Daily Sodium Monitoring and Fluid Intake Protocol: Preventing Recurrent Hospitalization in Adipsic Diabetes Insipidus.

Management of diabetes insipidus (DI) is usually facilitated by an intact thirst mechanism prompting water ingestion in times of rising osmolality. Maintenance of eunatremia can be quite difficult in patients with DI and adipsia because of the absence of this homeostatic mechanism. Few published protocols for management of these complex cases exist. We report a case of a 16-year-old girl who had a diagnosis of craniopharyngioma with preoperative hypopituitarism and central DI. She underwent transsphenoidal resection in 2013 and additionally developed postoperative cognitive impairment and hypothalamic dysfunction, including adipsia. She subsequently experienced widely dysregulated sodium levels, necessitating inpatient care ∼30% of days in 2014 and 2015. We created a protocol for this patient that uses a fixed daily dose of subcutaneous DDAVP combined with daily modulation of fluid intake based on daily serum sodium measurement. The protocol provides guidance for the day's fluid intake based on both the current sodium result and the rate of change from the previous day. Since the adoption of the protocol in June 2016, the patient has had a dramatic reduction in hospitalizations. Use of a protocol for providing recommendations for fluid intake based on the sodium level and rate of change may help to maintain normal sodium levels in such patients, decreasing hospitalization and improving quality of life.