Cost-effectiveness analysis of acute kidney injury biomarkers in pediatric cardiac surgery.

INTRODUCTION: Acute kidney injury (AKI) is significant problem in children with congenital heart disease (CHD) who undergo cardiac surgery. The economic impact of a biomarker-based diagnostic strategy for AKI in pediatric populations undergoing CHD surgery is unknown. The aim of this study was to perform the cost effectiveness analysis of using serum cystatin C (sCysC), urine neutrophil gelatinase-associated lipocalin (uNGAL) and urine liver fatty acid-binding protein (uL-FABP) for the diagnosis of AKI in children after cardiac surgery compared with current diagnostic method (monitoring of serum creatinine (sCr) level). MATERIALS AND METHODS: We developed a decision analytical model to estimate incremental cost-effectiveness of different biomarker-based diagnostic strategies compared to current diagnostic strategy. The Markov model was created to compare the lifetime cost associated with using of sCysC, uNGAL, uL-FABP with monitoring of sCr level for the diagnosis of AKI. The utility measurement included in the analysis was quality-adjusted life years (QALY). The results of the analysis are presented as the incremental cost-effectiveness ratio (ICER). RESULTS: Analysed biomarker-based diagnostic strategies for AKI were cost-effective compared to current diagnostic method. However, uNGAL and sCys C strategies yielded higher costs and lower effectiveness compared to uL-FABP strategy. uL-FABP added 1.43 QALY compared to current diagnostic method at an additional cost of $8521.87 per patient. Therefore, ICER for uL-FABP compared to sCr was $5959.35/QALY. CONCLUSIONS: Our results suggest that the use of uL-FABP would represent cost effective strategy for early diagnosis of AKI in children after cardiac surgery.

Oxidative status parameters in children with urinary tract infection.

INTRODUCTION: Urinary tract infection (UTI) is one of the most common bacterial infectious diseases in children. The aim of this study was to determine the total prooxidant and antioxidant capacity of children with UTI, as well as changes of oxidative status parameters according to acute inflammation persistence and acute kidney injury (AKI) development. MATERIALS AND METHODS: The patients enrolled in the study comprised 50 Caucasian children (median age was 6 months) with UTI. Total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), inflammation marker C-reactive protein (CRP) and renal function parameters urea and creatinine were analyzed in patient's serums. RESULTS: According to duration of inflammation during UTI, TAS values were significantly higher (0.99 vs. 0.58 mmol/L, P = 0.017) and OSI values were significantly lower (0.032 vs. 0.041 AU, P = 0.037) in the subjects with longer duration of inflammation than in the subjects with shorter duration of inflammation. We did not find significant difference in basal values of oxidative status parameters according to AKI development. CONCLUSION: OSI values could detect the simultaneous change of TAS and TOS due to change in the oxidative-antioxidant balance during the recovery of children with UTI. TAS and OSI as markers of oxidative stress during UTI are sensitive to accompanying inflammatory condition. Further investigations are needed to evaluate whether TAS, TOS and OSI could be used to monitor disease severity in children with UTI.

Clinical application neutrophil gelatinase-associated lipocalin and kidney injury molecule-1 as indicators of inflammation persistence and acute kidney injury in children with urinary tract infection.

BACKGROUND: The aim of this study was to examine the novel renal biomarkers neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) to assist pediatricians in the assessment of longer duration of inflammation and acute kidney injury (AKI) development during urinary tract infection (UTI). METHODS: The patients enrolled in the study comprised 50 children (mean age was 6 months) with UTI. NGAL in serum and urine (sNGAL and uNGAL, resp.) and KIM-1 in urine were measured by enzyme-linked immunosorbent assays. RESULTS: uNGAL levels in subjects with longer duration of inflammation were higher (115.37 ng/mL) than uNGAL levels in subjects with shorter duration of inflammation (67.87 ng/mL, P = 0.022). Difference in sNGAL and KIM-1 levels was not significant (P = 0.155 and P = 0.198, resp.). Significant difference was seen in KIM-1 excretion among groups with and without AKI (P = 0.038). KIM-1 was not able to discriminate between subjects with and without AKI (area under the curves (AUC) = 0.620, P = 0.175). CONCLUSIONS: uNGAL cannot be used for screening of the duration of inflammation during UTI. Accuracy of KIM-1 in screening of AKI development in children with UTI is low. We suggest larger studies to check the negative predictive value of KIM-1 for the development of AKI.

Biomarkers of acute kidney injury in pediatric cardiac surgery.

OBJECTIVES: Acute kidney injury (AKI) is a significant problem in children undergoing cardiopulmonary bypass (CPB). The aims of this study were to assess the diagnostic validity of serum CysC (sCysC), serum neutrophil gelatinase lipocalin (sNGAL), urine neutrophil gelatinase lipocalin (uNGAL), urine kidney injury molecule (uKIM)-1, and urine liver fatty acid-binding protein (uL-FABP) to predict AKI presence and severity in children undergoing CPB. DESIGN AND METHODS: We performed a prospective single-center evaluation of sCysC, sNGAL, uNGAL, uKIM-1 and uL-FABP at 0, 2, 6, 24 and 48 h postoperatively in children undergoing CPB during cardiac surgery. AKI was defined as ≥25% decrease in the estimated creatinine clearance (eCCl) from pre-operative baseline at 48h after surgery. RESULTS: Of the 112 patients, 18 patients (16.1%) developed AKI; four of them needed acute dialysis treatment and three AKI patients died. In the AKI compared to the non-AKI group, sCysC at 2h, and uNGAL and uL-FABP at 2-48 h were significantly increased, as well as CPB, aortic cross clamp time and length of hospital stay. Biomarkers increased with worsening AKI severity. At 2h after CPB the best accuracy for diagnosis of AKI had uL-FABP and sCysC with area under the receiver operator curve (AUC) of 0.89 and 0.73, respectively. At 6 and 24h after CPB the best AUC was found for uL-FABP (0.75 and 0.87 respectively) and for uNGAL (0.70 and 0.93, respectively). CONCLUSIONS: sCysC, uNGAL and uL-FABP are reliable early predictors for AKI after CPB. By allowing earlier timing of injury and earlier intervention, they could improve AKI outcome.

Bladder control training in girls with lower urinary tract dysfunction.

PURPOSE: To evaluate the efficacy of standard and biofeedback bladder control training (BCT) on the resolution of dysfunctional elimination syndrome (primary outcome), and on the reduction of urinary tract infections (UTI) and the use of medications such as antibacterial prophylaxis and/or anticholinergic/alpha-blockers (secondary outcome) in girls older than aged least 5 years. MATERIALS AND METHODS: 72 girls, median age of 8 years (interquartile range, IQR 7-10) were subjected to standard BCT (cognitive, behavioural and constipation treatment) and 12 one-hour sessions of animated biofeedback using interactive computer games within 8 weeks. Fifty patients were reevaluated after median 11 (IQR, 6-17) months. Effectiveness of BCT was determined by reduction of dysfunctional voiding score (DVS), daytime urinary incontinence (DUI), constipation, UTI, nocturnal enuresis (NE), post void residual (PVR), and improvements in bladder capacity and uroflow/EMG patterns. RESULTS: BCT resulted in significant normalization of DUI, NE, constipation, bladder capacity, uroflow/EMG, while decrease of PVR didn't reach statistical significance. In addition, the incidence of UTI, antibacterial prophylaxis and medical urotherapy significantly decreased. There were no significant differences in DVS, DVI, NE, bladder capacity and voiding pattern at the end of the BCT and at the time of reevaluation. The success on BCT was supported by parenteral perception of the treatment response in 63.9% and full response in additional 15.3% of the patients. CONCLUSION: Combination of standard and biofeedback BCT improved dysfunctional elimination syndrome and decreased UTI with discontinuation of antibacterial prophylaxis and/or anticholinergic/alpha-blockers in the majority of the patients. Better training results are expected in patients with higher bladder wall thickness as well as in those with vesicoureteral reflux, while presence of nocturnal enuresis may be a negative predictor of the training effect.

L-FABP can be an early marker of acute kidney injury in children.

BACKGROUND: Acute kidney injury (AKI) is a common postoperative complication following cardiopulmonary bypass (CPB) surgery. New biomarkers to identify patients with early AKI (before increases in serum creatinine) are needed to facilitate appropriate treatment. This study aimed to test the role of urinary liver fatty-acid-binding protein (L-FABP) as an early biomarker for AKI in children undergoing CPB surgery. METHODS: This is a case-control study of children undergoing CPB. AKI was defined as 50 % increase in serum creatinine at 48 h after surgery. For each patient, five serum and urine samples were obtained corresponding to time 0 h (presurgery) and 2, 6, 24, and 48 h after surgery. RESULTS: Twenty-seven patients, median age 360 days, were enrolled. AKI developed in 11 patients (41 %); three needed renal replacement therapy (peritoneal dialysis); there were two deaths. There were significant differences between patients with and without AKI in L-FABP levels at 2, 6, and 48 h after surgery, length of hospital stay, and CPB time; there were no differences in gender, patient age, and body weight. L-FABP was normalized to urinary creatinine concentration at all time points, with area under the receiver operator curve (AUC ROC) 0.867 at 2 and 6 h postoperatively. Correlation coefficient between L-FABP and length of hospital stay after surgery was statistically significant (r = 0.722, p value = 0.000). CONCLUSIONS: Our results suggest that urinary L-FABP can be used to diagnose AKI earlier than rise in serum creatinine in children undergoing CPB.