In-Hospital Outcomes of Acute Kidney Injury After Pediatric Cardiac Surgery: A Meta-Analysis

Association between postoperative ibuprofen exposure and acute kidney injury after pediatric cardiac surgery

BACKGROUND

Acute kidney injury (AKI) is a common complication after pediatric cardiac surgery and is associated with worse outcomes. Ibuprofen is widely used in the perioperative period and can affect kidney function in children. However, the association between ibuprofen exposure and AKI after pediatric cardiac surgery has not been determined yet.

METHODS

In this retrospective cohort study, children undergoing cardiac surgery with cardiopulmonary bypass were studied. Exposure was defined as given ibuprofen in the first 7 days after surgery. Postoperative AKI was diagnosed using the KDIGO criteria. A multivariable Cox regression model was used to assess the association between ibuprofen exposure and postoperative AKI by taking ibuprofen as a time-varying covariate.

RESULTS

Among 1,112 included children, 198 of them (17.8%) experienced AKI. In total, 396 children (35.6%) were exposed to ibuprofen. AKI occurred less frequently among children who were administered ibuprofen than among those who were not (46 of 396 [11.6%] vs. 152 of 716 [21.2%], p < 0.001). Using the Cox regression model accounting for time-varying exposures, ibuprofen treatment was not associated with AKI (adjusted HR, 0.99; 95% CI 0.70-1.39, p = 0.932). This insignificant association was consistent across the sensitivity and subgroup analyses.

CONCLUSIONS

Postoperative ibuprofen exposure in pediatric patients undergoing cardiac surgery was not associated with an increased risk of AKI.

Artificial intelligence in early detection and prediction of pediatric/neonatal acute kidney injury: current status and future directions

Acute kidney injury (AKI) has a significant impact on the short-term and long-term clinical outcomes of pediatric and neonatal patients, and it is imperative in these populations to mitigate the pathways leading to AKI and be prepared for early diagnosis and treatment intervention of established AKI. Recently, artificial intelligence (AI) has provided more advent predictive models for early detection/prediction of AKI utilizing machine learning (ML). By providing strong detail and evidence from risk scores and electronic alerts, this review outlines a comprehensive and holistic insight into the current state of AI in AKI in pediatric/neonatal patients. In the pediatric population, AI models including XGBoost, logistic regression, support vector machines, decision trees, naïve Bayes, and risk stratification scores (Renal Angina Index (RAI), Nephrotoxic Injury Negated by Just-in-time Action (NINJA)) have shown success in predicting AKI using variables like serum creatinine, urine output, and electronic health record (EHR) alerts. Similarly, in the neonatal population, using the "Baby NINJA" model showed a decrease in nephrotoxic medication exposure by 42%, the rate of AKI by 78%, and the number of days with AKI by 68%. Furthermore, the "STARZ" risk stratification AI model showed a predictive ability of AKI within 7 days of NICU admission of AUC 0.93 and AUC of 0.96 in the validation and derivation cohorts, respectively. Many studies have reported the superiority of using biomarkers to predict AKI in pediatric patients and neonates as well. Future directions include the application of AI along with biomarkers (NGAL, CysC, OPN, IL-18, B2M, etc.) in a Labelbox configuration to create a more robust and accurate model for predicting and detecting pediatric/neonatal AKI.

Outcomes of Prophylactic Peritoneal Dialysis Catheter Insertion in Children Undergoing Cardiac Surgery: A Systematic Review and Meta-Analysis

OBJECTIVES

The objective of this Prospective Register of Systematic Reviews (CRD42022384192) registered systematic review and meta-analysis was to determine whether prophylactic peritoneal dialysis (PD) catheter insertion at the time of pediatric cardiac surgery is associated with improved short-term outcomes.

DATA SOURCES

Databases search of the MEDLINE, EMBASE, CINAHL, and Cochrane Library completed in April 2021 and updated October 2023.

STUDY SELECTION

Two reviewers independently completed study selection, data extraction, and bias assessment. Inclusion criteria were randomized controlled trials (RCTs) and observational studies of children (≤ 18 yr) undergoing cardiac surgery with cardiopulmonary bypass. We evaluated use of prophylactic PD catheter versus not.

DATA EXTRACTION

The primary outcome was in-hospital mortality, as well as secondary short-term outcomes. Pooled random-effect meta-analysis odds ratio with 95% CI are reported.

DATA SYNTHESIS

Seventeen studies met inclusion criteria, including four RCTs. The non-PD catheter group received supportive care that included diuretics and late placement of PD catheters in the ICU. Most study populations included children younger than 1 year and weight less than 10 kg. Cardiac surgery was most commonly used for arterial switch operation. In-hospital mortality was reported in 13 studies; pooled analysis showed no association between prophylactic PD catheter placement and in-hospital mortality. There were mixed results for ICU length of stay and time to negative fluid balance, with some studies showing shortened duration associated with use of prophylactic PD catheter insertion and others showing no difference. Overall, the studies had high risk for bias, mainly due to small sample size and lack of generalizability.

CONCLUSIONS

In this meta-analysis, we have failed to demonstrate an association between prophylactic PD catheter insertion in children and infants undergoing cardiac surgery and reduced in-hospital mortality. Other relevant short-term outcomes, including markers of fluid overload, require further study.

Prevalence, risk factors, and outcomes of acute kidney injury in a pediatric cardiac intensive care unit: A cross-sectional study

Background and Aims

Acute kidney injury (AKI) is a common complication in pediatric cardiac intensive care unit (CICU). This study aims to identify the prevalence, risk factors, and outcomes of AKI in pediatrics admitted to a CICU unit of a tertiary hospital.

Methods

We retrospectively gathered the data of 253 randomly selected patients admitted to the CICU unit from March 2018 to March 2022. Data were collected from EHRs. We used the Kidney Disease Improving Global Outcomes (KDIGO) criteria for identifying AKI in patients.

Results

Overall, AKI prevalence was 22.9% in our population. In the multivariable analysis, vancomycin intake (odds ratio [OR]: 2.109, 95% confidence interval [CI]: 1.15-3.84), angiography (OR: 4.38, 95% CI: 1.28-14.93), and mechanical ventilation (OR: 2.08, 95% CI: 1.02-4.23) were independent risk factors of AKI development and patients with AKI had a higher in-hospital mortality rate (OR: 5.81, 95% CI: 2.55-13.19), higher need for cardiopulmonary resuscitation (OR: 3.08, 95% CI: 1.17-8.09), and longer ICU length of stay (OR: 6.49, 95% CI: 3.31-9.67). Furthermore, furosemide administration was associated with lower risk of developing AKI (OR: 0.52, 95% CI: 0.27-0.97).

Conclusion

AKI is common and is associated with worse outcomes in patients with congenital heart disease. Our results emphasize the importance of early identification and monitoring of AKI in the pediatric CICU setting.

Acute renal injury after aortic arch reconstruction with cardiopulmonary bypass for children: prediction models by machine learning of a retrospective cohort study

BACKGROUND

Acute renal injury (AKI) after aortic arch reconstruction with cardiopulmonary bypass leads to injury of multiple organs and increases perioperative mortality. The study was performed to explore risk factors for AKI. We aim to develop a prediction model that can be used to accurately predict AKI through machine learning (ML).

METHODS

A retrospective analysis was performed on 134 patients with aortic arch reconstruction with cardiopulmonary bypass who were treated at our hospital from January 2002 to January 2022. Risk factors for AKI were compositive and were evaluated with comprehensive analyses. Six artificial intelligence (AI) models were used for machine learning to build prediction models and to screen out the best model to predict AKI.

RESULTS

Weight, eGFR, cyanosis, PDA, newborn birth and duration of renal ischemia were closely related to AKI. By integrating the results of the training cohort and validation cohort, we finally confirmed that the logistic regression model was the most stable model among all the models, and the logistic regression model showed good discrimination, calibration and clinical practicability. Based on 6 independent factors, the dynamic nomogram can be used as a predictive tool for clinical application.

CONCLUSIONS

DHCA could be considered in aortic arch reconstruction if additional perfusion of lower body were not performed especially when renal ischemia is greater than 30 min. Machine Learning models should be developed for early recognition of AKI.

TRIAL REGISTRATION

ChiCTR, ChiCTR2200060552. Registered 4 june 2022.

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.

Long-term outcomes of acute kidney injury in children

PURPOSE OF REVIEW

Acute kidney injury (AKI) affects up to 35% of all critically ill children and is associated with substantial short-term morbidity and mortality. However, the link between paediatric AKI and long-term adverse outcomes remains incompletely understood. This review highlights the most recent clinical data supporting the role of paediatric AKI as a risk factor for long-term kidney and cardiovascular consequences. In addition, it stresses the need for long-term surveillance of paediatric AKI survivors.

RECENT FINDINGS

Recent large-scale studies have led to an increasing understanding that paediatric AKI is a significant risk factor for adverse outcomes such as hypertension, cardiovascular disease and chronic kidney disease (CKD) over time. These long-term sequelae of paediatric AKI are most often observed in vulnerable populations, such as critically ill children, paediatric cardiac surgery patients, children who suffer from severe infections and paediatric cancer patients.

SUMMARY

A growing body of research has shown that paediatric AKI is associated with long-term adverse outcomes such as CKD, hypertension and cardiovascular disease. Although therapeutic pathways tailored to individual paediatric AKI patients are yet to be validated, we provide a framework to guide monitoring and prevention in children at the highest risk for developing long-term kidney dysfunction.

Outcomes associated with unrecognized acute kidney injury in postoperative pediatric cardiac patients

BACKGROUND

The present retrospective study was carried out to determine the incidence of unrecognized cardiac surgery-associated acute kidney injury (CSA-AKI) due to infrequency of serum creatinine (SCr) measurements in pediatric cardiac patients and to assess the association between unrecognized CSA-AKI and clinical outcomes.

METHODS

This study was a single-center, retrospective study of pediatric patients who underwent cardiac surgery. Patients were diagnosed with CSA-AKI based on SCr measurements, and unrecognized CSA-AKI was defined under the assumptions that there had been only one or two SCr measurements within 48 h after surgery: CSA-AKI unrecognized by one SCr measurement (AKI-URone), CSA-AKI unrecognized by two SCr measurements (AKI-URtwo), and CSA-AKI recognized by one and two SCr measurements (AKI-R). The change of SCr from baseline to postoperative day 30 (delta SCr_30d) was assessed as a surrogate of kidney recovery.

RESULTS

In a total of 557 cases, 313 patients (56.2%) were diagnosed with CSA-AKI, 188 (33.8%) of whom had unrecognized CSA-AKI. Delta SCr_30d in the AKI-URtwo group and delta SCr_30d in the AKI-URone group was not significantly different from delta SCr_30d in the non-AKI group (p = 0.67 and p = 0.79, respectively). There were significant differences in the durations of mechanical ventilation, serum B-type natriuretic peptide levels, and lengths of stay in hospital between the non-AKI group and the AKI-URtwo group and between the non-AKI group and the AKI-URtwo group.

CONCLUSIONS

Unrecognized CSA-AKI due to infrequent SCr measurements is not rare and is associated with prolonged mechanical ventilation, high postoperative BNP level, and prolonged length of stay in hospital. A higher resolution version of the Graphical abstract is available as Supplementary information.

Machine Learning-Based Prediction of Acute Kidney Injury Following Pediatric Cardiac Surgery: Model Development and Validation Study

BACKGROUND

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a major complication following pediatric cardiac surgery, which is associated with increased morbidity and mortality. The early prediction of CSA-AKI before and immediately after surgery could significantly improve the implementation of preventive and therapeutic strategies during the perioperative periods. However, there is limited clinical information on how to identify pediatric patients at high risk of CSA-AKI.

OBJECTIVE

The study aims to develop and validate machine learning models to predict the development of CSA-AKI in the pediatric population.

METHODS

This retrospective cohort study enrolled patients aged 1 month to 18 years who underwent cardiac surgery with cardiopulmonary bypass at 3 medical centers of Central South University in China. CSA-AKI was defined according to the 2012 Kidney Disease: Improving Global Outcomes criteria. Feature selection was applied separately to 2 data sets: the preoperative data set and the combined preoperative and intraoperative data set. Multiple machine learning algorithms were tested, including K-nearest neighbor, naive Bayes, support vector machines, random forest, extreme gradient boosting (XGBoost), and neural networks. The best performing model was identified in cross-validation by using the area under the receiver operating characteristic curve (AUROC). Model interpretations were generated using the Shapley additive explanations (SHAP) method.

RESULTS

A total of 3278 patients from one of the centers were used for model derivation, while 585 patients from another 2 centers served as the external validation cohort. CSA-AKI occurred in 564 (17.2%) patients in the derivation cohort and 51 (8.7%) patients in the external validation cohort. Among the considered machine learning models, the XGBoost models achieved the best predictive performance in cross-validation. The AUROC of the XGBoost model using only the preoperative variables was 0.890 (95% CI 0.876-0.906) in the derivation cohort and 0.857 (95% CI 0.800-0.903) in the external validation cohort. When the intraoperative variables were included, the AUROC increased to 0.912 (95% CI 0.899-0.924) and 0.889 (95% CI 0.844-0.920) in the 2 cohorts, respectively. The SHAP method revealed that baseline serum creatinine level, perfusion time, body length, operation time, and intraoperative blood loss were the top 5 predictors of CSA-AKI.

CONCLUSIONS

The interpretable XGBoost models provide practical tools for the early prediction of CSA-AKI, which are valuable for risk stratification and perioperative management of pediatric patients undergoing cardiac surgery.

Long-Term Consequences of Acute Kidney Injury After Pediatric Cardiac Surgery: A Systematic Review

OBJECTIVE

The objective of this study was to evaluate the available data on long-term kidney dysfunction, hypertension, and mortality after cardiac surgery-associated acute kidney injury (AKI) in the pediatric population.

STUDY DESIGN

PubMed/MEDLINE, Embase, Scopus, and reference lists of relevant articles were searched for eligible studies published from inception through March 2022. Long-term outcomes after pediatric cardiac surgery complicated by AKI and those without were investigated.

RESULTS

We identified 14 studies published between 2013 and 2022 that included a total of 6701 patients (AKI: 1376 patients; no AKI: 5325 patients). These studies used different well-established classifications to define AKI. All the studies suggested that AKI after heart surgery is common in the pediatric patient population and reported a potential link between cardiac surgery-associated AKI and important clinical outcomes. However, only 4 out of 11 studies found a strong association between (absence of recovery from) cardiac surgery-associated AKI and risk of developing chronic kidney disease, and 3 out of 5 studies found a significant increase in mortality rates for pediatric patients who developed AKI after cardiac surgery. Only 1 out of 4 studies found an association between AKI and hypertension at 12 months postoperatively, but found no association at later follow-up times.

CONCLUSIONS

Although there is a trend, evidence on the long-term consequences of cardiac surgery-associated AKI in the pediatric population is mixed. Genetic syndromes, preexisting kidney disease, univentricular or cyanotic heart conditions, and/or high-complexity surgery may be more important for the development of kidney dysfunction by adolescence and early adulthood. Regardless, these children may benefit from a long-term kidney follow-up.

Association between nitric oxide synthase 3 genetic variant and acute kidney injury following pediatric cardiac surgery

BACKGROUND

Acute kidney injury (AKI) complicates 30% to 50% of cardiac surgeries in pediatric patients. Genetic variants that affect renal blood flow and inflammation have been associated with AKI after cardiac surgery in diverse populations of adults but have not been studied in children. The objective of this study is to test the hypothesis that common candidate genetic variants are associated with AKI following pediatric cardiac surgery.

METHODS

This is a retrospective cohort study at a single tertiary referral children's hospital of 2,062 individual patients undergoing surgery for congenital heart disease from September 2007 to July 2020. Pre-specified variants in candidate genes (AGTR1, APOE, IL6, NOS3, and TNF) were chosen. AKI was defined using Kidney Disease: Improving Global Outcomes serum creatinine criteria in the first week following surgery. Outcomes were analyzed by univariate and multivariable analysis of demographic, clinical, and genetic factors.

RESULTS

The study population had median age of 6 (interquartile range [IQR], 1-53) months, 759 (37%) of whom met criteria for postoperative AKI. In unadjusted analyses of each genetic variant, only NOS3 (rs2070744) was associated with lower risk for AKI (OR 0.75, 95% CI 0.62-0.9, P = .002). In logistic regression analyses adjusting for body surface area, previously identified genetic syndrome, Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery (STAT) score, cardiopulmonary bypass time, and nephrotoxic medication exposure, the NOS3 variant remained protective against AKI (OR 0.7, 95% CI 0.58-0.85, P<.001).

CONCLUSIONS

A common variant in NOS3 is associated with decreased incidence of AKI in children undergoing cardiac surgery. Further analysis of the genetic contributions to postoperative AKI may help identify individual risk in the pediatric population.

Reliability of glomerular filtration rate estimating formulas compared to iohexol plasma clearance in critically ill children

Accurate renal function assessment is crucial to guide intensive care decision-making and drug dosing. Estimates of glomerular filtration rate (eGFR) are routinely used in critically ill children; however, these formulas were never evaluated against measured GFR (mGFR) in this population. We aimed to assess the reliability of common eGFR formulas compared to iohexol plasma clearance (CL_iohexol) in a pediatric intensive care (PICU) population. Secondary outcomes were the prevalence of acute kidney injury (AKI) (by pRIFLE criteria) and augmented renal clearance (ARC) (defined as standard GFR for age + 2 standard deviations (SD)) within 48 h after admission based on mGFR and eGFR by the revised Schwartz formula and the difference between these two methods to diagnose AKI and ARC. In children, between 0 and 15 years of age, without chronic renal disease, GFR was measured by CL_iohexol and estimated using 26 formulas based on creatinine (Scr), cystatine C (CysC), and betatrace protein (BTP), early after PICU admission. eGFR and mGFR results were compared for the entire study population and in subgroups according to age, using Bland-Altman analysis with calculation of bias, precision, and accuracy expressed as percentage of eGFR results within 30% (P30) and 10% (P10) of mGFR. CL_iohexol was measured in 98 patients. Mean CL_iohexol (± SD) was 115 ± 54 ml/min/1.73m². Most eGFR formulas showed overestimation of mGFR with large bias and poor precision reflected by wide limits of agreement (LoA). Bias was larger with CysC- and BTP-based formulas compared to Scr-based formulas. In the entire study population, none of the eGFR formulas showed the minimal desired P30 > 75%. The widely used revised Schwartz formula overestimated mGFR with a high percentage bias of - 18 ± 51% (95% confidence interval (CI) - 29; - 9), poor precision with 95% LoA from - 120 to 84% and insufficient accuracy reflected by P30 of only 51% (95% CI 41; 61), and P10 of 21% (95% CI 13; 66) in the overall population. Although performance of Scr-based formulas was worst in children below 1 month of age, exclusion of neonates and younger children did not result in improved agreement and accuracy. Based on mGFR, prevalence of AKI and ARC within 48 h was 17% and 45% of patients, respectively. There was poor agreement between revised Schwartz formula and mGFR to diagnose AKI (kappa value of 0.342, p < 0.001; sensitivity of 30%, 95% CI 5; 20%) and ARC (kappa value of 0.342, p < 0.001; sensitivity of 70%, 95% CI 33; 58).

CONCLUSION

In this proof-of-concept study, eGFR formulas were found to be largely inaccurate in the PICU population. Clinicians should therefore use these formulas with caution to guide drug dosing and therapeutic interventions in critically ill children. More research in subgroup populations is warranted to conclude on generalizability of these study findings.

CLINICALTRIALS

gov NCT05179564, registered retrospectively on January 5, 2022.

WHAT IS KNOWN

• Both acute kidney injury and augmented renal clearance may be present in PICU patients and warrant adaptation of therapy, including drug dosing. • Biomarker-based eGFR formulas are widely used for GFR assessment in critically ill children, although endogenous filtration biomarkers have important limitations in PICU patients and eGFR formulas have never been validated against measured GFR in this population.

WHAT IS NEW

• eGFR formulas were found to be largely inaccurate in the PICU population when compared to measured GFR by iohexol clearance. Clinicians should therefore use these formulas with caution to guide drug dosing and therapeutic interventions in critically ill children. • Iohexol plasma clearance could be considered an alternative for accurate GFR assessment in PICU patients.

Kidney disease and congenital heart disease: Partnership for life

The literature on the relationship between kidney and cardiovascular diseases is continuously expanding. Scientists have elucidated many of the neurohormonal and hemodynamic pathways involved in cardiorenal disease. However, little is known about kidney disease in patients with congenital heart disease. Given advances in the medical and surgical care of this highly complex patient population, survival rates have dramatically improved leading to a higher percentage of adults living with congenital heart disease. Accordingly, a noticeable increase in the prevalence of kidney disease is appreciated in these patients. Some of the main risk factors for developing chronic kidney disease in the adult congenital heart disease population include chronic hypoxia, neurohormonal derangements, intraglomerular hemodynamic changes, prior cardiac surgeries from minimally invasive to open heart surgeries with ischemia, and nephrotoxins. Unfortunately, data regarding the prevalence, pathophysiology, and prognosis of chronic kidney disease in the adult congenital heart disease population remain scarce. This has led to a lack of clear recommendations for evaluating and managing kidney disease in these patients. In this review, we discuss contemporary data on kidney disease in adults with congenital heart disease in addition to some of the gaps in knowledge we face. The article highlights the delicate interaction between disease of the heart and kidneys in these patients, and offers the practitioner tools to more effectively manage this vulnerable population.

Novel Biomarkers of Kidney Disease in Advanced Heart Failure: Beyond GFR and Proteinuria

PURPOSE

Kidney disease is a common finding in patients with heart failure and can significantly impact treatment decisions and outcomes. Abnormal kidney function is currently determined in clinical practice using filtration markers in the blood to estimate glomerular filtration rate, but the manifestations of kidney disease in the setting of heart failure are much more complex than this. In this manuscript, we review novel biomarkers that may provide a more well-rounded assessment of kidney disease in patients with heart failure.

RECENT FINDINGS

Galectin-3, ST2, FGF-23, suPAR, miRNA, GDF-15, and NAG may be prognostic of kidney disease progression. L-FABP and suPAR may help predict acute kidney injury (AKI). ST2 and NAG may be helpful in diuretic resistance. Several biomarkers may be useful in determining prognosis of long-term kidney disease progression, prediction of AKI, and development of diuretic resistance. Further research into the mechanisms of kidney disease in heart failure utilizing many of these biomarkers may lead to the identification of therapeutic targets.

Persistent Markers of Kidney Injury in Children Who Developed Acute Kidney Injury After Pediatric Cardiac Surgery: A Prospective Cohort Study

Background

Acute kidney injury (AKI) after pediatric cardiac surgery is common. Longer‐term outcomes and the incidence of chronic kidney disease after AKI are not well‐known.

Methods and Results

All eligible children (aged <16 years) who had developed AKI following cardiac surgery at our tertiary referral hospital were prospectively invited for a formal kidney assessment ≈5 years after AKI, including measurements of estimated glomerular filtration rate, proteinuria, α₁‐microglobulin, blood pressure, and kidney ultrasound. Longer‐term follow‐up data on kidney function were collected at the latest available visit. Among 571 patients who underwent surgery, AKI occurred in 113 (19.7%) over a 4‐year period. Fifteen of these (13.3%) died at a median of 31 days (interquartile range [IQR], 9–57) after surgery. A total of 66 patients participated in the kidney assessment at a median of 4.8 years (IQR, 3.9–5.7) after the index AKI episode. Thirty‐nine patients (59.1%) had at least 1 marker of kidney injury, including estimated glomerular filtration rate <90 mL/min per 1.73 m² in 9 (13.6%), proteinuria in 27 (40.9%), α₁‐microglobinuria in 5 (7.6%), hypertension in 13 (19.7%), and abnormalities on kidney ultrasound in 9 (13.6%). Stages 1 to 5 chronic kidney disease were present in 18 (27.3%) patients. Patients with CKD were more likely to have an associated syndrome (55.6% versus 20.8%, P=0.015). At 13.1 years (IQR, 11.2–14.0) follow‐up, estimated glomerular filtration rate <90 mL/min per 1.73 m² was present in 18 of 49 patients (36.7%), suggesting an average estimated glomerular filtration rate decline rate of −1.81 mL/min per 1.73 m² per year.

Conclusions

Children who developed AKI after pediatric cardiac surgery showed persistent markers of kidney injury. As chronic kidney disease is a risk factor for cardiovascular comorbidity, long‐term kidney follow‐up in this population is warranted.

Risk factors for acute kidney injury after pediatric cardiac surgery: a meta-analysis

BACKGROUND

Cardiac surgery-associated acute kidney injury (AKI) is associated with increased morbidity and mortality in both adults and children.

OBJECTIVES

This study aimed to identify clinical risk factors for AKI following cardiac surgery in the pediatric population.

DATA SOURCES

PubMed/MEDLINE, Embase, Scopus, and reference lists of relevant articles were searched for studies published by August 2020.

STUDY ELIGIBILITY CRITERIA

Studies were included if (1) the population consisted of pediatric patients (< 18 years old), (2) patients underwent cardiac surgery, (3) risk factors were compared between patients who developed AKI and those who did not, and (4) studies were prospective or retrospective observational studies or randomized controlled trials.

PARTICIPANTS AND INTERVENTIONS

Children undergoing pediatric cardiac surgery.

STUDY APPRAISAL AND SYNTHESIS METHODS

Random-effects meta-analysis was performed, comparing potential risk factors between pediatric patients who developed CS-AKI and those who did not.

RESULTS

Sixty-one publications including a total of 19,680 participants (AKI: 7257 participants; no AKI: 12,423 participants) were included from studies published between 2008 and 2020. The pooled estimated incidence of AKI was 34.3% (95% confidence interval 30.0-38.8%, I² = 96.8%). Binary risk factors that were significantly and consistently associated with AKI were the presence of pulmonary hypertension, cyanotic heart disease, univentricular heart, risk adjustment for congenital heart surgery 1 (RACHS-1) score ≥ 3, vasopressor use, cardiopulmonary bypass use, reoperation, and sepsis. Significant continuous risk factors included younger age, lower body weight, lower preoperative creatinine, higher preoperative estimated glomerular filtration rate (eGFR), higher RACHS-1 score, longer surgery time, longer cardiopulmonary bypass time, longer aortic cross-clamp time, and higher red blood cell transfusion volume.

LIMITATIONS

Results are limited by heterogeneity and potential residual confounding.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

Our meta-analysis identified clinical risk factors that are associated with AKI in children undergoing cardiac surgery. This might help clinicians anticipate and manage more carefully this population and implement standardized preventive strategies.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42021262699. A higher resolution version of the Graphical abstract is available as Supplementary information.

Strategies to Prevent Acute Kidney Injury after Pediatric Cardiac Surgery: A Network Meta-Analysis

BACKGROUND AND OBJECTIVES

AKI is a common complication after pediatric cardiac surgery and has been associated with higher morbidity and mortality. We aimed to compare the efficacy of available pharmacologic and nonpharmacologic strategies to prevent AKI after pediatric cardiac surgery.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

PubMed/MEDLINE, Embase, Cochrane Controlled Trials Register, and reference lists of relevant articles were searched for randomized controlled trials from inception until August 2020. Random effects traditional pairwise, Bayesian network meta-analyses, and trial sequential analyses were performed.

RESULTS

Twenty randomized controlled trials including 2339 patients and 11 preventive strategies met the eligibility criteria. No overall significant differences were observed compared with control for corticosteroids, fenoldopam, hydroxyethyl starch, or remote ischemic preconditioning in traditional pairwise meta-analysis. In contrast, trial sequential analysis suggested a 80% relative risk reduction with dexmedetomidine and evidence of <57% relative risk reduction with remote ischemic preconditioning. Nonetheless, the network meta-analysis was unable to demonstrate any significant differences among the examined treatments, including also acetaminophen, aminophylline, levosimendan, milrinone, and normothermic cardiopulmonary bypass. Surface under the cumulative ranking curve probabilities showed that milrinone (76%) was most likely to result in the lowest risk of AKI, followed by dexmedetomidine (70%), levosimendan (70%), aminophylline (59%), normothermic cardiopulmonary bypass (57%), and remote ischemic preconditioning (55%), although all showing important overlap.

CONCLUSIONS

Current evidence from randomized controlled trials does not support the efficacy of most strategies to prevent AKI in the pediatric population, apart from limited evidence for dexmedetomidine and remote ischemic preconditioning.