Disorders of Salt and Water Balance After Pituitary Surgery

Abstract

Transsphenoidal surgery (TSS) is the first line treatment for many clinically significant pituitary tumors and sellar lesions. Although complication rates are low when performed at high-volume centers, disorders of salt and water balance are relatively common post-operatively. Both, or either, central diabetes insipidus (DI), caused by a deficiency in production and/or secretion of arginine vasopressin (AVP), and hyponatremia, most commonly secondary to the syndrome of inappropriate antidiuresis (SIAD), may occur. These conditions can extend hospital stay and increase the risk of readmission. This article discusses common presentations of salt and water balance disorders following pituitary surgery, the pathophysiology of these conditions and their diagnosis and management.

Postoperative Hormonal and Water Balance Disturbances After Non-Functioning Pituitary Macroadenoma Surgery

“…Excessive treatment of AVP-D raises the risk of inducing hyponatremia. (9) Oral administration of desmopressin tablets has been linked to a lower occurrence of hyponatremia compared to nasal formulations, and it is now the preferred choice for many patients. Strict postoperative monitoring is essential for all patients who have undergone pituitary surgery, which includes observing the fluid intake, urine output, and thirst, and conducting daily electrolyte monitoring.…”

“…Strict postoperative monitoring is essential for all patients who have undergone pituitary surgery, which includes observing the fluid intake, urine output, and thirst, and conducting daily electrolyte monitoring. (9) We performed endonasal endoscopic transsphenoidal hypophysectomy as a surgical procedure in treating pituitary macroadenoma at our institute. This procedure aligns with many previous studies.…”

Pituitary Stalk Morphology as a Predictor of New-Onset Adrenocortical Insufficiency and Arginine Vasopressin Deficiency after Transsphenoidal Resections of Pituitary Macroadenomas: A Retrospective Single-Center Study with a Focus on iMRI

“…Hydrocortisone substitution was established with an administration of 100 mg intraoperatively, 80 mg on the first day, 70 mg on the second day, 40 mg on the third day, and 25 mg on all following days post-surgery until a functioning adrenocortical axis was evidenced in an ITT or CRH test 4-6 weeks or 10-14 months after TSS. (Transient) AVP-D was defined as a urine volume greater than 300 mL/h, increased serum sodium above 145 mmol/L, and a specific urine weight less than 1.005 [17].…”

“…Therefore, 2.7 mm was determined to be a cut-off value of the minimal PSD for AVP-D. However, regarding AVP-D, several easy-to-acquire parameters, such as polyuria, negative fluid balance, decreased urine specific gravity, and osmolality with increased plasma sodium and serum osmolality, have already been established to determine this deficiency in postoperative inpatient settings [17,21]. Thus, clinically, the connection between iMRI findings and AVP-D seems even more relevant from a pathophysiological angle, as described below.…”

Gender potentially affects early postoperative hyponatremia in pituitary adenoma: XGBoost-based predictive modeling

“…The primary treatment for pituitary adenomas is transnasal sphenoid surgery, which has a low incidence of complications [ 2 ]. However, postoperative salt and water imbalance is a common occurrence, with a 28% likelihood of hyponatremia [ 3 ]. These electrolyte imbalances can lead to adverse effects such as nausea, vomiting, altered mental status, and seizures, which can prolong hospitalization and increase the risk of readmission [ [4] , [5] , [6] , [7] ].…”