Recognition and reporting of AKI in very low birth weight infants

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Nephrotoxic medications and associated acute kidney injury in hospitalized neonates

OBJECTIVES

Hospitalized neonates are often treated with nephrotoxic medications, a known risk factor for acute kidney injury (AKI). Nephrotoxic medications and AKI, especially in periviable neonates, could be detrimental to nephrogenesis. Our objectives were to evaluate the prevalence of neonatal treatment with nephrotoxic medications and its relationship with AKI in in the first 28 days of life, and to delineate the associated demographics and diagnoses.

STUDY DESIGN

Multicenter retrospective analysis using the national Pediatric Hospital Information System database, including 49 pediatric hospitals. Neonates admitted within the first two postnatal days were included. Treatment with 37 nephrotoxic medications across demographics and clinical variables, and relationship with AKI were evaluated. AKI was determined by using the International Classification of Diseases codes.

RESULTS

Of 192,229 neonates, 74% were treated with at least one nephrotoxic medication. Incidence of AKI was significantly higher in the treated group (aRR 3.68 [95% CI: 2.85, 4.75]). The aRRs of treatment were increased in infants born < 32-week, and < 2000 g. Nephrotoxic medications were prescribed to 90-95% of  neonates born ≤ 28-week gestational age. Most treatments (95-98%) occurred in the first 3 days. Intravascular aminoglycosides were the most frequent type; 28% of neonates were treated for ≥ 4 calendar days. Most common diagnoses were infections (25%) and patent ductus arteriosus (20%).

CONCLUSIONS

Neonatal treatment with nephrotoxic medications is common, especially among the smallest, most immature preterm neonates and demonstrates a need for initiatives to reduce neonatal exposure to these agents, when feasible. Across all gestational age categories, the prevalence of AKI is higher in the neonates treated with nephrotoxic drugs. The long-term effects of treatment with nephrotoxic medications and subsequent AKI on nephrogenesis and nephron endowment will need to be evaluated.

Prematurity and Low Birth Weight in Neonates as a Risk Factor for Obesity, Hypertension, and Chronic Kidney Disease in Pediatric and Adult Age

Low weight at birth may be due to intrauterine growth restriction or premature birth. Preterm birth is more common in low- and middle-income countries: 60% of preterm birth occur in sub-Saharan African or South Asian countries. However, in some higher-income countries, preterm birth rates appear to be increasing in relation to a reduction in the lower threshold of fetal viability. The cutoff is at 22–23 weeks, with a birth weight of approximately 500 g, although in developed countries such as Japan, the viability cutoff described is 21–22 weeks. There is evidence of the long-term consequences of prenatal programming of organ function and its relationship among adult diseases, such as hypertension (HT), central obesity, diabetes, metabolic syndrome, and chronic kidney disease (CKD). Premature delivery before the completion of nephrogenesis and intrauterine growth restriction leads to a reduction in the number of nephrons that are larger due to compensatory hyperfiltration and hypertrophy, which predisposes to the development of CKD in adulthood. In these patients, the long-term strategies are early evaluation and therapeutic interventions to decrease the described complications, by screening for HT, microalbuminuria and proteinuria, ultrasound monitoring, and renal function, with the emphasis on preventive measures. This review describes the effects of fetal programming on renal development and the risk of obesity, HT, and CKD in the future in patients with low birth weight (LBW), and the follow-up and therapeutic interventions to reduce these complications.

Improving the identification of acute kidney injury in the neonatal ICU: three centers' experiences

OBJECTIVE

To describe three different standardized approaches to improving neonatal acute kidney injury (AKI) identification and the impact on AKI identification, incidence, and nephrology consultation and referral.

STUDY DESIGN

A retrospective cohort study in three academic NICUs. We compared AKI identification, AKI incidence, nephrology consultation, and nephrology follow-up before and after implantation of local protocols to standardize neonatal AKI identification.

RESULT

Neonatal AKI identification improved in all three NICUs following protocol implementation (26-85%, P < 0.0001). Each center also saw increases in nephrology consultation (15-83%, P < 0.0001) and nephrology follow-up (7-73%, P < 0.0001). AKI incidence decreased significantly (21-12%, P < 0.0001).

CONCLUSION

Multiple strategies can be successfully operationalized to improve neonatal AKI identification. While different in approach, each strategy resulted in increased AKI identification and nephrology involvement. This study emphasizes the importance of local standardized approaches to AKI to improve AKI identification and nephrology involvement in the NICU.

Dosing of vancomycin and target attainment in neonates: a systematic review

INTRODUCTION

Neonatal infections caused by Gram-positive bacteria are commonly treated with vancomycin. However, there is a lack of agreement on the optimal vancomycin dosing regimen and corresponding vancomycin exposure to correlate with efficacy and toxicity.

OBJECTIVES

This review aimed to evaluate dosing of vancomycin in neonates, therapeutic target attainment and clinical toxicity and efficacy outcomes.

METHODS

Two electronic databases - Embase and PubMed (Medline) - were systematically searched between 1995-2020. Studies that reported dosing regimens, drug concentrations, toxicity, and efficacy of vancomycin in neonates were eligible for inclusion. Descriptive analysis and a narrative synthesis were performed.

RESULTS

The systematic review protocol was registered with the PROSPERO International Prospective Register of Systematic reviews in 2020 (registration number: CRD42020219568). Twenty-four studies were included for final analysis. Overall, the data from the included studies showed a great degree of heterogeneity. Therapeutic drug monitoring practices were different between institutions. Although most studies used trough concentration with a target range of 10-20 mg/L, target attainment was different across the studies. The probability of target attainment was < 80% in all tested dosing algorithms. Few studies reported on vancomycin efficacy and toxicity.

CONCLUSION

This is a comprehensive overview of dosing strategies of vancomycin in neonates. There was inadequate evidence to propose an optimal therapeutic regimen in the newborn population, based on the data obtained, due to the heterogeneity in the design and objectives of the included studies. Consistent and homogeneous comparative randomised clinical trials are needed to identify a dosing regimen with a probability of target attainment of > 90% without toxicity.

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.

AKI in Hospitalized Children: Poorly Documented (and Underrecognized)

Background: Acute kidney injury (AKI) is common in hospitalized children. We hypothesized that hospital-acquired AKI would be underrecognized and under-reported, with potential implications for prevention of future AKI and CKD risk stratification. Methods: Five hundred thirty-two cases of AKI occurring over a 1 year period in a tertiary children's hospital in the United States were studied. AKI documentation was defined as any mention of AKI in the admission history and physical note, progress notes, or discharge summary. Nephrology follow-up was defined as a completed outpatient clinic visit within 1 year of discharge. Logistic regression was used to assess factors associated with documentation, consultation, and follow-up. Results: AKI developed during 584/7,640 (7.6%) of hospitalizations: 532 cases met inclusion criteria. Documentation was present in 34% (185/532) of AKI cases and 90 (16.9%) had an inpatient nephrology consult. Among 501 survivors, 89 (17.8%) had AKI in their hospital discharge summary and 54 had outpatient nephrology follow up. Stage 3 AKI, peak creatinine >1 mg/dL and longer length of stay were associated with documentation. Stage 3 AKI and higher baseline creatinine were associated with inpatient nephrology consultation. Inpatient nephrology consultation was positively associated with outpatient nephrology follow up, but documentation in the discharge summary was not. Conclusion: Most cases of AKI were not documented and the proportion of children seen by a nephrologist was low, even among those with more severe injury. Increased severity of AKI was associated with documentation and inpatient consultation. Poor rates of documentation has implications for AKI recognition and appropriate management and follow up.

Management of Acute Kidney Injury in Extremely Low Birth Weight Infants

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

Advances in pediatric acute kidney injury

The objective of this study was to inform the pediatric nephrologists of recent advances in acute kidney injury (AKI) epidemiology, pathophysiology, novel biomarkers, diagnostic tools, and management modalities. Studies were identified from PubMed, EMBASE, and Google Scholar for topics relevant to AKI. The bibliographies of relevant studies were also reviewed for potential articles. Pediatric (0-18 years) articles from 2000 to May 2020 in the English language were included. For epidemiological outcomes analysis, a meta-analysis on data regarding AKI incidence, mortality, and proportion of kidney replacement therapy was performed and an overall pooled estimate was calculated using the random-effects model. Other sections were created highlighting pathophysiology, novel biomarkers, changing definitions of AKI, evolving tools for AKI diagnosis, and various management modalities. AKI is a common condition seen in hospitalized children and the diagnosis and management have shown to be quite a challenge. However, new standardized definitions, advancements in diagnostic tools, and the development of novel management modalities have led to increased survival benefits in children with AKI. IMPACT: This review highlights the recent innovations in the field of AKI, especially in regard to epidemiology, pathophysiology, novel biomarkers, diagnostic tools, and management modalities.

Structural and functional changes in the kidney caused by adverse fetal and neonatal environments

Health and disease risk in the adulthood are known to be affected by the early developmental environment. Kidney diseases are one of these diseases, and kidneys are altered both structurally and functionally by adverse pre- and perinatal events. The most known structural change is low nephron number seen in subjects born low birth weight and/or preterm. In various animal models of intrauterine growth restriction (IUGR), one of the causes of low birth weight, the mechanism of low nephron number was investigated. While apoptosis of metanephric mesenchyme has been suggested to be the cause, I showed that suppression of ureteric branching, global DNA methylation, and caspase-3 activity also contributes to the mechanism. Other structural changes caused by adverse fetal and neonatal environments include peritubular and glomerular capillary rarefaction and low podocyte endowment. These are aggravated by postnatal development of focal glomerulosclerosis and tubulointerstitial fibrosis that result from low nephron number. Functional changes can be seen in tubules, endothelium, renin-angiotensin system, sympathetic nervous system, oxidative stress, and others. As an example, I reported that aggravated nitrosative stress in a rat IUGR model resulted in more severe tubular necrosis and tubulointerstitial fibrosis after unilateral ureteral obstruction. The mechanism of various functional changes needs to be clarified but may be explained by epigenetic modifications.

Association between Elevated Urine Neutrophil Gelatinase-Associated Lipocalin and Postoperative Acute Kidney Injury in Neonates

OBJECTIVE

To examine the incidence of postoperative neonatal acute kidney injury (AKI) following general surgical procedures and to test the hypothesis that postoperative urine neutrophil gelatinase-associated lipocalin (uNGAL) concentrations predict AKI. The secondary objective was to evaluate for an association between AKI and hospital mortality.

STUDY DESIGN

Prospective observational study of infants undergoing abdominal and thoracic surgical procedures in the neonatal intensive care unit from October 2018 to March 2020. The primary outcome was incidence of neonatal AKI (defined by the neonatal modified Kidney Diseases Improving Global Outcomes criteria) following each procedure to postoperative day 5. Severe AKI was defined as stage 2 or 3 AKI. Urine samples were obtained pre- and postoperatively at 6 time points to evaluate for levels of uNGAL. Secondary outcomes were in-hospital mortality and length of stay.

RESULTS

Subjects (n = 141) underwent a total of 192 general surgical procedures during the study period. Neonatal AKI and severe AKI occurred following 36 (18%) and 15 (8%) procedures (n = 33 subjects). Percent change of uNGAL from 24 hours preoperatively to 24 hours postoperatively was greater in subjects with neonatal AKI (190.2% [IQR 0.0, 1666.7%] vs 0.7% [IQR -31.2%,140.2%], P = .0374). The strongest association of uNGAL and AKI occurred at 24 hours postoperatively (area under the receiver operator curves of 0.81, 95% CI 0.72, 0.89). Increased mortality risk was observed in subjects with any postoperative AKI (aOR 11.1 95% CI 2.0, 62.8, P = .0063) and severe AKI (aOR 13.8; 95% CI 3.0, 63.1, P = .0007).

CONCLUSION

Elevation in uNGAL 24 hours postoperative was associated with AKI. Neonates with postoperative AKI had increased mortality.

Advances in Neonatal Acute Kidney Injury

In this state-of-the-art review, we highlight the major advances over the last 5 years in neonatal acute kidney injury (AKI). Large multicenter studies reveal that neonatal AKI is common and independently associated with increased morbidity and mortality. The natural course of neonatal AKI, along with the risk factors, mitigation strategies, and the role of AKI on short- and long-term outcomes, is becoming clearer. Specific progress has been made in identifying potential preventive strategies for AKI, such as the use of caffeine in premature neonates, theophylline in neonates with hypoxic-ischemic encephalopathy, and nephrotoxic medication monitoring programs. New evidence highlights the importance of the kidney in "crosstalk" between other organs and how AKI likely plays a critical role in other organ development and injury, such as intraventricular hemorrhage and lung disease. New technology has resulted in advancement in prevention and improvements in the current management in neonates with severe AKI. With specific continuous renal replacement therapy machines designed for neonates, this therapy is now available and is being used with increasing frequency in NICUs. Moving forward, biomarkers, such as urinary neutrophil gelatinase-associated lipocalin, and other new technologies, such as monitoring of renal tissue oxygenation and nephron counting, will likely play an increased role in identification of AKI and those most vulnerable for chronic kidney disease. Future research needs to be focused on determining the optimal follow-up strategy for neonates with a history of AKI to detect chronic kidney disease.

Neonatal acute kidney injury: a case-based approach

Neonatal acute kidney injury (AKI) is increasingly recognized as a common complication in critically ill neonates. Over the last 5-10 years, there have been significant advancements which have improved our understanding and ability to care for neonates with kidney disease. A variety of factors contribute to an increased risk of AKI in neonates, including decreased nephron mass and immature tubular function. Multiple factors complicate the diagnosis of AKI including low glomerular filtration rate at birth and challenges with serum creatinine as a marker of kidney function in newborns. AKI in neonates is often multifactorial, but the cause can be identified with careful diagnostic evaluation. The best approach to treatment in such patients may include diuretic therapies or kidney support therapy. Data for long-term outcomes are limited but suggest an increased risk of chronic kidney disease (CKD) and hypertension in these infants. We use a case-based approach throughout this review to illustrate these concepts and highlight important evidence gaps in the diagnosis and management of neonatal AKI.

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.

Nephrotoxicity in Neonates

Acute kidney injury (AKI) is classified based on prerenal, intrinsic, and postrenal causes. In the newborn, AKI can occur after an insult during the prenatal, perinatal, or postnatal period. AKI is usually an underrecognized condition and its true incidence is unknown. AKI may result from the administration of a number of different nephrotoxic medications, which are often used concurrently in critically ill neonates, exponentially increasing the risk of renal injury. Drug toxicity may also compromise the formation and development of nephrons, and this is particularly important in preterm infants, who have incomplete nephrogenesis. Little is known about the pharmacokinetics and pharmacodynamics of different medications used in neonates, especially for the most immature infant, and the use of most medications in this population is off label. Strategies to prevent AKI include the avoidance of hypotension, hypovolemia, fluid imbalances, hypoxia, and sepsis as well as judicious use of nephrotoxic medications. Treatment strategies aim to maintain fluids and electrolytic and acid-base homeostasis, along with an adequate nutritional status. Neonates are especially prone to long-term sequelae of AKI and benefit from long-term follow-up. This review summarizes the most relevant aspects of nephrotoxicity in neonates and describes the prevention, treatment, and follow-up of AKI in neonates.

Renal Oxygenation Measured by Near-Infrared Spectroscopy in Neonates

BACKGROUND

Acute kidney injury (AKI) affects approximately 30% of infants admitted to the neonatal intensive care unit (NICU), and increases mortality risk by 50%. Current diagnostic criteria (serum creatinine rise with oliguria) cannot detect early-onset AKI, as up to 50% of nephron damage may occur by the time these abnormalities present. Once AKI is established, clinical management is often ineffective; therefore, prevention is key. Near-infrared spectroscopy (NIRS) offers a feasible, noninvasive approach to continuously monitor renal oxygenation trends over time, serving as a surrogate marker for renal perfusion.

PURPOSE

To provide an overview of NIRS principles for measuring renal oxygenation, and to describe current evidence of how this technology is being used among infants admitted to the NICU relative to the prediction and identification of AKI.

METHODS

A comprehensive search of PubMed and CINHAL focused on renal NIRS studies in NICU preterm and term infants was conducted.

RESULTS

Findings from 34 studies were included. In term infants, reduced renal oxygenation correlated to invasive SvO2 monitoring, predicted survivability and AKI. In preterm infants, reduced renal oxygenation was associated with AKI in one study, yet contrasting findings were reported in those with patent ductus arteriosus, including those who received prostaglandin inhibitors. Normative data in all infants were sparse.

IMPLICATIONS FOR PRACTICE

Renal NIRS may offer a noninvasive measurement of kidney hypoperfusion that may precede conventional diagnostic measures.

IMPLICATIONS FOR RESEARCH

Normative data are lacking, the threshold for renal ischemia is not defined, and consensus guiding clinical treatment based on NIRS data is nonexistent.

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

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

Relationship between intraventricular hemorrhage and acute kidney injury in premature infants and its effect on neonatal mortality

Intraventricular hemorrhage (IVH) and acute kidney injury (AKI) are important neonatal morbidities in premature infants. This study aimed to investigate the relationship between IVH and AKI in premature infants and whether this association affects the incidence of neonatal mortality. Infants [gestational age (GA) ≤ 32 weeks; birth weight (BW) < 1500 g] were retrospectively evaluated in a large tertiary neonatal intensive care unit. Of 710 premature infants, 268 (37.7%) developed AKI. Infants with IVH were more likely to have AKI than those without IVH. Infants with severe IVH had a higher incidence of AKI than infants with mild IVH. Infants younger than 28 weeks with IVH were more likely to have AKI than those without IVH. An association between IVH grades and AKI stages was observed in the overall study population, in infants with GA < 28 weeks, and in infants with GA between 28 and 32 weeks. Mortality was increased 1.5 times in infants with IVH and AKI compared with that in infants with IVH but without AKI. Furthermore, mortality was increased in infants with IVH and AKI compared with infants without IVH or AKI. This study shows a direct relationship between the severity of IVH and the degree of AKI; both IVH and AKI increase the incidence of neonatal mortality.

The Impact of Erythropoietin on Short- and Long-Term Kidney-Related Outcomes in Neonates of Extremely Low Gestational Age. Results of a Multicenter, Double-Blind, Placebo-Controlled Randomized Clinical Trial

OBJECTIVE

To evaluate whether extremely low gestational age neonates (ELGANs) randomized to erythropoietin have better or worse kidney-related outcomes during hospitalization and at 22-26 months of corrected gestational age (cGA) compared with those randomized to placebo.

STUDY DESIGN

We performed an ancillary study to a multicenter double-blind, placebo-controlled randomized clinical trial of erythropoietin in ELGANs.

RESULTS

The prevalence of severe (stage 2 or 3) acute kidney injury (AKI) was 18.2%. We did not find a statistically significant difference between those randomized to erythropoietin vs placebo for in-hospital primary (severe AKI) or secondary outcomes (any AKI and serum creatinine/cystatin C values at days 0, 7, 9, and 14). At 22-26 months of cGA, 16% of the cohort had an estimated glomerular filtration rate (eGFR) <90 mL/min/1.73 m², 35.8% had urine albumin/creatinine ratio >30 mg/g, 23% had a systolic blood pressure (SBP) >95th percentile for age, and 40% had a diastolic blood pressure (DBP) >95th percentile for age. SBP >90th percentile occurred less often among recipients of erythropoietin (P < .04). This association remained even after controlling for gestational age, site, and sibship (aOR 0.6; 95% CI 0.39-0.92). We did not find statistically significant differences between treatment groups in eGFR, albumin/creatinine ratio, rates of SBP >95th percentile, or DBP >90th or >95th percentiles at the 2 year follow-up visit.

CONCLUSIONS

ELGANs have high rates of in-hospital AKI and kidney-related problems at 22-26 months of cGA. Recombinant erythropoietin may protect ELGANs against long-term elevated SBP but does not appear to protect from AKI, low eGFR, albuminuria, or elevated DBP at 22-26 months of cGA.

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.

Cystatin C compared to serum creatinine as a marker of acute kidney injury in critically ill neonates

BACKGROUND

Acute kidney injury (AKI) is one of the most common causes of neonatal morbidity and mortality. Diagnosing AKI in neonates is challenging as it lacks specific signs, symptoms, and biomarkers. However, detecting AKI in critically ill neonates is crucial to determine appropriate management and prevent complications. Cystatin C (CysC) has been recognized as a superior kidney biomarker reflecting kidney function in neonates. The objective of this study is to evaluate the diagnostic value of CysC as an AKI biomarker in critically ill neonates.

METHODS

We performed a diagnostic test between cystatin C-based estimated glomerular filtration rate (eGFR-CysC) and serum creatinine-based estimated glomerular filtration rate (eGFR-SCr) as the gold standard to diagnose AKI in 135 critically ill neonates treated in Cipto Mangunkusumo National Hospital from July 2017 to January 2018.

RESULTS

Prevalence of AKI was 23.7% predominantly in neonates with a very preterm gestational age, low birthweight, probable sepsis, and those receiving invasive oxygen therapy or nephrotoxic drugs. The proportion of AKI based on neonate RIFLE criteria was 72.7% risk, 18.9% injury, and 9% failure. eGFR-CysC had the following parameters: sensitivity, 84.8%; specificity, 61.8%; PPV, 41.8%; NPV, 89.7%; LR(+), 2.2; LR(-), 0.24; and accuracy, 67.4%. The AUROC for CysC was 84.9%. The optimal cut-off value for CysC was 1.605 mg/l.

CONCLUSIONS

CysC may be used as a screening biomarker of AKI in critically ill neonates; yet, it was not superior to serum creatinine. Graphical abstract.

Advances in Kidney Replacement Therapy in Infants

Acute kidney injury continues to be a highly occurring disease in the intensive care unit, specifically affecting up to a third of critically ill neonates as per various studies. Although first-line treatments of acute kidney injury are noninvasive, kidney replacement therapy (KRT) is indicated when conservative management modes fail. There are various modalities of KRT which can be used for neonatal populations, including peritoneal dialysis, hemodialysis, and continuous KRT. However, these KRT modalities present their own challenges in this specific patient population Thus, it is the aim of this review to introduce each of these KRT modalities in terms of their challenges, advances, and future directions, with specific emphasis on new technology including the Cardio-Renal Pediatric Emergency Dialysis Machine, Newcastle infant dialysis and ultrafiltration system, and the Aquadex system for ultrafiltration.

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

BACKGROUND

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

CASE-DIAGNOSIS/TREATMENT

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

CONCLUSIONS

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

Nephrotoxic medications and acute kidney injury risk factors in the neonatal intensive care unit: clinical challenges for neonatologists and nephrologists

Neonatal acute kidney injury (AKI) is common. Critically ill neonates are at risk for AKI for many reasons including the severity of their underlying illnesses, prematurity, and nephrotoxic medications. In this educational review, we highlight four clinical scenarios in which both the illness itself and the medications indicated for their treatment are risk factors for AKI: sepsis, perinatal asphyxia, patent ductus arteriosus, and necrotizing enterocolitis. We review the available evidence regarding medications commonly used in the neonatal period with known nephrotoxic potential, including gentamicin, acyclovir, indomethacin, vancomycin, piperacillin-tazobactam, and amphotericin. We aim to illustrate the complexity of decision-making involved for both neonatologists and pediatric nephrologists when managing infants with these conditions and advocate for ongoing multidisciplinary collaboration in the development of better AKI surveillance protocols and AKI mitigation strategies to improve care for these vulnerable patients.

Renal follow-up in pediatrician practice after discharge from neonatology units: about a survey

There is growing evidences of long-term renal and cardiovascular consequences of prematurity, intra-uterine growth restriction, and neonatal acute kidney injury (AKI). We performed an online survey to describe current pediatric management in this population, sent to 148 ambulatory pediatricians in Geneva. Among the 40% of pediatricians who completed the survey, 43% modify their blood pressure measurement practice in case of neonatal acute kidney injury, 24% and 19% in a context of prematurity or intra-uterine growth restriction, respectively. Twenty-five percent provide information about cardiovascular risk factors or catch up growth. In case of prematurity or intra-uterine growth restriction, renal tests (ultrasound, serum creatinine, micro albuminuria) or referral to nephrologist were realized by less than 5% of the pediatricians. For neonatal acute kidney injury, renal tests, and referral to specialists are performed by 30 and 60% of pediatricians, respectively. When prematurity or intra-uterine growth restriction was associated with abnormal blood pressure or abnormal renal tests, the referral to the specialist reached 80%.Conclusion: Ambulatory renal and cardio-vascular follow-up in case of neonatal medical history can be enhanced, with necessity to raise awareness and to edict guidelines available to pediatricians. What is Known: • There is a compelling evidence of long-term renal and cardiovascular consequences of prematurity and low birth weight. • Specific cardiovascular and renal follow-up guidelines, coming from professional organizations, are currently not available for these patients. What is New: • Pediatricians in ambulatory setting do not adapt their renal and cardiovascular follow-up in case of neonatal medical history. • There is a necessity to raise awareness about these long-term consequences among pediatricians and to edict guidelines available to them.

Challenges of acute peritoneal dialysis in extremely-low-birth-weight infants: a retrospective cohort study

Background

Peritoneal dialysis (PD) has been used occasionally in extremely-low-birth-weight (ELBW) infants with acute kidney injury (AKI). This study aimed to evaluate the clinical characteristics and outcomes of ELBW infants with AKI treated with PD.

Methods

In this retrospective cohort study, the medical records of ELBW infants with AKI, who underwent PD from January 2008 to February 2018, were reviewed. A PD catheter (7.5–9.0 Fr) or central venous catheter (4 Fr) was used for the peritoneal access. Treatment with PD solutions (2.5 or 4.25%) was started at 10 mL/kg, which was increased to 20–30 mL/kg for 60–120 min/cycle continuing for 24 h.

Results

Twelve ELBW infants (seven male and five female infants) were treated, and their mean (±SD) gestational age and birth weight were 27.2 (±3.3) weeks and 706.5 (±220.5) g, respectively. Two patients had severe perinatal asphyxia (5-min Apgar score ≤ 3). The most important indication for starting PD was AKI due to sepsis. The average (±SD) duration of PD was 9.4 (± 7.7) days. The potassium levels in the ELBW infants with hyperkalemia decreased from 6.8 to 5.0 mg/mL after 9.3 (± 4.4) days. The most common complication of PD was mechanical dysfunction of the catheters, such as dialysate leakage (75%). Two patients were successful weaned off PD. The mortality rate of the infants treated with PD was 91.7%.

Conclusions

In this series, the mortality rate of ELBW infants with AKI treated with PD was relatively high because of their incompletely developed organ systems. Therefore, the use of PD should be carefully considered for the treatment of ELBW infants with AKI in terms of decisions regarding resuscitation.

A Review on Drug-Induced Nephrotoxicity: Pathophysiological Mechanisms, Drug Classes, Clinical Management, and Recent Advances in Mathematical Modeling and Simulation Approaches

A variety of marketed drugs belonging to various therapeutic classes are known to cause nephrotoxicity. Nephrotoxicity can manifest itself in several forms depending on the specific site involved as well as the underlying pathophysiological mechanisms. As they often coexist with other pathophysiological conditions, the steps that can be taken to treat them are often limited. Thus, drug-induced nephrotoxicity remains a major clinical challenge. Prior knowledge of risk factors associated with special patient populations and specific classes of drugs, combined with early diagnosis, therapeutic drug monitoring with dose adjustments, as well as timely prospective treatments are essential to prevent and manage them better. Most incident drug-induced renal toxicity is reversible only if diagnosed at an early stage and treated promptly. Hence, diagnosis at an early stage is the need of the hour to counter it. Significant recent advances in the identification of novel early biomarkers of nephrotoxicity are not beyond limitations. In such a scenario, mathematical modeling and simulation (M&S) approaches may help to better understand and predict toxicities in a clinical setting. This review summarizes pathophysiological mechanisms of drug-induced nephrotoxicity, classes of nephrotoxic drugs, management, prevention, and diagnosis in clinics. Finally, it also highlights some of the recent advancements in mathematical M&S approaches that could be used to better understand and predict drug-induced nephrotoxicity.

Urine biomarkers for monitoring acute kidney injury in premature infants

Background

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

Methods

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

Results

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

Conclusion

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

Prenatal Endotoxin Exposure Induces Fetal and Neonatal Renal Inflammation via Innate and Th1 Immune Activation in Preterm Pigs

Chorioamnionitis (CA) predisposes to preterm birth and affects the fetal mucosal surfaces (i.e., gut, lungs, and skin) via intra-amniotic (IA) inflammation, thereby accentuating the proinflammatory status in newborn preterm infants. It is not known if CA may affect more distant organs, such as the kidneys, before and after preterm birth. Using preterm pigs as a model for preterm infants, we investigated the impact of CA on fetal and neonatal renal status and underlying mechanisms. Fetal pigs received an IA dose of lipopolysaccharide (LPS), were delivered preterm by cesarean section 3 days later (90% gestation), and compared with controls (CON) at birth and at postnatal day 5. Plasma proteome and inflammatory targets in kidney tissues were evaluated. IA LPS-exposed pigs showed inflammation of fetal membranes, higher fetal plasma creatinine, and neonatal urinary microalbumin levels, indicating renal dysfunction. At birth, plasma proteomics revealed LPS effects on proteins associated with renal inflammation (up-regulated LRG1, down-regulated ICA, and ACE). Kidney tissues of LPS pigs at birth also showed increased levels of kidney injury markers (LRG1, KIM1, NGLA, HIF1A, and CASP3), elevated molecular traits related to innate immune activation (infiltrated MPO⁺ cells, complement molecules, oxidative stress, TLR2, TLR4, S100A9, LTF, and LYZ), and Th1 responses (CD3⁺ cells, ratios of IFNG/IL4, and TBET/GATA3). Unlike in plasma, innate and adaptive immune responses in kidney tissues of LPS pigs persisted to postnatal day 5. We conclude that prenatal endotoxin exposure induces fetal and postnatal renal inflammation in preterm pigs with both innate and adaptive immune activation, partly explaining the potential increased risks of kidney injury in preterm infants born with CA.

A retrospective study on the incidence of acute kidney injury and its early prediction using troponin-I in cooled asphyxiated neonates

Acute kidney injury (AKI) is a common complication of perinatal asphyxia and is associated with poorer short-term and long-term outcomes. This retrospective study describes the incidence of AKI in asphyxiated neonates who have received therapeutic hypothermia using the proposed modified Kidney Diseases: Improving Global Outcomes (KDIGO) definition and investigates clinical markers that would allow earlier recognition of at-risk neonates. We included asphyxiated  neonates who underwent therapeutic hypothermia between the period of January 2011 and May 2018 in our study. The serum creatinine levels within a week of birth were used in establishing AKI according to the modified KDIGO definition. Demographic data, resuscitation details, laboratory results and use of medications were collected and compared between the AKI and non-AKI groups to identify variables that differed significantly. A total of 66 neonates were included and 23 out of them (35%) were found to have AKI. The neonates with AKI had a lower gestational age (p = 0.006), lower hemoglobin level (p = 0.012), higher lactate level before and after therapeutic hypothermia (p = 0.013 and 0.03 respectively) and higher troponin-I level after therapeutic hypothermia (p < 0.001). After logistic regression analysis, elevated troponin-I after therapeutic hypothermia was independently associated with risk of AKI (OR 1.69, 95% CI 1.067–2.699, p = 0.025). The receiver operating curve showed that troponin-I after therapeutic hypothermia had an area under curve of 0.858 at the level 0.288 ng/ml. Our study concludes that the incidence of AKI among asphyxiated newborns who received therapeutic hypothermia is 35% and an elevated troponin-I level after therapeutic hypothermia is independently associated with an increased risk of AKI in asphyxiated newborns.

Acute kidney injury, fluid balance and risks of intraventricular hemorrhage in premature infants

OBJECTIVE

Evaluate association between fluid balance and intraventricular hemorrhage (IVH).

STUDY DESIGN

Retrospective review of infants <30 weeks gestation admitted to Kentucky Children's Hospital Neonatal Intensive Care Unit.

RESULTS

Infants with acute kidney injury (AKI) had a 2.4-fold increased risk of IVH (OR 2.38, 95% CI 1.46-3.87) and a 3.5-fold increased risk of severe IVH (OR 3.45, 95% CI 1.98-6.04). Infants above birthweight on day 4 had a 1.9-fold increased risk of IVH (OR 1.86, 95% CI 1.05-3.27) and a 2.0-fold increased risk of severe IVH (OR 1.96, 95% CI 1.03-3.74). When controlling for confounding factors, infants with AKI or above birthweight on day 4 had a 4.6-fold (aOR 4.60, 95% CI 1.80-11.78) and 3.0-fold (aOR 2.96, 95% CI 1.01-8.65) increased risk of severe IVH, respectively.

CONCLUSION

Infants with AKI during the first week of life had a higher association of severe IVH even after controlling for confounding factors.

The impact of increased awareness of acute kidney injury in the Neonatal Intensive Care Unit on acute kidney injury incidence and reporting: results of a retrospective cohort study

OBJECTIVE

To evaluate the impact of nephrology integration in the NICU on acute kidney injury (AKI) incidence, provider reporting, and nephrology referral.

STUDY DESIGN

Cohort study in a single-center NICU from January 2012 to December 2017 (n = 1464). We assessed the impact of clinical practice changes including neonatal-nephrology rounds on the incidence of AKI.

RESULTS

AKI occurred in 318 neonates (22%). AKI occurred less frequently in those admitted after clinical practice changes (P < 0.001). After multivariable adjustment, clinical practice changes were associated with reduced odds of AKI (adjusted odds ratio, 0.31; 95% CI 0.22-0.44, P < 0.001). Provider reporting of AKI improved (P < 0.001) and more neonates were referred for nephrology follow-up (P < 0.001).

CONCLUSIONS

Increased nephrology integration in the NICU was associated with decreased AKI incidence. While recognition of AKI improved, AKI remained poorly reported and nephrology AKI follow-up did not routinely occur. This study supports the importance of increased nephrology involvement in the NICU.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Renal Replacement Therapy in Neonates

Acute kidney injury (AKI) is a highly prevalent disease entity in the NICU, affecting nearly one-quarter of critically ill neonates by some reports. Though medical management remains the mainstay in the treatment of AKI, renal replacement therapy (RRT) is indicated when conservative measures are unable to maintain electrolytes, fluid balance, toxins, or waste products within a safe margin. Several modalities of RRT exist for use in neonatal populations, including peritoneal dialysis, hemodialysis, and continuous RRT. It is the aim of this review to introduce each of these RRT modalities, as well as to discuss their technical considerations, benefits, indications, contraindications, and complications.

Acute Kidney Injury Guidelines Are Associated With Improved Recognition and Follow-up for Neonatal Patients

BACKGROUND

Studies demonstrate that neonatal acute kidney injury (AKI) is associated with increased morbidity and mortality. Acute kidney injury survivors are at risk for renal dysfunction and chronic kidney disease and require long-term follow-up.

PURPOSE

To maximize identification of AKI and ensure referral, we created guidelines for diagnosis, evaluation, and management of AKI.

METHODS/SEARCH STRATEGY

Retrospective cohort study of neonatal intensive care unit patients treated before guideline implementation (cohort 1; n = 175) and after (cohort 2; n = 52). Outcome measures included AKI incidence, documented diagnosis, and pediatric nephrology consultation. Statistical methods included t tests, Fisher exact tests, and Wilcoxon rank sum tests.

FINDINGS/RESULTS

We found 68 AKI episodes in 52 patients in cohort 1 and 15 episodes in 12 patients in cohort 2. Diagnosis and documentation of AKI improved after guideline implementation (C1:24/68 [35%], C2: 12/15 [80%]; P = .003) as did pediatric nephrology consultation (C1:12/68 [18%]; C2: 12/15 [80%]; P < .001) and outpatient referral (C1: 3/47 [6%], C2:5/8 [63%]; P < .01).

IMPLICATIONS FOR PRACTICE

Neonatal AKI guideline implementation was associated with improvements in recognition, diagnosis, and inpatient and outpatient nephrology consultation. Early recognition and diagnosis along with specialist referral may improve outcomes among neonatal AKI survivors, ensuring appropriate future monitoring and long-term follow-up.

IMPLICATIONS FOR RESEARCH

Future research should continue to determine the long-term implications of early diagnosis of AKI and appropriate subspecialty care with follow-up.

Renal Replacement Therapy in Pediatric Acute Kidney Injury

Acute kidney injury (AKI) is common in critically ill children and affects nearly 30-40% of patients admitted to the pediatric intensive care unit (ICU). Even with technological advances in critical care and dialysis, there is a high mortality rate of 66.8% to 90% in ICU patients. Renal replacement therapy (RRT) is often performed to treat patients with AKI. However, for optimal RRT treatment, it is crucial to consider the indications, modes of access, and prescription of each RRT method. Therefore, this review aims to discuss the various modalities of RRT in pediatric patients, which include peritoneal dialysis (PD), hemodialysis (HD), continuous RRT (CRRT), and sustained low-efficiency dialysis (SLED).

Acute Kidney Injury in Children Hospitalized With Diarrheal Illness in the United States

OBJECTIVES

To determine the incidence, correlates, and consequences of acute kidney injury (AKI) among children hospitalized with diarrheal illness in the United States.

METHODS

Using data from Kids' Inpatient Database in 2009 and 2012, we studied children hospitalized with a primary diagnosis of diarrheal illness (weighted N = 113 195). We used the International Classification of Diseases, Ninth Revision, Clinical Modification, diagnosis codes 584.5 to 584.9 to capture AKI. We calculated the incidence, correlates, and consequences (mortality, length of stay [LOS], and costs) of AKI associated with hospitalized diarrheal illness using stepwise logistic regression and generalized linear models.

RESULTS

The average incidence of AKI in children hospitalized with diarrheal illness was 0.8%. Hospital location and teaching status were associated with the odds of AKI, as were older age, solid organ transplant, hypertension, chronic kidney disease, and rheumatologic and hematologic conditions. The development of AKI in hospitalized diarrheal illness was associated with an eightfold increase in the odds of in-hospital mortality (odds ratio 8.0; 95% confidence interval [CI] 4.2-15.4). AKI was associated with prolonged LOS (mean increase 3.0 days; 95% CI 2.3-3.8) and higher hospital cost (mean increase $9241; 95% CI $4661-$13 820).

CONCLUSIONS

Several demographic factors and comorbid conditions are associated with the risk of AKI in children hospitalized with diarrheal illness. Although rare, development of AKI in this common pediatric condition is associated with increased mortality, LOS, and hospital cost.

Low birth weight trends: possible impacts on the prevalences of hypertension and chronic kidney disease

Worldwide, hypertension and chronic kidney disease (CKD) are highly prevalent disorders and are strong risk factors for cardiovascular disease and end-stage renal disease (ESRD). The developmental origins of health and disease (DOHAD) concept suggests that undesirable perinatal environmental conditions, such as malnutrition, contribute to disease development in adults. Among the known hypertension and CKD risk factors, DOHAD plays a potential role in determining susceptibility to the onset of these diseases in later adulthood. Since low birth weight (LBW) is a surrogate marker for adverse fetal environmental conditions, the high incidence of LBW in developing countries and its increasing incidence in most developed countries (attributed to multiple pregnancies and prepregnancy maternal factors, such as undernutrition, advanced maternal age, and smoking) is concerning. Thus, LBW is an important public health problem not only because of the associated infant mortality and morbidity but also because it is a risk factor for adult-onset hypertension/CKD. During their reproductive years, pregnant women who were born with LBWs have an increased risk of hypertensive disorders of pregnancy, which contribute to the risk of developing cardiovascular disease and ESRD. The offspring of LBW females are also likely to be LBW, which suggests that susceptibility to hypertension/CKD may reflect transgenerational inheritance. Therefore, there is global concern about the increasing prevalence of LBW-related diseases. This review summarizes the relevance of hypertension and CKD in conjunction with DOHAD and discusses recent studies that have examined the impact of the upward LBW trend on renal function and blood pressure.

Clinical Documentation for Intensivists: The Impact of Diagnosis Documentation

OBJECTIVES

The aim of this review is to describe the interaction of clinical documentation with patient care, measures of patient acuity, quality metrics, research database accuracy, and healthcare reimbursement in order to highlight potential areas of improvement for intensivists.

DATA SOURCES

An online search of PubMed was undertaken as well as review of resources published by the American Academy of Pediatrics, the Society of Critical Care Medicine, the American Medical Association, and the Association of Clinical Documentation Improvement Specialists.

STUDY SELECTION

Selected publications included those that described coding, medical record documentation, healthcare reimbursement, quality metrics, administrative databases, Clinical Documentation Improvement programs, medical scribe programs, and various payment models.

DATA EXTRACTION

Relevant information was extracted to highlight the impact of diagnosis documentation on patient care, perceived patient severity of illness, quality metrics, and healthcare reimbursement. Query data from our hospital's Clinical Documentation Improvement program were reviewed to highlight areas of improvement within our own Division of Critical Care Medicine. Additionally, interventions to improve clinical documentation were incorporated into this review.

DATA SYNTHESIS

Available data in the literature indicate that documentation of precise diagnoses in the medical record has a positive impact on quality metrics, accuracy of administrative databases, hospital reimbursement, and perceived patient complexity. However, there is insufficient data to make conclusions regarding documentation of specific diagnoses and effects on patient care. Administrative responsibilities associated with documentation have been increasing, especially with the introduction of electronic medical records.

CONCLUSIONS

Documentation of specific diagnoses in the medical record is important in the broad context of our existing medical system but there is an associated burden in doing so. Widespread implementation of electronic medical record systems has inadvertently led to clinician dissatisfaction and burnout. Research is needed to further evaluate the impact of documentation on patient care as well as steps to decrease the associated burden.

Proteomic identification of early urinary-biomarkers of acute kidney injury in preterm infants

The immature preterm kidney is likely to be vulnerable to acute kidney injury (AKI). However, the biomarkers currently used for AKI are not sensitive or specific and are also inadequate for the timely detection of AKI in preterm infants. The objectives of this study were to identify novel urinary biomarkers of AKI using proteomic techniques, and to verify and validate that the candidates can serve as early predictive biomarkers for AKI. In total, 1,810 proteins were identified in the discovery phase. Among those proteins, 174 were selected as the 1^st targeted proteins. A total of 168 proteins were quantified, and the levels of 6 were significantly increased in the AKI group in the verification phase. Using a clinical assay, the results were confirmed and validated using samples of the first urine after birth from the biorepository. Finally, enzyme-linked immunosorbent assays revealed that the levels of annexin A5, neutrophil gelatinase-associated lipocalin (NGAL), and protein S100-P were significantly higher in the samples of the first urine from patients with AKI than in those from patients without AKI. In conclusion, urinary annexin A5, NGAL and protein S100-P levels are promising biomarkers for early, accurate prediction of AKI in preterm infants.

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.

Preventing CKD in Developed Countries

Chronic kidney disease (CKD) is an important public health concern in developed countries because of both the number of people affected and the high cost of care when prevention strategies are not effectively implemented. Prevention should start at the governance level with the institution of multisectoral polices supporting sustainable development goals and ensuring safe and healthy environments. Primordial prevention of CKD can be achieved through implementation of measures to ensure healthy fetal (kidney) development. Public health strategies to prevent diabetes, hypertension, and obesity as risk factors for CKD are important. These approaches are cost-effective and reduce the overall noncommunicable disease burden. Strategies to prevent nontraditional CKD risk factors, including nephrotoxin exposure, kidney stones, infections, environmental exposures, and acute kidney injury (AKI), need to be tailored to local needs and epidemiology. Early diagnosis and treatment of CKD risk factors such as diabetes, obesity, and hypertension are key for primary prevention of CKD. CKD tends to occur more frequently and to progress more rapidly among indigenous, minority, and socioeconomically disadvantaged populations. Special attention is required to meet the CKD prevention needs of these populations. Effective secondary prevention of CKD relies on screening of individuals at risk to detect and treat CKD early, using established and emerging strategies. Within high-income countries, barriers to accessing effective CKD therapies must be recognized, and public health strategies must be developed to overcome these obstacles, including training and support at the primary care level to identify individuals at risk of CKD, and appropriately implement clinical practice guidelines.

Peritoneal dialysis in extremely and very low-birth-weight infants

The outcome of extremely low-birth-weight (ELBW) and very low-birth-weight (VLBW) infants has substantially improved in recent years. As acute kidney injury is frequent in these infants due to various risk factors, there is an increasing demand for renal replacement therapy in these patients. Data on that topic, however, are scarce. We review the available literature on that topic and report our experience on temporary dialysis in three extremely immature infants (two ELBW and one VLBW) with acute kidney failure. Peritoneal dialysis (PD) was performed for 19, 23, and 44 days until recovery of native renal function. At recent follow-up of 18 and 24 months, two patients are in good clinical condition with chronic kidney disease stages 1 and 4, respectively. One patient deceased at the age of 12 months due to secondary liver failure. The dialysis regimen applied in our study differed significantly from older infants with extremely short dwell times and accordingly high numbers of daily cycles. The use of rigid acute PD catheters was associated with less catheter-related complications (leakage, dislocation, and obstruction) as compared to ascites drainage catheters. In summary, PD was technically feasible and effective also in extremely immature infants, but frequent adjustments of dialysis regimens and high numbers of daily cycles posed immense efforts on both, parents and medical staff.

Near-Infrared Spectroscopy in Extremely Preterm Infants

With advances in neonatal care, survival of premature infants at the limits of viability has improved significantly. Despite these improvement in mortality, infants born at 22-24 weeks gestation are at a very high risk for short- and long-term morbidities associated with prematurity. Many of these diseases have been attributed to abnormalities of tissue oxygenation and perfusion. Near-infrared spectroscopy utilizes the unique absorption properties of oxyhemoglobin and deoxyhemoglobin to provide an assessment of regional tissue oxygen saturation, which can be used to calculate the fractional tissue oxygen extraction. This allows for a non-invasive way to monitor tissue oxygen consumption and enables targeted hemodynamic management. This mini-review provides a brief and complete overview of the background and physiology of near-infrared spectroscopy, practical use in extremely preterm infants, and potential applications in the neonatal intensive care unit. In this mini-review, we aim to summarize the three primary application sites for near-infrared spectroscopy, disease-specific indications, and available literature regarding use in extremely preterm infants.

AWAKEN-Ing a New Frontier in Neonatal Nephrology

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

Acute kidney injury in hospitalized children: consequences and outcomes

Over the past decade, the nephrology and critical care communities have adopted a consensus approach to diagnosing acute kidney injury (AKI) and, as a result, we have seen transformative changes in our understanding of pediatric AKI epidemiology. The data regarding outcomes among neonates and children who develop AKI have become far more robust and AKI has been clearly linked with an increased need for mechanical ventilation, longer inpatient stays, and higher mortality. Though AKI was historically thought to be self-limited, we now know that renal recovery is far from universal, particularly when AKI is severe; the absence of recovery from AKI also carries longitudinal prognostic implications. AKI survivors, especially those without full recovery, are at risk for chronic renal sequelae including proteinuria, hypertension, and chronic kidney disease. This review comprehensively describes AKI-related outcomes across the entire pediatric age spectrum, using the most rigorous studies to identify the independent effects of AKI events.