[Pediatric renal abscesses: a diagnostic challenge]. / Absceso renal en Pediatría: un desafío diagnóstico.

Kidney abscess is an unusual entity in childhood with few studies about its clinical characteris tics. OBJECTIVE: To report the clinical presentation, diagnosis, and therapy used in a cohort of 20 children with kidney abscess. PATIENTS AND METHOD: retrospective study of cases of kidney abscess during a 10-year period at the Hospital Roberto del Río. The analysis of clinical, laboratory, and imaging characteristics were evaluated as well as the treatment usedfor this condition. RESULTS: 20 cases were reported among which 65% were women with a median age of 3.6 years. The most com mon clinical presentation was fever, vomit, and dysuria. Eighty percent of patients presented an increase of inflammatory parameters, 88% presented positive urine culture, and the most common organism identified was Escherichia Coli (77.8%). The diagnosis was mostly made through kidney ultrasound (75%) followed by an abdominal CT scan (35%). 93% of abscesses were unilateral. About 95% of the patients only required antibiotic treatment. Vesicoureteral reflux was diagno sed in 28% of the patients with no sphincter control, and only one of them presented high-grade reflux. In patients with sphincter control, bladder and bowel dysfunction (BBD) was diagnosed in 90% of the cases. Forty four percent of the patients with late DMSA renal scintigraphy presented renal scarring. CONCLUSIONS: In this series, pediatric kidney abscess appears with persistent fever despite the treatment, requiring prolonged antibiotic therapy and rarely surgical drains. We su ggest a study aimed at detecting modifiable factors, such as vesicoureteral reflux in patients with no sphincter control and BBD in patients with sphincter control, as well as identifying renal paren chymal sequels in all patients.

[Ambulatory Blood Pressure Monitoring (ABPM): Statement from chilean pediatric nephrology committee]. / Monitorización Ambulatoria de Presión Arterial (MAPA): Recomendaciones de la rama de nefrología pediátrica.

Ambulatory blood pressure monitoring (ABPM) is a useful clinical tool for the diagnosis and confir mation of arterial hypertension in pediatrics, and also allows the diagnosis of special conditions such as white coat hypertension and masked hypertension. There are international recommendations for its implementation and interpretation, however, there are still unresolved questions. This guide summarizes the available literature and attempts to standardize, through consensus of national specia lists, the application of this technique. More research studies are needed that provide new reference values and determine the relationship of alterations in ABPM with long-term clinical results.

Monitorización ambulatoria de presión arterial (MAPA): recomendaciones de la rama de nefrología pediátrica / Ambulatory blood pressure monitoring (ABPM): statement from chilean pediatric nephrology committee

Resumen: La monitorización ambulatoria de la presión arterial (MAPA) es una herramienta clínica útil para el diagnóstico y confirmación de hipertensión arterial en pediatría y permite igualmente el diagnóstico de condiciones especiales como la hipertensión de delantal blanco e hipertensión enmascarada. Exis ten recomendaciones internacionales para su realización e interpretación, sin embargo, aún quedan interrogantes por resolver. En esta guía se resume la bibliografía disponible y se intenta estandarizar, a través de consenso de especialistas nacionales, la aplicación de esta técnica. Se necesitan más estudios de investigación en niños que aporten nuevos valores de referencia y que determinen la relación de alteraciones en MAPA con resultados clínicos a largo plazo.

Abstract: Ambulatory blood pressure monitoring (ABPM) is a useful clinical tool for the diagnosis and confir mation of arterial hypertension in pediatrics, and also allows the diagnosis of special conditions such as white coat hypertension and masked hypertension. There are international recommendations for its implementation and interpretation, however, there are still unresolved questions. This guide summarizes the available literature and attempts to standardize, through consensus of national specia lists, the application of this technique. More research studies are needed that provide new reference values and determine the relationship of alterations in ABPM with long-term clinical results.

[Blood hypertension in children. Guideliness for diagnosis and treatment. Part 2 Pediatric Nephrology Branch, Chilean Pediatric Society]. / Hipertensión arterial en la infancia. Recomendaciones para su diagnóstico y tratamiento. Parte 2 Rama de Nefrología Infantil, Sociedad Chilena de Pediatría.

Hypertension (HTN) in children and adolescents is an important pathology, of, guarded prognosis, associated with modifiable and non-modifiable factors. The estimated prevalence is around 3.5% which increases progressively with age. The ideal method for its diagnosis is the measurement of blood pressure (BP) with auscultatory instruments. According to the American Academy of Pedia trics (AAP), BP should be measured in children older than three years of age once a year, and in children younger than three years of age if they present risk factors. Once the HTN is confirmed, the evaluation should be directed towards the detection of a causative disease and/or the search for risk factors associated with a primary HTN. The objective of treating primary and secondary HTN in pediatrics is to achieve a BP level that decreases the risk of target organ damage. Therapeutic op tions include treatment according to specific etiology, non-pharmacological and pharmacological one. This paper presents the position of the Chilean Society of Pediatrics Nephrology Branch with the aim of guiding pediatricians and pediatric nephrologists in the correct management of HTN in childhood. In this second part, recommendations on antihypertensive treatment are presented with an emphasis on lifestyle changes.

Hipertensión arterial en la infancia: recomendaciones para su diagnóstico y tratamiento. Parte 2 Rama de Nefrología Infantil, Sociedad Chilena de Pediatría / Blood hypertension in children: guideliness for diagnosis and treatment. Part 2 Pediatric Nephrology Branch, Chilean Pediatric Society

Resumen: La hipertensión arterial (HTA) en niños y adolescentes es una importante patología, de reservado pronóstico, asociada a factores modificables y no modificables. La prevalencia estimada es de apro ximadamente un 3,5%, la cual va aumentando progresivamente con la edad. El método ideal para su diagnóstico es la medición de la presión arterial (PA) con instrumentos auscultatorios. De acuerdo a la Academia Americana de Pediatría (AAP) la PA debe ser medida en niños mayores de 3 años una vez al año, y en niños menores de 3 años, si presentan factores de riesgo. Una vez confirmada la HTA, la evaluación debe dirigirse hacia la detección de una enfermedad causal y/o a la búsqueda de factores de riesgo asociados a una HTA primaria. El objetivo del tratamiento de la HTA primaria y secundaria en pediatría es lograr un nivel de PA que disminuya el riesgo de daño de los órganos blanco. Las opciones terapéuticas incluyen: tratamiento según etiología específica, no farmacológico y farmacológico. En esta Guia se presenta la posición de la Rama de Nefrología de la Sociedad Chile na de Pediatría con el objetivo de orientar a pediatras y nefrólogos infantiles en correcto manejo de la HTA en la infancia. En esta segunda parte se presentan las recomendaciones sobre el tratamiento antihipertensivo, haciendo énfasis en los cambios de estilo de vida.

Abstract: Hypertension (HTN) in children and adolescents is an important pathology, of, guarded prognosis, associated with modifiable and non-modifiable factors. The estimated prevalence is around 3.5% which increases progressively with age. The ideal method for its diagnosis is the measurement of blood pressure (BP) with auscultatory instruments. According to the American Academy of Pedia trics (AAP), BP should be measured in children older than three years of age once a year, and in children younger than three years of age if they present risk factors. Once the HTN is confirmed, the evaluation should be directed towards the detection of a causative disease and/or the search for risk factors associated with a primary HTN. The objective of treating primary and secondary HTN in pediatrics is to achieve a BP level that decreases the risk of target organ damage. Therapeutic op tions include treatment according to specific etiology, non-pharmacological and pharmacological one. This paper presents the position of the Chilean Society of Pediatrics Nephrology Branch with the aim of guiding pediatricians and pediatric nephrologists in the correct management of HTN in childhood. In this second part, recommendations on antihypertensive treatment are presented with an emphasis on lifestyle changes.

Adecuación en diálisis peritoneal pediátrica: Del test de equilibrio peritoneal a las aquaporinas / Peritoneal dialysis adequacy in pediatrics: From the peritoneal equilibration test to the aquaporins

La evaluación de las características de transporte de solutos y agua del peritoneo es esencial para adecuar la prescripción dialítica en pacientes portadores de enfermedad renal crónica. Existen una serie de modelos para realizar esta evaluación. El test de equilibrio peritoneal (PET) evalúa la capacidad de transporte del peritoneo clasificando a los pacientes en 4 categorías de transportador: alto, promedio alto, promedio bajo y bajo. El short PET realiza la misma evaluación en solo 2 h, y ha sido validado en pacientes pediátricos. Por otro lado, el MiniPET otorga información adicional al evaluar la capacidad de transporte de agua libre por los poros ultrapequeños, y el Accelerated Peritoneal Examination Time (APEX) evalúa el punto de intersección de las curvas de equilibrio de urea y glucosa, y ha sido propuesto como el tiempo de permanencia óptimo para lograr una UF adecuada. Se analiza la información actual sobre estos métodos diagnósticos, en particular los últimos aportes de la literatura respecto al transporte de agua libre vía aquaporinas, que podrían representar una herramienta importante para optimizar el transporte de agua y solutos en pacientes en diálisis peritoneal crónica, en particular respecto al pronóstico cardiovascular.

An evaluation of the characteristics of peritoneal solute and water transport is essential to assess the suitability of prescribing dialysis in patients suffering from chronic renal disease. There are currently a series of models to perform this evaluation. The peritoneal equilibration test (PET) evaluates the peritoneal transport capacity, classifying the patients into four transport categories: high, high-average, low-average, and low. The short PET enables the same evaluation to be made in only 2 hours, and has been validated in paediatric patients. On the other hand, the MiniPET provides additional information by evaluating the free water transport capacity by the ultra-small pores, and the Accelerated Peritoneal Examination Time (APEX) evaluates the time when the glucose and urea equilibration curves cross, and has been proposed as the optimum dwell time to achieve adequate ultrafiltration. An analysis is presented on the current information on these diagnostic methods as regards free water transport via aquaporins, which could be an important tool in optimising solute and water transport in patients on chronic peritoneal dialysis, particularly as regards the cardiovascular prognosis.

[Peritoneal dialysis adequacy in pediatrics. From the peritoneal equilibration test to the aquaporins]. / Adecuación en diálisis peritoneal pediátrica. Del test de equilibrio peritoneal a las aquaporinas.

An evaluation of the characteristics of peritoneal solute and water transport is essential to assess the suitability of prescribing dialysis in patients suffering from chronic renal disease. There are currently a series of models to perform this evaluation. The peritoneal equilibration test (PET) evaluates the peritoneal transport capacity, classifying the patients into four transport categories: high, high-average, low-average, and low. The short PET enables the same evaluation to be made in only 2hours, and has been validated in paediatric patients. On the other hand, the MiniPET provides additional information by evaluating the free water transport capacity by the ultra-small pores, and the Accelerated Peritoneal Examination Time (APEX) evaluates the time when the glucose and urea equilibration curves cross, and has been proposed as the optimum dwell time to achieve adequate ultrafiltration. An analysis is presented on the current information on these diagnostic methods as regards free water transport via aquaporins, which could be an important tool in optimising solute and water transport in patients on chronic peritoneal dialysis, particularly as regards the cardiovascular prognosis.

Birth weight is inversely associated with blood pressure and serum aldosterone and cortisol levels in children.

CONTEXT: Low birth weight has been independently associated with adult hypertension, and renin-angiotensin system (RAS) plays a role in this connection. OBJECTIVE: To characterize the associations between birth weight (BW) and serum aldosterone (SA), serum cortisol, plasma renin activity (PRA) and blood pressure (BP). DESIGN: Cross-sectional study. SUBJECTS: Children from the community born at a gestational age >32 weeks. METHODS: Systolic and diastolic BP indices (SBPi and DBPi) were calculated using the observed BP/50th percentile BP for gender, age and stature. BW was transformed to a standard deviation score (SDS) for gestational age, whereas SA, serum cortisol and PRA were transformed using the natural log. RESULTS: We selected 288 subjects between the ages of 4·9 and 15·5 years (Females, 50%). After adjusting for body mass index (BMI) SDS and Tanner, multiple regression analysis revealed that BW (SDS) was both independently and inversely associated with the natural log of SA (ß = -0·065; P = 0·039), the natural log of serum cortisol (ß = -0·064; P = 0·009), SBPi (ß = -0·012; P = 0·020) and DBPi (ß = -0·023; P = 0·002). An association was not observed with PRA (P = 0·178) and aldosterone renin ratio (ARR) (P = 0·452). Serum cortisol levels were positively associated with SA (r = 0·125; P = 0·034), while an association with PRA (P = 0·251) and ARR (P = 0·052) was not observed. CONCLUSIONS: The results of this study demonstrate an inverse association between birth weight and blood pressure and serum aldosterone and cortisol levels. This association is independent of BMI and Tanner, suggesting foetal programming of the hypothalamic-pituitary-adrenal axis.

Frequency of familial hyperaldosteronism type 1 in a hypertensive pediatric population: clinical and biochemical presentation.

Familial hyperaldosteronism type 1 is an autosomal dominant disorder attributed to a chimeric CYP11B1/CYP11B2 gene (CG). Its prevalence and manifestation in the pediatric population has not been established. We aimed to investigate the prevalence of familial hyperaldosteronism type 1 in Chilean hypertensive children and to describe their clinical and biochemical characteristics. We studied 130 untreated hypertensive children (4 to 16 years old). Blood samples for measuring plasma potassium, serum aldosterone, plasma renin activity, aldosterone/renin ratio, and DNA were collected. The detection of CG was performed using long-extension PCR. We found 4 (3.08%) of 130 children with CG who belonged to 4 unrelated families. The 4 patients with CG had very high aldosterone/renin ratio (49 to 242). In addition, we found 4 children and 5 adults who were affected among 21 first-degree relatives. Of the 8 affected children, 6 presented severe hypertension, 1 presented prehypertension, and 1 presented normotension. High serum aldosterone levels (>17.7 ng/dL) were detected in 6 of 8 subjects (range: 18.6 to 48.4 ng/dL) and suppressed plasma renin activity (≤0.5 ng/mL per hour) and high aldosterone/renin ratio (>10) in 8 of 8 children (range: 49 to 242). Hypokalemia was observed in only 1 of 8 children. We demonstrated that the prevalence of familial hyperaldosteronism type 1 in a pediatric hypertensive pediatric population was surprisingly high. We found a high variability in the clinical and biochemical characteristics of the affected patients, which suggests that familial hyperaldosteronism type 1 is a heterogeneous disease with a wide spectrum of presentations even within the same family group.

Aldosterone, plasma Renin activity, and aldosterone/renin ratio in a normotensive healthy pediatric population.

Primary aldosteronism is an important cause of secondary hypertension and is suspected in adults with an aldosterone/renin ratio > or =25. The normal aldosterone/renin ratio is unknown in children. The aim was to establish serum aldosterone, plasma renin activity, and aldosterone/renin ratio values in a healthy pediatric population. A cross-sectional study was performed in 211 healthy normotensive children (4 to 16 years old). Two subgroups of normotensive children were obtained: with hypertensive parents (NH) (n=113) and normotensive parents (n=98). Blood samples for measuring serum aldosterone, plasma renin activity, aldosterone/renin ratio, and DNA were collected. In subjects with aldosterone/renin ratio > or =25, the chimeric CYP11B1/CYP11B2 gene was investigated by long-extension PCR. Results are expressed as median [Q(1)-Q(3)]. NH and normotensive parents groups were similar in serum aldosterone (6.5 [3.6 to 9.0] ng/dL versus 6.5 [2.9 to 9.7] ng/dL; P=0.968) and plasma renin activity (2.3 [1.6 to 3.1] versus 2.4 [1.7 to 3.7] ng/mL per hour; P=0.129). The aldosterone/renin ratio was higher in the NH group, but this difference did not reach statistical significance (2.8 [1.9 to 4.1] versus 2.5 [1.4 to 4.0], P=0.104). In one subject of the NH group, the chimeric CYP11B1/CYP11B2 gene was detected. We demonstrated that normal aldosterone/renin ratio values in a healthy pediatric population without NH were lower than those reported for an adult normotensive population.

Primary aldosteronism and its impact on the generation of arterial hypertension, endothelial injury and oxidative stress.

Aldosterone plays an important role in blood pressure homeostasis, the regulation of circulating volume, and the maintenance of the sodium-potassium balance by binding to the mineralocorticoid receptor (MR). Primary aldosteronism (PA) states are associated with an increased cardiovascular risk, mediated not only by hypertension but also by the action of aldosterone in the modulation of vasodilation/vasoconstriction and oxidative stress. In this review, we discuss some of the cardiovascular actions of aldosterone and the most frequent causes of PA.