A Study Of The Relationship Of Hyponatremia To Plasma ANP,ALD And ADH After Transsphenoidal Surgery Of Pituitary Adenomas

Objectives:It is inclined to occur hyponatremia after transsphenoidal surgery of pituitary adenomas. This research is to detect serum natrium and to study the changes ofatrial natriuretic polypeptide (ANP), aldosterone (ALD) and antidiuretic hormone (ADH) in plasma among 32 cases with pituitary adenoma before and after operation, to explore the incidence rate of hyponatremia after operation and the relationship of hyponatremia to plasma ANP, ALD and ADH, and to illuminate the specific mechanisms in hyponatremia after transsphenoidal surgery of pituitary adenomas.Materials and Methods:The clinic data of 32 patients with pituitary adenomas (cases) were obtained from March 2006 to July 2007 in this hospital. Pituitary function and serum electroytes were detected preoperatively. ANP, ALD and ADH were all measured by radioimmunoassary. The changes of ANP, ALD and ADH were observed sequentially in the first, third, fifth seventh day after transsphenoidal surgery of pituitary adenomas. Clinical and laboratory data, including daily serum sodium concentration, 24-hour urinary volume were obtained sequentially up to the 7th day after transsphenoidal surgery of pituitary adenomas. The blood samples of control group were obtained randomly from 8 healthy volunteer.Results:All pituitary adenomas of 32 cases were resected transsphenoidally, and 19 cases occurred hyponatremia, the incidence rate was 59.4%. The level of ANP preoperative was higher than that of healthy people, but the difference was not obvious. After operation the level of ANP rised obviously, especially the levels on the first and third day were significantly correlated with that of pre-operation. Then it decreased gradually, and got close to normal volume within one week (P=0.35). The level of ALD preoperative was also higher than that of healthy people, but the difference was insignificant (P=0.85). Then it decreased gradually after operation, and got to minimum at about the fifth day after operation. However, the level of ADH pre-operative was insignificantly correlated with that on the first day after operation. (Pgig=0.87,Pmac=0.96,Pmic=0.34).The level of ANP of patients with hyponatremia on the first,third,fifth day after operation was obviously different from that of no-hyponatremia, which had statistical significance (P1=0.007,P3<0.001,P5=0.014). And the different level of ALD during the same period did not show any statistical significance (P0=0.592,P1=0.495,P3=0.869,P5=0.205,P7=0.445).Adrenocorticotrophic hormone of patients of hyponatremia was lower than that of no-hyponatremia, but it was insignificant (P=0.57). Urinary volume of patients of hyponatremia was related to the level of ANP,r=0.045 (P=0.045).Conclusions:1.It is inclined to occur hyponatremia after transsphenoidal surgery of pituitary adenomas.2.The level of ANP of patients with pituitary adenoma slightly increased, it is hinted that patients with pituitary adenoma are trend to eject natrium preoperatively.3.ADH of patients with pituitary adenoma does not change a lot after transsphenoidal surgery,it is denoted that SIADH is not main factor which influence hyponatremia;However ANP and ALD changes obviously,it is signify that ANP,ALD is main factor causing hyponatremia.4.It is main factor to promote hyponatremia that the level of ANP of patients with hyponatremia rises after operation.