Diagnosis and Treatment of Acute Kidney Injury in Pediatrics

Development of acute kidney injury following pediatric cardiac surgery

Acute kidney injury (AKI) in the pediatric population is a relatively common phenomenon. Specifically, AKI has been found in increasing numbers within the pediatric population following cardiac surgery, with up to 43% of pediatric patients developing AKI post-cardiac surgery. However, recent advances have allowed for the identification of risk factors. These can be divided into preoperative, intraoperative, and postoperative factors. Although the majority of pediatric patients developing AKI after cardiac surgery completely recover, this condition is associated with worse outcomes. These include fluid overload and increased mortality and result in longer hospital and intensive care unit stays. Detecting the presence of AKI has advanced; use of relatively novel biomarkers, including neutrophil gelatinase associated lipocalin, has shown promise in detecting more subtle changes in kidney function when compared to conventional methods. While a single, superior treatment has not been elucidated yet, novel functions of medications, including fenoldopam, theophylline and aminophylline, have been shown to have better outcomes for these patients. With the recent advances in identification of risk factors, outcomes, diagnosis, and management, the medical community can further explain the complexities of AKI in the pediatric population post-cardiac surgery.

Prediction of Acute Kidney Injury on Admission to Pediatric Intensive Care

OBJECTIVES

Up to 37% of children admitted to the PICU develop acute kidney injury as defined by Kidney Disease: Improving Global Outcomes criteria. We describe the prevalence of acute kidney injury in a mixed pediatric intensive care cohort using this criteria. As tools to stratify patients at risk of acute kidney injury on PICU admission are lacking, we explored the variables at admission and day 1 that might predict the development of acute kidney injury.

DESIGN

Single-center retrospective observational study.

SETTING

Thirty-six-bed surgical/medical tertiary PICU.

PATIENTS

Children from birth to less than or equal to 16 years old admitted between 2015 and 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Clinical data were extracted from the PICU clinical information system. Patients with baseline creatinine at admission greater than 20 micromol/L above the calculated normal creatinine level were classified as "high risk of acute kidney injury." Models were created to predict acute kidney injury at admission and on day 1. Out of the 7,505 children admitted during the study period, 738 patients (9.8%) were classified as high risk of acute kidney injury at admission and 690 (9.2%) developed acute kidney injury during PICU admission. Compared to Kidney Disease: Improving Global Outcomes criteria as the reference standard, high risk of acute kidney injury had a lower sensitivity and higher specificity compared with renal angina index greater than or equal to 8 on day 1. For the admission model, the adjusted odds ratio of developing acute kidney injury for high risk of acute kidney injury was 4.2 (95% CI, 3.3-5.2). The adjusted odds ratio in the noncardiac cohort for high risk of acute kidney injury was 7.3 (95% CI, 5.5-9.7). For the day 1 model, odds ratios for high risk of acute kidney injury and renal angina index greater than or equal to 8 were 3.3 (95% CI, 2.6-4.2) and 3.1 (95% CI, 2.4-3.8), respectively.

CONCLUSIONS

The relationship between high risk of acute kidney injury and acute kidney injury needs further evaluation. High risk of acute kidney injury performed better in the noncardiac cohort.

Acute Abdomen in Pediatric Patients With Lassa Fever: Prevalence and Response to Nonoperative Management

Few reports on the prevalence of acute abdomen (AAbd) in pediatric patients with Lassa fever (LF) are available, and no firm policy on its management exists. Here, we report on its prevalence in and the response to treatment among a cohort of children with confirmed LF. Six (10.3%) of 58 children with LF had AAbd, whereas 6 (2.8%) of 215 children with AAbd had LF. Nonoperative treatment was successful in 5 of the 6 children with both AAbd and LF. We conclude that AAbd is not uncommon in pediatric patients with LF, and it could be responsive to nonoperative treatment. Testing for LF in all children with febrile AAbd might be justified in areas in which LF is endemic.

Renal dysfunction is already evident within the first month of life in Australian Indigenous infants born preterm

Antecedents of the high rates of chronic kidney disease in Australian Indigenous peoples may originate early in life. Fourteen percent of Australian Indigenous infants are born preterm (under 37 weeks gestation) and, therefore, at risk. Here, our observational cohort study sought to determine the impact of preterm birth on renal function in Australian Indigenous and non-Indigenous infants. Renal function was assessed between 4-29 days postnatally in 60 Indigenous and 42 non-Indigenous infants born at 24-36 weeks gestation. Indigenous ethnicity was associated with impaired renal function, with significantly higher serum creatinine (geometric mean ratio (GMR) 1.15 [1.06, 1.25]), fractional excretion of sodium (GMR 1.21 [1.04, 1.39]), and urine albumin (GMR 1.57 [1.05, 2.34]), β-2 microglobulin (GMR 1.82 [1.11, 2.98]) and cystatin C (GMR 3.27 [1.54, 6.95]) when controlling for gestational/postnatal age, sex and birth weight Z-score. Renal injury, as indicated by high urine neutrophil gelatinase-associated lipocalin levels, was associated with maternal smoking and postnatal antibiotic exposure. Indigenous infants appeared to be most susceptible to the adverse impact of antibiotics. These findings show that preterm Australian Indigenous infants are highly vulnerable to renal dysfunction. Preterm birth may contribute to their increased risk of chronic kidney disease. Thus, we recommended that renal function should be closely monitored life-long in Indigenous children born preterm.

Acute kidney injury after pediatric cardiac surgery

Acute kidney injury (AKI) is a common complication of pediatric cardiac surgery and is associated with increased morbidity and mortality. Literature of AKI after pediatric cardiac surgery is comprehensively reviewed in terms of incidence, risk factors, biomarkers, treatment and prognosis. The novel RIFLE (pediatric RIFLE for pediatrics), Acute Kidney Injury Network (AKIN) and Kidney Disease Improving Global Outcomes (KDIGO) criteria have brought about unified diagnostic standards and comparable results for AKI after cardiac surgery. Numerous risk factors, either renal or extrarenal, can be responsible for the development of AKI after cardiac surgery, with low cardiac output syndrome being the most pronounced predictor. Early fluid overload is also crucial for the occurrence of AKI and prognosis in pediatric patients. Three sensitive biomarkers, neutrophil gelatinase-associated lipocalin, cystatin C (CysC) and liver fatty acid-binding protein, are regarded as the earliest (increase at 2-4 h), and another two, kidney injury molecule-1 and interleukin-18 represent the intermediate respondents (increase at 6-12 h after surgery). To ameliorate the cardiopulmonary bypass techniques, improve renal perfusion and eradicate the causative risk factors are imperative for the prevention of AKI in pediatric patients. The early and intermediate biomarkers are helpful for an early judgment of occurrence of postoperative AKI. Improved survival has been achieved by prevention, renal support and modifications of hemofiltration techniques. Further development is anticipated in small children.

[Association of hypoalbuminemia with acute kidney injury in children after cardiac surgery]

OBJECTIVE

To study whether hypoalbuminemia after pediatric cardiopulmonary bypass (CPB) for cardiac surgery is a risk factor for postoperative acute kidney injury (AKI).

METHODS

A retrospective analysis was performed on the clinical data of 1 110 children who underwent CPB surgery between 2012 and 2016. According to the minimum serum albumin within 48 hours postoperatively, these patients were divided into hypoalbuminemia group (≤35 g/L) and normal albumin group (>35 g/L). The two groups were compared in terms of perioperative data and the incidence of AKI. Furthermore, the incidence of AKI was compared again after propensity score matching for the unbalanced factors during the perioperative period. The perioperative risk factors for postoperative AKI were analyzed by logistic regression.

RESULTS

The overall incidence rate of postoperative AKI was 13.78% (153/1 110), and the mortality rate was 2.52% (28/1 110). The mortality rate of children with AKI was 13.1% (20/153). The patients with hypoalbuminemia after surgery (≤35 g/L) accounted for 44.50% (494/1 110). Before and after propensity score matching, the hypoalbuminemia group had a significantly higher incidence of AKI than the normal albumin group (P<0.05). The children with AKI had a significantly lower serum albumin level after surgery than those without AKI (P<0.05). The multivariate logistic regression analysis showed albumin ≤35 g/L was one of the independent risk factors for postoperative AKI.

CONCLUSIONS

Albumin ≤35 g/L within 48 hours postoperatively is an independent risk factor for postoperative AKI in children after CPB surgery.

[Clinical characteristics and prognostic analysis of children with congenital heart disease complicated by postoperative acute kidney injury]

OBJECTIVE

To analyze the perioperative clinical data of children with congenital heart disease complicated by acute kidney injury (AKI) after cardiopulmonary bypass (CPB) surgery, and to explore potential factors influencing the prognosis.

METHODS

A retrospective analysis was performed among 118 children with congenital heart disease who developed AKI within 48 hours after CPB surgery.

RESULTS

In the 118 patients, 18 died after 48 hours of surgery. Compared with the survivors, the dead children had significantly higher incidence of cyanotic disease and Risk Adjustment for Congenital Heart Surgery-1 (RACHS-1) scores before surgery; during surgery, the dead children had significantly longer CPB time and aortic cross-clamping time, a significantly higher proportion of patients receiving crystalloid solution for myocardial protection, and a significantly higher mean blood glucose level. Within 48 hours after surgery, the dead children had significantly higher positive inotropic drug scores, significantly higher creatinine values, a significantly higher incidence of stage 3 AKI, a significantly higher proportion of patients receiving renal replacement the, and significantly higher usage of blood products (P<0.05). The mortality rate of the patients increased with increased intraoperative blood glucose levels (P<0.05). Patients with intraoperative blood glucose levels >8.3 mmol/L had a significantly lower postoperative cumulative survival rate and a significantly shorter mean survival time than those with blood glucose levels ≤ 8.3 mmol/L (P<0.05).

CONCLUSIONS

Intraoperative blood glucose levels are associated with the prognosis in children with congenital heart disease complicated by AKI after CPB surgery. Maintaining good intraoperative blood glucose control can improve the prognosis of the children.