Clinical implications of primary "occult" vesicoureteral reflux in male children.

OBJECTIVES: To compare characteristics and outcomes of vesicoureteral reflux (VUR) detected solely on isotopic cystography (IC) ("occult" VUR) with voiding cystourethrography (VCUG)-detected VUR. MATERIALS AND METHODS: Between 2015 and 2020, we retrospectively enrolled all male children first undergoing VCUG and, if negative, IC in the same session. Kidney injury (KI) was defined by abnormal estimated glomerular filtration rate and/or blood pressure and/or proteinuria. RESULTS: We enrolled 421 males with a median age of 3 months and a follow-up of 5.3 years. None exhibited KI initially, but 10% of those with VUR developed KI during follow-up. Two hundred and twenty-two patients (52.7%) did not show VUR, 152 (36.1%) had VCUG-diagnosed VUR, and 47 (11.2%) had occult VUR. Therefore, 47/199 patients (23.6%) with VUR had occult VUR. Among these, 34/47 (72.3%) had dilated VUR, and 22/47 (46.8%) exhibited split renal function < 45% and/or scar (scintigraphic damage). Compared to patients with occult VUR, those with VCUG-diagnosed VUR showed a similar prevalence of febrile urinary tract infection (fUTI) before and after VUR diagnostics and KI at the last follow-up but a higher prevalence of dilated VUR, of scintigraphic damage, and underwent surgery more frequently. At multiple logistic regression analysis, patients with VCUG-diagnosed VUR presented an increased risk of fUTI either before or after VUR diagnosis and of KI, while patients with occult VUR presented an increased risk of fUTI before (and among patients with dilated VUR also after) VUR diagnosis and of KI. CONCLUSION: Occult VUR affects 23.6% of male children with VUR with a non-negligible risk of VUR-associated KI and fUTI. IC could select, among males with recurrent fUTIs and negative VCUG, those requiring surgery for a possible dilated occult VUR. CLINICAL RELEVANCE STATEMENT: Vesicoureteral reflux may be overlooked in 25% of boys during VCUG, yet they are at risk of fUTIs and KI. In case of recurrent infections post-negative cystourethrography, IC could detect occult reflux, guiding surgical intervention.

Prevalence and determinants of failure to thrive in children with vesico-ureteral reflux.

AIM: To assess the prevalence and determinants of failure to thrive (FTT) among patients with vesico-ureteral reflux (VUR) and evaluating the effects of supplementation on growth in patients with urinary solute losses. METHODS: We retrospectively enrolled 1277 patients with VUR (mean age at diagnosis = 6.5 months). Patients with FTT were screened for renal tubular function impairment (TFI). If fractional excretion of sodium (FENa) >2% or blood bicarbonate <20 mmol/L, supplementation was provided. RESULTS: Among 1277 patients, 56 (4.4%) had FTT. Of these, 42 (75%) presented extrarenal causes of FTT, 3 (5.4%) had chronic kidney disease (CKD), 9 (16.1%) had TFI, and 2 (3.5%) had CKD and TFI. FTT occurred in 8/208 patients (3.8%) with and in 48/1069 patients (4.5%) without (p = 0.68) recurrent urinary tract infections (UTIs). At multiple logistic regression, birthweight <10th percentile, preterm birth, TFI, identified or suspected syndromes and other diseases were predictors of FTT. Eleven (19.6%) patients with FTT had TFI; five with increased FENa and/or acidosis received supplementation and showed catch-up growth. The remaining six patients exhibited spontaneous catch-up growth. CONCLUSION: FTT was found in <5% of children with VUR. It was not determined by recurrent UTIs and was mainly associated with extrarenal causes. Supplementation with sodium and bicarbonates could be useful in selected cases.

Evolution of congenital anomalies of urinary tract in children with and without solitary kidney.

BACKGROUND: We hypothesized that children with congenital solitary functioning kidney (CSFK) present forms of congenital urinary tract anomalies (CUTA) with higher chance of spontaneous resolution compared with patients with two kidneys. METHODS: We retrospectively selected 75 consecutive children with CUTA of the CSFK and 75 matched patients with unilateral CUTA but without CSFK (controls) with prenatal suspicion of unilateral CUTA and early evaluation. We compared the spontaneous CUTA resolution and the prevalence of kidney injury between groups at last follow-up. Patients and controls were clustered under the categories of "severe" and "non-severe" CUTA. RESULTS: The mean age at first and last follow-up was 0.17 ± 0.07 and 8.5 ± 5.2 years. Compared with controls, patients with CSFK had lower prevalence of severe CUTA at first evaluation; lower prevalence of febrile urinary tract infections, need of surgical correction, and higher rate of spontaneous CUTA resolution during follow-up; and a similar prevalence of mild kidney injury at last follow-up. CSFK compared with controls presented higher cumulative proportion of spontaneous resolution from severe CUTA (100 vs 41.8%; p < 0.001) and from the single CUTA sub-categories (severe vesicoureteral reflux, non-obstructive hydronephrosis, and megaureter). CONCLUSIONS: CSFK patients had lower prevalence of severe forms and better outcomes of their CUTA compared with controls. IMPACT: One-third of patients with congenital solitary functioning kidney (CSFK) present congenital urinary tract anomalies (CUTA) and manifest poorer outcomes compared with CSFK without CUTA. CSFK patients had lower prevalence of severe forms and better outcomes of their CUTA in spite of similar prevalence of kidney injury compared with controls. This adds evidence about disturbed nephrogenesis in CSFK patients and emboldens conservative management of many of their non-obstructive CUTA.

Heart rate cut-offs to identify non-febrile children with dehydration and acute kidney injury.

We hypothesized that the heart rate (HR) variation in an acute setting compared with HR in wellbeing status could be a good marker of both dehydration and acute kidney injury (AKI). Since HR in wellbeing status is unknown in most cases, we assumed as reliable surrogate the 50th percentile of HR according to age and gender. We evaluated if the estimated percentage of heart rate variation in acute setting compared with 50th percentile of HR (EHRV) could be marker of dehydration and AKI in children. Two independent cohorts, one prospective comprehending 185 children at type 1 diabetes mellitus onset (derivation) and one retrospective comprehending 151 children with acute gastroenteritis and pneumonia (validation), were used to develop and externally validate EHRV as predictor of the ≥ 5% dehydration and/or AKI composite outcome. Febrile patients were excluded. EHRV was calculated as ((HR at admission-50th percentile of HR)/HR at admission) × 100. The prevalences of ≥ 5% dehydration and AKI were 61.1% and 43.8% in the derivation and 34.4% and 24.5% in the validation cohort. For the ≥ 5% dehydration and/or AKI composite outcome, the area under receiver-operating characteristic curve of the EHRV in the derivation cohort was 0.69 (95%CI, 0.62-0.77; p < 0.001) and the best EHRV cut-off was > 24.5%. In the validation cohort, EHRV > 24.5% showed specificity = 100% (95%CI, 96.2-100.0), positive predictive value = 100%, and negative predictive value = 67.1% (95%CI, 64.7-69.5). The positive likelihood ratio was infinity, and odds ratio was not calculable because all the patients with EHRV > 24.5% showed ≥ 5% dehydration and/or AKI.    Conclusions: EHRV appears a rather reliable marker of dehydration and AKI. Further validations could allow implementing EHRV in the clinical practice. What is Known: • Increased heart rate (HR) is an easily and quickly detectable sign of dehydration in childhood, but its cut-off to suspect dehydration or acute kidney injury (AKI) is not defined. What is New: • We found that a percentage of estimated HR variation in acute setting in comparison with 50th percentile of HR (EHRV)>24.5% predicted ≥5% dehydration and/or AKI in non-febrile patients. • We provide a one-page tool to suspect ≥5% dehydration and/or AKI on the basis of the HR. If furtherly validated, this tool could be implemented in the daily clinical practice.

Congenital Solitary Kidney from Birth to Adulthood.

PURPOSE: To evaluate the course of prenatally diagnosed and early-enrolled congenital solitary functioning kidney patients followed until adulthood and to identify risk factors for kidney injury. MATERIALS AND METHODS: Among all congenital solitary functioning kidney patients followed (1993-2018), we recalled 56 patients with prenatal diagnosis and congenital solitary functioning kidney confirmation at 1-3 months of life reaching at least 18 years of age. Serum uric acid, heavy smoking (≥25 cigarettes/day) and overweight/obesity were clustered as modifiable risk factors. Kidney injury was defined by estimated glomerular filtration rate <90 ml/minute/1.73 m2 and/or 24-hour ambulatory blood pressure monitoring confirmed hypertension and/or proteinuria. Modifiable risk factors and congenital anomalies of the kidney and urinary tract (CAKUT) of congenital solitary functioning kidney were evaluated as risk factors for kidney injury. RESULTS: The mean followup period was 21.1 years (range 18-33 years). Mild kidney injury was found in 15 out of 56 patients (26.8%). The mean age at proteinuria, reduced estimated glomerular filtration rate and hypertension onset was 19.7 years (1.2 SDS), 20.7 years (2.7 SDS), and 22 years (5.6 SDS), respectively. Patients with CAKUT of congenital solitary functioning kidney and with both CAKUT of congenital solitary functioning kidney and modifiable risk factors presented survival free from kidney injury of 0% at 22.2 and 24.2 years of age, respectively. Patients with modifiable risk factors presented 42.4% of survival at 30 years. Patients without CAKUT of congenital solitary functioning kidney nor modifiable risk factors presented 100% of survival at 30 years of age (p=0.002). The presence of CAKUT of congenital solitary functioning kidney was the only significant risk factor (HR 4.9; 95% CI 1.8-14.2; p=0.003). CONCLUSIONS: The outcomes of congenital solitary functioning kidney in early adulthood appear better than previously reported. Prompt diagnosis of congenital solitary functioning kidney, healthy lifestyle promotion and monitoring of serum uric acid may improve the prognosis of congenital solitary functioning kidney patients.

Acute kidney injury in children hospitalized for community acquired pneumonia.

BACKGROUND: Acute kidney injury (AKI) enhances the risk of later chronic kidney disease. Significant prevalence of AKI is reported in adults with community acquired pneumonia (CAP). We investigated prevalence of and prognostic factors for AKI in children hospitalized for CAP. METHODS: We retrospectively collected clinical and biochemical data of 186 children (48.4% male; mean age 2.6±2.4 years) hospitalized for X-ray-confirmed CAP. AKI was defined according to Kidney Disease/Improving Global Outcomes creatinine criteria. We considered as basal serum creatinine the value estimated with Hoste (age) equation assuming basal eGFR were median age-based eGFR normative values for children ≤ 2 years of age and eGFR= 120 mL/min/1.73m2 for children > 2 years. Univariate and multivariate logistic regression models were used to explore associations with AKI. RESULTS: AKI was found in 38/186 (20.4%) patients. No patient required hemodialysis nor reached AKI stage 3, 5 (2.7%) reached AKI stage 2, and 33 (17.7%) AKI stage 1. Mean length of stay was 6.0±1.7, 6.9±2.3, and 12.2±1.5 days, for patients without AKI, stage 1 AKI, and stage 2 AKI (p < 0.001), respectively. Duration of symptoms before hospitalization (OR 1.2; 95%CI 1.09-1.43; p = 0.001), severe pneumonia (OR 11.9; 95%CI 4.3-33.3; p < 0.001), and serum C-reactive protein levels (OR 1.1; 95%CI 1.04-1.23; p = 0.004) were independent AKI predictors. CONCLUSIONS: About 1/5 of children hospitalized for CAP present a generally mild AKI with a longer stay for those with more severe AKI. Attention should be paid to kidney health of children with CAP especially in presence of higher duration of symptoms before hospitalization, severe pneumonia and higher serum CRP levels.

Nephrogenic Diabetes Insipidus in Childhood: Assessment of Volume Status and Appropriate Fluid Replenishment.

Patients affected by nephrogenic diabetes insipidus (NDI) can present with hypernatremic dehydration, and first-line rehydration schemes are completely different from those largely applied in usual conditions determining a mild to severe hypovolemic dehydration/shock. In reporting the case of a patient affected by NDI and presenting with severe dehydration triggered by acute pharyngotonsillitis and vomiting, we want to underline the difficulties in managing this condition. Restoring the free-water plasma amount in patients affected by NDI may not be easy, but some key points can help in the first line management of these patients: (1) hypernatremic dehydration should always be suspected; (2) even in presence of severe dehydration, skin turgor may be normal and therefore the skinfold recoll should not be considered in the dehydration assessment; (3) decreased thirst is an important red flag for dehydration; (4) if an incontinent patient with NDI appears to be dehydrated, it is important to place the urethral catheter to accurately measure urine output and to be guided in parenteral fluid administration; (5) if the intravenous route is necessary, the more appropriate fluid replenishment is 5% dextrose in water with an infusion rate that should slightly exceed the urine output; (6) the 0.9% NaCl solution (10 mL/kg) should only be used to restore the volemia in a shocked NDI patient; and (7) it could be useful to stop indomethacin administration until complete restoration of hydration status to avoid a possible worsening of a potential prerenal acute renal failure.

Micturition Syncope in Childhood: How to Recognize and Manage It.

Frequently, general pediatricians could face a patient with syncope, which represents approximately 1% to 3% of emergency visits. Micturition syncope is a transient loss of consciousness with onset immediately before, during, or after micturition. Literature evidence indicates that healthy young men are a population with major risk for presenting micturition syncope, with a peak of incidence around 40 to 50 years of age. Usually, this syncope occurs in the morning, after wake-up, or, more generally, when the male patients assume the orthostatic position after a period of supine position in a warm bed. No information on micturition syncope clinical presentation and prevalence in childhood is available in the literature, and probably, this kind of syncope is unrecognized in childhood. We describe 4 unreported pediatric patients with a diagnosis of micturition syncope and well-defined clinical presentation. In all patients, the syncope has been presented in the same conditions: in the morning; after wake-up; in an orthostatic position; just before, after, or during urinary bladder voiding; and with spontaneous recovery in few minutes. Interestingly, 1 patient presented with the syncope during urinary bladder voiding by autocatheterization. In our patients, all investigations made as the first approach in the pediatric emergency department did not show any abnormal results, possibly underlying the syncope episodes. By describing our experience, we want to underline the clinical presentation of micturition syncope and give to the clinicians the elements to recognize and manage it easily in children.

Anthropometric and Biochemical Determinants of Estimated Glomerular Filtration Rate in a Large Cohort of Obese Children.

OBJECTIVE: We aimed to investigate which clinical and metabolic factors could influence the estimated glomerular filtration rate (eGFR) levels, evaluating a large population of obese children without suspect of primary kidney disease. DESIGN: Retrospective, cross-sectional study. SETTING: Pediatric university department. SUBJECTS: We enrolled 2,957 obese children and adolescents consecutively attending our department between January 2000 and 2017. Inclusion criteria were body mass index (BMI) > 95th percentile and eGFR > 90 mL/min/1.73 m2. Exclusion criteria were secondary forms of obesity, eGFR < 90 mL/min/1.73 m2, proteinuria/hematuria at urine dipstick, or consumption of any medication. INTERVENTIONS: Weight, waist circumference, height, waist to height ratio (W/Hr), BMI-standard deviation score (SDS), pubertal stage, systolic blood pressure (SBP) and diastolic blood pressure (DBP), duration of obesity, insulin, eGFR, and homeostasis model assessment (HOMA-IR) were obtained. A general linear model was performed for a multiple variable analysis. MAIN OUTCOME MEASURE: The population was divided in tertiles for BMI-SDS, W/Hr, SBP- and DBP-SDS, HOMA-IR, and duration of obesity. We compared eGFR levels among these tertiles. RESULTS: The eGFR levels significantly increased across both BMI-SDS and W/Hr tertiles. Conversely the eGFR levels significantly decreased across SBP-SDS, HOMA-IR, and duration of obesity tertiles. No significant differences in eGFR levels across DBP-SDS tertiles were detected. Pubertal patients presented significantly lower eGFR values compared with prepubertal patients. A general linear model for eGFR variance including as covariates W/Hr, HOMA-IR, duration of obesity, pubertal stage, BMI-SDS, and SBP-SDS (model R2 39.7%; model P < .00001) was performed. It confirmed a direct association of eGFR values with BMI-SDS and an indirect association with HOMA-IR, duration of obesity, pubertal stage, and SBP-SDS. CONCLUSIONS: We showed a positive correlation of eGFR with both BMI-SDS and a negative one with SBP-SDS, HOMA-IR, pubertal stage, and duration of obesity. The duration of obesity was the variable most significantly associated to eGFR levels.