What endocrine complications occur in the perioperative period?
Abnormalities of fluid and sodium balance are common after TSS because of antidiuretic hormone (ADH) dysregulation from pituitary stalk and/or posterior pituitary gland manipulation. Transient diabetes insipidus (DI), caused by impaired ADH secretion, may occur in the first 1 to 2 postoperative days in ∼ 20% to 30% of TSS patients; DI presents as high-volume, and dilute, urine output (> 250 cc/hr for > 2 to 3 consecutive hours, or > 3 L/day in adults). A second phase, which typically occurs during postoperative days 5 to 10, is characterized by the syndrome of inappropriate ADH release (SIADH), during which time patients are at risk for developing hyponatremia. Very rarely, permanent DI develops (< 2%) after ADH stores are exhausted, and only if there is significant destruction (> 85%) of the hypothalamic ADH neurons. The classic triphasic, DI–SIADH–DI, response is relatively rare. More commonly, isolated SIADH occurs without antecedent DI (20%–25%) and necessitates close follow-up during the first 2 weeks after TSS. Additional new-onset pituitary hormone deficiencies are also uncommon after TSS, particularly at experienced neurosurgery centers (5% to 7%), although adrenal insufficiency should be considered in patients with early and persistent hyponatremia.