The nurse is providing postoperative care to a patient who underwent a transsphenoidal hypophysectomy for a benign pituitary tumor. The nurse administers replacement hydrocortisone, thyroid hormone, and vasopressin

Question

The nurse evaluates that the vasopressin replacement is effective when: a. the patient's blood glucose is 110 mg/dL.
b. the patient maintains a core body temperature of 98.2° F (36.8° C).
c. the patient's urine specific gravity decreases.
d. 2 liters of urine are produced in a 24-hour period.

Answer 1

D
Vasopressin is administered to replace antidiuretic hormone following a hypophysectomy. Other life-sustaining hormones such as cortisol and thyroid hormone that involve a feedback system between the pituitary gland and the target gland also must be replaced. Vasopressin produces elevation of blood pressure, causes retention of fluid, and reduces urine output. The result is a decrease in serum sodium and serum osmolality secondary to hemodilution and increase in urine specific gravity. Blood glucose control is not affected by vasopressin; cortisol would directly affect blood glucose. Core body temperature would be most directly affected by thyroid hormone. Urine specific gravity would increase, not decrease, following vasopressin administration.