Recognition and reporting of AKI in very low birth weight infants

Acute kidney injury in neonates with hypoxic ischemic encephalopathy based on serum creatinine decline compared to KDIGO criteria

BACKGROUND

Neonates with hypoxic ischemic encephalopathy receiving therapeutic hypothermia (HIE + TH) are at risk for acute kidney injury (AKI). The standardized Kidney Disease Improving Global Outcomes (KDIGO) criteria identifies AKI based on a rise in serum creatinine (SCr) or reduced urine output. This definition is challenging to apply in neonates given the physiologic decline in SCr during the first week of life. Gupta et al. proposed alternative neonatal criteria centered on rate of SCr decline. This study aimed to compare the rate of AKI based on KDIGO and Gupta in neonates with HIE and to examine associations with mortality and morbidity.

METHODS

A retrospective review was performed of neonates with moderate to severe HIE + TH from 2008 to 2020 at a single center. AKI was assessed in the first 7 days after birth by KDIGO and Gupta criteria. Mortality, brain MRI severity of injury, length of stay, and duration of respiratory support were compared between AKI groups.

RESULTS

Among 225 neonates, 64 (28%) met KDIGO, 69 (31%) neonates met Gupta but not KDIGO, and 92 (41%) did not meet either definition. Both KDIGO-AKI and GuptaOnly-AKI groups had an increased risk of the composite mortality and/or moderate/severe brain MRI injury along with longer length of stay and prolonged duration of respiratory support compared to those without AKI.

CONCLUSIONS

AKI in neonates with HIE + TH was common and varied by definition. The Gupta definition based on rate of SCr decline identified additional neonates not captured by KDIGO criteria who are at increased risk for adverse outcomes. Incorporating the rate of SCr decline into the neonatal AKI definition may increase identification of clinically relevant kidney injury in neonates with HIE + TH.

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

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

Effects of diethylene glycol contamination of pharmaceutical products on unexplained acute kidney injury in children: a systematic review

Unexplained acute kidney injury (AKI) in children owing to diethylene glycol (DEG) contamination during drug production has gained attention in recent years. This qualitative study investigated the effects of DEG exposure on the incidence of unknown AKI in children. A systematic review following the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines was proposed to search for studies using predefined search terms in the PubMed, EBSCO, and Web of Science data-bases without publication date restrictions. The inclusion criteria are observational study, case study, case report, and case series design; and having provided accurate data for DEG poisoning and AKI diagnosis in children. All authors performed the study screening, data extraction, and data synthesis processes. Consensus was reached by mutual agreement. The data synthesis was conducted according to the DEG and unexplained AKI in children by examining the statistical data using Microsoft Excel 2017 and storing the data using the cloud service of Universitas Islam Indonesia. Of the 115 included studies, 21 met the inclusion criteria, including 2 case-control studies, 1 cross-sectional study, 4 case studies, and 14 case reports. DEG-contaminated paracetamol caused unexplained AKI in children. Other drugs including cough expectorants, antihistamines, and sedatives were administered. Chemicals other than DEG, such as propylene glycol and ethylene glycol, also induce AKI owing to overprescription and unintentional exposure. A recent epidemic of unexplained AKI showed contaminated paracetamol as the poisoning agent regardless of formula.

Advocating for the inclusion of kidney health outcomes in neonatal research: best practice recommendations by the Neonatal Kidney Collaborative

Acute kidney injury (AKI) occurs in nearly 30% of sick neonates. Chronic kidney disease (CKD) can be detected in certain populations of sick neonates as early as 2 years. AKI is often part of a multisystem syndrome that negatively impacts developing organs resulting in short- and long-term pulmonary, neurodevelopmental, and cardiovascular morbidities. It is critical to incorporate kidney-related data into neonatal clinical trials in a uniform manner to better understand how neonatal AKI or CKD could affect an outcome of interest. Here, we provide expert opinion recommendations and rationales to support the inclusion of short- and long-term neonatal kidney outcomes using a tiered approach based on study design: (1) observational studies (prospective or retrospective) limited to data available within a center's standard practice, (2) observational studies involving prospective data collection where prespecified kidney outcomes are included in the design, (3) interventional studies with non-nephrotoxic agents, and (4) interventional studies with known nephrotoxic agents. We also provide recommendations for biospecimen collection to facilitate ancillary kidney specific research initiatives. This approach balances the costs of AKI and CKD ascertainment with knowledge gained. We advocate that kidney outcomes be included routinely in neonatal clinical study design. Consistent incorporation of kidney outcomes across studies will increase our knowledge of neonatal morbidity.

Acute kidney injury requiring dialysis in children: a multicentric, emerging country perspective

BACKGROUND

Acute kidney injury (AKI) is a life-threatening condition, especially in extreme age groups and when kidney replacement therapy (KRT) is necessary. Studies worldwide report mortality rates of 10-63% in pediatric patients undergoing KRT.

METHODS

Over 13 years, this multicenter study analyzed data from 693 patients with AKI, all receiving KRT, across 74 hospitals and medical facilities in Rio de Janeiro, Brazil.

RESULTS

The majority were male (59.5%), under one year old (55.6%), and treated in private hospitals (76.5%). Sixty-six percent had comorbidities. Pneumonia and congenital heart disease were the most common admission diagnoses (21.5% and 20.2%, respectively). The mortality rate was 65.2%, with lower rates in patients over 12 years (50%). Older age was protective (HR: 2.35, IQR [1.52-3.62] for neonates), and primary kidney disease had a three-fold lower mortality rate. ICU team experience (HR: 0.74, IQR [0.60-0.91]) correlated with lower mortality, particularly in hospitals treating 20 or more patients. Among the deceased, 40% died within 48 h of KRT initiation, suggesting possible late referral or treatment futility.

CONCLUSIONS

This study confirms the high mortality in pediatric dialytic AKI in middle-income countries, underlining early mortality and offering critical insights for improving outcomes.

Acute Kidney Injury in Neonatal Intensive Care Unit: Epidemiology, Diagnosis and Risk Factors

Acute kidney injury (AKI) is associated with long-term consequences and poor outcomes in the neonatal intensive care unit. Its precocious diagnosis represents one of the hardest challenges in clinical practice due to the lack of sensitive and specific biomarkers. Currently, neonatal AKI is defined with urinary markers and serum creatinine (sCr), with limitations in early detection and individual treatment. Biomarkers and risk factor scores were studied to predict neonatal AKI, to early identify the stage of injury and not the damage and to anticipate late increases in sCr levels, which occurred when the renal function already began to decline. Sepsis is the leading cause of AKI, and sepsis-related AKI is one of the main causes of high mortality. Moreover, preterm neonates, as well as patients with post-neonatal asphyxia or after cardiac surgery, are at a high risk for AKI. Critical patients are frequently exposed to nephrotoxic medications, representing a potentially preventable cause of AKI. This review highlights the definition of neonatal AKI, its diagnosis and new biomarkers available in clinical practice and in the near future. We analyze the risk factors involving patients with AKI, their outcomes and the risk for the transition from acute damage to chronic kidney disease.

Sustained acute kidney injury as an independent risk factor for neurodevelopmental and growth outcomes in a single NICU center

PURPOSE

Acute kidney injury (AKI) is commonly seen in neonatal intensive care units (NICUs) and is potentially associated with adverse prognoses in later stages of life. Our study evaluated the impact of sustained AKI (SAKI) on both neurodevelopmental impairment (NDI) and early growth restriction (EGR) in neonates.

METHODS

This case-control study retrospectively analyzed the medical records of neonates diagnosed with SAKI in the NICU of a tertiary medical center during the period from January 2007 to December 2020. Cases without subsequent follow-up and those resulting in death were excluded. We analyzed demographic, biochemical, and clinical outcome data.

RESULTS

Of the 93 neonates with SAKI, 51 cases (54.8%) were included in this study, while 42 cases (45.2%) were excluded due to a lack of follow-up or death. An age-matched control group comprised 103 neonates, who had never experienced AKI or SAKI, were selected at random. In total, 59 (38.3%) cases were identified as NDI and 43 (27.9%) as EGR. Multivariate analysis revealed that patients with SAKI had significantly higher risks of developing NDI (odds ratio, [OR] = 4.013, p = 0.001) and EGR (OR = 4.894, p < 0.001). The AKI interval had an area under the receiver operating characteristic curve of 0.754 for NDI at 9.5 days and 0.772 for EGR at 12.5 days.

CONCLUSIONS

SAKI is an independent risk factor for both NDI and EGR in neonates. Consequently, regular monitoring, neurological development assessments, and appropriate nutritional advice are crucial to these infants who have experienced renal injury.

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.

Recurrent neonatal acute kidney injury: incidence, predictors, and outcomes in the neonatal intensive care unit

OBJECTIVE

Determine recurrent neonatal acute kidney injury (rAKI) incidence, risk factors, and associated outcomes.

STUDY DESIGN

Single-center retrospective cohort of neonates admitted to the NICU 1/1/20-6/30/21. Comparisons were made between those with no AKI, single AKI episode (sAKI), and rAKI. Multivariable linear and logistic regression models were used to assess associations between rAKI and length of mechanical ventilation (LMV), length of hospitalization stay (LOS), mortality, and hypertension (HTN) at discharge.

RESULTS

The incidence of AKI in the cohort of 869 infants was 19%: 705 (81%) no AKI, 100 (12%) sAKI, 64 (7%) rAKI. Both sAKI and rAKI were independently associated with longer LMV and LOS. sAKI was independently associated with almost 4x higher odds of mortality than rAKI.

CONCLUSION

In this single center cohort of neonates, sAKI independently predicts mortality, however rAKI is independently associated with increased LMV and LOS suggesting rAKI is clinically important and warrants further study.

A proposed framework for advancing acute kidney injury risk stratification and diagnosis in children: a report from the 26th Acute Disease Quality Initiative (ADQI) conference

Acute kidney injury (AKI) in children is associated with increased morbidity, reduced health-related quality of life, greater resource utilization, and higher mortality. Improvements in the timeliness and precision of AKI diagnosis in children are needed. In this report, we highlight existing, novel, and on-the-horizon diagnostic and risk-stratification tools for pediatric AKI, and outline opportunities for integration into clinical practice. We also summarize pediatric-specific high-risk diagnoses and exposures for AKI, as well as the potential role of real-time risk stratification and clinical decision support to improve outcomes. Lastly, the key characteristics of important pediatric AKI phenotypes will be outlined. Throughout, we identify key knowledge gaps, which represent prioritized areas of focus for future research that will facilitate a comprehensive, timely and personalized approach to pediatric AKI diagnosis and management.

Urinary Concentration of Renal Biomarkers in Healthy Term Neonates: Gender Differences in GST-pi Excretion

BACKGROUND Serum creatinine, the criterion standard in assessment of renal function, is not reliable for the neonatal period because of its dependence on renal immaturity and maternal creatinine levels. Thus, it is important to study other biomarkers of renal function in neonates. The present study aimed to measure the urinary concentration of renal biomarkers: calbindin, clusterin, GST-pi (glutathione-S-transferase-alpha), KIM-1 (kidney injury molecule 1), MCP-1 (monocyte chemoattractant protein-1), and B2M (beta 2-microglobulin) in healthy term neonates. MATERIAL AND METHODS In the study, we included 80 healthy term neonates - 40 females and 40 males. We collected the neonates' urine on their first day of life. Urinary concentrations of calbindin, clusterin, KIM-1, MCP-1, and B2M were assessed using an immunoassay for kidney toxicology research. Because dilution of the urine affects the concentrations of urinary biomarkers, we normalized them to the concentration of urinary creatinine (Cr) and present them as biomarker/Cr ratios. RESULTS We obtained the following values of the assessed biomarker/Cr ratios (median [Q1-Q3]): calbindin/Cr.: 197.04 (56.25-595.17), KIM-1/Cr: 0.09 (0.04-0.18), MCP-1/Cr: 0.05 (0.02-0.14), B2M/Cr: 126.12 (19.03-342.48), GST-pi/Cr in boys: 1.28 (0.46-3.77), GST-pi/Cr in girls: 8.66 (2.51-27.82), clusterin/Cr: 4.55 (1.79-12.97) ng/mg Cr. CONCLUSIONS We showed the urinary levels of calbindin, clusterin, GST-pi, KIM-1, MCP-1, B2M in white, West Slavic, healthy term neonates. We found that in there is an association between female sex and a higher urinary GST-pi excretion, but urinary excretion of calbindin, clusterin, KIM-1, MCP-1, and B2M is sex-independent. The urinary levels of the assessed biomarkers do not depend on the method of delivery.

Incidence, Risk Factors, and Outcomes Associated With Recurrent Neonatal Acute Kidney Injury in the AWAKEN Study

Importance

The incidence and associated outcomes of recurrent acute kidney injury (rAKI) in neonates remain largely unknown.

Objective

To determine the incidence, risk factors, and clinical outcomes associated with rAKI in critically ill neonates.

Design, Setting, and Participants

This cohort study was a secondary analysis of the multicenter, international Assessment of Worldwide Acute Kidney Injury Epidemiology in Neonates retrospective study. Comparisons were made among neonates with no AKI, a single AKI episode (sAKI), and rAKI. All neonates younger than 14 days who were admitted between January 1 and March 31, 2014, to 24 participating level II to IV neonatal intensive care units and received intravenous fluids for at least 48 hours were considered for inclusion. Neonates with congenital heart disease requiring surgery within the first week of life, lethal chromosomal anomalies, death within 48 hours of admission, or severe congenital kidney abnormalities were excluded. Data were analyzed from May 23, 2022, to December 8, 2023.

Exposure

Recurrent AKI using the neonatal Kidney Disease: Improving Global Outcomes criteria. Determination of each rAKI required a complete return to the baseline serum creatinine level that defined the prior AKI episode.

Main Outcomes and Measures

Incidence and risk factors of rAKI and associations of rAKI with length of stay (LOS; ie, birth to hospital discharge) and mortality.

Results

The study cohort (n = 2162) included 1233 male neonates (57.0%). Gestational age distribution was less than 29 weeks for 276 neonates (12.8%), 29 to less than 36 weeks for 958 (44.3%), and 36 weeks or older for 928 (42.9%). Of 605 neonates with AKI, 133 (22.0%) developed rAKI with risk factors including younger gestational age, lower birthweight, and higher stage of initial AKI. Infants with rAKI experienced longer median LOS (no AKI, 17 [IQR, 8-34] days; sAKI, 18 [IQR, 9-45] days; rAKI, 60 [IQR, 25-109] days; P < .001). Time-varying Cox proportional hazards regression models suggest rAKI is independently associated with a lower hazard of discharge (adjusted hazard ratio, 0.7 [95% CI, 0.6-0.9]; P = .01) when compared with sAKI, but mortality did not differ between groups (adjusted hazard ratio, 1.4 [95% CI, 0.6-3.0]; P = .44).

Conclusions and Relevance

In this cohort study, neonatal rAKI was independently associated with longer LOS when compared with sAKI, suggesting that rAKI in neonates may be an important clinical distinction warranting further study and careful monitoring after an initial AKI episode.

Urinary biomarkers associated with acute kidney injury in pediatric mechanical circulatory support patients

BACKGROUND

In patients requiring mechanical circulatory support (MCS), the incidence of acute kidney injury (AKI) is between 37 and 63%. In this study, we performed an exploratory analysis evaluating the relationship of multiple urine biomarkers with AKI development in pediatric MCS patients.

METHODS

This is a single center retrospective study in a pediatric cohort receiving MCS from August 2014 to November 2020. We measured 14 urine biomarkers of kidney injury on day 1 following MCS initiation and analyzed their association with development of AKI in the first 7 days of MCS initiation.

RESULTS

Sixty patients met inclusion criteria. Patients with AKI were more likely to be supported by venoarterial extracorporeal membrane oxygenation (65% vs. 8.3%, p < 0.001), compared to the no AKI group and less likely to have ventricular assist devices (10% vs. 50%, p < 0.001). There was a significant increase in the median urine albumin and urine osteoactivin in the AKI group, compared to the no AKI group (p = 0.020 and p = 0.018, respectively). When normalized to urine creatinine (UCr), an increased log osteoactivin/UCr was associated with higher odds of AKI development (OR: 2.05; 95% CI: 1.07, 4.44; p = 0.028), and higher log epidermal growth factor (EGF)/UCr (OR: 0.41; 95% CI: 0.15, 0.96) was associated with decreased odds of AKI.

CONCLUSIONS

Early increase in urine osteoactivin is associated with AKI development within 7 days of MCS initiation in pediatric patients. Contrary, an increased urine EGF is associated with kidney protection. A higher resolution version of the Graphical abstract is available as Supplementary information.

Duration of Simultaneous Exposure to High-Risk and Lower-Risk Nephrotoxic Antimicrobials in the Neonatal Intensive Care Unit (NICU) and Future Adolescent Kidney Health

OBJECTIVE

To determine whether greater duration of simultaneous exposure to antimicrobials with high nephrotoxicity risk combined with lower-risk antimicrobials (simultaneous exposure) in the neonatal intensive care unit (NICU) is associated with worse later kidney health in adolescents born preterm with very low birth weight (VLBW).

STUDY DESIGN

Prospective cohort study of participants born preterm with VLBW (<1500 g) as singletons between January 1, 1992, and June 30, 1996. We defined simultaneous exposure as a high-risk antimicrobial, such as vancomycin, administered with a lower-risk antimicrobial on the same date in the NICU. Outcomes were serum creatinine, estimated glomerular filtration rate (eGFR), and first-morning urine albumin-creatinine ratio (ACR) at age 14 years. We fit multivariable linear regression models with days of simultaneous exposure and days of nonsimultaneous exposure as main effects, adjusting for gestational age, birth weight, and birth weight z-score.

RESULTS

Of the 147 out of 177 participants who had exposure data, 97% received simultaneous antimicrobials for mean duration 7.2 days (SD 5.6). No participant had eGFR <90 ml/min/1.73 m2. The mean ACR was 15.2 mg/g (SD 38.7) and 7% had albuminuria (ACR >30 mg/g). Each day of simultaneous exposure was associated only with a 1.04-mg/g higher ACR (95% CI 1.01 to 1.06).

CONCLUSIONS

Despite frequent simultaneous exposure to high-risk combined with lower-risk nephrotoxic antimicrobials in the NICU, there were no clinically relevant associations with worse kidney health identified in adolescence. Although future studies are needed, these findings may provide reassurance in a population thought to be at increased risk of chronic kidney disease.

Adults are just big kids: pediatric considerations for adult critical care nephrology

PURPOSE OF REVIEW

In recent years, there has been growing attention to pediatric kidney health, especially pediatric acute kidney injury (AKI). However, there has been limited focus on the role of pediatric AKI on adult kidney health, specifically considerations for the critical care physician.

RECENT FINDINGS

We summarize what is known in the field of pediatric AKI to inform adult medical care including factors throughout the early life course, including perinatal, neonatal, and pediatric exposures that impact survivor care later in adulthood.

SUMMARY

The number of pediatric AKI survivors continues to increase, leading to a higher burden of chronic kidney disease and other long-term co-morbidities later in life. Adult medical providers should consider pediatric history and illnesses to inform the care they provide. Such knowledge may help internists, nephrologists, and intensivists alike to improve risk stratification, including a lower threshold for monitoring for AKI and kidney dysfunction in their patients.

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.

Epidemiology data on the cost and outcomes associated with pediatric acute kidney injury

BACKGROUND

Hospitalized children with acute kidney injury (AKI) have not been extensively studied for clinical outcomes including hospital stay, the need for mechanical ventilation, mortality rates, and healthcare utilization. We hypothesize significant financial costs and increased morbidity and mortality associated with pediatric AKI.

METHODS

This is a retrospective study of pediatric patients (age ≤18 years) included in the Kids' Inpatient Database (KID) between January 1, 2016, and December 31, 2021. The results of the data analysis were utilized for comparative testing between the AKI and non-AKI cohorts.

RESULTS

The study included 4842 children [with AKI (n = 2424) and without AKI (n = 2418)]. The odds of mortality (p = 0.004) and mechanical ventilation (p < 0.001) were observed to be significantly higher among those with AKI as compared to those without AKI. Additionally, the median (IQR) duration of stay in the hospital (p < 0.001) and total cost (p < 0.001) were significantly higher among those with AKI vs. those without AKI.

CONCLUSIONS

AKI in children was associated with higher odds of mortality, longer duration of hospital stay, increased requirement of mechanical ventilation, and increased hospital expenditure. The scientific community can utilize this information to better understand the outcomes associated with this disease process in this patient population.

IMPACT

This article has thoroughly evaluated epidemiologic data associated with pediatric acute kidney injury (AKI) in hospitalized patients This study assesses mortality, hospital expenditure, and other factors to strengthen single-center and few multi-center studies and provides novel data regarding insurance and cost associated with pediatric AKI With increased knowledge of current epidemiology and risk factors, the scientific community can better understand prevention and outcomes in hospitalized children with AKI.

Preceding risks and mortality outcomes of different neonatal acute kidney injury in preterm infants

BACKGROUND

The aim of the study was to examine preceding risks and mortality outcomes of oliguric and non-oliguric acute kidney injury (AKI) in very preterm infants.

METHODS

Infants born ≤30 weeks' gestation were included. AKI was diagnosed based on neonatal Kidney Disease: Improving Global Outcomes criteria and was classified as oliguric and non-oliguric according to the urine-output criteria. We used modified Poisson and Cox proportional-hazards models for statistical comparisons.

RESULTS

Of 865 enrolled infants (gestational age 27.2 ± 2.2 weeks and birth weight 983 ± 288 gm), 204 (23.6%) developed AKI. Before AKI, the oliguric AKI group had significantly higher prevalence of small-for-gestational age (p = 0.008), lower 5-min Apgar score (p = 0.009) and acidosis (p = 0.009) on admission, and hypotension (p = 0.008) and sepsis (p = 0.001) during admission than the non-oliguric AKI group. Oliguric (adjusted risk ratio 3.58, 95% CI 2.33-5.51; adjusted hazard ratio 4.93, 95% CI 3.14-7.72) instead of non-oliguric AKI had significantly higher mortality risks than no AKI. Oliguric AKI showed significantly higher mortality risks than non-oliguric AKI, irrespective of serum creatinine and severity of AKI.

CONCLUSIONS

Categorizing AKI as oliguric and non-oliguric was crucial because of the distinct preceding risks and mortality outcomes of these two types of AKI in very preterm neonates.

IMPACT

The differences of the underlying risks and prognosis between oliguric and non-oliguric AKI in very preterm infants remain unclear. We found that oliguric AKI, but not non-oliguric AKI, carries higher mortality risks than infants without AKI. Oliguric AKI possessed higher mortality risks than non-oliguric AKI, irrespective of concomitant serum creatinine elevation and severe AKI. Oliguric AKI is more associated with prenatal small-for-the-gestational age and perinatal and postnatal adverse events, while non-oliguric AKI is associated with nephrotoxins exposures. Our finding highlighted the importance of oliguric AKI and is helpful in developing future protocol in neonatal critical care.

Routine Diaper Change Alters Kidney Oxygenation in Premature Infants: A Non-A Priori Analysis

BACKGROUND

Reduction in oxygen delivery to developing kidneys of premature infants may be an important source for acute kidney injury in premature infants.

PURPOSE

To describe changes in continuous kidney oxygenation (RrSO 2 ) measures before, during, and after routine diaper changes.

METHODS

Non-a priori analysis of a prospective cohort that received continuous measurement of RrSO 2 with near-infrared spectroscopy (NIRS) over the first 14 days of life demonstrating acute RrSO 2 drops surrounding diaper changes.

RESULTS

In total, 26 of 38 (68%) infants (≤1800 g) from our cohort exhibited acute drops in RrSO 2 that temporally correlated with diaper changes. Mean (SD) RrSO 2 baseline prior to each diaper change event was 71.1 (13.2), dropped to 59.3 (11.6) during diaper change, and recovered to 73.3 (13.2). There was a significant difference between means when comparing baseline to diaper change ( P < .001; 95% CI, 9.9 to 13.8) and diaper change to recovery ( P < .001; 95% CI, -16.9 to -11.2). The mean decrease in RrSO 2 during diaper change averaged 12 points (17%) below 15-minute RrSO 2 mean prior to diaper change, with quick recovery to prediaper change levels. No decreases in SpO 2 , blood pressure, or heart rate were documented during the intermittent kidney hypoxic events.

IMPLICATIONS FOR PRACTICE AND RESEARCH

Routine diaper changes in preterm infants may increase the risk for acute reductions in RrSO 2 as measured by NIRS; however, the impact on kidney health remains unknown. Larger prospective cohort studies assessing kidney function and outcomes related to this phenomenon are needed.

Patient level factors increase risk of acute kidney disease in hospitalized children with acute kidney injury

BACKGROUND

Studies in adults have shown that persistent kidney dysfunction ≥7-90 days following acute kidney injury (AKI), termed acute kidney disease (AKD), increases chronic kidney disease (CKD) and mortality risk. Little is known about the factors associated with the transition of AKI to AKD and the impact of AKD on outcomes in children. The aim of this study is to evaluate risk factors for progression of AKI to AKD in hospitalized children and to determine if AKD is a risk factor for CKD.

METHODS

Retrospective cohort study of children age ≤18 years admitted with AKI to all pediatric units at a single tertiary-care children's hospital between 2015 and 2019. Exclusion criteria included insufficient serum creatinine values to evaluate for AKD, chronic dialysis, or previous kidney transplant.

RESULTS

A total of 528 children with AKI were included in the study. There were 297 (56.3%) hospitalized AKI survivors who developed AKD. Among children with AKD, 45.5% developed CKD compared to 18.7% in the group without AKD (OR 4.0, 95% CI 2.1-7.4, p-value <0.001 using multivariable logistic regression analysis including other covariates). Multivariable logistic regression model identified age at AKI diagnosis, PCICU and NICU admission, prematurity, malignancy, bone marrow transplant, previous AKI, mechanical ventilation, AKI stage, duration of kidney injury, and need for kidney replacement therapy during day 1-7 as risk factors for AKD after AKI.

CONCLUSIONS

AKD is common among hospitalized children with AKI and multiple risk factors are associated with AKD. Children that progress from AKI to AKD are at higher risk of developing CKD. A higher resolution version of the Graphical abstract is available as Supplementary information.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Epidemiology of childhood acute kidney injury in England using e-alerts

Background

Few studies describe the epidemiology of childhood acute kidney injury (AKI) nationally. Laboratories in England are required to issue electronic (e-)alerts for AKI based on serum creatinine changes. This study describes a national cohort of children who received an AKI alert and their clinical course.

Methods

A cross-section of AKI episodes from 2017 are described. Hospital record linkage enabled description of AKI-associated hospitalizations including length of stay (LOS) and critical care requirement. Risk associations with critical care (hospitalized cohort) and 30-day mortality (total cohort) were examined using multivariable logistic regression.

Results

In 2017, 7788 children (52% male, median age 4.4 years, interquartile range 0.9-11.5 years) experienced 8927 AKI episodes; 8% occurred during birth admissions. Of 5582 children with hospitalized AKI, 25% required critical care. In children experiencing an AKI episode unrelated to their birth admission, Asian ethnicity, young (<1 year) or old (16-<18 years) age (reference 1-<5 years), and high peak AKI stage had higher odds of critical care. LOS was higher with peak AKI stage, irrespective of critical care admission. Overall, 30-day mortality rate was 3% (n = 251); youngest and oldest age groups, hospital-acquired AKI, higher peak stage and critical care requirement had higher odds of death. For children experiencing AKI alerts during their birth admission, no association was seen between higher peak AKI stage and critical care admission.

Conclusions

Risk associations for adverse AKI outcomes differed among children according to AKI type and whether hospitalization was related to birth. Understanding the factors driving AKI development and progression may help inform interventions to minimize morbidity.

Development of a Family-Centered Communication Tool for Kidney Health in Premature Infants: Qualitative Focus Group Study Using Human-Centered Design Methodology

BACKGROUND

Premature infants are at increased risk of kidney-related complications, including acute kidney injury (AKI) and chronic kidney disease (CKD). The risk of CKD in prematurely born infants is underrecognized by health care teams and caregivers. Understanding how to communicate the risk of CKD to caregivers is essential for longitudinal clinical follow-up and adherence.

OBJECTIVE

This study aimed to determine family caregiver attitudes toward kidney health and risk communication during a neonatal intensive care admission. We also sought to understand caregiver preferences for the communication of information surrounding the risk of CKD in premature infants.

METHODS

We augmented standard qualitative group sessions with human-centered design methods to assess parent preferences and clinician perspectives. Caregivers recruited had a prematurely born child who spent time in the neonatal intensive care unit at Riley Hospital for Children in Indianapolis, Indiana, and experienced AKI or another kidney complication, which put them at risk for future CKD. We used a variety of specific design methods in these sessions, including card sorting, projective methods, experience mapping, and constructive methods.

RESULTS

A total of 7 clinicians and 8 caregivers participated in 3 group sessions. Caregivers and clinicians readily acknowledged barriers to and drivers of long-term kidney monitoring as well as opportunities for communication of the risk of long-term kidney disease. Caregivers' primary concerns were for both the type and depth of information conveyed as well as the time at which it was communicated. Participants emphasized the importance of collaboration between the hospital care team and the primary care provider. Participant input was synthesized into several prototype concepts and, ultimately, into a rough prototype of a website and an informational flyer.

CONCLUSIONS

Caregivers of premature infants are open to communication about kidney health during their neonatal admission. The next phase of this work will translate caregivers' preferences into family-centered communication tools and test their efficacy in the neonatal intensive care unit.

An Interesting Case of Neonatal AKI: What Is the Time to Consider Anuria Irreversible?

Acute kidney injury is a frequent complication for critical newborns. Its management is a significant challenge, especially in extremely low-birth-weight (ELBW) infants. Currently, peritoneal dialysis (PD) is the most manageable treatment. However, data are lacking regarding when diuresis can be declared irreversible relative to the start of PD. A female infant born at 28 + 0 weeks with a birth weight of 800 g by monochorionic diamniotic pregnancy, complicated by twin-to-twin transfusion syndrome, developed acute renal failure on the second day of life because of long-term intrauterine hypoperfusion. PD was started on day 7. The patient remained anuric until the 52nd day of dialysis, when she presented adequate urine output of 2.5 mL/kg/h and PD was suspended for 11 days. After an episode of sepsis, PD was re-started, and after 50 days of treatment, given a urine output of 1.5 mL/kg/h, it was discontinued. The patient died on day 132 after a disseminate infection, which led to multiorgan failure. In ELBW infants, PD is a valid therapeutic instrument to treat patients with renal failure. Despite the evidence of low renal functional reserve in these patients, the duration of recovery from diuresis after a period of anuria can be very long.

Prevention of Chronic Morbidities in Extremely Premature Newborns with LISA-nCPAP Respiratory Therapy and Adjuvant Perinatal Strategies

Less invasive surfactant administration techniques, together with nasal continuous airway pressure (LISA-nCPAP) ventilation, an emerging noninvasive ventilation (NIV) technique in neonatology, are gaining more significance, even in extremely premature newborns (ELBW), under 27 weeks of gestational age. In this review, studies on LISA-nCPAP are compiled with an emphasis on short- and long-term morbidities associated with prematurity. Several perinatal preventative and therapeutic investigations are also discussed in order to start integrated therapies as numerous organ-saving techniques in addition to lung-protective ventilations. Two thirds of immature newborns can start their lives on NIV, and one third of them never need mechanical ventilation. With adjuvant intervention, these ratios are expected to be increased, resulting in better outcomes. Optimized cardiopulmonary transition, especially physiologic cord clamping, could have an additively beneficial effect on patient outcomes gained from NIV. Organ development and angiogenesis are strictly linked not only in the immature lung and retina, but also possibly in the kidney, and optimized interventions using angiogenic growth factors could lead to better morbidity-free survival. Corticosteroids, caffeine, insulin, thyroid hormones, antioxidants, N-acetylcysteine, and, moreover, the immunomodulatory components of mother's milk are also discussed as adjuvant treatments, since immature newborns deserve more complex neonatal interventions.

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

BACKGROUND AND OBJECTIVES

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

STUDY DESIGN

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

RESULTS

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

CONCLUSIONS

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

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

OBJECTIVE

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

DESIGN

Retrospective cohort study.

SETTING

Two Level IV neonatal intensive care units.

PATIENTS

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSION

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

Neonatal AKI: An update

Neonatal acute kidney injury (AKI) is a common complication, especially in the neonatal intensive care unit, that is associated with long term consequences and poor outcomes. Early detection and treatment is critical. Currently, neonatal AKI is defined with urinary markers and serum creatinine, with limitations on early detection and individual treatment. There have been numerous biomarkers and risk factor scores that have been studied for their ability to predict neonatal AKI. To move towards personalized medicine, neonatal AKI must be categorized into phenotypes and subphenotypes that fully encapsulate the diverse causes and specific treatments. This review aims to advance our understanding of neonatal AKI detection through the use of biomarkers, subphenotypes, and phenotypes to move towards personalized treatment strategies.

Validation of the STARZ neonatal acute kidney injury risk stratification score in an independent prospective cohort

OBJECTIVE

A rapid AKI risk assessment score would allow for improving management and outcomes. STARZ (Sethi, Tibrewal, Agrawal, Raina, waZir) score was developed for acute kidney injury (AKI) risk stratification of critically ill neonates. This is the first independent validation for the novel score outside the original enrolled centres.

STUDY DESIGN

750 neonates were included in the study. The STARZ score was calculated after 12 hours of admission. Neonates admitted in NICU and receiving IV fluids for at least 48 hours were included.

RESULTS

A total of 8.8% neonates had AKI in the first 7 days post admission. The duration of hospital stay was significantly higher among neonates with AKI [10.5 (7-19) vs. 7 (5-10) days; p < 0.001]. Mortality risk was 6.4 times higher among those with AKI [8 (12.1%) vs. 13 (1.9%); p < 0.001; RR (95% CI): 6.38 (2.74-14.83)]. In this study, the STARZ neonatal scoring model showed a sensitivity of 89.4% in detecting AKI with a 90.9% specificity and a high negative predictive value of 98.9%. The area under ROC was 0.958 (0.934-0981) - a high discriminative power.

CONCLUSIONS

The STARZ score allows for AKI risk stratification, providing opportunity for therapeutic interventions which may improve outcomes in critically ill neonates.

Acute kidney injury and early fluid load in a retrospective cohort of neonatal sepsis

BACKGROUND

Sepsis and acute kidney injury (AKI) are associated with mortality in the newborn intensive care unit (NICU). There is a paucity of studies that describe AKI and fluid overload in neonatal sepsis and their association with mortality.

METHODS

Retrospective study of neonates with culture positive sepsis admitted to the NICU between June 2020 and June 2021 was conducted. Primary outcome was in-hospital mortality according to AKI as defined by the neonatal modified Kidney Diseases Improving Outcomes criteria. Secondary outcomes were early fluid overload and vasopressor use.

RESULTS

Thirty-three percent of neonates had AKI with sepsis, and 57% of cases were severe AKI. AKI was associated with mortality after adjusting for variables that were different between survivors and non-survivors (aOR 5.7 [95% CI 1.1-36], p = 0.04). Early fluid overload occurred in 27% of neonates who were at higher risk of having AKI with sepsis (OR 7.4 [95% CI 1.6-26.0], p = 0.01) and higher risk of mortality (aOR 17.8 [95% CI 2-7545], p = 0.02).

CONCLUSIONS

AKI and early fluid overload are associated with mortality in sepsis in our retrospective cohort. Mitigating AKI and early fluid overload in sepsis might be a fruitful strategy in reducing mortality with sepsis. A higher resolution version of the Graphical abstract is available as Supplementary information.

Risk factors of acute kidney injury in very low birth weight infants in a tertiary neonatal intensive care unit

OBJECTIVE

Acute kidney injury (AKI) in the neonatal period is associated with worst outcomes as increased mortality and increased length of hospital stay. Very low birth weight (VLBW) newborns are at higher risk for developing several other conditions that are associated with worst outcomes. Understanding the risk factors for AKI may help to prevent this condition and improve neonatal care for this population.

METHODS

This retrospective cohort study included 155 very low birth weight newborns admitted between 2015 and 2017. The authors compared the newborns who developed neonatal AKI with the non-AKI group and analyzed the main risk factors for developing AKI in the population. The authors also performed an analysis of the main outcomes defined as the duration of mechanical ventilation, length of stay, and death.

RESULTS

From the cohort, a total of 61 (39.4%) patients had AKI. The main risk factors associated with Neonatal AKI were necrotizing enterocolitis (aOR 7.61 [1.69 - 34.37]; p = 0.008), neonatal sepsis (aOR 2.91 [1.17 - 7.24], p = 0.021), and hemodynamic instability (aOR 2.99 [1.35 - 6.64]; p = 0.007). Neonatal AKI was also associated with an increase in the duration of mechanical ventilation in 9.4 days (p = 0.026) and in an increase in mortality 4 times (p = 0.009), after adjusting for the other variables.

CONCLUSION

The present results highlight the importance of minimizing sepsis and necrotizing enterocolitis, as well as the importance of identifying hemodynamic instability, to prevent AKI and diminish the burden of morbimortality in VLBW newborns.

Frequency of Acute Kidney Injury and Association With Mortality Among Extremely Preterm Infants

IMPORTANCE

Neonatal acute kidney injury (AKI) is common and associated with morbidity and mortality. The temporal relationship between AKI and critical illness, as well as the frequency of AKI definition components (urine output and serum creatinine [sCr] concentration change), are unknown in extremely low-birth-weight (ELBW) (<1000 g), extremely preterm (<29 weeks' completed gestational age [GA]) infants.

OBJECTIVE

To measure the frequency of AKI from birth to death or discharge with attention to the definition components as well as the temporal relationship of AKI to critical illness and death.

DESIGN, SETTING, AND PARTICIPANTS

A single-center, multiyear, retrospective cohort study was conducted at an academic level IV neonatal intensive care unit between January 1, 2012, and January 1, 2020. Participants included inborn ELBW and infants at 22 to 28 weeks' completed GA with confirmed congenital anomalies who survived 12 hours or more.

EXPOSURES

Extremely preterm birth and ELBW.

MAIN OUTCOMES AND MEASURES

The primary outcome was AKI frequency. The timing, severity, and criteria for AKI were measured. The temporal relationship between AKI, organ dysfunction, and outcomes were quantified using odds ratios (ORs), logistic regression, and Shapley Additive Explanations. Acute kidney injury recognition, imaging, pediatric nephrology consultation, and follow-up were determined.

RESULTS

A total of 436 infants (52% male; 44% Black) met the inclusion criteria (median BW, 725 g; median GA, 25.7 wk). Acute kidney injury was common in the first week of life (44%), primarily based on the change in the sCr concentration criterion (88%), and negatively associated with GA (OR, 0.69; 95% CI, 0.60-0.78), but positively associated with antecedent critical illness (OR, 1.17; 95% CI, 1.12-1.23), severe intraventricular hemorrhage (OR, 1.86; 95% CI, 1.12-3.08), late-onset sepsis (OR, 1.03; 95% CI, 1.02-1.03), and mortality (OR, 2.77; 95% CI, 1.63-4.72). Acute kidney injury had negligible clinical contribution to death within the model (Shapley Additive Explanation, <0.5% change to outcome) relative to antecedent patient-concentration organ dysfunction (6%-15% change). Among infants with severe AKI, recognition (32%), nephrology inpatient consultation (16%), and outpatient follow-up (9%) were not common.

CONCLUSIONS AND RELEVANCE

In this cohort study of ELBW infants, AKI was common in the first week of life, inversely associated with GA, and followed organ (primarily cardiovascular) dysfunction. Acute kidney injury considered as the primary pathway to mortality was rare, and amelioration of AKI to modify death was not well supported.

Costs associated with acute kidney injury in critically Ill neonates with patent Ductus arteriosus: pediatric health information system (PHIS) analysis

OBJECTIVE

Compare costs of hospitalization between critically-ill neonates with patent ductus arteriosus (PDA) who did and did not develop acute kidney injury (AKI).

STUDY DESIGN

Using the Children's Hospital Association's Pediatric Health Information System (PHIS) database, we ascertained the marginal estimated total cost of hospitalization between those who did and did not develop AKI.

RESULTS

Query of 49 PHIS centers yielded 14,217 neonates with PDA, 1697 with AKI and 12,520 without AKI. Predictors of cost included AKI, birth weight, ethnicity, race, length of stay (LOS), and Feudtner Complex Chronic Conditions Classification System. LOS was the strongest predictor (AKI: median 71 days [IQR 28-130]; No AKI: 28 days [10-76]; p < 0.01). Neonates with AKI had $48,416 greater costs (95% CI: $43,804-53,227) after adjusting for these predictors (AKI: $190,063, 95% CI $183,735-196,610; No AKI: $141,647, 95% CI $139,931-143,383 l; p < 0.01).

CONCLUSION

AKI is independently associated with increased hospital costs in critically-ill neonates with PDA.

Association between acute kidney injury and brain injury on term-equivalent age brain magnetic resonance imaging in very preterm infants

BACKGROUND

This study aimed to investigate the relationship between acute kidney injury (AKI) in the first 2 weeks of life and brain injury on term-equivalent age magnetic resonance imaging in very preterm infants.

METHODS

We included 116 infants with a birth weight of < 1500 g who were born at the King Saud Medical City at ≤ 32 gestational weeks. They were admitted to the neonatal intensive care unit and underwent term-equivalent age and pre-discharge brain magnetic resonance imaging. A negative binomial with generalized linear models and a robust variance estimator (Huber-White) was applied for univariate relative risk analysis. The Kidokoro score was then used to determine the effect of AKI on brain morphology and growth at term-equivalent age.

RESULTS

Sixty-eight (64.2%) infants had developed an AKI in the first 2 weeks of life. AKI was significantly associated with cerebellum signal abnormalities, cerebellar volume reduction, and a high total cerebellum score (P = 0.04, P < 0.001, P < 0.001, respectively).

CONCLUSIONS

AKI in the first 2 weeks of life is associated with brain insult, especially in the cerebellum. More well-designed studies are required to investigate the association and impact of AKI on the central nervous system. A higher resolution version of the Graphical abstract is available as Supplementary information.

Low birth weight, nephron number and chronic kidney disease

Chronic kidney diseases have a significant impact on morbidity and mortality worldwide. Low birth weight, fetal growth restriction and prematurity are indicators of fetal growth and development disorders associated with a congenital reduction in nephron number, which predisposes to an increased risk for chronic kidney disease. On an individual basis, a small nephron number at birth is not always enough to determine the onset of chronic kidney disease, but it decreases the ability of the kidneys to resist any insults to renal tissue that may occur later in life, such as exposure to nephrotoxic drugs or episodes of acute kidney injury. The high incidence of low birth weight and preterm birth globally suggests that, at the population level, the impact of alterations in fetal development on the subsequent onset of chronic kidney disease could be significant. The implementation of strategies aimed at reducing the incidence of prematurity, fetal growth restriction, as well as other conditions that lead to low birth weight and a reduced nephron number at birth, provides an opportunity to prevent the development of chronic kidney disease in adulthood. For these purposes the coordinated intervention of several specialists, including obstetricians, gynecologists, neonatologists, nephrologists, and family doctors, is necessary. Such strategies can be particularly useful in resource-poor countries, which are simultaneously burdened by maternal, fetal and child malnutrition; poor health; epidemics caused by communicable diseases; and little access to screening and primary care.

Acute kidney injury among preterm infants receiving nonsteroidal anti-inflammatory drugs: A pilot study

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are a frequently prescribed class of medications in the neonatal intensive care unit (NICU). We aimed to reveal acute kidney injury (AKI) epidemiology in NSAID-exposed premature infants admitted to the NICU using a standardized definition and determine the percentage of NSAID-exposed patients with adequate serum creatinine (SCr) monitoring.

METHODS

This retrospective study compared infants born at ≤34 weeks gestational age who received NSAID for intraventricular hemorrhage prophylaxis (prophylaxis group) or symptomatic treatment for patent ductus arteriosus (PDA; treatment group) between January and December 2014 at a tertiary NICU. All available SCr and 12-h urine output (UO) values were recorded from admission until day seven post-NSAID exposure. AKI incidence was determined using the neonatal modified Kidney Disease Improving Global Outcomes classification, defined as an increase in SCr (i.e., 1.5 fold rise from previous SCr measurement within seven days or 26.5 mmol/L increase within 48 h) or UO < 1 mL/kg/hour, excluding the first 24 h of life.

RESULTS

We identified 70 eligible subjects; 32 received prophylactic NSAIDs, and 38 received indomethacin or ibuprofen for treating symptomatic PDA. AKI incidence for the entire cohort was 23% (16/70). The prophylaxis group had a significantly lower AKI rate than the treatment group (9% vs. 34%; p = 0.014). The treatment group had a higher proportion of infants with adequate SCr monitoring during NSAID treatment than the prophylaxis group (87% vs. 13%, p < 0.001).

CONCLUSION

NSAID-associated AKI occurred in approximately one-quarter of premature infants overall, and the AKI incidence was higher in infants treated with NSAIDs for the symptomatic treatment of PDA than in those receiving prophylactic treatment during the first day of life. Standardized protocols for monitoring daily SCr and UO after exposure should be implemented for all neonates with NSAID exposure to improve early AKI recognition and management.

Serum and urinary biomarkers to predict acute kidney injury in premature infants: a systematic review and meta-analysis of diagnostic accuracy

BACKGROUND

Premature infants are at high risk for acute kidney injury (AKI) and current diagnostic criteria are flawed. The objective of this study was to determine the diagnostic accuracy of urine and serum biomarkers not currently used in routine clinical practice to predict AKI in premature infants.

METHOD

A systematic review was performed that followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Diagnostic Test Accuracy Studies (PRISMA-DTA). Data were extracted on the diagnostic accuracy of AKI biomarkers using serum creatinine or urine output as the reference standard. Quality and validity were assessed using modified Standards for Reporting Diagnostic Accuracy (STARD) criteria.

RESULTS

We identified 1024 articles, with 15 studies (791 infants) eligible for inclusion. Twenty-seven biomarkers were identified including serum cystatin C and urinary neutrophil gelatinase-associated lipocalin (uNGAL), osteopontin, kidney injury molecule-1, epidermal growth factor, and protein S100-P. However, many were only reported by one study each. A meta-analysis could only be conducted on uNGAL (288 infants from 6 studies) using a hierarchical, random-effects logistic-regression model. uNGAL had a summary sensitivity of 77% (95% CI 58-89%), specificity of 76% (95% CI 57-88%) and AUC-SROC of 0.83 (95% CI 0.80-0.86) for the diagnosis of AKI. By utilising uNGAL, the post-test probability of AKI increased to 52% (95% CI 37-66%) with a positive test and decreased to 9% (95% CI 5-16%) with a negative test if the pre-test probability was 25%.

CONCLUSION

uNGAL shows promise as a diagnostically accurate biomarker for AKI in premature infants.

Evaluation of neonatal acute kidney injury (AKI) after emergency gastrointestinal surgery

BACKGROUND

The overall incidence of acute kidney injury (AKI) in neonates undergoing emergency gastrointestinal surgery is yet to be determined. The study aims are to analyze our experience in emergency gastrointestinal surgery for neonates and to evaluate the incidence of AKI.

METHODS

We conducted a retrospective study of neonates undergoing emergency gastrointestinal surgery between June 31, 2018 and May 10, 2022 (N = 329). The primary outcome was the overall incidence of AKI. The diagnostic AKI was based on the Modified Kidney Disease: Improving Global Outcomes (KDIGO) definition of neonatal AKI. The secondary outcomes, including the postoperative length of hospital stay (PLOS), 24-h mortality, in-hospital mortality, and total in-hospital cost, were analyzed. The risk factors associated with the development of postoperative AKI were also analyzed.

RESULTS

The incidence of postoperative AKI was 9.1% (30/329). No significant differences were detected in the 24-h mortality and in-hospital mortality between the two cohorts. In the final model, patients undergoing mechanical ventilation before surgery, vasopressor support, surgical duration, intraoperative oliguria and preoperative lowest serum creatinine (SCr), were independently associated with AKI.

CONCLUSION

Our study found that patients undergoing mechanical ventilation before surgery, vasopressor support, surgical duration, intraoperative oliguria and preoperative lowest SCr were independently associated with postoperative AKI in neonates who accepted emergency gastrointestinal surgeries.

Antenatal Steroids and Acute Kidney Injury in Preterm Infants

OBJECTIVE

The aim of this study was to identify the effects of antenatal steroids (ANS) on acute kidney injury (AKI) in very low birth weight (VLBW) preterm infants.

STUDY DESIGN

We performed a retrospective cohort study of VLBW infants admitted to a tertiary-care neonatal intensive care unit between January 2016 and June 2019. Infants were divided into no ANS, partial ANS, and complete ANS groups. Serum creatinine (SCr) levels and rates of AKI during the first 2 weeks of life were compared.

RESULTS

During the study period, 335 infants met our inclusion criteria. Among no, partial, and complete ANS groups, there were significant differences in rates of stages 2 and 3 AKI (17, 11, and 6%, respectively). Logistic regression analysis revealed that complete ANS course was associated with lower rates of AKI (odds ratio [OR] = 0.41 95% confidence interval [CI]: 0.20-0.83) and stages 2 and 3 AKI (OR = 0.205 95% CI: 0.075-0.563) compared with no ANS. Infants in complete ANS group had significantly lower SCr at 72 hours of life and at discharge, SCr peak was compared with infants in no ANS group.

CONCLUSION

In VLBW infants, complete ANS exposure may be associated with improved renal function and decreased risk for AKI compared with no ANS.

KEY POINTS

· The effects of antenatal steroid treatment on renal function in preterm infants are not clear.. · A complete course of antenatal steroid decreases the risk for acute kidney injury in preterm infants.. · Infants who are not exposed to antenatal steroids need closer observation of their renal function..

Validation of the STARZ neonatal acute kidney injury risk stratification score

BACKGROUND

Neonatal acute kidney injury (AKI) is common in neonatal intensive care units (NICU) and leads to worse outcomes. Stratifying neonates into an "at risk" category allows health care providers to objectively recognize opportunities for improvements in quality of care.

METHODS

The "Neonatal AKI Risk Prediction Scoring" was devised as the "STARZ [Sethi, Tibrewal, Agrawal, Raina, waZir]" Score. The STARZ score was derived from our prior multicentre study analysing risk factors for AKI in neonates admitted to the NICU. This tool includes 10 variables with a total score ranging from 0 to 100 and a cut-off score of 31.5. In the present study, the scoring model has been validated in our multicentre cohort of 744 neonates.

RESULTS

In the validation cohort, this scoring model had sensitivity of 82.1%, specificity 91.7%, positive predictive value 81.2%, negative predictive value 92.2% and accuracy 88.8%. Based on the STARZ cut-off score of ≥ 31.5, an area under the receiver operating characteristic (ROC) curve was observed to be 0.932 (95% CI, 0.910-0.954; p < 0.001) signifying that the discriminative power was high. In the validation cohort, the probability of AKI was less than 20% for scores up to 32, 20-40% for scores between 33 and 36, 40-60% for scores between 37 and 43, 60-80% for scores between 44 and 49, and ≥ 80% for scores ≥ 50.

CONCLUSIONS

To promote the survival of susceptible neonates, early detection and prompt interventional measures based on highly evidenced research is vital. The risk of AKI in admitted neonates can be quantitatively determined by the rapid STARZ scoring system. A higher resolution version of the Graphical abstract is available as Supplementary information.

Recurrent acute kidney injury in preterm neonates is common and associated with worse outcomes and higher mortality

BACKGROUND

Acute kidney injury (AKI) in preterm neonates is associated with poor outcomes that may worsen in the setting of recurrent episodes of AKI. This study defines and studies the incidence, risk factors, and outcomes of recurrent AKI (rAKI).

METHODS

Retrospective chart review of the neonates born at a gestational age of ≤28 weeks admitted to the neonatal intensive care unit (NICU) between January 2014 and December 2018. We identified AKI based on the serum creatinine (Scr) concentrations using the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. rAKI was defined as the occurrence of AKI after Scr from the prior AKI had returned to baseline.

RESULTS

Forty-nine of the 205 (24%) preterm neonates developed rAKI. An earlier diagnosis (<7 days old) and a higher KDIGO stage (stage 3) at the initial episode of AKI was associated with rAKI (p = 0.03). Preterm neonates with rAKI had higher mortality as compared to those with a single episode of AKI (sAKI) (adjusted odds ratio (aOR) 4.55, 95% confidence interval (CI), 1.12-18.51). Length of stay (LOS) was longer among neonates with rAKI as compared to those with sAKI by 36 days (95% CI 24.9-47.1).

CONCLUSIONS

Recurrent AKI in preterm neonates was associated with earlier episodes and higher KDIGO stage of the initial AKI episode. Neonates with rAKI had higher mortality and longer LOS compared to those with sAKI.

IMPACT

Definition and study of the incidence of rAKI and its associated outcomes among preterm neonates. Recurrent AKI is common among preterm neonates and may contribute to worse outcomes for premature neonates in the NICU. Early recognition of the risk factors for AKI, and effective management of initial AKI and early phase of recurrent AKI may improve outcomes of these preterm neonates.

Documentation of acute kidney injury at discharge from the neonatal intensive care unit and role of nephrology consultation

OBJECTIVE

To investigate whether NICU discharge summaries documented neonatal AKI and estimate if nephrology consultation mediated this association.

STUDY DESIGN

Secondary analysis of AWAKEN multicenter retrospective cohort.

EXPOSURES

AKI severity and diagnostic criteria.

OUTCOME

AKI documentation on NICU discharge summaries using multivariable logistic regression to estimate associations and test for causal mediation.

RESULTS

Among 605 neonates with AKI, 13% had documented AKI. Those with documented AKI were more likely to have severe AKI (70.5% vs. 51%, p < 0.001) and SCr-only AKI (76.9% vs. 50.1%, p = 0.04). Nephrology consultation mediated 78.0% (95% CL 46.5-109.4%) of the total effect of AKI severity and 82.8% (95% CL 70.3-95.3%) of the total effect of AKI diagnostic criteria on documentation.

CONCLUSION

We report a low prevalence of AKI documentation at NICU discharge. AKI severity and SCr-only AKI increased odds of AKI documentation. Nephrology consultation mediated the associations of AKI severity and diagnostic criteria with documentation.

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

BACKGROUND AND OBJECTIVES

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

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

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

RESULTS

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

CONCLUSIONS

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

Diagnostic Performance of Height-Estimated Baseline Creatinine in Diagnosing Acute Kidney Injury in Children with Type 1 Diabetes Mellitus Onset

At type 1 diabetes mellitus (T1DM) onset, acute kidney injury (AKI) is very common. To diagnose AKI, the availability of a baseline serum creatinine (bSCr) is pivotal. However, in most hospitalized children the bSCr is unknown. We aimed to test whether the bSCr estimated on the basis of height (ebSCr) could be a reliable surrogate for AKI diagnosis compared with the measured bSCr (mbSCr). As the mbSCr, we considered the creatinine measured 14 days after T1DM onset while ebSCr (mg/dL) = (k × height [cm])/120 mL/min/1.73 m2, where k = 0.55 for children and adolescent girls and k = 0.7 for adolescent boys. AKI was defined as serum creatinine values >1.5 times the baseline creatinine. Kappa statistics and the percentage of agreement in AKI classification by ebSCr−AKI versus mbSCr−AKI definition methods were calculated. Bland−Altman plots were used to show the agreement between the creatinine ratio (highest/baseline creatinine; HC/BC) calculated with mbSCr and ebSCr. The number of 163 patients with T1DM onset were included. On the basis of mbSCr, 66/163 (40.5%) presented AKI while, on the basis of ebSCr, 50/163 (30.7%) accomplished AKI definition. ebSCr showed good correlation with mbSCr using both the Spearman test (rho = 0.67; p < 0.001) and regression analysis (r = 0.68; p < 0.001). Moreover, at the Bland−Altman plots, the bias of the highest/baseline creatinine ratio calculated on the basis of the mbSCr compared to ebSCr was minimal (bias = −0.08 mg/dL; 95% limits of agreement = −0.23/0.39). AKI determined using ebSCr showed 90% agreement with AKI determined using mbSCr (kappa = 0.66; p < 0.001). Finally, we compared the area under a receiver−operating characteristic curve (AUROC) of HC/BC ratio calculated on the basis of ebSCr with AUROC of the gold standard HC/BC ratio calculated on the basis of mbSCr. As expected, the gold standard had an AUROC = 1.00 with a 95% confidence interval (CI) between 0.98 and 1.00, p < 0.001. The HC/BC ratio calculated on the basis of ebSCr also had significant AUROC (AUROC = 0.94; 95% CI: 0.90−0.97; p < 0.001). The comparison of the two ROC curves showed a p < 0.001. In conclusion, when mbSCr is unknown in patients with T1DM onset, the ebSCr calculated on the basis of height could be an alternative to orientate clinicians toward AKI diagnosis.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Incidence, Risk Factors, and Outcomes of Acute Kidney Injury in Necrotizing Enterocolitis: A Prospective Single-Center Study

Necrotizing enterocolitis (NEC) is a significant cause of morbidity and mortality in the neonatal intensive care unit (NICU). Acute kidney injury (AKI) is considered to be one of the most well-established risk factors for mortality in neonates. The aim of this work was to study the incidence of AKI in neonates with NEC and to determine the associated conditions, risk factors, and outcomes. We carried out this prospective cross-sectional study on 104 neonates treated for NEC from September 2015 to September 2019. Diagnoses of AKI were made using the neonatal modified Kidney Disease: Improved Global Outcome criteria. AKI occurred in 63 neonates (61%), with 32 at Stage 1 (31%), 20 at Stage 2 (19%), and 11 at Stage 3 (11%), including three requiring dialysis. Vancomycin use and positive blood culture were risk factors for developing AKI in our NEC neonates (odds ratio: 2.47 and 2.41; P = 0.03 and 0.04, respectively). Neonates with AKI had a higher mortality rate (47.6% vs. 26.8 %, P = 0.03) and an increased length of stay (LOS) (69.8 days vs. 53.9 days, P <0.01) than the non-AKI group. Surgical intervention was required in 11 (10.5%) of our neonates. We concluded that AKI occurs in about 60% of neonates with NEC and is associated with higher mortality and LOS in the NICU. Therefore, it is very important to identify and manage all neonates who are at a high risk of developing AKI as quickly as possible.

Neonatal Acute Kidney Injury

Acute kidney injury (AKI) is a common occurrence in the neonatal intensive care unit (NICU). In recent years, our knowledge of the incidence and impact of neonatal AKI on outcomes has expanded exponentially. Neonatal AKI has been shown to be associated with adverse outcomes including increased length of mechanical ventilation, prolonged length of stay, and rise in mortality. There has also been increasing work suggesting that neonates with AKI are at higher risk of chronic kidney disease (CKD). In the past, AKI had been defined multiple ways. The utilization of the neonatal modified Kidney Disease: Improving Global Outcomes (KDIGO) criteria as the standard definition for neonatal AKI in research and clinical care has driven the advances in our understanding of neonatal AKI over the last 10 years. This definition has allowed researchers and clinicians to better understand the incidence, risk factors, and outcomes associated with neonatal AKI across populations through a multitude of single-center studies and the seminal, multicenter Assessment of Worldwide Acute Kidney Injury Epidemiology in Neonates (AWAKEN) study. As the impacts of neonatal AKI have become clear, a shift in efforts toward identifying those at highest risk, protocolizing AKI surveillance, improving prevention and diagnosis, and expanding kidney support therapy (KST) for neonates has occurred. These efforts also include improving risk stratification (identifying high risk populations, including those with nephrotoxic medication exposure) and diagnostics (novel biomarkers and diagnostic tools). Recent work has also shown that the targeted use of methylxanthines may prevent AKI in a variety of high-risk populations. One of the most exciting developments in neonatal AKI is the advancement in technology to provide KST to neonates with severe AKI. In this comprehensive review we will provide an overview of recent work and advances in the field of neonatal AKI. This will include a detailed review of (1) the definition of neonatal AKI, (2) the epidemiology, risk factors, and outcomes associated with neonatal AKI, (3) improvements in risk stratification and diagnostics, (4) mitigation and treatment, (5) advancements in the provision of KST to neonates, and (6) the incidence and risk of subsequent CKD.

Neonatal acute kidney injury risk stratification score: STARZ study

BACKGROUND

Neonates admitted in the neonatal intensive care unit are vulnerable to acute kidney injury leading to worse outcomes. It is important to identify "at-risk" neonates for early preventive measures.

METHODS

The study was a multicenter, national, prospective cohort study done in 11 centers in India. A multivariable logistic regression technique with step-wise backward elimination method was used, and a "Risk Prediction Scoring" was devised [the STARZ score].

RESULTS

The neonates with admission in the NICU within <25.5 h of birth, requirement of positive pressure ventilation in the delivery room, <28 weeks gestational age, sepsis, significant cardiac disease, urine output <1.32 ml/kg/h or serum creatinine ≥0.98 mg/dl during the first 12 h post admission, use of nephrotoxic drugs, use of furosemide, or use of inotrope had a significantly higher risk of AKI at 7 days post admission in the multivariate logistic regression model. This scoring model had a sensitivity of 92.8%, specificity of 87.4% positive predictive value of 80.5%, negative predictive value of 95.6%, and accuracy of 89.4%.

CONCLUSIONS

The STARZ neonatal score serves to rapidly and quantitatively determine the risk of AKI in neonates admitted to the neonatal intensive care unit.

IMPACT

The STARZ neonatal score serves to rapidly and quantitatively determine the risk of AKI in neonates admitted to the neonatal intensive care unit. These neonates with a higher risk stratification score need intense monitoring and daily kidney function assessment. With this intensification of research in the field of AKI risk stratification prediction, there is hope that we will be able to decrease morbidity and mortality associated with AKI in this population.

Under-Recognition of Neonatal Acute Kidney Injury and Lack of Follow-Up

OBJECTIVE

Acute kidney injury (AKI) incidence is 30% in neonatal intensive care units (NICU). AKI is associated with increased mortality and risk of chronic kidney disease (CKD) in children. To assess follow-up and early CKD, we retrospectively reviewed outcomes of Cincinnati Children's Hospital Medical Center (CCHMC) cohort of neonates from the AWAKEN trial (2014).

STUDY DESIGN

Data from 81 CCHMC patients were extracted from the AWAKEN dataset. KDIGO (Kidney Disease: Improving Global Outcomes) criteria for serum creatinine (SCr) and urine output (UOP) <1 mL/kg/h, reported per 24 hours on postnatal days 2 to 7, were used to define AKI. Charts were reviewed until May 2019 for death, nephrology consult, AKI diagnosis on discharge summary, follow-up, and early CKD at >6 months of age (defined as: estimated glomerular filtration rate < 90 mL/min/1.73 m², hyperfiltration, proteinuria, hypertension, or abnormal ultrasound). Patients were considered to have renal follow-up if they had ≥1 follow-up visit containing: SCr, urinalysis, or blood pressure measurement.

RESULTS

Seventy-seven patients had sufficient data to ascertain AKI diagnosis. In total 47 of 77 (61%) were AKI+ by SCr or UOP criteria (20 stage 1, 14 stage 2, 13 stage 3). Four died during their admission and five were removed from CKD analyses due to urologic anomalies. AKI-UOP alone outnumbered AKI-SCr (45 AKI+ vs 5 AKI+ for all stages). 33% of patients had <2 SCr measured while inpatient. Only 3 of 47 AKI+ patients had a nephrology consult (all stage 3 by SCr) and 2 of 47 had AKI included in discharge summary. 67% of AKI+ patients had follow-up. In total 10 of 43 (23%) AKI+ versus 12 of 25 (48%) AKI- patients had ≥1 marker of early CKD assessed after 6 months. Based on SCr, 3 of 7 (43%) AKI+ had hyperfiltration versus 0 of 7 (0%) AKI- (p = 0.19).

CONCLUSION

AKI is vastly under-recognized in the NICU, especially if based on SCr alone. This leads to insufficient follow-up to ascertain renal sequelae in this high-risk population.

KEY POINTS

· AKI is under-recognized in high-risk neonates.. · There is a lack of adequate follow-up.. · Identification of AKI by SCr alone is insufficient..