Association between moderate–severe bronchiolitis and syndrome of inappropriate antidiuretic hormone secretion in emergency departments

ObjectivesTo identify clinical characteristics that may lead to the early identification of patients hospitalised for moderate-to-severe bronchiolitis with urine results associated with the syndrome of inappropriate antidiuretic hormone secretion (SIADH).Patients and methodsA prospective observational study was conducted, spanning the bronchiolitis epidemic season (October 2012–March 2013), including all children who were hospitalised with a diagnosis of moderate-to-severe bronchiolitis. The following criteria were used to establish a diagnosis of SIADH: urine sodium level of 40 mmol/L or greater, urine osmolarity above 500 mosm/kg, and urine density of 1020 g/L or greater. Demographic characteristics, ventilation mode and clinical outcome were also analysed. A comparison was made between patients that met urine SIADH criteria and those that did not.ResultsA total of 126 children were included, 23 (18.6%) with urine SIADH criteria. Patients in this group had a higher incidence of pneumonia and/or atelectasis on chest X-ray (21.7% vs. 1.9%, p = .002), worse response to bronchodilator treatment with nebulised adrenaline (69.5% vs. 28,1%, p = .016), more need for respiratory assistance (high flow oxygen therapy (17.4% vs. 7.7%, p = .016)), or non-invasive mechanical ventilation (13% vs. 5.8%, p = .034), and more admissions to the PICU (26.1% vs. 6.8%, p = .007).ConclusionsPatients older than 1 month with acute moderate bronchiolitis and urine SIADH criteria present poorer progress and greater need for non-invasive mechanical ventilation, PICU admission, and a higher incidence of pneumonia on chest X-ray. For this reason, urine samples should be collected from these patients for early diagnosis of SIADH, and thus early treatment of fluid and electrolyte abnormalities.

ResumenObjetivosIdentificar precozmente y analizar las características de pacientes que precisan ingreso por bronquiolitis moderada o grave que cumplen criterios urinarios de SIADH.Pacientes y métodosEstudio prospectivo observacional, realizado entre octubre de 2012-marzo de 2013 en urgencias pediátricas. Se incluyen menores de 12 meses con bronquiolitis moderada o grave que requieren ingreso. Se consideran criterios urinarios de SIADH: sodio urinario ≥ 40 mmol/l, osmolaridad urinaria > 500 mOsm/kg y densidad urinaria > 1.020 g/l. Se recogen variables epidemiológicas y clínicas y se comparan 2 grupos definidos por cumplir o no criterios urinarios de SIADH.ResultadosSe incluyen 126 pacientes con bronquiolitis moderada, 23 (18,6%) cumplen criterios urinarios de SIADH, ninguno grave ni menor de un mes. Los pacientes con criterios urinarios de SIADH tienen mayor incidencia de neumonía y/o atelectasia en la radiografía de tórax (21,7% vs. 1,9%; p = 0,002), peor respuesta al tratamiento con adrenalina (69,5% vs. 28,1%; p = 0,016), mayor asistencia respiratoria: oxigenoterapia de alto flujo (17,4% vs. 7,7%; p = 0,016) y ventilación mecánica no invasiva (13% vs. 5,8%; p = 0,034). Requieren más días oxigenoterapia (p = 0,02) y tratamiento broncodilatador (p = 0,04) y mayor ingreso en cuidados intensivos pediátricos (26,1% vs. 6,8%; p = 0,007).ConclusionesLos pacientes mayores de 1 mes con bronquiolitis moderada y con criterios urinarios de SIADH tienen peor evolución respiratoria, mayor necesidad de soporte respiratorio, ingreso en UCIP y más alteraciones radiográficas. Por ello recomendamos realizar determinaciones de orina a estos pacientes para detectar precozmente el desarrollo de SIADH y cuidar el manejo hidroelectrolítico, previniendo el desarrollo de complicaciones potencialmente graves.