Evaluation of a protocol-based treatment strategy for postoperative diabetes insipidus in craniopharyngioma

Background: Postoperative diabetes insipidus (DI) is a significant cause of morbidity in craniopharyngiomas (CP) and its effective management improves outcome. Objective: The objective was to determine the efficacy of a treatment protocol in the management of early postoperative DI in CP. Materials and Methods: The quality of postoperative DI control in a prospective cohort of 26 patients treated utilizing a strict protocol (Group 1) was compared with a retrospective cohort of 34 patients (Group 2) managed without a protocol. A 6-h urine output more than 4 ml/kg/h or serum sodium (Na+) more than 145 mEq/L was diagnosed as DI. The quality of DI control was assessed by determining the incidence of serum Na+ values above 150 mEq/L or below 130 mEq/L and the incidence of wide (>10 mEq/L) intra-day fluctuations of serum Na+ levels. Results: The occurrence of high and low serum Na+ levels was significantly lower in Group 1(P = 0.032). The incidence of serum Na+ exceeding 150 mEq/L on postoperative days 2 and 3 was significantly higher in Group 2 as compared with those in Group 1 (25% vs. 7.6%, P = 0.0008). Hyponatremia was more frequent in Group 2 and tended to occur on postoperative days 6, 7, and 8 (14.2% vs. 3.2%; P = 0.004). The same patients who had hypernatremia in the early part of the week later developed hyponatremia. Although the incidence of wide intra-day fluctuations (>10 mEq/L) was higher in Group 2, it did not reach statistical significance. Conclusion: A strict protocol based management results in better control of postoperative DI in CP.