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

Biomarker urinary neutrophil gelatinase-associated lipocalin as a predictor of acute kidney injury in neonates

AIM

To evaluate urinary Neutrophil Gelatinase-Associated Lipocalin (uNGAL) as a predictive biomarker for Acute Kidney Injury (AKI) in neonates undergoing gastrointestinal surgery.

MATERIALS & METHODS

A prospective cohort study included 45 neonates with gastrointestinal congenital malformations who underwent abdominal surgery within the first 28 days of life at two pediatric centers in Almaty, Kazakhstan. AKI was diagnosed using modified neonatal KDIGO criteria, dividing neonates into AKI[+] and AKI[-] groups. uNGAL levels were measured pre-surgery and on postoperative days 1, 3, and 7. Statistical analysis, including ROC curve analysis, was performed using SPSS to evaluate uNGAL's sensitivity and specificity as a biomarker.

RESULTS

AKI was diagnosed in 42.2% of neonates. Pre-surgery uNGAL levels were significantly higher in the AKI group (184.4 ng/ml vs. 56.5 ng/ml). Post-surgery, uNGAL peaked at 493.9 ng/ml on day 1, with sensitivities of 89.5% and 94.7% on days 1 and 7. Specificity was highest on days 1 and 3 (96.2% and 100%). The mortality rate among AKI-affected neonates was 31.5%.

CONCLUSION

uNGAL is a sensitive and specific biomarker for early AKI detection in neonates post-gastrointestinal surgery, enabling timely interventions and potentially reducing mortality.

Necrotizing Enterocolitis-Associated Acute Kidney Injury-Transforming the Paradigm

Necrotizing enterocolitis (NEC) is one of the most common conditions requiring emergency surgery in the neonatal intensive care unit and is associated with a septic shock-like state contributing to multiorgan dysfunction. NEC affects 6 to 10% of very low-birth-weight infants and remains a leading cause of death. The occurrence of severe acute kidney injury (AKI) following surgical NEC is a harbinger of multiple morbidities. This review presents current evidence about the clinical impact of NEC-associated AKI on the clinical outcomes. Studies evaluating nephroprotective strategies to prevent AKI and its consequences are greatly needed to improve the postoperative recovery and clinical outcomes in neonates with NEC. Future observational studies and clinical trials in preterm infants with NEC prioritize measuring short-term (AKI) and longer term (chronic kidney disease) kidney outcomes. KEY POINTS: · Severe AKI is common following surgical NEC.. · Severe AKI following NEC is associated with poor clinical outcomes.. · Studies evaluating nephroprotective strategies to prevent AKI and its consequences are needed.. IMPACT: · Severe AKI (stage 2 and 3) occurs in 32.6% of neonates after NEC diagnosis and in 58.7% following surgical NEC diagnosis.. · NEC-associated AKI is associated with severe postoperative course, moderate-to-severe bronchopulmonary dysplasia, surgical complications, brain injury, and longer hospital stay in preterm infants.. · Severity of NEC-associated AKI can be utilized by bedside providers for the prognostication of clinical outcomes in preterm infants..

Timing and risk factors associated with acute kidney injury in infants with necrotizing enterocolitis

OBJECTIVE

To evaluate the prevalence, onset, risk factors, and mortality associated with acute kidney injury (AKI) in infants with necrotizing enterocolitis (NEC).

DESIGN/METHODS

Retrospective study at 2 centers in infants with NEC, with/without AKI. AKI assessed by serum creatinine and urine output. Statistical tests used included t, Mann-Whitney U, Chi-square, and Fisher Exact tests.

RESULTS

Among 80 eligible infants with NEC, 56 (70%) had AKI. Median onset of NEC was day 15, with median AKI onset two days (IQR, -5.75 to 0) prior to NEC onset. Vasopressors were significantly more likely to be used in infants with NEC and AKI (p = 0.009). Increased mortality (p = 0.01) was noted in infants with NEC and AKI.

CONCLUSIONS

The onset of AKI mostly precedes NEC onset, with moderate to severe AKI more prevalent than the milder form in infants with NEC. These infants are significantly more likely to be hemodynamically unstable and have increased mortality.

Fluid Overload and AKI After the Norwood Operation: The Correlation and Characterization of Routine Clinical Markers

The purpose of this study was to determine the correlation of different methods of assessing fluid overload and determine which metrics are associated with development of acute kidney injury (AKI) in the period immediately following Norwood palliation. This was a retrospective single-center study of Norwood patients from January 2011 through January 2021. AKI was defined using the Kidney Disease Improving Global Outcomes (KDIGO). Patients were separated into two groups: those with AKI and those without. A logistic regression analysis was conducted with AKI at any point in the study period as the dependent variable and clinical and laboratory data as independent variables. Analysis was conducted as a stepwise regression. The coefficients from the logistic regression were then used to develop a cumulative AKI risk score. Spearman correlations were conducted to analyze the correlation of fluid markers. 116 patients were included, and 49 (42.4%) developed AKI. The duration of open chest, duration of mechanical ventilation, need for dialysis, need for extracorporeal membrane oxygenation, and inpatient mortality were associated with AKI (p ≤ 0.05). Stepwise logistic regression demonstrated the following significant independent associations AKI: age at Norwood in days (p < 0.01), blood urea nitrogen (p < 0.01), central venous pressure (p = 0.04), and renal oxygen extraction ratio (p < 0.01). The area under the receiver operating characteristic curve for the logistic regression was 0.74. The fluid markers had weak R-value. Urea, central venous pressure, and renal oxygen extraction ratio are associated with AKI after the Norwood operation. Common clinical metrics used to assess fluid overload are poorly correlated with each other for postoperative Norwood patients.

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

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

Acute kidney injury surveillance in the high-risk neonatal population following implementation of creatinine screening protocol

AIM

Acute kidney injury (AKI) in neonates is associated with longer hospital stays and higher mortality rates. However, there is significant variability in prevalence rates of AKI and the true burden is incompletely understood. In November 2020, the University of Iowa Stead Family Children's Hospital Neonatal Intensive Care Unit implemented a creatinine screening protocol to enhance kidney function monitoring. We sought to evaluate adherence to the protocol to determine if increased surveillance led to increased detection of AKI events.

METHODS

A retrospective chart review was conducted for neonates born at <30 weeks' gestation admitted between 2015 and 2020. We reviewed 100 charts in both the pre (2015-2016) and post (2020-2021) implementation era of the AKI surveillance protocol. AKI was defined according to neonatal modified KDIGO criteria.

RESULTS

Following implementation of the protocol, neonates were significantly more likely to have creatinine checked (p < 0.001). Serum creatinine was drawn according to protocol guidelines 68% of the time, and 42% of patients (34/82) had an 80% or higher adherence to the protocol. There was a significant increase in detection of AKI in the post-protocol cohort (13/82, incidence of 16%) compared to the pre-protocol cohort (5/83, incidence of 6%), (p = 0.047).

CONCLUSION

The implementation of a serum creatinine screening protocol increased the frequency of creatinine draws and detection of AKI.

Recent Advances in Kidney Replacement Therapy in Infants: A Review

Kidney replacement therapy (KRT) is used to treat children and adults with acute kidney injury (AKI), fluid overload, kidney failure, inborn errors of metabolism, and severe electrolyte abnormalities. Peritoneal dialysis and extracorporeal hemodialysis/filtration can be performed for different durations (intermittent, prolonged intermittent, and continuous) through either adaptation of adult devices or use of infant-specific devices. Each of these modalities have advantages and disadvantages, and often multiple modalities are used depending on the scenario and patient-specific needs. Traditionally, these therapies have been challenging to deliver in infants due the lack of infant-specific devices, small patient size, required extracorporeal volumes, and the risk of hemodynamic stability during the initiation of KRT. In this review, we discuss challenges, recent advancements, and optimal approaches to provide KRT in hospitalized infants, including a discussion of peritoneal dialysis and extracorporeal therapies. We discuss each specific KRT modality, review newer infant-specific devices, and highlight the benefits and limitations of each modality. We also discuss the ethical implications for the care of infants who need KRT and areas for future research.

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

Importance

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

Objective

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

Design, Setting, and Participants

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

Exposure

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

Main Outcomes and Measures

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

Results

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

Conclusions and Relevance

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

Gestational age-specific clinical correlates of acute kidney injury in preterm infants with necrotizing enterocolitis

BACKGROUND

To study the gestational age-specific risk factors and outcomes of severe acute kidney injury (AKI) in neonates with necrotizing enterocolitis (NEC).

METHODS

Retrospective cohort study comparing gestational age (GA)-specific clinical data between infants without severe AKI (stage 0/1 AKI) and those with severe AKI (stages 2 and 3 AKI) stratified by GA ≤27 and >27 weeks.

RESULTS

Infants with GA ≤27 weeks had double the rate of severe AKI (46.3% vs. 20%). In infants with GA >27 weeks, male sex, outborn, and nephrotoxic medication exposure were associated with severe AKI. On multivariable logistic regression, in infants with GA ≤27 weeks, surgical NEC (OR 35.08 (CI 5.05, 243.73), p < 0.001) and ostomy (OR 6.2(CI 1.29, 29.73), p = 0.027) were associated with significantly higher odds of severe AKI. Surgical NEC infants with GA >27 weeks and severe AKI were significantly more likely to be outborn, have later NEC onset, need dopamine, and have longer hospitalization (158 days [110; 220] vs.75.5 days [38.8; 105]; p = 0.007 than those with non-severe AKI.

CONCLUSION

In neonates with NEC, surgical intervention was associated with moderate-to-severe AKI in infants with GA ≤27 weeks and with longer hospitalization in infants with GA >27 weeks.

IMPACT

In both cohorts need for surgery, stoma, cholestasis, and mechanical ventilation were associated with severe AKI; however, the infants with GA <27 weeks had twice the risk of severe AKI than GA >27 weeks group. The longer exposure to nephrotoxic medication and referral need were significant risk factors for AKI in GA >27 weeks group. GA-specific kidney protective and monitoring strategies to prevent AKI and its consequences are needed to improve the clinical outcomes in neonates with NEC. Understanding the risk factors and short- and long-term outcomes unique to different GA groups will help inform those strategies.

Acute kidney injury post-abdominal surgery in infants: implications for prevention and management

Acute kidney injury (AKI) is common in critically ill infants and is associated with long-term sequelae including hypertension and chronic kidney disease. The etiology of AKI in infants is multifactorial. There is robust literature highlighting the risk of AKI after cardiothoracic surgery in infants. However, risk factors and outcomes for AKI in infants after abdominal surgery remains limited. This article reviews the epidemiology and association of abdominal surgery with postoperative AKI and suggests methods for AKI management and prevention. Postoperative AKI may result from hemodynamic shifts, hypoxia, exposure to nephrotoxic medications, and inflammation. Infants in the intensive care unit after intraabdominal surgeries have a unique set of risk factors that predispose them to AKI development. Prematurity, sepsis, prolonged operation time, emergent nature of the procedure, and diagnosis of necrotizing enterocolitis increase risk of AKI after intrabdominal surgeries. Prevention, early diagnosis, and management of AKI post-abdominal surgery is imperative to clinical practice. Close monitoring of urine output, serum creatinine, and fluid status is necessary in infants after abdominal surgery. A recent study suggests elevated levels of a urinary biomarker, neutrophil gelatinase-associated lipocalin (NGAL), 24 h after an abdominal procedure may improve early prediction of AKI. Identification of risk factors, avoidance of nephrotoxic medications, careful fluid balance, early detection of AKI, and maintenance of hemodynamic stability is imperative to potentially prevent and/or mitigate AKI.

Clinical impact of severe acute kidney injury on post-operative and brain injury outcomes in preterm infants following surgical necrotizing enterocolitis

BACKGROUND

To evaluate post-operative outcomes and white matter injury (WMI) using brain MRI at term equivalent in neonates with and without severe acute kidney injury (AKI) following surgical necrotizing enterocolitis (NEC).

METHODS

A retrospective cohort study comparing neonates with severe (Stage 2/3) vs. other (no AKI/Stage 1) AKI using KDIGO classification with multivariable models assessing this association in the context of multiple systemic comorbidities.

RESULTS

Of 103 neonates with surgical NEC, 60 (58%) had severe AKI. Those with severe AKI had lower birth weight (BW; 715 vs. 950 g; p = .023), more frequently treated with indomethacin (18.3 vs. 2.4%); p = .014), higher CRP levels at 24 h after NEC onset (14.4 [6.4-19.8] vs. 4.8 [1.6-13.4]; p = .005), higher presence of cholestasis (73.3 vs. 51.2%); p = .023), later age of NEC onset (14 vs. 7 d); p = .004), longer length of bowel resected (14.9 vs. 4.3 cm); p = .011), longer post-operative ileus days (14 vs. 9 d); p < .001), longer post-operative days at starting enteral feedings (15 vs. 10 d; p < .001), longer days of attainment of full enteral feedings (75 vs. 44.5 d; p = .008) and longer length of stay (140.5 vs. 94 d; p = .028) compared to those without severe AKI. Compared to infants without AKI by serum creatinine, those with AKI had significantly more cases of white matter abnormality (WMA; 90 vs. 36.6%; p < .001) and retinopathy of prematurity (63.9 vs. 35.3%; p = .017). In addition, the presence of AKI Stage 2 and 3 by serum creatinine was independently associated with higher odds of sustaining severe WMI level on an ordinal scale (OR = 6.2; 95% CI = (1.1-35.5); p = .041).

CONCLUSIONS

Neonates with severe AKI following surgical NEC were more likely to experience longer post-operative morbidity and higher WMI by MRI at term.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Inadvertent hypothermia and acute kidney injury (AKI) in neonates undergoing gastrointestinal surgeries: a retrospective study

OBJECTIVE

The purpose of our study was to evaluate the association between intraoperative hypothermia and AKI in neonates undergoing gastrointestinal surgeries.

STUDY DESIGN

This retrospective study was conducted for neonates who underwent gastrointestinal surgeries from June 2018 to August 2020. Neonates with a minimum of two documented creatinine values before and after surgical procedures within 48 h were included. According to the mean intraoperative temperature, the eligible neonates were divided into three groups. The primary outcome was the incidence of AKI (as defined by the modified KDIGO criteria). The association between variables and AKI or hospital mortality was also examined.

RESULTS

A total of 295 neonates fulfilled the eligibility criteria. AKI was more common in patients with lower intraoperative temperature compared to the normothermia group. Intraoperative mean temperature was independently associated with AKI. Patients developing AKI had a higher hospital mortality. AKI and gestational age were independently associated with hospital mortality.

CONCLUSIONS

Inadvertent intraoperative hypothermia was associated with developing postoperative AKI.

Risk Factors and Consequences of Acute Kidney Injury After Noncardiac Surgery in Children

BACKGROUND

Postoperative acute kidney injury (AKI) is a serious complication that is associated with prolonged hospital stay, high risk of short-term postsurgical mortality, need for dialysis, and possible progression to chronic kidney disease. To date, very little data exist on the risk of postoperative AKI among children undergoing noncardiac surgical procedures. We used data from a large multicenter cohort to determine the factors associated with AKI among children who underwent inpatient noncardiac surgical procedures and its impact on the postoperative course.

METHODS

We utilized the National Surgical Quality Improvement Program Pediatric participant user files to identify a cohort of children who underwent inpatient surgery between 2012 and 2018 (n = 257,439). We randomly divided the study population into a derivation cohort of 193,082 (75%) and a validation cohort of 64,357 (25%), and constructed a multivariable logistic regression model to identify independent risk factors for AKI. We defined AKI as the occurrence of either acute renal failure or progressive renal insufficiency within the 30 days after surgery.

RESULTS

The overall rate of postoperative AKI was 0.10% (95% confidence interval [CI], 0.09-0.11). In a multivariable model, operating times longer than 140 minutes, preexisting hematologic disorder, and preoperative sepsis were the strongest independent predictors of AKI. Other independent risk factors for AKI were American Society of Anesthesiologists (ASA) physical status ≥III, preoperative inotropic support, gastrointestinal disease, ventilator dependency, and corticosteroid use. The 30-day mortality rate was 10.1% in children who developed AKI and 0.19% in their counterparts without AKI (P < .001). Children who developed AKI were more likely to require an extended hospital stay (≥75th percentile of the study cohort) relative to their peers without AKI (77.4% vs 21.0%; P < .001).

CONCLUSIONS

Independent preoperative risk factors for AKI in children undergoing inpatient noncardiac surgery were hematologic disorder, preoperative sepsis, ASA physical status ≥III, inotropic support, gastrointestinal disease, ventilator dependency, and steroid use. Children with AKI were 10 times more likely to die and nearly 3 times more likely to require an extended hospital stay, relative to their peers without AKI.

Intraoperative Hypotension and Acute Kidney Injury after Noncardiac Surgery in Infants and Children: A Retrospective Cohort Analysis

BACKGROUND

Age- and sex-specific reference nomograms for intraoperative blood pressure have been published, but they do not identify harm thresholds. The authors therefore assessed the relationship between various absolute and relative characterizations of hypotension and acute kidney injury in children having noncardiac surgery.

METHODS

The authors conducted a retrospective cohort study using electronic data from two tertiary care centers. They included inpatients 18 yr or younger who had noncardiac surgery with general anesthesia. Postoperative renal injury was defined using the Kidney Disease Improving Global Outcomes definitions, based on serum creatinine concentrations. The authors evaluated potential renal harm thresholds for absolute lowest intraoperative mean arterial pressure (MAP) or largest MAP reduction from baseline maintained for a cumulative period of 5 min. Separate analyses were performed in children aged 2 yr or younger, 2 to 6 yr, 6 to 12 yr, and 12 to 18 yr.

RESULTS

Among 64,412 children who had noncardiac surgery, 4,506 had creatinine assessed preoperatively and postoperatively. The incidence of acute kidney injury in this population was 11% (499 of 4,506): 17% in children under 6 yr old, 11% in children 6 to 12 yr old, and 6% in adolescents, which is similar to the incidence reported in adults. There was no association between lowest cumulative MAP sustained for 5 min and postoperative kidney injury. Similarly, there was no association between largest cumulative percentage MAP reduction and postoperative kidney injury. The adjusted estimated odds for kidney injury was 0.99 (95% CI, 0.94 to 1.05) for each 5-mmHg decrease in lowest MAP and 1.00 (95% CI, 0.97 to 1.03) for each 5% decrease in largest MAP reduction from baseline.

CONCLUSIONS

In distinct contrast to adults, the authors did not find any association between intraoperative hypotension and postoperative renal injury. Avoiding short periods of hypotension should not be the clinician's primary concern when trying to prevent intraoperative renal injury in pediatric patients.

EDITOR’S PERSPECTIVE

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.

Severe acute kidney injury in neonates with necrotizing enterocolitis: risk factors and outcomes

BACKGROUND

To study the risk factors and outcomes of severe acute kidney injury (AKI) in neonates with necrotizing enterocolitis.

METHODS

Retrospective chart review of 202 neonates with necrotizing enterocolitis (NEC) (Bell stage >IIa) from 2013 to 2018. AKI was defined as per-modified neonatal Kidney Disease: Improving Global Outcomes criteria. Demographic, clinical, and outcome data were compared between neonates without severe AKI (stage 0 and 1 AKI) and those with severe AKI (stage 2 and 3 AKI).

RESULTS

Severe AKI occurred in 66/202 (32.6%) of neonates after NEC diagnosis and after 61/104 (58.7%) of surgical NEC diagnoses. On adjusted model, surgical NEC [adjusted odds ratio (aOR) = 30.6; 95% confidence interval (CI) = 8.9, 130.6], outborn [aOR = 3.9; 95% CI = 1.54, 11.0], exposure to antenatal steroids [aOR = 3.0; 95% CI = 1.1, 8.9], and positive blood culture sepsis [aOR = 3.5; 95% CI = 1.3, 10.0] had increased odds for severe AKI. Those with severe AKI required longer hospitalization [124 days (interquartile range (IQR) 88-187) vs. 82 days (IQR 42-126), p < 0.001].

CONCLUSIONS

Severe AKI is common in neonates with NEC who require surgical intervention, are outborn, have positive blood culture sepsis, and receive antenatal steroids. Severe AKI is associated with a significantly longer length of hospitalization.

IMPACT

Neonates with NEC, who are transferred from outside hospitals, require surgical NEC management, and/or have a positive blood culture at NEC onset are at the highest odds for severe (stages 2 and 3) AKI. Assessment of urine output is important for patients with NEC. Without it, 11% of those with severe AKI would have been misdiagnosed using serum creatinine alone. Kidney-protective strategies in the pre-, peri-, and postoperative period may improve the morbidity and mortality associated with severe AKI in neonates with NEC.

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

OBJECTIVES

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

STUDY DESIGN

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

RESULTS

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

CONCLUSIONS

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

Dopamine and Drip Lasix in Pediatrics with Oliguria: A Clinical Trial Study

Background: Urine volume less than 1 mL/kg/h is called oliguria. The treatment of these patients is very important. Objectives: This study aimed to compare efficacy of dopamine and drip Lasix in children with oliguria. Methods: This study was performed as a clinical trial in the NICU, PICU, neonatal and pediatric wards of Amirkabir hospital in Arak. Children with oliguria with less than 1 mL/kg/h during treatment were considered the study group. Sixty children who met the inclusion criteria were selected and randomly divided into two groups, including 30 children in the dopamine group and 30 children in the Lasix group. In the dopamine group, the drug was administered at a dose of 3 µg/kg/min, in the second group, drip Lasix was administered at a dose of 0.05 mg/kg/h. Results: In this evaluation, after evaluating the patients in both groups, it was observed that mean ± SD of age was 2.76 ± 1.85 years, and 51.7% of children have female gender (P = 0.438). The mean ± SD of creatinine in children after receiving dopamine and drip Lasix was 0.87 ± 0.2 mg/dl (P = 0.0001) and 0.84 ± 0.17 mg/dl (P = 0.000), respectively. Conclusions: Both drip Lasix and dopamine improved the condition of patients with oliguria. In addition, there was no statistically significant difference between these two drugs, so both drugs could improve the condition of patients.