors of CAAKI were receiving a higher dose of CM (adjusted odds ratio [aOR] = 2.54; 95% confidence interval [CI] = [1.12-5.74]), prematurity (aOR = 4.6; 95% CI = [1.05-16.7]), and a higher eGFR (aOR= 1.01; 95% CI = [1.01-1.02]). Females had higher odds of CAAKI (aOR = 2.48; 95% CI = [1.18-5.18]) when compared with males. One CAAKI participant (2.2%) died; none of the participants who developed CAAKI and survived required dialysis and most of them (90%) were discharged before day 7. Day 7 eGFR results had returned to or near baseline values for those whose creatinine results were available.

Conclusions

Using the ESUR criteria, a significant proportion (22.9%) of children undergoing contrast-enhanced computed tomography (CT) scans at the UTH developed CAAKI. In contrast, using the KDIGO criteria only 4.5% had CAAKI. Being born as a preterm baby, being female, having a higher eGFR at baseline, and receiving a higher dose of CM were found to be independent risk factors for CAAKI development in Zambian children. Most of the cases of CAAKI in children were transient and of little clinical significance as only a minority of patients developing CAAKI required kidney replacement therapy and all resolved by day 7 post administration of CM.

Acute kidney injury in infants diagnosed with congenital diaphragmatic hernia

BACKGROUND

To assess the association and outcomes of acute kidney injury (AKI) in infants diagnosed with congenital diaphragmatic hernia (CDH).

METHODS

We analyzed the National Inpatient Sample dataset for the years 2010 through 2018. We evaluated the prevalence and outcomes associated with AKI in infants diagnosed with CDH. Outcomes were assessed using regression analysis while controlling for variables.

RESULTS

A total of 32,042,481 term infants were identified, of them 10,804 had CDH. Prevalence of AKI in infants with CDH was 6.5% compared to 0.05% in those without CDH (aOR = 14.7, CI: 13.0-16.6). ECMO was utilized at 62% of CDH infants that had AKI compared to 17% in infants without AKI (aOR = 4.22, CI: 3.38-5.27). Mortality was greater in CDH infants who developed AKI when compared to those without AKI (57.3 vs. 16.7%, aOR = 3.65, CI: 2.99-4.46). The trend of mortality in CDH infants who developed AKI decreased overtime, p < 0.001, while the trends for mortality in the overall CDH infants and in CDH infants without AKI did not change during the study period, p = 0.12.

CONCLUSION

AKI is not uncommon in infants diagnosed with CDH. ECMO utilization and mortality are substantially increased in CDH infants when they develop AKI.

IMPACT

Mortality in infants diagnosed with congenital diaphragmatic hernia (CDH) is relatively high despite advances in neonatal care. Infants with CDH are potentially at increased risk of acute kidney injury (AKI). Within CDH population, infants diagnosed with AKI are at increased risk for ECMO use and mortality. This is the largest study to address the association and outcomes of AKI in term infants diagnosed with CDH.

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.

Renal Function After Transcatheter Piccolo Patent Ductus Arteriosus Closure With Contrast Angiography in Extremely Premature Infants

Transcatheter patent ductus arteriosus (PDA) device closure is increasingly performed in extremely premature infants. Contrast angiography improves the procedural safety and effectiveness by precise anatomic delineation. Contrast nephropathy is a concern in clinically ill premature infants, especially with the presence of renal insufficiency. We hypothesized that the benefit of transcatheter PDA closure outweighs the harm of contrast nephropathy in extremely premature infants. A total of 160 infants underwent successful transcatheter (n = 59) and surgical (n = 101) PDA closure at a median age of 26 (7 to 78) days. The surgical group had a lower procedural weight (870 vs 960 g, p = 0.014). In the transcatheter group, serum creatinine decreased from 0.48 to 0.45 mg/100 ml at 24 hours (p = 0.003, n = 59) and decreased further to 0.37 mg/100 ml at 5 to 7 days after closure (p <0.001). Median contrast amount was 1.9 ml/kg (0.6 to 6.1). In 8 infants with pre-existing renal insufficiency who underwent transcatheter closure, serum creatine significantly improved from 1.44 to 1.36 mg/100 ml at 24 hours and 0.79 mg/100 ml at 5 to 7 days after closure (p <0.001). There was no difference in improvement of serum creatinine between transcatheter and surgical closure groups. In conclusion, despite the use of contrast, serum creatinine significantly improved with transcatheter PDA closure even in infants with pre-existing renal insufficiency. Contrast angiography should not be discouraged for transcatheter PDA closure because of the concern for contrast nephropathy in extremely premature infants.

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.

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.

Clinical course of neonatal acute kidney injury: multi-center prospective cohort study

Background

Neonatal acute kidney injury (AKI) has been associated with unfavorable outcomes, including increased mortality. We aimed to describe the clinical course and outcomes during the first 7 days after diagnosis in newborns with AKI in three neonatal intensive care units in Popayán-Colombia.

Methods

Multi-center prospective cohort study conducted between June 2019 and December 2020 in three NICUs after ethical approval. We included newborns between 2 and 28 days of life, first diagnosed with AKI using the KDIGO classification modified for newborns which consider increased serum creatinine values over baseline values as well as urine output over time in hours or both. Patients with chromosomal abnormalities, major kidney malformations, and complex congenital heart disease were excluded. Patients were followed for up to 7 days after diagnosis and the maximum KDIGO stage, recovery of kidney function, need for renal replacement therapy and cumulative incidence of death were evaluated.

Results

Over the 18 months of the study, 4132 newborns were admitted to the NICUs, and 93 patients (2.25, 95% CI 1.82–2.75%) developed neonatal AKI. 59.1% of the newborns were premature and there were no differences in severity according to gestational age. During follow-up, the maximum KDIGO was 64.5% for AKI-stage 1, 11.8% for AKI-stage 2, and 23.7% for AKI-stage 3. Kidney function recovery was higher in AKI-stage 1 patients vs. AKI-severe (AKI-stage 2 and 3) (95% vs. 48.5%). Five patients (5.4%) received renal replacement therapy and 15 died (16.1%), four in AKI-stage 1 vs. 11 in AKI-severe (6.7% vs 33.3%).

Conclusions

Newborns admitted to the NICUs can develop AKI regardless of gestational age, and it is more frequent between the second and ninth days of life. More patients whit AKI-stage 1 recover and die less than those in a severe stage.

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.

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

BACKGROUND AND OBJECTIVE

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

METHODOLOGY

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

RESULTS

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

CONCLUSION

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

Association of high-sensitivity C-reactive protein and anemia with acute kidney injury in neonates

BACKGROUND

The association of high-sensitivity C-reactive protein (hsCRP) and anemia with postoperative acute kidney injury (AKI) in neonates with congenital heart disease (CHD) is still unclear. The purpose of this study was to examine whether anemia-associated AKI is modulated by hsCRP in neonates.

METHODS

This study included 253 consecutive neonatal patients who underwent CHD surgery in a national tertiary hospital. We investigated the association between postoperative AKI with baseline hsCRP, anemia, and their interaction by multivariable logistic regression analyses.

RESULTS

The incidence of AKI was 24.1% in the entire cohort. After being adjusted for covariates, hsCRP level was negatively correlated with AKI (P < 0.01 for 1 mg/L threshold), whereas anemia emerged as an independent risk factor of AKI (P = 0.02). In addition, there was a significant interaction between anemia and hsCRP level (P = 0.01). In neonates with hsCRP < 1 mg/L, anemia was positively associated with AKI (P = 0.03). However, no significant association was found between anemia and AKI in the context of hsCRP ≥ 1 mg/L. Combination of anemia and hsCRP < 1 mg/L was independently correlated with the risk of AKI (P < 0.01), while concomitant anemia and hsCRP ≥ 1 mg/L or hsCRP < 1 mg/L combined with non-anemia was not.

CONCLUSIONS

In neonates with CHD, the risk of anemia-associated AKI may be modulated by hsCRP level. Attention should be paid to neonates with preoperative anemia and baseline hsCRP < 1 mg/L to reduce the risk of postoperative AKI.

Renal tissue oxygenation after caffeine administration in preterm neonates

BACKGROUND

Caffeine has been associated with reduced rates of acute kidney injury (AKI) in preterm neonates. The effect of caffeine on preterm neonatal renal regional saturation of oxygen (RrSO₂) is unknown.

METHODS

RrSO₂ was recorded continuously in neonates < 32 weeks' gestation until 7 days of age with INVOS™ neonatal near-infrared spectroscopy (NIRS) sensors. Baseline RrSO₂ values were established by averaging the saturations in the 20 min prior to caffeine administration. Subgroup analysis was performed based on pre-caffeine RrSO₂ averages. Change in RrSO₂ was recorded at 0.5, 1, 2, 3, 4, 6, and 12 h after maintenance caffeine administration.

RESULTS

Of 35 eligible neonates, 31 (median gestational age 28.4 weeks) received 156 caffeine doses (median 8 mg/kg). Analysis of combined doses showed no significant changes in RrSO₂ after caffeine administration at any time. However, neonates with baseline 20-29.9% had significant increases from 1 to 12 h (range of increase 5.9-13.9%), and those with baseline 30-39.9 had significant increases at 1 h (8.06%, p < 0.05).

CONCLUSIONS

Maintenance caffeine dosing increased RrSO₂ in neonates with low RrSO₂ in the first week. Further research is needed to determine the effect of loading doses of caffeine and if increases in RrSO₂ correlate with improved clinical kidney outcomes.

IMPACT

Caffeine administration is associated with increased renal tissue oxygenation in preterm neonates with low baseline values under 40%. The most significant renal tissue oxygenation changes occur in the first 3 h after IV caffeine administration. With recent studies suggesting low RrSO₂ values in preterm neonates are associated with AKI, caffeine should be studied as a potential therapeutic for this common and complex morbidity in preterm neonates.

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.

The progression of serum cystatin C concentrations within the first month of life after preterm birth-a worldwide systematic review

Multiple single-center studies have examined the progression of kidney function biomarkers such as serum cystatin C (Cys C) in the first 30 days of life (DOL) after preterm birth, but from different ethnicities and in different gestational ages (GA), without a functional summary available. We performed a systematic literature review within PubMed, Google Scholar, and Scopus, with additional use of the snowballing method to find studies including data on serum Cys C concentrations in the first 30 DOL. We identified 15 papers that met criteria, published from 2000 to 2019, from 10 countries across 4 continents, in 1468 babies born preterm. Cys C was superior to creatinine in 11/13 studies, and equal in 2/13. For infants born at 24-28 weeks GA, the DOL1 Cys C concentrations ranged from 1.44 to 1.90 mg/L, from 1.20 to 1.77 on DOL3, and from 1.36 to 2.02 between DOL 4 and 30. For infants born at 29-33 weeks GA, the DOL1 Cys C values ranged from 1.41 to 1.96 mg/L, from 1.28 to 1.70 on DOL3, and 1.51 to 1.87 between DOL 4 and 30. For preterm infants born after 34 weeks GA, the DOL1 Cys C values ranged from 1.22 to 1.96 mg/L, from 1.24 to 1.85 on DOL3, and 1.22 to 1.82 between DOL 4 and 30. This systematic review provides generalizable worldwide reference data on Cys C that could be used to estimate progression or resolution of abnormal kidney function in the first months after preterm birth, stratified by GA.

Evaluation of neonatal acute kidney injury after critical congenital heart disease surgery

BACKGROUND

Acute kidney injury (AKI) is a common complication of congenital heart diseases (CHDs) after cardiac surgery. This study aimed to define the frequency and critical course, risk factors and short-term outcomes of AKI in postoperative CHD neonates.

METHODS

Postoperatively followed term CHD newborn infants were enrolled in the study. Infants with congenital anomalies of the urinary tract and other major congenital anomalies were excluded. Neonatal modified KDIGO criteria were used to assess AKI.

RESULTS

A total of 199 postoperatively followed newborn infants were included in the study. Acute kidney injury was detected in 71 (35.6%) patients. Of these patients, 24 (33.8%) were in stage 1, 14 (19.7%) in stage 2, and 33 (46.5%) in stage 3. Acute kidney injury occurred within the first week (median 1 day [IQR 1-2 days]) of cardiac surgery in 93% of the patients. The duration of invasive respiratory support and extracorporeal membrane oxygenation (ECMO) and mortality were significantly higher in stage 3 patients. Higher vasoactive-inotropic score (OR, 1.02; 95% CI, 1.0-1.04; p = 0.008) and receiving ECMO (OR, 7.9; 95% CI, 2.6-24.4; p = 0.001) were associated with risk for the development of AKI. The mortality rate was 52.1% in the AKI (+) patients, and having AKI (OR 7.1; 95% CI, 3.5-14.18) was significantly associated with mortality.

CONCLUSION

Acute kidney injury, a common early complication after critical neonatal CHD cardiac surgery, is associated with increased morbidity and mortality. Stage 3 AKI is associated with significantly higher mortality rates.

Severe Acute Kidney Injury and Mortality in Extremely Low Gestational Age Neonates

BACKGROUND AND OBJECTIVES

AKI is associated with poor short- and long-term outcomes. Questions remain about the frequency and timing of AKI, and whether AKI is a cause of death in extremely low gestational age neonates.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Recombinant Erythropoietin for Protection of Infant Kidney Disease Study examines the kidney outcomes of extremely low gestational age neonates enrolled in the Preterm Epo Neuroprotection study, a randomized, placebo-controlled trial of recombinant human erythropoietin. We included 900 of 941 patients enrolled in Preterm Epo Neuroprotection. Baseline characteristics were compared by primary exposure (severe AKI versus none/stage 1 AKI) using unadjusted logistic regression models. Cox regression models estimated the relationship between severe AKI and death after adjustment for potential confounders. Time-dependent AKI was modeled as a binary outcome and a categorical variable by stage of AKI. We fit Cox models using time-dependent AKI status lagged by <7 days before death. Landmark analyses examined the relationship of death with development of severe AKI.

RESULTS

Severe AKI occurred in 168 of 900 (19%, 95% confidence interval, 17% to 20%) neonates, and stage 3 AKI occurred in 60 (7%, 95% confidence interval, 5% to 8%). Stage 3 AKI occurring 7 days before death (hazard ratio, 3.88; 95% confidence interval, 1.26 to 11.96), intraventricular hemorrhage (hazard ratio, 2.01; 95% confidence interval, 1.01 to 3.99) and sepsis (hazard ratio, 2.85; 95% confidence interval, 1.12 to 7.22) were all independently associated with death. Severe AKI occurring 7 days before death (hazard ratio, 2.21; 95% confidence interval, 0.92 to 5.26) was associated with death but not statistically significant. In a landmark analysis, after adjusting for potential confounders, late (after day 14 and before day 28) severe AKI was strongly associated with higher hazard of death (hazard ratio, 4.57; 95% confidence interval, 1.82 to 11.5).

CONCLUSIONS

Severe AKI occurs frequently in extremely low gestational age neonates. Stage 3 AKI is associated with mortality, and this association is present 7 days before death.

Renal insufficiency in children born preterm: examining the role of neonatal acute kidney injury

OBJECTIVE

To identify the prevalence of renal insufficiency (RI) in children with a history of prematurity and acute kidney injury (AKI).

STUDY DESIGN

This prospective cohort study evaluated renal function in children born preterm at 5-9 years of age. Univariable analyses compared perinatal and follow-up data from subjects with and without AKI history, and with and without current RI. Regression analyses were attempted to model RI as a function of AKI and other clinical risk factors.

RESULTS

Fifteen of 43 (35%) participants had previously undiagnosed RI. Only children with no AKI history or neonatal stage 1 AKI presented for follow-up. Children born preterm with a history of stage 1 AKI had higher serum creatinine (sCr) at follow-up, but were not more likely to have RI compared to children without stage 1 AKI history (RI prevalence 30% and 36% in AKI and non-AKI group, respectively).

CONCLUSION

The high prevalence of RI in this preterm cohort at middle childhood follow-up highlights the need for routine kidney health assessments in this population. Large multicenter studies are needed to further characterize the impact of premature birth and mild AKI on renal function throughout childhood.

Acute Kidney Injury Associated with Late-Onset Neonatal Sepsis: A Matched Cohort Study

OBJECTIVES

To determine incidence and severity of acute kidney injury (AKI) within 7 days of sepsis evaluation and to assess AKI duration and the association between AKI and 30-day mortality.

STUDY DESIGN

Retrospective, matched cohort study in a single-center level IV neonatal intensive care unit. Eligible infants underwent sepsis evaluations at ≥72 hours of age during calendar years 2013-2018. Exposed infants (cases) were those with culture-proven sepsis and antimicrobial duration ≥5 days. Nonexposed infants (controls) were matched 1:1 to exposed infants based on gestational and corrected gestational age, and had negative sepsis evaluations with antibiotic durations <48 hours. AKI was defined by modified neonatal Kidney Disease Improving Global Outcomes criteria. Statistical analysis included Mann-Whitney and χ² tests, multivariable logistic regression, and Kaplan-Meier time-to-event analysis.

RESULTS

Among 203 episodes of late-onset sepsis, 40 (20%) developed AKI within 7 days after evaluation, and among 193 episodes with negative cultures, 16 (8%) resulted in AKI (P = .001). Episodes of sepsis also led to greater AKI severity, compared with nonseptic episodes (P = .007). The timing of AKI onset and AKI duration did not differ between groups. Sepsis was associated with increased odds of developing AKI (aOR, 3.0; 95% CI, 1.5-6.2; P = .002). AKI was associated with increased 30-day mortality (aOR, 4.5; 95% CI, 1.3-15.6; P = .017).

CONCLUSIONS

Infants with late-onset sepsis had increased odds of AKI and greater AKI severity within 7 days of sepsis evaluation, compared with age-matched infants without sepsis. AKI was independently associated with increased 30-day mortality. Strategies to mitigate AKI in critically ill neonates with sepsis may improve outcomes.

Regional oxygen saturation and acute kidney injury in premature infants

BACKGROUND

Decreased renal blood flow plays a vital role in the etiology of acute kidney injury (AKI). In this study, we aim to investigate the role of renal regional oxygen saturation (rSO₂ ) reductions in predicting AKI in the first 24 h of life.

METHODS

One hundred premature babies with a gestational age of ≤32 weeks were included. Renal and cerebral rSO₂ s were monitored for 24 h by near-infrared spectroscopy. Infants were followed up for the first 7 days for the diagnosis of AKI.

RESULTS

Infants' median gestational age was 29 (23-32) weeks, and their birthweight was 1,192 ± 355 g. It was found that the renal rSO₂ values were lower in the first 24 h of life in patients who developed AKI, and this decrease was statistically significant in the first 6 h of life.

CONCLUSIONS

The low renal rSO₂ values in the early hours of life in premature babies may have a role in predicting AKI.

Risk Factors for Acute Kidney Injury in Critically Ill Neonates: A Systematic Review and Meta-Analysis

Background and Objective: Acute kidney injury (AKI) is recognized as an independent risk factor for mortality and long-term poor prognosis in neonates. The objective of the study was to identify the risk factors for AKI in critically ill neonates to provide an important basis for follow-up research studies and early prevention. Methods: The PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, WanFang Med, SinoMed, and VIP Data were searched for studies of risk factors in critically ill neonates. Studies published from the initiation of the database to November 19, 2020, were included. The quality of studies was assessed by the Newcastle-Ottawa Scale and the Agency for Healthcare Research and Quality (AHRQ) checklist. The meta-analysis was conducted with Stata 15 and drafted according to the guidelines of the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. Results: Seventeen studies (five cohort studies, ten case-control studies, and two cross-sectional studies) were included in meta-analysis, with 1,627 cases in the case group and 5,220 cases in the control group. The incidence of AKI fluctuated from 8.4 to 63.3%. Fifteen risk factors were included, nine of which were significantly associated with an increased risk of AKI in critically ill neonates: gestational age [standardized mean difference (SMD) = -0.31, 95%CI = (-0.51, -0.12), P = 0.002], birthweight [SMD = -0.37, 95%CI = (-0.67, -0.07), P = 0.015], 1-min Apgar score [SMD = -0.61, 95%CI = (-0.78, -0.43), P = 0.000], 5-min Apgar score [SMD = -0.71, 95%CI = (-1.00, -0.41), P = 0.000], congenital heart disease (CHD) [odds ratio (OR) = 2.94, 95%CI = (2.08, 4.15), P = 0.000], hyperbilirubinemia [OR = 2.26, 95%CI = (1.40, 3.65), P = 0.001], necrotizing enterocolitis (NEC) [OR = 6.32, 95%CI = (2.98, 13.42), P = 0.000], sepsis [OR = 2.21, 95%CI = (1.25, 3.89), P = 0.006], and mechanical ventilation [OR = 2.37, 95%CI = (1.50, 3.75), P = 0.000]. Six of them were not significantly associated with AKI in critically ill neonates: age [SMD = -0.25, 95%CI = (-0.54, 0.04), P = 0.095], male sex [OR = 1.10, 95%CI =(0.97, 1.24), P = 0.147], prematurity [OR = 0.90, 95%CI(0.52, 1.56), P = 0.716], cesarean section [OR = 1.52, 95%CI(0.77, 3.01), P = 0.234], prenatal hemorrhage [OR = 1.41, 95%CI = (0.86, 2.33), P = 0.171], and vancomycin [OR = 1.16, 95%CI = (0.71, 1.89), P = 0.555]. Conclusions: This meta-analysis provides a preliminary exploration of risk factors in critically ill neonatal AKI, which may be useful for the prediction of AKI. Systematic Review Registration: PROSPERO (CRD42020188032).

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.

Echocardiographic predictors of acute kidney injury in neonates with a patent ductus arteriosus

OBJECTIVE

To investigate acute kidney injury (AKI) in neonates with a patent ductus arteriosus (PDA) including incidence, risk factors, and possible correlations between PDA-related echocardiographic measurements and AKI incidence.

STUDY DESIGN

We conducted a single-center retrospective cohort study of infants admitted to the neonatal intensive care unit with a diagnosis of a PDA between July 2015 and July 2017. Infants were evaluated for development of AKI based on the KDIGO criteria and a multivariable logistic regression analysis was performed.

RESULTS

A total of 142 neonates with moderate or large PDAs were included, 43 (30%) developed AKI. Patients who developed AKI had longer length of stay, lower birth weights, lengths, and gestational ages. No echocardiographic measurements were predictive of an increased risk for developing AKI.

CONCLUSION

There are no significant differences in commonly measured echocardiographic markers of PDA hemodynamic significance in neonates who develop AKI.

Maternal and birth cohort studies in the Gulf Cooperation Council countries: a systematic review and meta-analysis

BACKGROUND

We systematically reviewed and chronicled exposures and outcomes measured in the maternal and birth cohort studies in the Gulf Cooperation Council (GCC) countries and quantitatively summarized the weighted effect estimates between maternal obesity and (1) cesarean section (CS) and (2) fetal macrosomia.

METHODS

We searched MEDLINE-PubMed, Embase, Cochrane Library, Scopus, and Web of Science electronic databases up to 30 June 2019. We considered all maternal and birth cohort studies conducted in the six GCC countries (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and United Arab Emirates (UAE)). We categorized cohort studies on the basis of the exposure(s) (anthropometric, environmental, medical, maternal/reproductive, perinatal, or socioeconomic) and outcome(s) (maternal or birth) being measured. Adjusted weighted effect estimates, in the form of relative risks, between maternal obesity and CS and fetal macrosomia were generated using a random-effects model.

RESULTS

Of 3502 citations, 81 published cohort studies were included. One cohort study was in Bahrain, eight in Kuwait, seven in Qatar, six in Oman, 52 in Saudi Arabia, and seven in the UAE. Majority of the exposures studied were maternal/reproductive (65.2%) or medical (39.5%). Birth and maternal outcomes were reported in 82.7% and in 74.1% of the cohort studies, respectively. In Saudi Arabia, babies born to obese women were at a higher risk of macrosomia (adjusted relative risk (aRR), 1.15; 95% confidence interval (CI), 1.10-1.20; I2 = 50%) or cesarean section (aRR, 1.21; 95% CI, 1.15-1.26; I2 = 62.0%). Several cohort studies were only descriptive without reporting the magnitude of the effect estimate between the assessed exposures and outcomes.

CONCLUSIONS

Cohort studies in the GCC have predominantly focused on reproductive and medical exposures. Obese pregnant women are at an increased risk of undergoing CS delivery or macrosomic births. Longer-term studies that explore a wider range of environmental and biological exposures and outcomes relevant to the GCC region are needed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017068910.

A Prediction Nomogram for Acute Kidney Injury in Very-Low-Birth-Weight Infants: A Retrospective Study

Background and objective: Acute kidney injury (AKI) is recognized as an independent predictor for mortality in very-low-birth-weight (VLBW) infants and is reported to have a high incidence. In this study, we sought to identify the predictors for AKI in VLBW infants and thereby develop a prediction nomogram for the early detection and management of VLBW infants at high risk of developing AKI. Methods: We designed a retrospective study wherein we investigated the baseline hospitalization data of VLBW infants treated at our hospital between January 2012 and October 2018. Independent predictors of AKI in VLBW infants, as identified by multivariate logistic regression, were incorporated into a model. Hosmer-Lemeshow test was used to test the goodness of fit of the model, and a receiver operating characteristic (ROC) curve was plotted to assess the discriminative ability of the model. The model was internally validated using the 10-fold cross-validation method. A nomogram was plotted to predict the risk of AKI in VLBW infants on the basis of the results of multivariate logistic regression analysis. Results: We investigated the data of 604 VLBW infants, of which 144 (23.8%) developed AKI; in 111 (77.1%) of these infants, AKI occurred within 7 days of birth. Multivariate logistic regression analysis identified the following as predictive factors for AKI in VLBW infants: gestational age, red blood cell count within 3 days of birth, serum calcium concentration within 3 days of birth, maternal age of ≥35 years, and pulmonary arterial hypertension or myocardial injury. Furthermore, the nomogram was found to be effective in estimating the risk of AKI in VLBW infants, with an area under the curve (AUC) of 0.794 [95% confidence interval (CI): 0.754-0.834; P < 0.001]. Internal validation done by cross-validation showed that the average AUC was 0.788. Conclusion: The nomogram developed in this study was found to be sensitive and specific for the preoperative prediction of AKI in VLBW infants, as per the Kidney Disease: Improving Global Outcomes (KDIGO) criteria modified for neonates.

Caffeine exposure and acute kidney injury in premature infants with necrotizing enterocolitis and spontaneous intestinal perforation

BACKGROUND

Acute kidney injury (AKI) is common in preterm infants, but specific therapies remain scarce. Recent studies have demonstrated an association between caffeine exposure and less frequent AKI in the first 7-10 days after birth. We hypothesized that patients with necrotizing enterocolitis (NEC) and spontaneous intestinal perforation (SIP) would provide a better natural model of AKI to evaluate this association.

METHODS

We reviewed all premature patients diagnosed with NEC or SIP at our institution from 2008 to 2014. AKI was defined by change in serum creatinine using the neonatal Kidney Disease: Improving Global Outcomes definition. Caffeine was prescribed for apnea of prematurity and caffeine exposure was determined by chart review.

RESULTS

A total of 146 patients with NEC/SIP were reviewed. Of these, 119 (81.5%) received caffeine, and 91 (62.3%) developed AKI. AKI occurred less frequently in patients who received caffeine than in those who did not (55.5% vs. 92.6%; odds ratio (OR) 0.10; 95% confidence interval (CI) 0.02-0.44). This association persisted in multivariable models after adjustment for potential confounders (adjusted OR 0.08; 95% CI 0.01-0.42; number needed to be exposed to caffeine to prevent one case of AKI = 2.6). Although baseline serum creatinine did not differ by caffeine exposure, patients receiving caffeine had lower peak creatinine (median 1.0 mg/dl vs. 1.5 mg/dl; p = 0.008) and absolute creatinine change (median 0.42 mg/dl vs. 0.68 mg/dl; p = 0.003) than those who did not.

CONCLUSIONS

Caffeine exposure in preterm infants with NEC/SIP is associated with decreased incidence and severity of AKI.