Predictors of Postoperative Diabetes Insipidus Following Surgery of Sellar-Suprasellar Tumor

Abstract

Background: Higher postoperative morbidity and longer hospital stay are linked to diabetes insipidus (DI) after surgery of sellar or suprasellar tumors.

Objective: To find out the predictors of postoperative DI following sellar or suprasellar surgery.

Methods: This case-control study was conducted at the National Institute of Neurosciences and Hospital, Dhaka, from January 2023 to June 2023. Patients with sellar or suprasellar tumors admitted to the neurosurgery department for surgery were included by non-probability consecutive sampling (n=109, age 39.4±13.7 years, 44.9% female). All patients were treated surgically by standard protocol. A standard institutional inpatient monitoring system was used in all postoperative patients regardless of symptoms, including hourly intake and output measurements. Participants were followed up regularly during their hospital stay and then after 6 weeks of surgery up to 6 months. Specific criteria were used to confirm the diagnosis of DI for each patient. All clinical and laboratory data were recorded in a data sheet. Finally patients developing DI were grouped as case and rest of them grouped as control. All clinical and laboratory parameters were compared between two groups.

Result: Transient DI (resolved within 6 weeks of surgery) was present in 53 (49%) and prolonged DI (persisted >6 weeks of surgery) in 22 (20%) participants. Transient DI were more frequent in participants with 1st postoperative serum sodium level >145 mmol/L (p<0.001). Participants with younger age (p=0.044), non pituitary sellar tumor (p=0.044), preoperative hypothyroidism (p=0.048), gross total removal of tumor (p=0.027) and 1st postoperative serum sodium level >145 mmol/L (p<0.001) had higher frequency of prolonged DI. However, in logistic regression, preoperative hypothyroidism (OR 3.4; 95% CI 1.0-11.6; p=0.048) and 1st post operative serum sodium >145 mmol/l (OR 11.4; 95% CI 2.8-46.4; p<0.001) showed a significant association with prolonged DI when adjusted for age, tumor type, route and extent of resection.

Conclusion: First post-operative serum sodium >145 mmol/L is a significant predictor of transient DI; whereas first post-operative serum sodium >145 mmol/L and preoperative hypothyroidism are found to be significant predictor of prolonged DI.

Bangladesh Medical Res Counc Bull 2025; 51(1):4-10