Diabetes insipidus and syndrome of inappropriate secretion of antidiuretic hormone in children with midline suprasellar brain tumors.

Salt and water balance within the body is controlled by the hormonal influence of vasopressin. Vasopressin is produced in the hypothalamus, stored and released from the posterior lobe of the pituitary, and travels via the blood to the kidneys to regulate the amount and concentration of urine excreted. Oversecretion or undersecretion of vasopressin, eg, diabetes insipidus (DI) or syndrome of inappropriate secretion of antidiuretic hormone (SIADH) results in an imbalance of the salt-to-water ratio. In children this hormonal imbalance may occur secondary to a suprasellar brain tumor and/or the treatment of such. Approximately 50% to 75% of children with suprasellar tumors will develop permanent DI and the remainder will experience transient postoperative DI or SIADH. Pathophysiology of vasopressin's control on salt and water balance and its relationship to suprasellar brain tumors in children are presented. Nursing assessment and intervention parameters for management of DI and SIADH in children with brain tumors are also discussed.