Factors associated with acute kidney injury or failure in children undergoing cardiopulmonary bypass: a case-controlled study

Acute kidney injury after arterial switch operation: incidence, risk factors, clinical impact - a retrospective single-center study

BACKGROUND

This retrospective study aimed to determine the incidence, risk factors, and outcomes of acute kidney injury (AKI) in neonates following the arterial switch operation (ASO) for transposition of great arteries (TGA).

METHODS

Retrospective review of medical data of children who underwent ASO in 2019-2020 in the Ukrainian Children's Cardiac Center.

RESULTS

76 consecutive neonatal patients were included, 48 developed AKI after ASO (51.7%), and 24 - had severe AKI (25.8%). Severe AKI development was associated with longer cross-clamp time: 82 (61-127) versus 73.5 (53-136) in the non-severe AKI group (p = 0.02). 76 min of cross-clamp time were defined as a threshold value for increased severe AKI risk, OR 4.4 (95% CI: 1.5 - 13, p = 0.01). Higher lactate levels during cardiopulmonary bypass (CPB) increased severe AKI development risk, OR 1.5 (95% CI: 1.0 - 2.0, p = 0.03). Children with severe AKI had prolonged mechanical ventilation, longer time to negative fluid balance, and higher postoperative day 3 (POD3) Inotropic Score (IS). Only one patient required peritoneal dialysis.

CONCLUSIONS

In our study, 51.7% of patients developed AKI after ASO, 25.8%-severe AKI. Prolonged cross-clamp time and higher lactate levels during cardiopulmonary bypass increased the risk for severe AKI development. The development of AKI was associated with prolonged mechanical ventilation, longer time to negative fluid balance, higher POD 3 Inotropic Score.

Drug-induced kidney injury in Chinese critically ill pediatric patients

Background: Drug-induced acute kidney injury (DIKI) is a common adverse drug reaction event but is less known in pediatric patients. The study explored the DIKI in Chinese pediatric patients using the Pediatric Intensive Care database (PIC). Method: We screened pediatric patients with acute kidney injury (AKI) using the KDIGO criteria from the PIC and then assessed the relationship between their drugs and DIKI using the Naranjo scale. For the fifteen frequently used DIKI-suspected drugs, we divided patients into drug-exposed and non-exposed groups, using the outcome of whether DIKI was presented or not. Propensity score matching (PSM) was used to control for the effects of four confounders, age, gender, length of hospital stay, and major diagnosis. Unconditional logistic regression was used to identify statistically significant differences between the two groups. Results: A total of 238 drugs were used 1,863 times by the 81 patients with DIKI during their hospital stay. After screening the Naranjo scale to identify the top 15 suspected DIKI drugs with a high frequency of use, we found that furosemide injection (p = 0.001), midazolam injection (p = 0.001), 20% albumin prepared from human plasma injection (p = 0.004), fentanyl citrate injection (p = 0.001), compound glycyrrhizin injection (p = 0.026), vancomycin hydrochloride for intravenous (p = 0.010), and milrinone lactate injection (p = 0.009) were associated with DIKI. Conclusion: In critically ill pediatric patients, DIKI is more likely to occur after using furosemide injection, midazolam injection, 20% albumin prepared from human plasma injection, fentanyl citrate injection, compound glycyrrhizin injection, vancomycin hydrochloride for intravenous, milrinone lactate injection.

Monitoring of intraoperative femoral oxygenation predicts acute kidney injury after pediatric cardiac surgery

Cardiopulmonary bypass-associated acute kidney injury (CPB-AKI) is a pediatric cardiac surgery postoperative complication that is associated with a longer duration of mechanical ventilation and length of hospital stay. Identifying an early predictor of CPB-AKI is critical. Near infrared spectroscopy (NIRS), which can provide real-time monitoring of regional tissue oxygen saturation (rSO₂) during CPB, may predict CPB-AKI in an early phase of surgical treatment. This study analyzed clinical data from 87 children who underwent an elective surgical repair of ventricular septal defect (VSD) from January 2013 to March 2019. NIRS sensors were placed on the patients' forehead, abdomen, and thighs. The pediatric modified risk, injury, failure, loss, and end-stage (p-RIFLE) score was determined for each patient postoperatively. The incidence of AKI based on the p-RIFLE classification was 11.5% at the end of surgery, 23.0% at 24 h after surgery, and 5.7% at 48 h after surgery. The AKI incidence rate was highest at 24 h after surgery. Multiple regression analysis revealed that femoral oxygenation (rSO₂) during CPB, CPB time, oxygen delivery index (DO₂i), and lactate at the end of CPB were independent risk factors for AKI. Receiver-operating characteristic curve analysis indicated that femoral oxygenation of 74% or less predicted AKI development within 24 h after surgery. In conclusion, rSO₂ measured at the thigh during CPB is highly predictive of CPB-AKI.

Postoperative physiological parameters associated with severe acute kidney injury after pediatric heart transplant

BACKGROUND

The primary objective was to evaluate associations between perioperative clinical variables and postoperative hemodynamic indices after HT with the development of severe AKI. The secondary objective was to evaluate associations between UOP or creatinine as AKI indicators and morbidity after HT.

METHODS

Retrospective study of all patients who underwent HT 1/2016-11/2019 at a quaternary pediatric institution. Severe AKI was defined as KDIGO stage 2 or higher.

RESULTS

Of 94 HT patients, 73 met inclusion criteria; 45% of patients developed severe AKI. In univariate analysis, non-Hispanic Black race, preoperative AKI, longer CPB duration, lower weight, and peak lactate within 12 h post-HT were associated with severe AKI. CVP ≤12 h post-HT had a quadratic relationship, rather than linear, with severe AKI. PPV >18% was significantly associated with severe AKI but equated to noncontiguous 10 min of high variation over a 12-h period, and thus was deemed not clinically significant. In multivariate analysis, Black race, longer CPB duration, and higher CVP remained associated with severe AKI (c: 0.84, 95% CI 0.73-0.92). Severe AKI per creatinine, but not UOP criteria, was associated with longer duration of ventilation (p = .012) and longer intensive care unit length of stay (p = .003).

CONCLUSIONS

In pediatric HT patients, non-Hispanic Black race, longer CPB time, and higher postoperative CVP ≤12 h post-HT were associated with severe AKI. AKI based on creatinine, not UOP, was associated with postoperative HT morbidity.

Evaluation of postoperative renal functions and its effect on body perfusion in patients with double aortic cannulation

BACKGROUND

The optimal visceral preservation method during aortic arch reconstruction is still controversial. It has been thought that double aortic cannulation is effective. Herein, it was aimed to evaluate this technique in providing distal perfusion.

METHODS

A total of 74 patients who underwent arch reconstruction between 2011 and 2019 were included. Patients were grouped according to ventricular physiology and cannulation strategies. Group 1 were univentricle patients, and all had double aortic cannulation. Group 2 were biventricular patients. Group 2A double aortic cannulation-done and Group 2B non-double aortic cannulation were included. Lactate, urea, creatinine values, renal functions, and need for peritoneal dialysis of patients were evaluated.

RESULTS

There were no complications observed due to descending aortic cannulation in any of the patients. A delayed sternal closure and the need for peritoneal dialysis were more common in the Group 1 (p < 0.01). The preoperative and postoperative 1st- and 2nd-day lactate, urea, and creatinine values in the Group 1 were higher (p < 0.05) when compared with the Group 2A and 2B. The same values were higher in Group 2A than the Group 2B (p < 0.05).

CONCLUSION

The positive effect of double aortic cannulation on renal dysfunction could not be demonstrated. This may be associated with a <1 month of age, low weight, complex surgical procedure, and high preoperative lactate, urea, and creatinine values in patients with double aortic cannulation.

Filtering Down to Risks and Solutions: Risk Factors and Stratification After Pediatric Cardiac Surgery

Acute kidney injury after cardiac surgery (CS-AKI) is common in neonatal and pediatric populations and is a risk factor for poor outcomes, such as mortality and increased hospital resource utilization. This review presents a summary of CS-AKI risk factors, integration of biomarkers, and the need to improve risk stratification for targeting future clinical trials. To date, studies examining CS-AKI risk factors cannot be generalized easily owing to variability in patient age, surgical complexity or population, AKI definition, and center-specific practices. However, certain risk associations, such as younger age at surgery, history of prematurity, cardiopulmonary bypass time, and surgical complexity, have been identified across multiple, but not all, studies. CS-AKI appears to have different severity and duration phenotypes, and serum creatinine is limited in its ability to identify CS-AKI early and predict CS-AKI course. Treatment strategies are largely supportive, and efforts are ongoing to use biomarkers and clinical features to risk-stratify patients, which in turn may facilitate differential CS-AKI phenotyping and management with supportive care bundles, clinical decision support techniques, and modulation of modifiable risk factors.

Ameliorating Effect of Pentadecapeptide Derived from Cyclina sinensis on Cyclophosphamide-Induced Nephrotoxicity

Cyclophosphamide (CTX) is a widely used anticancer drug with severe nephrotoxicity. The pentadecapeptide (RVAPEEHPVEGRYLV) from Cyclina sinensis (SCSP) has been shown to affect immunity and to protect the liver. Hence, the purpose of this study was to investigate the ameliorating effect of SCSP on CTX-induced nephrotoxicity in mice. We injected male ICR mice with CTX (80 mg/kg·day) and measured the nephrotoxicity indices, levels of antioxidant enzymes, malondialdehyde (MDA), inflammatory factors, as well as the major proteins of the NF-κB and apoptotic pathways. Cyclophosphamide induced kidney injury; the levels of kidney-injury indicators and cytokines recovered remarkably in mice after receiving SCSP. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) increased, while there was a significant decrease in MDA levels. The kidney tissue damage induced by CTX was also repaired to a certain extent. In addition, SCSP significantly inhibited inflammatory factors and apoptosis by regulating the NF-κB and apoptotic pathways. Our study shows that SCSP has the potential to ameliorate CTX-induced nephrotoxicity and may be used as a therapeutic adjuvant to ameliorate CTX-induced nephrotoxicity.

Acute Kidney Injury after Congenital Heart Disease Surgery: A Single-Center Experience in a Low- to Middle-Income Country

Background Acute kidney injury (AKI) is a commonly recognized clinical problem after congenital heart disease (CHD) surgery. Increased perioperative morbidity, development of chronic kidney disease, and increased mortality are the major concerns. We investigated frequency, risk factors, and outcomes of AKI after CHD surgery at our hospital. Methods This study was a retrospective analytic review conducted from January 2013 to October 2016 on patients aged between 1 month and 45 years who underwent cardiopulmonary bypass (CPB) for CHD surgery. The modified Kidney Disease Improving Global Outcomes criteria based on serum creatinine value was adopted to diagnose AKI. We assessed AKI frequency and its staging, and outcomes as AKI resolution, length of stay, and mortality. Stages II and III (plasma creatinine level two or more times the baseline) were labeled as severe AKI. Univariate and multivariate logistic regression analyses were conducted, and results were reported as mean with standard deviation and as frequencies with percentage. Odds ratios (ORs) with 95% confidence intervals (CIs) were reported for factors associated with the development of AKI. Results Of the 840 patients who underwent CHD surgery, 237 (28%) developed AKI. AKI stages II1 and III were seen in 101 (42%) and 103 (43%) patients, respectively. Prolonged CPB time > 120 minutes (adjusted OR [AOR]: 1.87; 95% CI: 1.22-2.88; p = 0.004) and hemoglobin > 16 gm/dL (AOR: 1.80; 95% CI: 1.16-2.78; p = 0.008) were associated with the development of AKI on multivariate analysis. AKI resolved spontaneously in 222 (94%) patients, and 10 (4%) patients who developed AKI died. Conclusions Most patients with AKI showed spontaneous resolution. Prolonged CPB time and increased hemoglobin were found to be significant risk factors. Our study found spontaneous resolution of AKI in most cases. However, preplanning and careful monitoring in patients with expected prolonged CPB time and increased baseline hemoglobin can prevent and identify AKI at an early stage.

The Inadequate Oxygen Delivery Index and Low Cardiac Output Syndrome Score As Predictors of Adverse Events Associated With Low Cardiac Output Syndrome Early After Cardiac Bypass

OBJECTIVES

To evaluate the effectiveness of two scoring systems, the inadequate oxygen delivery index, a risk analytics algorithm (Etiometry, Boston, MA) and the Low Cardiac Output Syndrome Score, in predicting adverse events recognized as indicative of low cardiac output syndrome within 72 hours of surgery.

DESIGN

A retrospective observational pair-matched study.

SETTING

Tertiary pediatric cardiac ICU.

PATIENTS

Children undergoing cardiac bypass for congenital heart defects. Cases experienced an adverse event linked to low cardiac output syndrome in the 72 hours following surgery (extracorporeal membrane oxygenation, renal replacement therapy, cardiopulmonary resuscitation, and necrotizing enterocolitis) and were matched with a control patient on criteria of procedure, diagnosis, and age who experienced no such event.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of a total 536 bypass operations in the study period, 38 patients experienced one of the defined events. Twenty-eight cases were included in the study after removing patients who suffered an event after 72 hours or who had insufficient data. Clinical and laboratory data were collected to derive scores for the first 12 hours after surgery. The inadequate oxygen delivery index was calculated by Etiometry using vital signs and laboratory data. A modified Low Cardiac Output Syndrome Score was calculated from clinical and therapeutic markers. The mean inadequate oxygen delivery and modified Low Cardiac Output Syndrome Score were compared within each matched pair using the Wilcoxon signed-rank test. Inadequate oxygen delivery correctly differentiated adverse events in 13 of 28 matched pairs, with no evidence of inadequate oxygen delivery being higher in cases (p = 0.71). Modified Low Cardiac Output Syndrome Score correctly differentiated adverse events in 23 of 28 matched pairs, with strong evidence of a raised score in low cardiac output syndrome cases (p < 0.01).

CONCLUSIONS

Although inadequate oxygen delivery is an Food and Drug Administration approved indicator of risk for low mixed venous oxygen saturation, early postoperative average values were not linked with medium-term adverse events. The indicators included in the modified Low Cardiac Output Syndrome Score had a much stronger association with the specified adverse events.

Acute Kidney Injury among Hospitalized Children in China

BACKGROUND AND OBJECTIVES

High-quality epidemiologic data on AKI in children are particularly lacking in developing countries. This study aimed to assess the epidemiology and clinical correlates of AKI among hospitalized children in China.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed a multicenter study, in a cohort of hospitalized children aged 1 month to 18 years, from 25 general and children's hospitals in China during 2013-2015. We obtained patient-level data from the electronic hospitalization information system and laboratory databases of all children who had at least two serum creatinine tests within any 7-day window during their first 30 days of hospitalization. We identified AKI events according to the creatinine criteria of Kidney Disease Improving Global Outcomes. The in-hospital outcomes of AKI, including mortality, kidney recovery, and length of stay, were assessed. We estimated the corresponding hazard ratios using a Cox proportional hazard model, with adjustment for age, sex, comorbidities, and clinical procedures.

RESULTS

A total of 19,908 (20%) patients with AKI were identified among 101,836 pediatric inpatients, of which 7220 (7%) were community acquired and 12,688 (13%) were hospital acquired. Up to 96% of these AKI events were not diagnosed on the discharge records. The cumulative incidence of AKI in infants (28%) was twice that in adolescents (12%). The profiles of risk factors differed between community-acquired and hospital-acquired AKI and varied with age. Diarrhea and sepsis were the top risk factors for community-acquired AKI, each contributing 6% of the risk. Congenital heart disease/cardiac surgery was the major risk factor for hospital-acquired AKI, contributing to 19% of cases. Exposure to nephrotoxic drugs, mostly nonsteroidal anti-inflammatory drugs and proton pump inhibitors, was common in hospitalized children and was associated with a higher risk of AKI. Death occurred in 842 out of 19,908 patients (4%) with AKI versus 450 out of 81,478 children (0.5%) without AKI. The risk of in-hospital death was higher among children with severe AKI, shock, and respiratory failure. Pediatric AKI was associated with longer hospital stay and higher daily cost, even after adjustment for covariates.

CONCLUSIONS

Pediatric AKI is common and is substantially underdiagnosed in China.

Acute Kidney Injury in Children with Kidney Transplantation

BACKGROUND AND OBJECTIVES

AKI is associated with progression of CKD. Little is known about AKI after kidney transplantation in pediatric recipients. We aim to describe the epidemiology, risk factors, consequences, and outcomes of AKI in this population.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed a retrospective longitudinal analysis of pediatric kidney transplant recipients followed at The Hospital for Sick Children (Toronto, Canada) from 2001 to 2012. AKI was defined as an increase in serum creatinine ≥1.5 times baseline, and a rise of serum creatinine ≥1.25 but <1.5 times baseline defined subacute AKI.

RESULTS

Of 179 children, 122 were eligible for analysis. At baseline (3 months post-transplant), median age of the children was 13 years old (interquartile range, 9-16 years old), and 53% had CKD stage 2. Congenital anomalies of the kidney and urinary tract accounted for 46% of children. Over the study period (12 years), the incidence of AKI was 37% (n=45 children), and 65% (79 children) experienced subacute AKI. Twenty-seven percent (33 children) did not develop AKI or subacute AKI. The main causes of AKI were infections other than urinary tract infections, rejection, and urinary tract infections. In a multivariable Poisson regression analysis, independent risk factors for AKI included younger age, girls, grafts from deceased donors, and lower baseline eGFR. AKI was significantly associated with lower long-term GFR and graft loss independent of rejection episodes. Moreover, subacute AKI was associated with progression of CKD.

CONCLUSIONS

AKI and subacute AKI were common after pediatric kidney transplantation, and they were associated with graft loss, lower eGFR, and more rapid progression of CKD.

Prevention of Acute Kidney Injury in Children Undergoing Cardiac Surgery: A Narrative Review

Children undergoing cardiac surgery are at risk of developing acute kidney injury (AKI). Preventing cardiac surgery-associated AKI (CS-AKI) is important as it is associated with increased early- and long-term mortality and morbidity. Targeting modifiable risk factors (eg, avoiding poor renal perfusion, nephrotoxic drugs, and fluid overload) reduces the risk of CS-AKI. There is currently no strong evidence for the routine use of pharmacological approaches (eg, aminophylline, dexmedetomidine, fenoldopam, and steroids) to prevent CS-AKI. There is robust evidence to support the role of early peritoneal dialysis as a nonpharmacologic approach to prevent CS-AKI.

Acute kidney injury following first-stage palliation in hypoplastic left heart syndrome: hybrid versus Norwood palliation

OBJECTIVE

The aim of this study was to evaluate the prevalence of acute kidney injury after first-stage surgical palliation in patients with a single ventricle and to explore associated risk factors and outcomes. Design and patients This single-centre retrospective study included neonates who underwent either Norwood or Hybrid procedure from 2008 to 2015 for a single ventricle. Postoperative acute kidney injury was defined using the paediatric risk, injury, failure, loss, end-stage renal disease (pRIFLE), criteria within 72 hours of the procedure. Main results Our cohort (n=48) underwent surgical palliation at a mean (SD) age of 12 (11) days. Postoperative acute kidney injury was diagnosed in 14 (29%) patients. The prevalence of acute kidney injury in the Hybrid group was 16% and 53% in the Norwood group. Infants who developed acute kidney injury underwent surgery at younger ages [6 (5-10) versus 10 (8-16) days, p=0.016], and had a higher peak lactate level in the initial 24 hours [5.9 (4.2-9.1) versus 3.4 (2.4-6.7), p=0.007]. Norwood procedure was significantly associated with acute kidney injury [odds ratio 11.7 (95% confidence interval 1.3-101.9), p=0.03]. ICU stay [38 (21-84) versus 16 (6-45) days, p=0.038] and time to extubation [204 (120-606) versus 72 (26-234) hours, p=0.014] were longer in those with acute kidney injury. The two patients who developed early postoperative renal failure as per pRIFLE died before discharge from associated comorbidities.

CONCLUSIONS

Acute kidney injury occurs in a third of the patients with single ventricle after surgical palliation but is mostly transient. Norwood, compared with Hybrid procedure, is a risk factor for postoperative acute kidney injury, which, in turn, is associated with longer ICU stay and time to extubation.

Identifying Risk for Acute Kidney Injury in Infants and Children Following Cardiac Arrest

OBJECTIVES

Our goal was to identify risk factors for acute kidney injury in children surviving cardiac arrest.

DESIGN

Retrospective analysis of a public access dataset.

SETTING

Fifteen children's hospitals associated with the Pediatric Emergency Care Applied Research Network.

PATIENTS

Two hundred ninety-six subjects between 1 day and 18 years old who experienced in-hospital or out-of-hospital cardiac arrest between July 1, 2003, and December 31, 2004.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Our primary outcome was development of acute kidney injury as defined by the Acute Kidney Injury Network criteria. An ordinal probit model was developed. We found six critical explanatory variables, including total number of epinephrine doses, postcardiac arrest blood pressure, arrest location, presence of a chronic lung condition, pH, and presence of an abnormal baseline creatinine. Total number of epinephrine doses received as well as rate of epinephrine dosing impacted acute kidney injury risk and severity of acute kidney injury.

CONCLUSIONS

This study is the first to identify risk factors for acute kidney injury in children after cardiac arrest. Our findings regarding the impact of epinephrine dosing are of particular interest and suggest potential for epinephrine toxicity with regard to acute kidney injury. The ability to identify and potentially modify risk factors for acute kidney injury after cardiac arrest may lead to improved morbidity and mortality in this population.

Acute Kidney Injury Following Cardiac Surgery in Neonates and Young Infants: Experience of a Single Center Using Novel Perioperative Strategies

OBJECTIVE

Acute kidney injury (AKI) following cardiac surgery is a serious complication with a reported incidence of 30% to 50%. This study sought to determine the prevalence and risk factors for AKI among neonates and young infants undergoing repair of cardiac defects at an institution using novel perioperative strategies.

METHODS

A retrospective analysis of 102 consecutive infants (<2 months) undergoing repair of cardiac defects on cardiopulmonary bypass formed the study group. Cardiac diagnoses were stratified according to the Society of Thoracic Surgeons Congenital Heart Surgery (STAT) mortality categories. The prevalence of AKI within 72 hours was defined according to the three-stage Acute Kidney Injury Network criteria. Novel bypass strategies to preserve renal function included maintenance of higher hematocrit and high flow rates on cardiopulmonary bypass despite systemic hypothermia, and avoidance of albumin and milrinone in the perioperative period.

RESULTS

Mean age was 24 ± 19 days. Eighteen patients were less than 7 days of age at the time of surgery. Patient distribution according to STAT categories was as follows: 1 (n = 21), 2 (n = 12), 3 (n = 22), 4 (n = 28), and 5 (n = 19). The incidence of stages 1, 2, and 3 AKI in the population was 8% (n = 9), 2% (n = 2), and 0% (n = 0), respectively. On multivariate analysis higher STAT category was the only significant risk factor for AKI.

CONCLUSION

Current incidence of AKI following cardiac surgery in young infants at our institution is low. Novel perioperative strategies may have contributed to the low observed incidence of AKI in our patient population. Increased complexity of heart disease was a risk factor for AKI.

Protection of resveratrol on acute kidney injury in septic rats

AIM

The aim of the study is to investigate protective effect of resveratrol (Res) on acute kidney injury (AKI) in sepsis.

METHODS

Rats in sham group received sham operation; in sham + Res received sham operation and Res (3 mg/kg); in cecal ligation and puncture (CLP) established as sepsis; in CLP + Res (3 mg/kg) with sepsis and Res (3 mg/kg); and in CLP + Res (10 mg/kg) with sepsis and Res (10 mg/kg). Survival rate, serum indexes, inflammatory factors, NF-κB-P65, and SIRT1 were detected. Lipopolysaccharide (LPS) mesangial cell was with Res and SIRT1 silencing.

RESULTS

(1) Res intervention improved survival rate of CLP rat. (2) Compared to sham, serum creatinine, blood urine nitrogen, serum cystatin C, neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, tumor necrosis factor-α, interleukin-1β, IL-6, and renal injury index increased in CLP group, while decreased in CLP + Res (3 mg/kg) and CLP + Res (10 mg/kg), significantly, as dose-dependent ( p < 0.05). (3) With Res, NF-κB-P65 and de-acetylated SIRT1 decreased, while SIRT1 and de-acetylated Nuclear factor kB-p65 9 NF-κB-P65) increased, significantly ( p < 0.05). (4) SIRT1 and de-acetylated NF-κB-P65 decreased in LPS cells, while SIRT1 increased after Res intervention, significantly ( p < 0.05). After silencing SIRT1, de-acetylated NF-κB-P65 increased, significantly ( p < 0.05).

CONCLUSIONS

Res increases the survival rate of septic rats by inhibiting inflammatory factors to ease AKI and promotes NF-κB-P65 de-acetylation by upregulating SIRT1.

Incidence of and risk factors for severe acute kidney injury in children with heart failure treated with renin-angiotensin system inhibitors

No large cohort study has yet determined the incidence of acute kidney injury (AKI) in children with heart failure treated with renin-angiotensin system (RAS) inhibitors. We thus retrospectively analyzed the incidence and risk factors for severe AKI (stages 2-3 according to the Kidney Disease Improving Global Outcomes (KDIGO) guidelines) at our institutions from 2008 to 2011. Among 312 children (162 boys; median age, 7.3 months), 59 cases of AKI occurred in 45 children. The incidence of AKI was 14.3 cases per 100 person-years overall (follow-up 413.6 person-years), or 27.3, 16.8, and 4.5 cases per 100 person-years in children aged <1, 1-3, and ≥4 years, respectively. Among them, 23 (39.0 %) children had metabolic acidosis and 14 (23.7 %) had hyperkalemia. Younger age, myocardial disease, cyanotic congenital heart disease, use of spironolactone, and cardiac surgery were independent risk factors for AKI. Furthermore, 37.3 % of children suffered dehydration during AKI.

CONCLUSION

AKI incidence is relatively high in children, particularly younger children, with heart failure treated using RAS inhibitors. Careful monitoring of renal function and serum electrolytes is essential. Proper management of fluid balance after infection and cardiac surgery may reduce the risk of AKI. Temporary discontinuation in RAS inhibitors should be considered during dehydration or surgery.

WHAT IS KNOWN

• Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are the two main classes of renin-angiotensin system (RAS) inhibitors used to treat hypertension, heart failure, and chronic kidney disease. Acute kidney injury (AKI) and hyperkalemia are potentially life-threatening complications associated with the use of ACEIs and ARBs. Some reports have suggested that dehydration and cardiac surgery are risk factors for AKI in children. However, no large-scale cohort studies have determined the incidence of AKI, its risk factors, and its outcomes in children with heart failure treated with ACEIs and/or ARBs. What is new: • In this retrospective cohort study, we determined the incidence, severity, and risk factors for severe AKI in children with heart failure treated with ACEIs and/or ARBs. The incidence of AKI in these children was relatively high (14.3 episodes per 100 person-years). In addition, younger age, myocardial disease, cyanotic congenital heart disease, concomitant use of spironolactone, and cardiac surgery were risk factors for AKI. Furthermore, 37.3 % of children had dehydration during AKI episodes. • Our results suggested that appropriate fluid balance after infection and cardiac surgery might reduce the risk of AKI and its complications. Temporary discontinuation or reductions in the levels of ACEIs and/or ARBs during dehydration or before surgery may also be warranted in these patients.

Acute kidney injury after heart transplant in young children: risk factors and outcomes

BACKGROUND

Critical illness following heart transplantation can include acute kidney injury (AKI). Study objectives were to define the epidemiology of, risk factors for, or impact on outcomes of AKI after pediatric heart transplant.

METHODS

Using data from a prospective study of 66 young children, we evaluated: (1) post-operative AKI rate (by pediatric modified RIFLE criteria); (2) pre, intra, and early post-operative AKI risk factors using stepwise logistic regression (3) effect of AKI on short-term outcomes (ventilation and length of pediatric intensive care unit (PICU) stay) using stepwise multiple regression.

RESULTS

AKI occurred in 73 % of children. Pre-transplant ventilation and higher baseline estimated creatinine clearance (eCCl) were independent risk factors for AKI. Pre-operative inotrope use was associated with reduced risk of AKI. Tacrolimus level emerged as important in multivariable risk prediction. Children with AKI had a longer duration of ventilation and length of pediatric intensive care unit (PICU) stay, with AKI being an independent predictor.

CONCLUSIONS

AKI was common after heart transplant and associated with more complicated early post-transplant course. Lower baseline eCCl was associated with lower incidence of AKI; this merits further investigation. The association of pre-operative inotropes with less AKI may reflect a pathophysiological mechanism or be a surrogate for clinical factors and management prior to transplant. Avoiding high tacrolimus levels may be a modifiable risk factor for AKI.

Acute Kidney Injury in Pediatric Acute Decompensated Heart Failure

OBJECTIVE

Acute kidney injury in adult patients with acute decompensated heart failure is associated with increased mortality. There is limited literature in pediatric patients with acute decompensated heart failure and acute kidney injury. We aim to study acute kidney injury in the pediatric acute decompensated heart failure population and its association with specific outcomes.

DESIGN

Retrospective, case-control study.

SETTING

Cardiac ICU in a children's tertiary care hospital.

PATIENTS

Index admissions of patients younger than 21 years with acute decompensated heart failure between January 2008 and December 2012.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Index admissions of patients younger than 21 years with acute decompensated heart failure between January 2008 and December 2012 were reviewed, and the presence or absence of acute kidney injury at admission was determined based on the Pediatric Risk, Injury, Failure, Loss, End-Stage criteria. Descriptive statistics and multivariate analyses were performed to determine the association between acute kidney injury and a composite outcome of cardiac transplantation and/or mortality. Fifty-seven patients, with median age 12 years (interquartile range, 1.1, 16), were included for study. The median left ventricular ejection fraction was 27% (interquartile range, 18, 48). Twenty-one patients (36%) underwent cardiac transplantation and five patients (8.7%) died. Of the 57 patients, 44 (77%) had evidence of acute kidney injury (41% Risk; 39% Injury; 20% Failure). Of the 44 patients with acute kidney injury, 25 (57%) met the composite outcome, compared with 1 (7%) without acute kidney injury. Multivariate analyses demonstrated that a left ventricular ejection fraction up to 25% was significantly associated with the presence of acute kidney injury (adjusted odds ratio, 12.3; 95% CI, 1.4-109; p = 0.03), and acute kidney injury was significantly associated with the composite outcome (adjusted odds ratio, 19.1; 95% CI, 2.3-160; p < 0.001).

CONCLUSIONS

Acute kidney injury is common during the initial presentation of pediatric patients with acute decompensated heart failure. A left ventricular ejection fraction up to 25% is associated with acute kidney injury. The presence of acute kidney injury in this population is significantly associated with cardiac transplantation and/or death.

Long-term mortality associated with acute kidney injury in children following congenital cardiac surgery

OBJECTIVE

Children undergoing congenital cardiac surgery (CCS) are at increased risk for acute kidney injury (AKI) due to a number of factors. Recent evidence suggests AKI may influence mortality beyond the immediate postoperative period and hospitalization. We sought to determine the association between renal failure and longer-term mortality in children following CCS.

METHODS

Our Study population included all patients that underwent cardiac surgery at our institution during a period of 3 years from 2004 through 2006. The primary definition of acute renal injury was based on pRIFLE using estimated creatinine clearance (pRIFLE eCCL).

RESULTS

Predictors of mortality. Age, single ventricle status, and renal failure as defined by pRIFLE stage F were associated with mortality. The hazard ratio for a patient with renal failure as defined by pRIFLE stage F was 3.82 (CI 1.89-7.75). Predictors of AKI as defined by pRIFLE. Duration of cardiopulmonary bypass (CPB) and age were the only variables associated with pRIFLE by univariate analysis. However, in the ordinal or survival model, age was the only variable associated with renal failure as defined by pRIFLE. As patient age increases from 0.30 to 3.5 years, the risks of having renal injury (pRIFLE stage I) or failure (pRIFLE stage F) decreases (OR 0.44, CI 0.21-0.94).

CONCLUSION

Mortality risk following CCS is increased in younger patients and those experiencing postoperative renal failure as defined by pRIFLE for a period of time that extends well beyond the immediate postoperative period and the time of hospitalization.

Preoperative prediction of acute kidney injury--from clinical scores to biomarkers

Early acute kidney injury (AKI) diagnosis in critically ill children has been an important recent research focus because of the known association of AKI with poor outcomes and the requirement of early intervention to mitigate negative effects of AKI. In children having surgery, the preoperative period offers a unique opportunity to predict postoperative acute kidney injury (AKI), well before AKI occurs. Pediatric AKI epidemiologic studies have begun to identify which preoperative factors may predict development of postoperative cardiac surgery. Using these clinical risk factors, it may be possible to derive preoperative clinical risk scores and improve upon our ability to risk-stratify children into AKI treatment trials, pre-emptively provide conservative renal injury prevention strategies, and ultimately improve patient outcomes. Developing risk scores requires rigorous methodology and validation before widespread use. There is little information currently on the use of preoperative biological or physiological biomarkers to predict postoperative AKI, representing an important area of future research. This review will provide an overview of methodology of preoperative risk score development, discuss pediatric-specific issues around deriving such risk scores, including the combination of preoperative clinical and biologic biomarkers for AKI prediction, and suggest future research avenues.

AKI in hospitalized children: epidemiology and clinical associations in a national cohort

BACKGROUND AND OBJECTIVES

Although AKI is common among hospitalized children, comprehensive epidemiologic data are lacking. This study characterizes pediatric AKI across the United States and identifies AKI risk factors using high-content/high-throughput analytic techniques.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

For the cross-sectional analysis of the 2009 Kids Inpatient Database, AKI events were identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes. Demographics, incident rates, and outcome data were analyzed and reported for the entire AKI cohort as well as AKI subsets. Statistical learning methods were applied to the highly imbalanced dataset to derive AKI-related risk factors.

RESULTS

Of 2,644,263 children, 10,322 children developed AKI (3.9/1000 admissions). Although 19% of the AKI cohort was ≤ 1 month old, the highest incidence was seen in children 15-18 years old (6.6/1000 admissions); 49% of the AKI cohort was white, but AKI incidence was higher among African Americans (4.5 versus 3.8/1000 admissions). In-hospital mortality among patients with AKI was 15.3% but higher among children ≤ 1 month old (31.3% versus 10.1%, P<0.001) and children requiring critical care (32.8% versus 9.4%, P<0.001) or dialysis (27.1% versus 14.2%, P<0.001). Shock (odds ratio, 2.15; 95% confidence interval, 1.95 to 2.36), septicemia (odds ratio, 1.37; 95% confidence interval, 1.32 to 1.43), intubation/mechanical ventilation (odds ratio, 1.2; 95% confidence interval, 1.16 to 1.25), circulatory disease (odds ratio, 1.47; 95% confidence interval, 1.32 to 1.65), cardiac congenital anomalies (odds ratio, 1.2; 95% confidence interval, 1.13 to 1.23), and extracorporeal support (odds ratio, 2.58; 95% confidence interval, 2.04 to 3.26) were associated with AKI.

CONCLUSIONS

AKI occurs in 3.9/1000 at-risk US pediatric hospitalizations. Mortality is highest among neonates and children requiring critical care or dialysis. Identified risk factors suggest that AKI occurs in association with systemic/multiorgan disease more commonly than primary renal disease.

Acute kidney injury based on corrected serum creatinine is associated with increased morbidity in children following the arterial switch operation

BACKGROUND AND OBJECTIVES

Evaluate risk factors for and impact of acute kidney injury on children following the arterial switch operation.

DESIGN

Single-center retrospective chart review.

SETTING

A tertiary children's hospital.

PATIENTS

A total of 92 patients receiving the arterial switch operation from 1997 to 2008 at severe acute kidney injury was defined as a 100% serum creatinine rise over baseline.

RESULTS

Of 92 patients, 18 (20%) developed severe acute kidney injury. Neither patient age or weight nor cardiopulmonary bypass time correlated with the development of acute kidney injury. Acute kidney injury was associated with the following: higher postoperative day 1 (POD1) fluid balance, higher inotrope scores (POD1 and POD2), and longer: postoperative ICU length of stay (p = 0.005), overall ICU length of stay (p = 0.05), and postoperative hospital length of stay (p = 0.006). The time to peak creatinine for acute kidney injury patients was between POD1 and POD2. Correction of serum creatinine for fluid balance increased the population defined as severe acute kidney injury and strengthened the association of acute kidney injury with postoperative morbidity.

CONCLUSIONS

Acute kidney injury following the arterial switch operation is associated with increased morbidity. In this single center, single population, and homogenous cohort of patients, the development of acute kidney injury was not correlated with age, size, or cardiopulmonary bypass time, but was still associated with prolonged duration of ventilation and hospitalization. Notably, the failure to correct serum creatinine for fluid balance underestimates the prevalence and impact of acute kidney injury.

Factors associated with survival in patients who undergo peritoneal dialysis catheter placement following cardiac surgery

PURPOSE

Pediatric post-cardiac surgery patients are at risk for acute kidney injury and intraabdominal hypertension. The present study assesses indications and outcomes of postoperative peritoneal dialysis catheter (PDC) placement in this population.

METHODS

We retrospectively reviewed single-institution patients who underwent PDC placement post-cardiac surgery between 1999 and 2011 (n=55). Baseline, clinical course, and outcome data were recorded pre- and post-PDC. We used multivariable logistic and Cox analyses to assess factors associated with mortality.

RESULTS

In-hospital mortality of the study cohort was 67.3% (n=37). Peritoneal dialysis was performed in 21 patients (38.2%). Five patients (9.1%) experienced adverse events related to PDC placement. Greater post-PDC decreases in abdominal girth (adjusted odds ratio [OR]=2.43; P=0.02) and BUN (OR=1.06; P=0.04) were associated with survival. Additionally, preoperative ventilator independence (hazard ratio [HR]=1.18; P<0.01) and lower creatinine (HR=8.32; P<0.01), as well as greater post-PDC decrease in inotrope score (HR=1.33; P<0.02) were associated with survival.

CONCLUSIONS

In-hospital mortality of the study cohort was 67%. Less severe pre-PDC renal impairment, increased pre-PDC abdominal girth, and greater post-PDC improvement of abdominal girth, renal function, and inotrope requirements were associated with survival. Prospective trials are needed to assess appropriate indications and timing of PDC placement, with consideration of more aggressive treatment for intraabdominal hypertension.

Peri-operative interventions, but not inflammatory mediators, increase risk of acute kidney injury after cardiac surgery: a prospective cohort study

PURPOSE

Cardiopulmonary bypass (CPB)-related inflammatory response might be one mechanism by which cardiac surgery associated acute kidney injury (CS-AKI) occurs. Interventions that may attenuate inflammation, including glucocorticoids or phosphodiesterase inhibitors, could therefore have a role in its prevention. We aimed to determine the role of inflammatory mediators in CS-AKI in children and the efficacy of commonly used peri-operative interventions to reduce CS-AKI risk.

METHODS

We prospectively studied 109 children undergoing heart surgery. Using regression modeling (adjusting for covariates), we (1) evaluated the association between inflammatory mediators [interleukin (IL)-6, IL-8, C-reactive protein, and tumor necrosis factor-α levels] and CS-AKI, and (2) evaluated risk/prevention factors for CS-AKI including glucocorticoid and milrinone administration. CS-AKI was defined based on pRIFLE methods.

RESULTS

CS-AKI occurred in 68% of children. No inflammatory mediator measured had an independent association with CS-AKI. Higher pre-operative glomerular filtration rate (GFR), sustained decrease in mean arterial pressure during CPB, post-operative single ventricle physiology, deep hypothermic circulatory arrest, and milrinone use at 24 h post-operatively were significant independent predictors of CS-AKI. Intra-operative steroid administration had no effect on the rate of CS-AKI.

CONCLUSIONS

Although inflammatory mediators are up-regulated following CPB, we found no association between levels of inflammatory cytokines and CS-AKI. CS-AKI has complex pathophysiology and the observation that milrinone was associated with increased AKI risk (and that higher GFR predicts more injury) suggests that mechanisms beyond inflammation play a significant role. Intra-operative administration of glucocorticoid does not appear to be an effective intervention for reducing the risk of CS-AKI.

Risk factors for and outcomes of acute kidney injury in neonates undergoing complex cardiac surgery

OBJECTIVE

To characterize the epidemiology of and identify risk factors for neonatal cardiac surgery-associated acute kidney injury (CS-AKI) and determine its impact on clinical outcomes.

STUDY DESIGN

Using secondary analysis of data from an ongoing multiprovincial prospective cohort study, we studied 264 neonates undergoing complex cardiac repair. CS-AKI was defined based on the Acute Kidney Injury Network (AKIN) definition. We used regression modeling and survival analysis (adjusting for covariates) to evaluate associations.

RESULTS

CS-AKI occurred in 64% of the neonates in our study cohort. Lower age, longer cardiopulmonary bypass time, hypothermic circulatory arrest, type of repair, lower preoperative serum creatinine (SCr) level, lower gestational age, and preoperative ventilation were independent risk factors for developing CS-AKI. Neonates with CS-AKI had longer times to extubation, intensive care discharge, and hospital discharge, after adjusting for covariates. Mortality was significantly increased in neonates with AKIN stage 2 or higher CS-AKI. The neonates with CS-AKI had a lower z-score for height at 2-year follow-up and were seen by more specialists.

CONCLUSION

Neonatal CS-AKI is common and independently predicts important clinical outcomes, including mortality. Many risk factors are similar to those in older children, but some are unique to neonates. The observation that lower baseline SCr predicts CS-AKI merits further study. The AKIN definition, based on preoperative SCr value, is a reasonable method for defining CS-AKI in neonates. Many previous studies of CS-AKI have excluded neonates; we suggest that future intervention studies on approaches to reducing CS-AKI incidence and improving outcomes should include neonates.

Acute kidney injury after surgery for congenital heart disease

BACKGROUND

The RIFLE criteria (risk, injury, failure, loss, and end-stage kidney disease) have been used to assess acute kidney injury (AKI) in various populations of critically ill children. There are limited reports of AKI using RIFLE criteria in large pediatric populations undergoing congenital heart disease surgery.

METHODS

Records of patients 18 years and younger who underwent surgery for congenital heart disease between January 2006 and November 2009 were reviewed. The RIFLE score was determined for each patient postoperatively. Multivariate logistic regression analyses were performed to determine risk factors for AKI and the association with clinical outcomes, with subanalyses of patients 1 month of age or younger.

RESULTS

Data for 458 patients (median age, 7.6 months) were collected and analyzed. Evidence of AKI was demonstrated in 234 patients (51%), the vast majority of whom recovered within 48 hours. Younger age, higher RACHS-1 (risk-adjusted classification for congenital heart surgery) category, and longer cardiopulmonary bypass time were associated with development of AKI. Acute kidney injury was associated with longer duration of ventilation and lengths of intensive care unit and hospital stay. Incidence of AKI in patients 1 month of age or younger was 60.9%, of which more than half required greater than 72 hours to recover. In patients 1 month of age or younger, use of cardiopulmonary bypass, lower preoperative serum creatinine, and higher preoperative blood urea nitrogen were associated with AKI, and AKI was the only factor associated with longer intensive care unit and hospital lengths of stay.

CONCLUSIONS

Incidence of AKI based on RIFLE criteria in patients undergoing congenital heart disease surgery is higher than previously reported. Risk factors include age 1 month or younger and use of cardiopulmonary bypass. Acute kidney injury is associated with longer lengths of stay.

High-dose fenoldopam reduces postoperative neutrophil gelatinase-associated lipocaline and cystatin C levels in pediatric cardiac surgery

INTRODUCTION

The aim of the study was to evaluate the effects of high-dose fenoldopam, a selective dopamine-1 receptor, on renal function and organ perfusion during cardiopulmonary bypass (CPB) in infants with congenital heart disease (CHD).

METHODS

A prospective single-center randomized double-blind controlled trial was conducted in a pediatric cardiac surgery department. We randomized infants younger than 1 year with CHD and biventricular anatomy (with exclusion of isolated ventricular and atrial septal defect) to receive blindly a continuous infusion of fenoldopam at 1 μg/kg/min or placebo during CPB. Perioperative urinary and plasma levels of neutrophil gelatinase-associated lipocaline (NGAL), cystatin C (CysC), and creatinine were measured to assess renal injury after CPB.

RESULTS

We enrolled 80 patients: 40 received fenoldopam (group F) during CPB, and 40 received placebo (group P). A significant increase of urinary NGAL and CysC levels from baseline to intensive care unit (ICU) admission followed by restoration of normal values after 12 hours was observed in both groups. However, urinary NGAL and CysC values were significantly reduced at the end of surgery and 12 hours after ICU admission (uNGAL only) in group F compared with group P (P = 0.025 and 0.039, respectively). Plasma NGAL and CysC tended to increase from baseline to ICU admission in both groups, but they were not significantly different between the two groups. No differences were observed on urinary and plasma creatinine levels and on urine output between the two groups. Acute kidney injury (AKI) incidence in the postoperative period, as indicated by pRIFLE classification (pediatric score indicating Risk, Injury, Failure, Loss of function, and End-stage kidney disease level of renal damage) was 50% in group F and 72% in group P (P = 0.08; odds ratio (OR), 0.38; 95% confidence interval (CI), 0.14 to 1.02). A significant reduction in diuretics (furosemide) and vasodilators (phentolamine) administration was observed in group F (P = 0.0085; OR, 0.22; 95% CI, 0.07 to 0.7).

CONCLUSIONS

The treatment with high-dose fenoldopam during CPB in pediatric patients undergoing cardiac surgery for CHD with biventricular anatomy significantly decreased urinary levels of NGAL and CysC and reduced the use of diuretics and vasodilators during CPB.

TRIAL REGISTRATION

Clinical Trial.Gov NCT00982527.

Antecedent acute kidney injury worsens subsequent endotoxin-induced lung inflammation in a two-hit mouse model

Acute kidney injury (AKI) contributes greatly to morbidity and mortality in critically ill adults and children. Patients with AKI who subsequently develop lung injury are known to suffer worse outcomes compared with patients with lung injury alone. Isolated experimental kidney ischemia alters distal lung water balance and capillary permeability, but the effects of such an aberration on subsequent lung injury are unknown. We present a clinically relevant two-hit murine model wherein a proximal AKI through bilateral renal ischemia (30 min) is followed by a subsequent acute lung injury (ALI) via intratracheal LPS endotoxin (50 μg at 24 h after surgery). Mice demonstrated AKI by elevation of serum creatinine and renal histopathological damage. Mice with ALI and preexisting AKI had increased lung neutrophilia in bronchoalveolar lavage fluid and by myeloperoxidase activity over Sham-ALI mice. Additionally, lung histopathological damage was greater in ALI mice with preexisting AKI than Sham-ALI mice. There was uniform elevation of monocyte chemoattractant protein-1 in kidney, serum, and lung tissue in animals with both AKI and ALI over those with either injury alone. The additive lung inflammation after ALI with antecedent AKI was abrogated in MCP-1-deficient mice. Taken together, our two-hit model demonstrates that kidney injury may prime the lung for a heightened inflammatory response to subsequent injury and MCP-1 may be involved in this model of kidney-lung cross talk. The model holds clinical relevance for patients at risk of lung injury after ischemic injury to the kidney.