A Study Of The Correlation Of Hypontremia To Plasma BNP Leves After Surgery Of The Pituitaryademomas

Objective:Hyponatremia is one of postoperative complications of transsphenoidal pituitary adenoma. This study investigated the relationship between postoperative hyponatremia and BNP by detecting the preoperative and postoperative serum sodium and plasma B-type natriuretic peptide(plasma B-type natriuretic BNP) in 30 pituitary adenoma patients, which will provide a theoretical basis for better diagnosis mechanism of hyponatremia after single nostril transsphenoidal pituitary adenoma surgery and obtain more reliable clinical scheme for the prevention of postoperative hyponatremia and treatment, as well as to forecast and prevent postoperative hyponatremia.Methods:The experimental group consisted of 30 patients who were diagnosed as Pituitary Adenoma and operated by Transsphenoidal Approach for Micro-resection of Pituitary Adenoma in the Lanzhou university second hospital. In the preoperative day morning, the 24h urinary sodium, fasting serum sodium and plasma BNP was tested. On the lth,3th and 7th postoperative days, routine biochemical urine,such as the urinary sodium, plasma BNP and other specific urine biochemical indexes were exemined with spacemen of 24h urine and random urine. At the same time,10 volunteers,from Lanzhou University second hospital medical center, agreeed with the examinations of urinary sodium, fasting serum sodium and plasma BNP when they had physical test.Results:(1) In the experimental group,17(56.7%) patients suffered from hyponatremiaits. The preoperative plasma BNP level in the experimental group is higher than control group’s, but there was no significant difference. Compared with the preoperative, the lth and 3th days’ plasma BNP level significantly increased(P< 0.05). Then plasma BNP level began to reduce slowly after the 3th day, and recovered to normal levels on the 7th day. The serum sodium before surgery of patients suffered from pituitary adenoma increased compared to that of the control group (P> 0.775), but there was no statistically significant. Compared with the preoperative, the lth and 3th days’serum sodium level significantly decreased(P<0.012) and the serum sodium level recovered to normal on the 7th day.At the same time, the fluctuation trend of the serum sodium after surgery of patients suffered from pituitary adenoma was in accordance with that of the plasma BNP level. (2) Between the postoperative hyponatremia group and the hyponatremia group, the difference of plasma BNP levels have significant difference on the lth and 3th postoperative days(.P< 0.05), what’s more, in the urinary hyponatremia group, there is a positive correlation among urinary sodium, urinary volume and plasma BNP:r尿�'�=0.328, r尿量=0.549(P<0.05).(3) The urine of the experimental group after surgery increased significantly compared to that before surgery(P< 0.05) and there was significant difference.The urinary sodium of the postoperative hyponatremia group increased significantly compared to the beforeoperative group(P< 0.05) and there was statistically significant. The urinary sodium of the postoperative non-hyponatremia group also increased compared to the beforeoperative group(P>0.05), but there was no statistically significant.Conclusion:1.Postoperative hyponatremia was earier to occur for patients with transsphenoidal pituitary adenoma surgery.2.The plasma BNP levels of preoperative and postoperative patients were higher than normal control, which prompts the patients have high platoon sodium tendency before surgery.3.Postoperative plasma BNP levels increased significantly along with the rising level of urinary sodium and urine output, and gradually returned to normal level after correcting hyponatremia. Pituitary adenomas BNP levels were associated with postoperative hyponatremia, which is one of the factors for promoting the hyponatremia.4.The occurrence of hyponatremia of patients suffered from pituitary adenoma probably because of over-traction of the pituitary gland, hypothalamus and the influence of all kinds of active substances in the blood in the process of surgery, the quantity of the hypothalamus BNP secretion increased, thus inhibiting the renin-angiotensin-aldosterone system, improving the glomerular filtration rate, inhibiting the manifold to sodium ions in the heavy absorption, promoting the excretion of urine sodium and urine volume increases, which is cause of a kind of CSWS by cerebral saltwasting hyponatremia.5.The serum sodium metabolic disorders after surgery of patients suffered from pituitary adenoma was diverse,the reason of related hyponatremia was also diverse. The detection of plasma BNP level could be used as the early detection index of the occurrence of hyponatremia of patients suffered from pituitary adenoma in clinical work which could provide evidence for the prevention of postoperative hyponatremia.