Hyperuricemia: an unrecognized risk factor for kidney-related sequelae in children with hemolytic uremic syndrome.

BACKGROUND: Chronic kidney-related sequelae after STEC-HUS occur in 20-40% of patients. Hyperuricemia (HU) may cause acute and chronic toxicity involving the kidneys. We retrospectively assessed if there was an association between the presence of HU during the acute illness and that of kidney-related sequelae in children with STEC-HUS. METHODS: Children with STEC-HUS who had clinical and laboratory data at 2 years of follow-up were included in this case-control study. Univariate and multivariate analyses were performed between patients with (cases) or without (controls) kidney-related sequelae to identify factors associated with outcomes, including different measures of serum uric acid (sUA) (baseline level, peak, and duration of HU). HU was defined as sUA > 8 mg/dL. RESULTS: Of 86 patients included, 77.9% had HU. Patients with sequelae (n = 41) had a higher prevalence of HU (41/41 vs. 26/45, p < 0.01), higher baseline leukocyte count, serum creatinine (sCr), and sUA levels as well as lower sodium than controls. During hospitalization, cases also had higher sCr peak, sUA peak and duration of HU, requirement and duration of dialysis, extrarenal complications, and hypertension. By multivariate analysis, after adjusting for length of dialysis, only duration of HU (p = 0.0005; OR 1.7, 95% CI 1.27-2.36) remained as an independent predictor of sequelae, with a best cutoff of 5.5 days (AUC 0.95, specificity 80%, sensitivity 100%). CONCLUSIONS: The presence of HU is a common finding in children with STEC-HUS and its duration during the acute stage was associated with kidney-related sequelae, regardless of the duration of dialysis. A higher resolution version of the Graphical abstract is available as Supplementary Information.

Transient early-childhood hyperkalaemia without salt wasting, pathophysiological approach of three cases.

Two types of early childhood hyperkalemia had been recognized, according to the presence or absence of urinary salt wasting. This condition was attributed to a maturation disorder of aldosterone receptors and is characterized by sustained hyperkalemia, hyperchloremic metabolic acidosis (MA) due to reduced ammonium urinary excretion and bicarbonate loss, and normal creatinine with growth delay. We present 3 patients of the type without salt wasting, which we will call transient early-childhood hyperkalemia (TECHH) without salt wasting, and discuss its physiopathology according to new insights into sodium and potassium handling by the aldosterone in distal nephron. In 3 children from 30 to 120-day-old admitted with bronchiolitis and growth delay hyperkalemia was found in routine laboratory. Further studies revealed a normal creatinine with inappropriately normal or low fractional excretion (FE) of potassium, accompanied by inadequately normal serum aldosterone and plasma renin activity for their higher plasma potassium levels, but without urine salt wasting. They also presented hyperchloremic MA with FE of bicarbonate 0.58%-2.2%, positive urinary anion gap during MA and normal ability to acidify the urine. Based on these findings a diagnosis of TECHH without salt wasting was made and they were treated sodium bicarbonate and hydrochlorothiazide with favorable response. The condition was transient in all cases leading to treatment discontinuation. Given that TECCH without salt wasting is a tubular disorder of transient nature with mild symptoms; it must be keep in mind in the differential diagnosis of hyperkalemia in young children.

Hiperpotasemia transitoria del lactante sin pérdida salina, enfoque fisiopatológico de tres casos / Transient early-childhood hyperkalemia without salt wasting, physiopathological approach of three cases

Se reconocen 2 variedades de hiperpotasemia temprana de la infancia (del inglés Early childhood hyperkalemia) según la presencia o no de pérdida salina urinaria. Se trata de una entidad atribuida a un desorden madurativo en los receptores de aldosterona caracterizada por hiperpotasemia, acidosis metabólica hiperclorémica por diminución de la eliminación de amonio y bicarbonaturia, y creatinina normal con retraso de crecimiento. Presentamos 3 pacientes de la forma con ausencia de pérdida salina, a la que denominaremos hiperpotasemia transitoria del lactante sin pérdida salina, y discutimos su fisiopatología con relación a los nuevos conocimientos en el manejo tubular del sodio y el potasio por la aldosterona. En 3 pacientes de entre 30 y 120 días de edad con bronquiolitis y retraso de crecimiento se encontró hiperpotasemia en laboratorio de rutina. Presentaban creatinina normal, excreción fraccionada de potasio disminuida o inapropiadamente normal junto a niveles de aldosterona y renina plasmática inadecuadamente normales para el estado de hiperpotasemia, pero sin pérdida salina. También cursaban con acidosis metabólica hiperclorémica con bicarbonaturia (excreción fraccionada de bicarbonato 0,58-2,2%), anión restante urinario positivo durante acidosis metabólica y capacidad normal para acidificar la orina. En base a estos hallazgos se diagnosticó hiperpotasemia transitoria del lactante sin pérdida salina y se trataron con bicarbonato de sodio e hidroclorotiazida con buena respuesta. El cuadro fue transitorio permitiendo la suspensión del tratamiento. Dado que la hiperpotasemia transitoria del lactante sin pérdida salina es un desorden tubular transitorio con síntomas leves debe tenerse presente en el diagnóstico diferencial de hiperpotasemia en niños pequeños. (AU)

Two types of early-childhood hyperkalemia had been recognized, according to the presence or absence of urinary salt wasting. This condition was attributed to a maturation disorder of aldosterone receptors and is characterized by sustained hyperkalemia, hyperchloremic metabolic acidosis due to reduced ammonium urinary excretion and bicarbonate loss, and normal creatinine with growth delay. We present three patients of the type without salt wasting, which we will call transient early-childhood hyperkalemia without salt wasting, and discuss its physiopathology according to new insights into sodium and potassium handling by the aldosterone in distal nephron. In three children from 30 to 120-day-old admitted with bronchiolitis and growth delay hyperkalemia was found in routine laboratory. Further studies revealed a normal creatinine with inappropriately normal or low fractional excretion of potassium, accompanied by inadequately normal serum aldosterone and plasma renin activity for their higher plasma potassium levels, but without urine salt wasting. They also presented hyperchloremic metabolic acidosis with fractional excretion of bicarbonate 0.58–2.2%, positive urinary anion gap during metabolic acidosis and normal ability to acidify the urine. Based on these findings a diagnosis of transient early-childhood hyperkalemia without salt wasting was made and they were treated sodium bicarbonate and hydrochlorothiazide with favorable response. The condition was transient in all cases leading to treatment discontinuation. Given that transient early-childhood hyperkalemia without salt wasting is a tubular disorder of transient nature with mild symptoms; it must be keep in mind in the differential diagnosis of hyperkalemia in young children. (AU)

Erythropoietin in children with hemolytic uremic syndrome: a pilot randomized controlled trial.

BACKGROUND: The efficacy of recombinant human erythropoietin (rHuEPO) in sparing red blood cell (RBC) transfusions in children with hemolytic uremic syndrome related to Shiga toxin-producing Escherichia coli (STEC-HUS) is uncertain. METHODS: We conducted a pilot randomized controlled open trial between December 2018 and January 2021. Children were randomized to the intervention (subcutaneous rHuEPO 50 U/kg three times weekly until discharge + RBC transfusion if hemoglobin ≤ 7 g/dL and/or hemodynamic instability) or to the control arm (RBC transfusion if hemoglobin ≤ 7 g/dL and/or hemodynamic instability). Primary outcome was the number of RBC transfusions received during hospitalization. Secondary outcomes were to explore whether baseline EPO levels were adequate to the degree of anemia, to correlate selected acute phase parameters with the number of RBC transfusions, and to assess possible adverse events. RESULTS: Twelve patients per arm were included; they were comparable at recruitment and throughout the disease course. Median number of RBC transfusions was similar between groups (1.5, p = 0.76). Most patients had baseline EPO levels adequate to the degree of anemia, which did not correlate with the number of transfusions (r = 0.19, p = 0.44). Conversely, baseline (r = 0.73, p = 0.032) and maximum lactic dehydrogenase levels (r = 0.78, p = 0.003), creatinine peak (r = 0.71, p = 0.03) and dialysis duration (r = 0.7, p = 0.04) correlated significantly with RBC requirements. No side effects were recorded. CONCLUSION: In children with STEC-HUS, the administration of rHuEPO did not reduce the number of RBC transfusions. Larger studies addressing higher doses and similar severity of kidney failure at rHuEPO initiation (e.g. at start of dialysis) are warranted. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03776851. A higher resolution version of the Graphical abstract is available as Supplementary information.

Hemolytic uremic syndrome due to Shiga toxin­producing Escherichia coli and hypocomplementemia with favorable response to eculizumab: a case report / [Síndrome urémico hemolítico por Escherichia Coli e hipocomplementemia con respuesta favorable a eculizumab: comunicación de un caso]

Introduction: Neurologic involvement in hemolytic uremic syndrome related to Shiga toxin­producing Escherichia coli (STEC-HUS) is the main cause of death. In last years has been demonstrated that activation of complement alternative pathway also contributes to organ damage. This finding led to the recognition of decreased C3 levels at admission as a marker of poor prognosis as well as the evaluation of the use of eculizumab in cases with neurologic compromise. Objective: to report a patient with STEC-HUS and hypocomplementemia with neurological involvement treated with eculizumab. Clinical case: A 17-month-old male was admitted due to seizures and anuria for last 24 h with a history of 48 h of bloody diarrhea. He presented a laboratory profile compatible with STEC-HUS and severe hyponatremia, results of brain tomography were normal. Also there was complement activation: C3 73 mg/dl (normal > 90 mg/dL) and C5b-9 778.9 ng/ml (normal 135.8-385.3 ng/ml). Initial treatment includes normal saline solution and anticonvulsants drugs, sodium correction and peritoneal dialysis. On third day of hospitalization, because of progression of the neurologic involvement a dose of eculizumab (300 mg) was given, showing at 24 h a markedly neurologic improvement along with and increasing platelet count and a descending lactic dehydrogenase levels. He was discharged after 14 days in a good condition. Later a STEC O157:H7 infection was confirmed and he also normalized the C3 level. Conclusion: This case shows that decreased C3 level at admission was associated to neurologic involvement and suggests that eculizumab might be a favorable therapeutic option.

Introducción: En compromiso neurológico en el síndrome urémico hemolítico producido por Eschericha coli productor de Shiga toxina (STEC-SUH) es la primera causa de mortalidad. En los últimos años se ha demostrado que también contribuye al daño de órgano la activación de la vía alterna del complemento. Este hallazgo dio lugar al reconocimiento del descenso de C3 como marcador de mal pronóstico así como a la evaluación del uso de eculizumab ante compromiso neurológico severo. Objetivo: Comunicar un paciente con STEC-SUH e hipocomplementemia con compromiso neurológico tratado con eculizumab. Caso clínico: Varón de 17 meses que ingresa por síndrome convulsivo y 24 horas de anuria con antecedente de diarrea con sangre de 48 horas de evolución. Presentaba al ingreso laboratorio compatible con STEC-HUS e hiponatremia severa, con tomografía de cerebro normal. Además presentaba activación del complemento: C3 73 mg/dl (normal > 90 mg/dL) y C5b-9 778,9 ng/ml (normal 135,8-385,3 ng/ml). Se administró solución fisiológica y anticonvulsivantes, se corrigió la natremia y comenzó diálisis peritoneal. Al tercer día, por progresión del compromiso neurológico, se administró eculizumab (300 mg) experimentando una notable recuperación neurológica a las 24 horas junto a aumento de plaquetas y descenso de láctico deshidrogenasa. El paciente fue dado de alta luego de 14 días en buen estado general. Posteriormente se confirmó aislamiento de STEC O157:H7 y normalización de C3. Conclusión: este caso demuestra que el descenso de C3 al ingreso se asoció con daño neurológico y sugiere que la administración de eculizumab podría ser una alternativa terapéutica favorable.

Transient early-childhood hyperkalemia without salt wasting, physiopathological approach of three cases. / Hiperpotasemia transitoria del lactante sin pérdida salina, enfoque fisiopatológico de tres casos.

Two types of early-childhood hyperkalemia had been recognized, according to the presence or absence of urinary salt wasting. This condition was attributed to a maturation disorder of aldosterone receptors and is characterized by sustained hyperkalemia, hyperchloremic metabolic acidosis due to reduced ammonium urinary excretion and bicarbonate loss, and normal creatinine with growth delay. We present three patients of the type without salt wasting, which we will call transient early-childhood hyperkalemia without salt wasting, and discuss its physiopathology according to new insights into sodium and potassium handling by the aldosterone in distal nephron. In three children from 30 to 120-day-old admitted with bronchiolitis and growth delay hyperkalemia was found in routine laboratory. Further studies revealed a normal creatinine with inappropriately normal or low fractional excretion of potassium, accompanied by inadequately normal serum aldosterone and plasma renin activity for their higher plasma potassium levels, but without urine salt wasting. They also presented hyperchloremic metabolic acidosis with fractional excretion of bicarbonate 0.58-2.2%, positive urinary anion gap during metabolic acidosis and normal ability to acidify the urine. Based on these findings a diagnosis of transient early-childhood hyperkalemia without salt wasting was made and they were treated sodium bicarbonate and hydrochlorothiazide with favorable response. The condition was transient in all cases leading to treatment discontinuation. Given that transient early-childhood hyperkalemia without salt wasting is a tubular disorder of transient nature with mild symptoms; it must be keep in mind in the differential diagnosis of hyperkalemia in young children.

Prodromal Phase of Hemolytic Uremic Syndrome Related to Shiga Toxin-Producing Escherichia coli: The Wasted Time.

OBJECTIVES: This study aimed to evaluate practice patterns during prodromal phase of hemolytic uremic syndrome related to Shiga toxin-producing Escherichia coli (STEC-HUS). METHODS: Trajectories of children from first symptoms until STEC-HUS admitted consecutively at our center (period 2000-2017) were retrospectively reviewed. Early recommended practices include identification of STEC infections, antibiotics and antiperistaltic avoidance, and administration of anticipatory intravenous fluids; therefore, implementation and changes over time (before and after 2011) of such interventions were assessed. In addition, early management was correlated with acute disease outcomes. RESULTS: Of 172 patients, 98 (57%) had early consults, 75 of them visit the pediatric emergency department. Those seen with watery diarrhea (n = 74) were managed as outpatients, whereas 27 of the 45 assisted with bloody diarrhea were hospitalized for diagnosis other than STEC-HUS. Stool cultures were performed in 13.4% (23/172), 18% (31/172) received antibiotics, and 12.8% (22/172) received endovenous fluids; none received antiperistaltic agents. Shiga toxin-producing E. coli infection was proven in 4% (7/172) before HUS. Rate of cultured patients and treated with intravenous fluids remained unchanged over time (P = 0.13 and P = 0.48, respectively), whereas antibiotic prescription decreased from 42.8% to 16.6% (P = 0.005). Main acute outcomes (need for dialysis, pancreatic compromise, central nervous system involvement, and death) were similar (P > 0.05) regardless of whether they received antibiotics or intravenous fluids. CONCLUSIONS: During the diarrheal phase, 57% of patients consulted; three-quarters of them consulted to the pediatric emergency department. Shiga toxin-producing E. coli detection was poor, antibiotic use remained high, and anticipatory volume expansion was underused. These findings outline the critical need to improve the early management of STEC-HUS.

Rasburicase in hemolytic uremic syndrome related to Shiga toxin-producing Escherichia coli: a report of nine cases.

BACKGROUND: Hyperuricemia might induce additional renal damage in children with hemolytic uremic syndrome related to Shiga toxin-producing Escherichia coli (STEC-HUS). A few case reports have shown rasburicase to be effective in decreasing serum uric acid (UA) and improving renal function. However, there is only one report on the use of rasburicase in a child with STEC-HUS, which shows satisfactory results. We describe here the safety and efficacy of rasburicase in nine additional cases. CASE-DIAGNOSIS/TREATMENT: Data from 9 children (5 females, median age 2 years) who received rasburicase were reviewed. At admission, 6 were dehydrated and 3 euvolemic. Dehydrated patients received saline solution and afterwards, as well as for those initially euvolemic, we aimed to keep a neutral fluid balance. Despite this, urine output did not increase. Baseline creatinine was 3.35 mg/dL (1.47-9.1) and UA 11.4 mg/dL (8.3-19.2). A single dose of rasburicase (0.2 mg/kg) was given 6-8 h after admission, which reduced UA levels to 1.8 mg/dL (0.3-5, p = 0.009) on the next day. However, renal parameters worsen and dialysis had to be initiated. Then, while still on dialysis, a UA rebound occurred in all cases reaching a peak of 8.9 mg/dL (4.5-13.8). Just after a steady increase in urine output, a sustained decline in UA levels concomitantly occurred with an improvement in renal function. At discharge, all patients reached normal UA levels. No side effects were recorded. CONCLUSIONS: Administration of rasburicase in children with STEC-HUS was safe but failed to provide any significant benefit despite fall in serum UA levels.

Blood urea nitrogen to serum creatinine ratio as a prognostic factor in diarrhea-associated hemolytic uremic syndrome: a validation study.

Identifying those children with complicated forms of diarrhea-associated hemolytic uremic syndrome (D+HUS) on admission can optimize their management. Recently, the blood urea nitrogen to serum creatinine ratio (BCR) at admission has been proposed as a novel and accurate predictor of complicated clinical outcome in D+HUS; therefore, we performed this retrospective study aimed to validate such observation in a larger series of patients. A complicated course was defined as developing one or more of the following: severe neurological or bowel injury, pancreatitis, cardiac or pulmonary involvement, hemodynamic instability, hemorrhage, and death. Data from 161 children were reviewed, 50 of them with a complicated disease including five deaths. Those with worse evolution presented a lower admission BCR than those with good outcome (22.5 vs. 30.8; p = 0.005). BCR at admission showed a limited ability to identify children at risk of a complicated course, with an AUC of 0.63 (95% CI 0.58-0.71) and an optimal cutoff point of ≤ 26.7, which achieves a sensitivity of 70% (95% CI 55.2-81.7) and a specificity of 56.7% (95% CI 47-66). CONCLUSION: In this validation study, the BCR at admission provided a limited value to predict severe forms of D+HUS. What is Known: • BCR at admission has been proposed as an accurate predictor of complicated clinical course in children with D+HUS. What is New: • In a larger series of children with D+HUS, we were unable to confirm the usefulness of the admission BCR to early identify those at risk of complicated forms of the disease. • Further research is warranted to improve the optimal detection of these high-risk patients.

Early erythropoietin in post-diarrheal hemolytic uremic syndrome: a case-control study.

BACKGROUND: Although erythropoietin (EPO) deficiency has been reported in children with post-diarrheal hemolytic uremic syndrome (D + HUS), very limited clinical data on EPO use in this disease are currently available. In this case-control study we examined whether EPO administration would reduce the number of red blood cell (RBC) transfusions in D + HUS patients under our care. METHODS: Data from children treated exclusively with RBC transfusions (controls; n = 21) were retrospectively compared with data on those who also received EPO for the treatment of anemia (cases; n = 21). RESULTS: Both patient groups were similar in age (p = 0.9), gender (p = 0.12), weight (p = 1.00) and height (p = 0.66). Acute phase severity was also comparable, as inferred by the need for dialysis (p = 0.74), the duration of dialysis (p = 0.3), length of hospitalization (p = 0.81), presence of severe bowel (p = 1.00) or neurological injury (p = 0.69), arterial hypertension (p = 1.00) and death (p = 1.00). No differences in the hemoglobin level at admission (p = 0.51) and discharge (p = 0.28) were noted. Three children treated with EPO and two controls did not require any RBC transfusion (p = 1.00). Median number of RBC transfusions needed by cases and controls was 2 (p = 0.52). CONCLUSION: Treatment with EPO did not reduce the number of RBC transfusions in D + HUS children. Assessment of EPO efficacy in D + HUS merits further studies.

Hipercalciuria idiopática en niños con infección del tracto urinario / Idiopathic hypercalciuria in children with urinary tract infection

Introducción. La hipercalciuria idiopática (HI) predispone al desarrollo de infección del tracto urinario (ITU); sin embargo, hay escasa información local sobre dicha asociación. Nuestros objetivos fueron estimar la prevalencia de HI en niños con ITU y evaluar si esta difería según la presencia o no de reflujo vesicoureteral (RVU). Complementariamente, analizamos la asociación entre HI y la ingesta de sal. Población y métodos. Determinamos la calciuria a pacientes menores de 18 años con ITU estudiada (ecografía y cistouretrografía miccional) y ausencia de causas secundarias de hipercalciuria. Consideramos HI al cociente calcio/creatinina > 0,8; 0,6; 0,5 y 0,2 en niños de 0-6 meses, 7-12 meses, 12-24 meses y en los mayores de 2 años, respectivamente; e ingesta elevada de sodio, al cociente sodio/potasio urinario > 2,5. Resultados. En 136 pacientes (87 niñas, mediana de edad 3 años), la prevalencia de HI fue de 20%. Los pacientes con (n= 54) y sin (n= 82) RVU fueron similares en género, peso, talla, edad al diagnóstico y al momento del estudio, características clínicas (hematuria, nefrolitiasis, dolor cólico y recurrencia de ITU), antecedentes familiares de nefrolitiasis y en la prevalencia de HI (26% vs. 16%, p= 0,24). Los niños hipercalciúricos presentaron ingesta elevada de sodio más frecuentemente que los normocalciúricos (76% vs. 46%, p= 0,007). Conclusiones. La prevalencia de HI en niños con ITU fue alta (20%) y no difirió entre los pacientes con y sin RVU. Sería recomendable la búsqueda de HI en los niños con ITU, independientemente de la presencia o no de RVU.(AU)

Introduction. Idiopathic hypercalciuria (IH) predisposes to urinary tract infections (UTIs); however, there is scarce local information regarding such association. Our objectives were to estimate IH prevalence in children with UTI and to assess whether there were differences in relation to the presence or absence of vesicoureteral reflux (VUR). Additionally, the association between IH and salt intake was studied. Population and Methods. Calciuria was determined in patients younger than 18 years old on whom UTI had been studied (ultrasound and voiding cystourethrogram), and who had no secondary causes of hypercalciuria. IH was defined as a calcium to creatinine ratio of >0.8, 0.6, 0.5 and 0.2 in children aged 0 to 6 months old, 7 to12 months old, 12 to 24 months old and older than 2 years old, respectively; and a high sodium intake with a urinary sodium to potassium ratio of >2.5. Results. IH prevalence among 136 patients (87 girls, median age: 3 years old) was 20%. Patients with VUR (n= 54) and without VUR (n= 82) had similar characteristics in terms of sex, weight, height, age at diagnosis and age at the time of the study, and clinical features (hematuria, nephrolithiasis, colicky pain, and recurrent UTI), family history of kidney stone formation, and IH prevalence (26% versus 16%, p= 0.24). A high sodium intake was more frequently observed in children with hypercalciuria than in those with normal urine calcium levels (76% versus 46%, p= 0.007). Conclusions. IH prevalence in children with UTI was high (20%), with no differences observed between patients with and without VUR. As a recommendation, the presence of IH should be detected in children with UTI, regardless of VUR presence or absence.(AU)

Hipercalciuria idiopática en niños con infección del tracto urinario / Idiopathic hypercalciuria in children with urinary tract infection

Introducción. La hipercalciuria idiopática (HI) predispone al desarrollo de infección del tracto urinario (ITU); sin embargo, hay escasa información local sobre dicha asociación. Nuestros objetivos fueron estimar la prevalencia de HI en niños con ITU y evaluar si esta difería según la presencia o no de reflujo vesicoureteral (RVU). Complementariamente, analizamos la asociación entre HI y la ingesta de sal. Población y métodos. Determinamos la calciuria a pacientes menores de 18 años con ITU estudiada (ecografía y cistouretrografía miccional) y ausencia de causas secundarias de hipercalciuria. Consideramos HI al cociente calcio/creatinina > 0,8; 0,6; 0,5 y 0,2 en niños de 0-6 meses, 7-12 meses, 12-24 meses y en los mayores de 2 años, respectivamente; e ingesta elevada de sodio, al cociente sodio/potasio urinario > 2,5. Resultados. En 136 pacientes (87 niñas, mediana de edad 3 años), la prevalencia de HI fue de 20%. Los pacientes con (n= 54) y sin (n= 82) RVU fueron similares en género, peso, talla, edad al diagnóstico y al momento del estudio, características clínicas (hematuria, nefrolitiasis, dolor cólico y recurrencia de ITU), antecedentes familiares de nefrolitiasis y en la prevalencia de HI (26% vs. 16%, p= 0,24). Los niños hipercalciúricos presentaron ingesta elevada de sodio más frecuentemente que los normocalciúricos (76% vs. 46%, p= 0,007). Conclusiones. La prevalencia de HI en niños con ITU fue alta (20%) y no difirió entre los pacientes con y sin RVU. Sería recomendable la búsqueda de HI en los niños con ITU, independientemente de la presencia o no de RVU.

Introduction. Idiopathic hypercalciuria (IH) predisposes to urinary tract infections (UTIs); however, there is scarce local information regarding such association. Our objectives were to estimate IH prevalence in children with UTI and to assess whether there were differences in relation to the presence or absence of vesicoureteral reflux (VUR). Additionally, the association between IH and salt intake was studied. Population and Methods. Calciuria was determined in patients younger than 18 years old on whom UTI had been studied (ultrasound and voiding cystourethrogram), and who had no secondary causes of hypercalciuria. IH was defined as a calcium to creatinine ratio of >0.8, 0.6, 0.5 and 0.2 in children aged 0 to 6 months old, 7 to12 months old, 12 to 24 months old and older than 2 years old, respectively; and a high sodium intake with a urinary sodium to potassium ratio of >2.5. Results. IH prevalence among 136 patients (87 girls, median age: 3 years old) was 20%. Patients with VUR (n= 54) and without VUR (n= 82) had similar characteristics in terms of sex, weight, height, age at diagnosis and age at the time of the study, and clinical features (hematuria, nephrolithiasis, colicky pain, and recurrent UTI), family history of kidney stone formation, and IH prevalence (26% versus 16%, p= 0.24). A high sodium intake was more frequently observed in children with hypercalciuria than in those with normal urine calcium levels (76% versus 46%, p= 0.007). Conclusions. IH prevalence in children with UTI was high (20%), with no differences observed between patients with and without VUR. As a recommendation, the presence of IH should be detected in children with UTI, regardless of VUR presence or absence.

Idiopathic hypercalciuria in children with urinary tract infection.

INTRODUCTION: Idiopathic hypercalciuria (IH) predisposes to urinary tract infections (UTIs); however, there is scarce local information regarding such association. Our objectives were to estimate IH prevalence in children with UTI and to assess whether there were differences in relation to the presence or absence of vesicoureteral reflux (VUR). Additionally, the association between IH and salt intake was studied. POPULATION AND METHODS: Calciuria was determined in patients younger than 18 years old on whom UTI had been studied (ultrasound and voiding cystourethrogram), and who had no secondary causes of hypercalciuria. IH was defined as a calcium to creatinine ratio of >0.8, 0.6, 0.5 and 0.2 in children aged 0 to 6 months old, 7 to12 months old, 12 to 24 months old and older than 2 years old, respectively; and a high sodium intake with a urinary sodium to potassium ratio of >2.5. RESULTS: IH prevalence among 136 patients (87 girls, median age: 3 years old) was 20%. Patients with VUR (n= 54) and without VUR (n= 82) had similar characteristics in terms of sex, weight, height, age at diagnosis and age at the time of the study, and clinical features (hematuria, nephrolithiasis, colicky pain, and recurrent UTI), family history of kidney stone formation, and IH prevalence (26% versus 16%, p= 0.24). A high sodium intake was more frequently observed in children with hypercalciuria than in those with normal urine calcium levels (76% versus 46%, p= 0.007). CONCLUSIONS: IH prevalence in children with UTI was high (20%), with no differences observed between patients with and without VUR. As a recommendation, the presence of IH should be detected in children with UTI, regardless of VUR presence or absence.

Laboratory predictors of acute dialysis in hemolytic uremic syndrome.

BACKGROUND: Strict guidelines on use of dialysis in children with post-diarrheal hemolytic uremic syndrome (D + HUS) are lacking. This study investigated laboratory predictors of acute dialysis because they are more objective than clinical features. Added to this, given that urine output is also an objective parameter, its ability to predict dialysis requirements was also investigated. METHODS: Out of 153 D + HUS children reviewed, 88 received dialysis and 65 did not. Initial laboratory parameters and diuresis between both groups were analyzed. RESULTS: Dialyzed patients had higher creatinine, urea, alanine aminotransferase, hematocrit and leukocyte count; and lower sodium, bicarbonate, and pH compared to non-dialyzed ones. Serum creatinine was the only independent predictor (P = 0.003) of dialysis; therefore, its ability to predict dialysis was estimated on receiver operating characteristic (ROC) curve analysis and using the Acute Kidney Injury Network (AKIN) staging system. Area under the ROC curve was 0.92 (95% confidence interval [95%CI]: 0.83-1) with a creatinine cut-off of 1.25 mg/dL (sensitivity, 100%; specificity, 76.5%) for children <1 year, and 0.93 (95%CI: 0.88-0.98) with a threshold of 2 mg/dL (sensitivity, 91%; specificity, 87.5%) for older children. AKIN stage 3 at admission predicted dialysis with a sensitivity of 92% and specificity of 84.2%. Urine output had the highest accuracy for dialysis prediction (sensitivity, 100%; specificity, 95.3%). CONCLUSIONS: Initial serum creatinine concentration was the best laboratory predictor of dialysis, but the first 24 h diuresis was even better for this purpose. But, given that serum creatinine is an immediate available parameter, the cut-offs identified may label D + HUS children who will probably need dialysis, prompting early referral to centers able to provide dialysis.

Idiopathic hypercalciuria in children with urinary tract infection. / Idiopathic hypercalciuria in children with urinary tract infection.

INTRODUCTION: Idiopathic hypercalciuria (IH) predisposes to urinary tract infections (UTIs); however, there is scarce local information regarding such association. Our objectives were to estimate IH prevalence in children with UTI and to assess whether there were differences in relation to the presence or absence of vesicoureteral reflux (VUR). Additionally, the association between IH and salt intake was studied. POPULATION AND METHODS: Calciuria was determined in patients younger than 18 years old on whom UTI had been studied (ultrasound and voiding cystourethrogram), and who had no secondary causes of hypercalciuria. IH was defined as a calcium to creatinine ratio of >0.8, 0.6, 0.5 and 0.2 in children aged 0 to 6 months old, 7 to12 months old, 12 to 24 months old and older than 2 years old, respectively; and a high sodium intake with a urinary sodium to potassium ratio of >2.5. RESULTS: IH prevalence among 136 patients (87 girls, median age: 3 years old) was 20

. Patients with VUR (n= 54) and without VUR (n= 82) had similar characteristics in terms of sex, weight, height, age at diagnosis and age at the time of the study, and clinical features (hematuria, nephrolithiasis, colicky pain, and recurrent UTI), family history of kidney stone formation, and IH prevalence (26

versus 16

, p= 0.24). A high sodium intake was more frequently observed in children with hypercalciuria than in those with normal urine calcium levels (76

versus 46

, p= 0.007). CONCLUSIONS: IH prevalence in children with UTI was high (20

), with no differences observed between patients with and without VUR. As a recommendation, the presence of IH should be detected in children with UTI, regardless of VUR presence or absence.

Acute kidney injury in critically ill children: incidence and risk factors for mortality.

INTRODUCTION: Acute kidney injury is a common complication associated with an increase in mortality in children who require intensive care. The objective of this study was to determine the incidence of acute kidney injury and identify risk factors for mortality in critically ill patients hospitalized in our facility. PATIENTS AND METHODS: This was a prospective and observational study conducted at the Intensive Care Unit (ICU) of Hospital Pedro de Elizalde between 2005 and 2009. All patients with acute kidney injury were included, and those with chronic renal failure, prerenal acute kidney injury, hepatorenal syndrome, newborn infants, and postoperative cardiovascular surgery patients were excluded. The sample was divided into survivors and deceased patients so as to identify risk factors for mortality using univariate and multivariate analyses, taking their clinical characteristics as predictive variable, and death at the ICU as the outcome variable. RESULTS: Out of 1496 patients, 66 developed acute kidney injury (4.4%). The cause was secondary in 72.8% of cases, and due to primary kidney disease in 27.2% of cases. Mortality rate was 44% (29 patients). The univariate analysis showed that the presence of anuria (p= 0.0003; OR: 7.01; 95% CI: 2.3-21.35) and the need of dialysis (p= 0.0009; OR: 6.35; 95% CI: 2.03-9.88) were signifcantly higher in deceased patients. The multiple regression analysis identifed that the need of dialysis (p = 0.0002; OR: 5.94; 95% CI: 1.85-19.04) was an independent risk factor for mortality. CONCLUSIONS: The incidence of acute kidney injury in critically ill children was 4.4%, and the need of dialysis was an independent predictor of mortality.

Acute kidney injury in critically ill children: incidence and risk factors for mortality / Daño renal agudo en niños críticos: incidencia y factores de riesgo de mortalidad

Introduction. Acute kidney injury is a common complication associated with an increase in mortality in children who require intensive care. The objective of this study was to determine the incidence of acute kidney injury and identify risk factors for mortality in critically ill patients hospitalized in our facility. Patients and Methods. This was a prospective and observational study conducted at the Intensive Care Unit (ICU) of Hospital Pedro de Elizalde between 2005 and 2009. All patients with acute kidney injury were included, and those with chronic renal failure, prerenal acute kidney injury, hepatorenal syndrome, newborn infants, and postoperative cardiovascular surgery patients were excluded. The sample was divided into survivors and deceased patients so as to identify risk factors for mortality using univariate and multivariate analyses, taking their clinical characteristics as predictive variable, and death at the ICU as the outcome variable. Results. Out of 1496 patients, 66 developed acute kidney injury (4.4%). The cause was secondary in 72.8% of cases, and due to primary kidney disease in 27.2% of cases. Mortality rate was 44% (29 patients). The univariate analysis showed that the presence of anuria (p= 0.0003; OR: 7.01; 95% CI: 2.3-21.35) and the need of dialysis (p= 0.0009; OR: 6.35; 95% CI: 2.03-9.88) were signifcantly higher in deceased patients. The multiple regression analysis identifed that the need of dialysis (p = 0.0002; OR: 5.94; 95% CI: 1.85-19.04) was an independent risk factor for mortality. Conclusions. The incidence of acute kidney injury in critically ill children was 4.4%, and the need of dialysis was an independent predictor of mortality.

Introducción. El daño renal agudo es una complicación frecuente que se asocia a un aumento de la mortalidad en los niños que requieren cuidados intensivos. El objetivo de este estudio fue determinar su incidencia e identifcar los factores de riesgo de mortalidad en los pacientes críticos internados en nuestra institución. Pacientes y métodos. Estudio prospectivo y observacional realizado en la unidad de terapia intensiva (UTI) del Hospital Pedro de Elizalde entre 2005 y 2009. Se incluyeron todos los pacientes con daño renal agudo, exceptuando a aquellos con insufciencia renal crónica, daño agudo prerrenal, síndrome hepatorrenal, recién nacidos y posquirúrgicos cardiovasculares. La muestra se dividió en sobrevivientes y fallecidos para identifcar los factores de riesgo de mortalidad mediante un análisis univariado y multivariado, considerando como variable de predicción sus características clínicas, y de resultado, la muerte en la UTI. Resultados. De 1496 pacientes, 66 presentaron daño renal agudo (4,4%). En el 72,8% de los casos fue de causa secundaria y en el 27,2%, por enfermedad renal primaria. La mortalidad fue de 44% (29 pacientes). En el análisis univariado la presencia de anuria (p= 0,0003; OR 7,01; IC 95% 2,3 a 21,35) y la necesidad de diálisis (p= 0,0009; OR 6,35; IC 95% 2,03 a 9,88) fueron signifcativamente mayores en los fallecidos. Por regresión múltiple se identifcó la necesidad de diálisis (p= 0,0002; OR 5,94; IC 95% 1,85 a 19,04) como factor de riesgo independiente de mortalidad. Conclusiones. La incidencia de daño renal agudo en los niños críticos fue de 4,4% y el requerimiento de diálisis fue un predictor independiente de mortalidad.

Acute kidney injury in critically ill children: incidence and risk factors for mortality / Daño renal agudo en niños críticos: incidencia y factores de riesgo de mortalidad

Introduction. Acute kidney injury is a common complication associated with an increase in mortality in children who require intensive care. The objective of this study was to determine the incidence of acute kidney injury and identify risk factors for mortality in critically ill patients hospitalized in our facility. Patients and Methods. This was a prospective and observational study conducted at the Intensive Care Unit (ICU) of Hospital Pedro de Elizalde between 2005 and 2009. All patients with acute kidney injury were included, and those with chronic renal failure, prerenal acute kidney injury, hepatorenal syndrome, newborn infants, and postoperative cardiovascular surgery patients were excluded. The sample was divided into survivors and deceased patients so as to identify risk factors for mortality using univariate and multivariate analyses, taking their clinical characteristics as predictive variable, and death at the ICU as the outcome variable. Results. Out of 1496 patients, 66 developed acute kidney injury (4.4%). The cause was secondary in 72.8% of cases, and due to primary kidney disease in 27.2% of cases. Mortality rate was 44% (29 patients). The univariate analysis showed that the presence of anuria (p= 0.0003; OR: 7.01; 95% CI: 2.3-21.35) and the need of dialysis (p= 0.0009; OR: 6.35; 95% CI: 2.03-9.88) were signifcantly higher in deceased patients. The multiple regression analysis identifed that the need of dialysis (p = 0.0002; OR: 5.94; 95% CI: 1.85-19.04) was an independent risk factor for mortality. Conclusions. The incidence of acute kidney injury in critically ill children was 4.4%, and the need of dialysis was an independent predictor of mortality.(AU)

Introducción. El daño renal agudo es una complicación frecuente que se asocia a un aumento de la mortalidad en los niños que requieren cuidados intensivos. El objetivo de este estudio fue determinar su incidencia e identifcar los factores de riesgo de mortalidad en los pacientes críticos internados en nuestra institución. Pacientes y métodos. Estudio prospectivo y observacional realizado en la unidad de terapia intensiva (UTI) del Hospital Pedro de Elizalde entre 2005 y 2009. Se incluyeron todos los pacientes con daño renal agudo, exceptuando a aquellos con insufciencia renal crónica, daño agudo prerrenal, síndrome hepatorrenal, recién nacidos y posquirúrgicos cardiovasculares. La muestra se dividió en sobrevivientes y fallecidos para identifcar los factores de riesgo de mortalidad mediante un análisis univariado y multivariado, considerando como variable de predicción sus características clínicas, y de resultado, la muerte en la UTI. Resultados. De 1496 pacientes, 66 presentaron daño renal agudo (4,4%). En el 72,8% de los casos fue de causa secundaria y en el 27,2%, por enfermedad renal primaria. La mortalidad fue de 44% (29 pacientes). En el análisis univariado la presencia de anuria (p= 0,0003; OR 7,01; IC 95% 2,3 a 21,35) y la necesidad de diálisis (p= 0,0009; OR 6,35; IC 95% 2,03 a 9,88) fueron signifcativamente mayores en los fallecidos. Por regresión múltiple se identifcó la necesidad de diálisis (p= 0,0002; OR 5,94; IC 95% 1,85 a 19,04) como factor de riesgo independiente de mortalidad. Conclusiones. La incidencia de daño renal agudo en los niños críticos fue de 4,4% y el requerimiento de diálisis fue un predictor independiente de mortalidad.(AU)