Endocrine Abstracts

Introduction: Water-electrolyte disorders are serious complications after transnasal adenomectomy for formations of the hypothalamic-pituitary region. The purpose of this work was to evaluate the incidence of postoperative hyponatremia in the tactics of active control of sodium levels in the blood.

Materials and methods: The study included the results of a dynamic study of blood sodium levels in 53 patients (mean age 46.6 years [min 19; max 68]) with pituitary adenomas (GH-secreting - 31 patients, ACTH-secreting - 14 patients, hormonally inactive - 6 patients, TSH-secreting - 1 patient), who underwent endoscopic transnasal transsphenoidal adenomectomy. Sodium control was carried out initially before surgery, after 12-24 hours, on days 2-3, 4-5 and 6-7 after surgery. Comparison of the frequency of hyponatremia was carried out with data on the lack of alertness about the possibility of developing postoperative hyponatremia and the lack of blood sodium control in 2008 (0.7%), the absence of alertness, but periodic monitoring of blood sodium but without mandatory monitoring of blood sodium levels in 2017 (7.2%).

Results: Initially, before surgery, only one patient with a TSH-secreting pituitary tumor had a decrease in the sodium concentration in the blood to 135 mmol/l (reference values 136-145 mmol/l) - 1/53 (1.8%). During the first 12-24 hours and on days 2-3 after surgery, hyponatremia of 135 mmol/l was also detected in 1 case in different patients with ACTH-secreting pituitary adenomas (1.8%), as well as 1 case of low sodium blood to 130 mmol/l in the period of 2-3 days after the operation, which was of a long-term nature and a tendency to reduce the level of sodium in the blood to 125 mmol/l. On days 4-5, a total of 5 hyponatremias (4 newly emerged), 3 of which were of moderate severity 129-125 mmol/l (7.5%), were detected, on days 6-7, 12 hyponatremias were recorded (8 newly emerged), of of which 4 were of moderate severity, and 8 of mild severity (22.6%). The overall incidence of postoperative hyponatremia was 28.3%.

Conclusions: Transient hyponatremia of the early postoperative period up to the 3^rd day after surgery does not appear to be clinically significant. An increase in the frequency and severity of hyponatremia was noted from the 4^th post-operative intervention, which necessitates mandatory monitoring of blood sodium levels. The approach of active monitoring of the blood sodium level allowed to increase the detection of hyponatremia by 3.9-32.6 times