Critical serum creatinine values in very preterm newborns

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.

Organ dysfunction and mortality in preterm neonates with late-onset bloodstream infection

BACKGROUND

Organ dysfunction (ODF) in late-onset bloodstream infection (LBSI) is associated with increased risk of adverse outcomes. However, no established definition of ODF exists among preterm neonates. Our objective was to describe an outcome-based ODF definition for preterm infants, and assess factors associated with mortality.

METHODS

This is a six-year retrospective study of neonates <35 weeks gestational age, >72 h of age, with non-CONS bacterial/fungal LBSI. Discriminatory ability of each parameter for mortality was evaluated: base deficit ≤-8 mmol/L (BD8), renal dysfunction (urine output <1 cc/kg/h or creatinine ≥100 μmol/L), hypoxic respiratory failure (HRF, ventilated, FiO2 = 1.0), or vasopressor/inotrope use (V/I). Multivariable logistic regression analysis was performed to derive a mortality score.

RESULTS

One hundred and forty-eight infants had LBSI. BD8 had the highest individual predictive ability for mortality (AUROC = 0.78). The combination BD8 + HRF + V/I was used to define ODF (AUROC = 0.84). Fifty-seven (39%) infants developed ODF, among which 28 (49%) died. Mortality increased inversely relative to GA at LBSI-onset (aOR 0.81 [0.67, 0.98]) and directly relative to ODF occurrence (12.15 [4.48, 33.92]). Compared to no-ODF, ODF infants had lower GA and age at illness, and higher frequency of Gram-negative pathogen.

CONCLUSIONS

Among preterm neonates with LBSI, significant metabolic acidosis, HRF, and vasopressor/inotrope use may identify infants high risk for mortality. These criteria could help identify patients for future studies of adjunctive therapies.

IMPACT

Sepsis-related organ dysfunction is associated with increased risk of adverse outcomes. Among preterm neonates, significant metabolic acidosis, use of vasopressors/inotropes, and hypoxic respiratory failure may identify high-risk infants. This can be used to target research and quality improvement efforts toward the most vulnerable infants.

Neurodevelopmental Outcome at Corrected Age of 2 Years among Children Born Preterm with Operative Vaginal Delivery: A Population-Based Study (LIFT Cohort)

The aim of the study was to determine whether operative vaginal delivery (OVD) was associated with non-optimal neurocognitive development at the corrected age of 2 years for preterm singletons using the Loire Infant Follow-up Team (LIFT) longitudinal cohort, a French regional perinatal network and prospective, population-based cohort of preterm infants. For this study, we included women with cephalic singletons and planned vaginal delivery from 24 to 34 weeks' gestation between 2006 and 2016. The main exposure was the mode of delivery (spontaneous vaginal delivery (SVD), OVD, and cesarean delivery (CS) during labor). The primary outcome was non-optimal neurodevelopmental outcome at the corrected age of 2 years assessed by a physical examination, a neuropsychological test, and/or a parental questionnaire. Secondary outcomes were survival at discharge and survival at discharge without morbidity. We used the multivariate logistic regression and propensity score methods to compare outcomes associated with OVD. The study included 1934 infants born preterm: 1384 (71.6%) with SVD, 87 (4.5%) with OVD, and 463 (23.9%) with CS. Neonates with SVD, OVD, and CS did not differ in survival (97.0%, 97.7%, and 97.8%, respectively; p = 0.79) or in survival without morbidity (82.8%, 86.2%, and 82.7%, respectively; p = 0.71). In survived infants, 1578 (81.6%) were evaluated at age two: 279 (17.7%) were considered to have a non-optimal neurodevelopmental outcome (18.3% after SVD, 18.0% after OVD, and 15.9% after CS; p = 0.57). Propensity score analysis showed that OVD was not associated with non-optimal neurocognitive development at age two, with an adjusted odds ratio (aOR) of 0.86 and a 95% confidence interval (95% CI) of 0.47-1.69, compared with SVD; and an aOR of 0.76 and a 95% CI of 0.31-1.8, compared with CS. Operative vaginal delivery was not associated with non-optimal neurocognitive development at 2 years of corrected age for preterm singletons.

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.

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.

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

Background

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

Methods

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

Results

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

Conclusions

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

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.

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.

The incidence of osteopenia of prematurity in preterm infants without phosphate supplementation: A prospective, observational study

To meet their requirements for bone mineralization, it is recommended that preterm infants receive nutritional support containing calcium and phosphate. There are no clear data on the incidence of osteopenia of prematurity (OFP) in preterm infants without phosphate supplementation.This study aimed to investigate the incidence of OFP in preterm infants without phosphate supplementation and its relationship with the duration of parenteral nutrition (PN).This was a prospective and observational study.This study included 30 infants aged <32 gestational weeks and weighed <1500 g at birth. All infants received PN according to a standard protocol, beginning on day 1 with calcium, without phosphate. Starting from the first day of life, all infants received human milk without fortifiers. Oral vitamin D (400 IU/d) was administered when enteral nutrition reached 100 mL/kg/d.The diagnosis of OFP was based on radiographs that were taken of both wrists. Serum alkaline phosphatase (ALP) was measured 3 times: at the start of PN (ALP 1), at the end of PN (ALP 2), and at discharge or the expected due date (ALP 3). Radiographs were obtained on the same day as ALP 3. The duration of PN was analyzed in the presence of OFP using receiver operating characteristic curve analysis.Among the 30 infants, 13 (43%) were diagnosed with OFP. The duration of PN was significantly longer in the OFP group than in the group without OFP (16 vs 12 days; P < .05). The provision of PN for >15 days significantly increased the risk of OFP (odds ratio, 5.40; 95% confidence interval, 1.12-26.04; P = .035).We found a high incidence of OFP in preterm infants without phosphate supplementation. An association was found between the duration of PN and the incidence of OFP. Further research is needed to prevent the development of osteopenia in preterm infants.

Preterm birth and neonatal acute kidney injury: implications on adolescent and adult outcomes

As a result of preterm birth, immature kidneys are exposed to interventions in the NICU that promote survival, but are nephrotoxic. Furthermore, the duration of renal development may be truncated in these vulnerable neonates. Immaturity and nephrotoxic exposures predispose preterm newborns to acute kidney injury (AKI), particularly in the low birth weight and extremely preterm gestational age groups. Several studies have associated preterm birth as a risk factor for future chronic kidney disease (CKD). However, only a few publications have investigated the impact of neonatal AKI on CKD development. Here, we will review the evidence linking preterm birth and AKI in the NICU to CKD and highlight the knowledge gaps and opportunities for future research. For neonatal intensive care studies, we propose the inclusion of AKI as an important short-term morbidity outcome and CKD findings such as a reduced glomerular filtration rate in the assessment of long-term outcomes.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Creatinine filtration kinetics in critically Ill neonates

BACKGROUND

Creatinine values are unreliable within the first weeks of life; however, creatinine is used most commonly to assess kidney function. Controversy remains surrounding the time required for neonates to clear maternal creatinine.

METHODS

Eligible infants had multiple creatinine lab values and were admitted to the neonatal intensive care unit (NICU). A mathematical model was fit to the lab data to estimate the filtration onset delay, creatinine filtration half-life, and steady-state creatinine concentration for each subject. Infants were grouped by gestational age (GA) [(1) 22-27, (2) >27-32, (3) >32-37, and (4) >37-42 weeks].

RESULTS

A total of 4808 neonates with a mean GA of 34.4 ± 5 weeks and birth weight of 2.34 ± 1.1 kg were enrolled. Median (95% confidence interval) filtration onset delay for Group 1 was 4.3 (3.71, 4.89) days and was significantly different than all other groups (p < 0.001). Creatinine filtration half-life of Groups 1, 2, and 3 were significantly different from each other (p < 0.001). There was no difference in steady-state creatinine concentration among the groups.

CONCLUSIONS

We quantified the observed kidney behavior in a large NICU population as a function of day of life and GA using creatinine lab results. These results can be used to interpret individual creatinine labs for infants to detect those most at risk for acute kidney injury.

IMPACT

One of the largest cohorts of premature infants to describe the evolution of kidney development and function over their entire hospitalization. New concept introduced of the kidney filtration onset delay, the time needed for the kidney to begin clearance of creatinine, and that it can be used as an early indicator of kidney function. The smallest premature infants from 22 to 27 weeks gestation took the longest time to begin and complete maternal creatinine clearance. Clinicians can easily compare the creatinine level of their patient to the normative curves to improve understanding of kidney function at the bedside.

Incidence and Risk Factors of Early Onset Neonatal AKI

BACKGROUND AND OBJECTIVES

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

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

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

Incidence and Risk Factors of Early Onset Neonatal AKI

BACKGROUND AND OBJECTIVES

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

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Ibuprofen exposure in early neonatal life does not affect renal function in young adolescence

INTRODUCTION

Ibuprofen exposure results in acute transient renal dysfunction in preterm neonates, but we are unaware of data on long-term renal safety.

METHODS

In a previously studied cohort of extreme low birth weight (ELBW, <1000 g) cases, the PREMATurity as predictor of children's Cardiovascular-renal Health study generated data on renal function (renal length, estimated glomerular filtration rate based on cystatin C (eGFR_cysC) at the age of 11 years. This data set in 93 ELBW cases may also generate data on long-term drug safety on ibuprofen. In this post hoc analysis, we linked markers of renal function in young adolescence in ELBW cases with their perinatal (prenatal maternal, setting at birth, treatment modalities including drug prescription during neonatal stay, neonatal creatinine values, postdischarge growth) characteristics, including but not limited to ibuprofen exposure during neonatal stay.

RESULTS

Ibuprofen exposure was not associated with significant differences in renal length or eGFR_cysC. Moreover, we were unable to identify any other risk factor (perinatal characteristics, postnatal creatinine trends, postdischarge growth) on renal outcome in this cohort.

CONCLUSIONS

Neonatal exposure to ibuprofen did not affect renal function. Larger studies are needed to explore the confounders of variability in renal function in former ELBW cases. This matters since ELBW relates to risk for hypertension, cardiovascular events and renal disease in later life and identification of risk factors holds the promise of secondary prevention.

TRIAL REGISTRATION NUMBER

NCT02147457.

Acute kidney injury in preterm neonates with ≤30 weeks of gestational age and its risk factors

BACKGROUND

Acute kidney injury (AKI), an abrupt decline in kidney function, is a challenging diagnosis among preterm infants due to some specific features of this population. The aim of this study was to determine the risk factors of developing AKI and the predictive factors for its severity in preterm neonates with less than 31 weeks of gestational age.

METHODS

All neonates with less than 31 weeks of gestational age, admitted in our NICU between January 2012 and December 2015, were included. Maternal and neonatal records about demographics, placental abnormalities, perinatal and neonatal period and evolution in NICU, as well as electrolytic analysis and serum creatinine and urea values during their hospitalization were retrospectively collected and analyzed.

RESULTS

A total of 106 neonates were included. Of those, 24 were diagnosed with AKI, resulting in a prevalence of 22.6%, and 82 were used as controls. Gestational age (OR=0.39; 95% CI=0.2-0.76; P=0.006), congenital malformations (OR=36.93; 95%CI=2.48-550.59; P=0.009), vasoactive drugs (OR=27.06; 95%CI=3.58-204.45; P=0.001), nonsteroidal anti-inflammatory drugs (OR=9.61; 95%CI=1.78-51.73; P=0.008) and sepsis (OR=7.78; 95%CI=1.32-46.04; P=0.024) were found to be independent risk factors. Cardiac surgery was a predictive factor for AKI severity (OR=25; 95%CI=2.09-298.29; P=0.011). The mortality rate in the AKI group was 41.7%.

CONCLUSIONS

AKI in preterm neonates is an important feature that contributes to increase the mortality in NICUs. Thus, it is crucial to know its risk factors to establish prompt diagnosis and prevention and, in this way, be able to improve the prognosis.

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

Background

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

Methods

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

Results

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

Conclusion

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

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Renal function in the fetus and neonate - the creatinine enigma

The use of serum creatinine levels to estimate glomerular function in infants is admittedly fraught with inherent inaccuracies which are both physiological and methodological in nature. This characteristic can understandably reduce the neonatal clinician's confidence in the ability of serum creatinine levels to provide useful information relevant to their patients' medical care. The aim of this review is to provide further insight into the peculiarities of serum creatinine trends in both premature and term infants with special focus on the maturational and developmental changes occurring in the kidney during this crucial time-period. Though newer markers of glomerular function are gaining increasing traction in the clinical realm, the most prominent of which is currently cystatin C, creatinine nonetheless remains an important player in the scientific evolution of glomerular filtration rate (GFR) estimation. Not only do its limitations provide a level of distinction for newer markers of GFR, but its advantages persist in refining the precision of newer GFR formulae which incorporate multiple patient characteristics.

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

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

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Neonatal Acute Kidney Injury

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

Neonatal creatinemia trends as biomarker of subsequent cognitive outcome in extremely low birth weight neonates

BACKGROUND AND AIMS

Serum creatinine is traditionally used as a marker of renal function in neonates and relates to gestational age and disease severity in extremely low birth weight (ELBW) infants. Creatinine is commonly used as a biomarker for early morbidity, but we aim to compare postnatal creatinemia trends as a biomarker for subsequent cognitive outcome. We hypothesize that impaired microcirculation not only in the kidney, but also in general (i.e. brain development) can explain this possible link.

STUDY DESIGN AND OUTCOME MEASURES

A cohort of ELBW infants was analyzed by Bayley Scales of Infant Development (BSID-II) at the corrected age of 2years old. Besides other perinatal indicators, neonatal creatinemia trends of survivors (n=140) and BSID scores (n=96) are compared and analyzed using optimal matching analysis. Hierarchical clustering analysis is applied to identify createnimia trends.

RESULTS

Four different creatinemia trends were identified (persistently high, normal, low, high but normalizing). A low creatinemia trend is significantly associated with the lowest percentages of postnatal corticosteroids, NSAIDS and intraventricular hemorrhage (p=0.005, p=0.013 and p=0.041 respectively) compared to a normal or persistently high creatinemia trend and associated with the best cognitive outcome (+13 points compared to the mean creatinemia trend and +23 points compared to a persistently high creatinemia trend).

CONCLUSIONS

Creatinemia trends after birth are not only useful to predict renal function, but are also associated with cognitive outcome in extremely low birth weight infants. Neonates who have low creatinemia trends after birth, have the highest BSID scores at the age of two years old.

Chronic kidney disease in the neonate

An increased emphasis has been placed on the early identification of chronic kidney disease (CKD) in the neonatal population, given the long-term health consequences that can accompany this diagnosis. The definition of CKD in neonates and young infants differs from that of children older than 2 years and, if severe, treatment may mandate dialysis with appropriate ethical considerations. Special attention must also be directed to optimal nutrition because of its impact on height, weight, and brain development in the young child experiencing impaired kidney function. There has been steady improvement in patient survival over the last decade.

Acute kidney injury in the neonate

Critically ill neonates are at risk for acute kidney injury (AKI). AKI has been associated with increased risk of morbidity and mortality in adult and pediatric patients, and increasing evidence suggests a similar association in the neonatal population. This article describes the current AKI definitions (including their limitations), work on novel biomarkers to define AKI, diagnosis and management strategies, long-term outcomes after AKI, and future directions for much-needed research in this important area.