The role of renal biomarkers to predict the need of surgery in congenital urinary tract obstruction in infants.

INTRODUCTION: The diagnosis of renal function impairment and deterioration in congenital urinary tract obstruction (UTO) continues to be extremely challenging. The use of new renal biomarkers in this setting may favor early renal injury detection, allowing for a reliable choice of optimal therapeutic options and the prevention or minimization of definitive renal damage. OBJECTIVE: The aim of the study was to investigate a selection of promising biomarkers of renal injury with the intention of evaluating and comparing their profile with clinically based decisions for surgical intervention of infants with congenital obstructive uropathies. STUDY DESIGN: The first-year profile of renal biomarkers, serum creatinine (sCr), serum and urine cystatin C (CyC), neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), transforming growth factor beta-1 (TGF-ß1), retinol-binding protein (RBP), and microalbuminuria (µALB), was analyzed in a cohort of 37 infants with congenital UTO, divided into three subgroups, 14 cases with grade III unilateral hydro(uretero)nephrosis, 13 cases with grade III bilateral hydro(uretero)nephrosis, and 10 cases with low urinary tract obstruction (LUTO), compared with 24 healthy infants matched by gestational age and birth weight. Serum and urine samples were stored at -70 °C and thereafter analyzed by quantitative enzymatic immunoassay. RESULTS: Compared with the control group (Figure), all renal biomarker values were significantly increased in patients (P ≤ 0.02). In the unilateral hydronephrosis and LUTO group, RBP (P ≤ 0.043), NGAL (P ≤ 0.043), KIM-1 (P ≤ 0.03), and TGF-ß1 (P ≤ 0.034) values dropped significantly after surgery. Neutrophil gelatinase-associated lipocalin alone and in combination with urine and serum CyC demonstrated the best performance in determining the need for surgery (area under the curve, 0.801 and 0.881, respectively). Biomarker profile analysis was suggestive of surgical intervention in 55.4% (7/13) of non-operated cases, and most of the biomarker values were above the cutoff levels within at least 3 months before the clinically based surgical decision in 58% (14/24) of all operated patients. DISCUSSION: To the best of the authors' knowledge, this is the first study to present the clinical use of selected group of serum and urinary biomarkers in the setting of UTO to distinguish between patients who would benefit from surgery intervention. The most promising results were obtained using NGAL, RBP, TGF-ß1, and KIM-1, especially in the unilateral hydro(uretero)nephrosis and LUTO subgroups when compared with the control group. CONCLUSIONS: Urine biomarkers, alone and in combination, demonstrated high potential as a non-invasive diagnostic tool for identifying infants who may benefit from earlier surgical intervention.

Assessment of splanchnic perfusion with gastric tonometry in the immediate postoperative period of cardiac surgery in children.

OBJECTIVE - A prospective, nonrandomized clinical study to assess splanchnic perfusion based on intramucosal pH in the postoperative period of cardiac surgery and to check the evolution of patients during hospitalization. METHODS - We studied 10 children, during the immediate postoperative period after elective cardiac surgery. Sequential intramucosal pH measurements were taken, without dobutamine (T0) and with 5mcg/kg/min (T1) and 10 (T2) mcg/kg/min. In the pediatric intensive care unit, intramucosal pH measurements were made on admission and 4, 8, 12, and 24 hours thereafter. RESULTS - The patients had an increase in intramucosal pH values with dobutamine 10mcg/kg/min [7.19+/- 0.09 (T0), 7.16+/-0.13(T1), and 7.32+/-0.16(T2)], (p=0.103). During the hospitalization period, the intramucosal pH values were the following: 7.20+/-0.13 (upon admission), 7.27+/-0.16 (after 4 hours), 7.26+/-0.07 (after 8 hours), 7.32+/-0.12 (after 12 hours), and 7.38+/-0.08 (after 24 hours), (p=0.045). No deaths occurred, and none of the patients developed multiple organ and systems dysfunction. CONCLUSION - An increase in and normalization of intramucosal pH was observed after dobutamine use. Measurement of intramucosal pH is a type of monitoring that is easy to perform and free of complications in children during the postoperative period of cardiac surgery.

[Airway pressure release in postoperative cardiac surgery in pediatric patients]. / Liberação de pressão de vias aéreas em pacientes pediátricos submetidos à cirurgia cardíaca.

OBJECTIVE: Comparison of three modes of MV: intermittent mandatory ventilation with positive end expiratory pressure (IMV + PEEP), APRV and continuous positive airway pressure (CPAP) in children during cardiac surgery post operative with pulmonary hypertension and mild or moderate pulmonary lesion. METHODS: Ten patients were studied with respiratory monitoring (Bear Neonatal Volume Monitor-1) in MV with a continuous flow, time cycled and pressure limited ventilator. The cardiocirculatory variables analyzed were central venous pressure (CVP), oxygen extraction ratio, cardiac rate, systolic arterial pressure, and arterial-mixed venous CO2 difference. Friedman's test (nonparametric) was used to compare the variables in three modalities of ventilation and the Wilcoxon test was used for the variables obtained in two of the modalities. RESULTS: The mean airway pressure (MAP) showed a significant increasing during APRV compared to IMV + PEEP (p = 0.012). The positive inspiratory pressure (PIP), the minute volume and the ratio of oxygen arterial pressure to oxygen inspired fraction (PaO2/FiO2) didn't show statistical difference. During APRV there was a significant decrease in respiratory rate (p = 0.004) and an increase in tidal volume (p = 0.045) when compared to CPAP and IMV + PEEP. In the cardiocirculatory system only CVP showed a significant increased (p = 0.019) during APRV. CONCLUSION: Due to the methodology utilized MAP was higher with APRV resulting in an increased tidal volume without respiratory or cardiocirculatory adverse effects when the three modes were compared. Our results suggest that APRV is a simple and safe method of ventilation.