Disturbances of Sodium and Water. Diabetes Insipidus in Children; Chapter [24]

Abstract

Disturbance of sodium and water is the most common disorders in clinical practice because of high prevalence of diseases associated with dehydration. Hyponatremia (serum sodium less than 135 mmol/L) and hypernatremia (serum sodium level above 145 mmol/L) are common in hospitalized children and it is an independent mortality risk factor in intensive care. The aim of this article is to review the main reasons of hyponatremia and hypernatremia and present the guidelines of treatment. Diabetes insipidus (DI) is a condition when large volumes of dilute urine are excreted due to defect of syntesis or deficiency of arginine vasopressin (AVP) secretion, causing central DI, or due to renal tubular resistence to AVP-nephrogenic DI, and sometimes can occur due to secondary suppression of AVP production after excessive fluid intake in primary polydipsia. DI is characterized by polyuria and polydipsia, causing dehydration and hypernatremia if the patient is deprived of water. The goal of treatment of DI is to decrease urine output and thirst, allowing for appropriate sodium and water balance and child‘s development.