DDAVP use in patients undergoing transsphenoidal surgery for pituitary adenomas

Background. Disorders of fluid and sodium regulation, often termed diabetes insipidus, are a frequent occurrence following surgery for pituitary adenomas. The present study was undertaken to identify the incidence of diabetes insipidus after pituitary surgery and its associated factors. Methods. A retrospective review of the medical records 300 patients who underwent transsphenoidal surgery for pituitary adenoma was undertaken. Information regarding patient gender, perioperative serum sodium levels and urinary output volumes, tumor size, previous pituitary surgery, tumor subtype, and the use of DDAVP was gathered. A multivariate statistical analysis was performed. Findings. Follow-up data were available on 288 patients. During the inpatient postoperative hospital stay, DDAVP was administered to 19% of all patients and 16% of patients not taking DDAVP preoperatively. Of patients with normal fluid/sodium regulation preoperatively, DDAVP was prescribed for 9% at discharge and 4% at 6 weeks postoperatively. Only 1.4% of patients were taking vasopressing replacement at the time of last follow-up. Significant correlations were found between gender, previous surgery, serum sodium levels, and urine volumes at various time points. Immunohistochemical type of tumor and tumor size were not related to DDAVP requirement. Conclusions. Transient hypotonic polyuria is frequently encountered after pituitary surgery. However, only a small number of patients will develop a long-term requiring for ongoing medical treatment. Previous surgery, female gender, and elevated serum sodium and urine volumes in perioperative period were associated with DDAVP requirement.