RESUMEN
Introduction: Diabetes insipidus (DI) is a syndrome characterized by polyuria and polydipsia secondary to a decreased secretion or action of the antidiuretic hormone (ADH). An early diagnosis is essential. Diagnosis is made by measuring plasma and urinary osmolarity and their changes under water deprivation and after DDAVP administration. Objective: Lo describe the clinical, radiological characteristics as well as the initial treatment of eight children with DI, 3 of them nephrogenic DI (DIN) and 5 with central DI. Methods: A Retrospective, descriptive study in DI patients under control at the Catholic University of Chile and Sotero del Rio Hospital between 1998-2008 is presented. Clinical files were evaluated collecting clinical, epidemiologic, biochemical and image data. Serum (Sosm) and urinary osmolarity (Uosm) were registered. DI was diagnosed with a Sosm > 300 and Usm < 600 mOsm/L. Central DI was defined as the inability to reach a Uosm > 600 or a 50 percent-increase after DDAVP treatment. Otherwise DI was classified as DIN. Results: Eight patients (5 males) were studied. Chief complaints were polydipsia/polyuria (5/8), hyperthermia (2/8), and failure to grow (1/8). MRI showed endocraneal lesion in all patients with Central DI. All of these utilized oral or inhalatory DDAVP treatment. Patients with Nephrogenic DI were trated with Hydrochlrothiazide. Conclusion: Polydipsia, polyuria, hyperthermia with hypernatremia are suggestive of DI in the first year of life. Water deprivation test is diagnostic in differentiating Central and Nephrogenic DI. MRI is an essential diagnostic tool in CDI. Manegement should be multidisciplinary, including a pediatician, nephrologist, endocrinologist and nutricionist.
Introducción: La diabetes insípida (DI) se caracteriza por poliuria y polidipsia, secundario a una disminución de la secreción o acción de la hormona antidiurética. Su diagnóstico precoz es fundamental. Objetivo: Describir las características clínicas, radiológicas y tratamiento inicial de una serie de ocho pacientes con DI. Diseño: Estudio descriptivo-restrospectivo. Universo: Pacientes con DI evaluados en la Universidad Católica de Chile y Hospital Dr. Sótero del Río entre 1998-2008. Pacientes y Métodos: Desde la ficha clínica se analizaron variables clínicas, epidemiológicas, bioquímicas e imágenes. Se determinó Osmolaridad sérica (OsmS) y urinaria (OsmU). Se consideró DI sí la OsmS > 300 mOsm con OsmU < 600 mOsm, Di-central (DIC) sí posterior a DDAVP la OsmU aumento > 50 por ciento ó > 600 mOsm, de los contrario se clasificó como nefrogénica (DIN). Resultados: Se reclutaron ocho pacientes con DI (5 varones), fueron DIN 3/8. El motivo de consulta fue: polidipsia-poliuria (5/8), hipertermia (2/8) y talla baja (1/8). La RNM mostró lesión intracraneana en todos los pacientes con DIC: nodulo hipofisiario, aracnoidocele selar, Histiocitosis X, germinoma y un paciente sin se±al de neurohipófisis. Los sujetos con DIC usaron DDAVP inhalatoria (4) y oral (1). Los sujetos con DIN usaron hidroclorotiazida. Conclusión: Polidipsia, poliuria, hipertermia con hipernatremia y falla de medro en lactantes son sugerentes de DI. La prueba de deprivación hídrica es fundamental en la diferenciación de DIC y DIN. La RNM cerebral es una herramienta diagnóstica imprescindible en la DIC. El tratamiento de estos pacientes debe ser multidiciplinario interactuando pediatra, nefrólogo, endocrinólogo y nutricionista.