Influential Factors And Treatment Of Delayed Hyponatremia After Transsphenoidal Pituitary Adenoma Surgery

Objective: To identify the influencing factors and treatment methods of delayed hyponatremia by retrospective study of patients who underwent transsphenoidal pituitary adenomas.Methods: The clinical data of 404 patients were collected who underwent transsphenoidal approach for pituitary adenoma surgery in the Department of Neurosurgery,Tianjin Medical University General Hospital from January 2012 to December 2017.The operation was performed by the same surgeon and confirmed by pathology as pituitary tumor.The surgical methods include the microscopic transsphenoidal surgery and the endoscopic transsphenoidal surgery.The patient’s blood sodium level was continuously monitored postoperatively,hyponatremia means blood sodium <135mmol/L,and delayed hyponatremia means newly developed hyponatremia more than 5 days after surgery.According to the results of blood sodium,it was divided into delayed hyponatremia group and normal blood sodium group.The age,gender,pituitary tumor pathological type,tumor size,tumor invasiveness and pituitary function were included as risk facters.Logistic regression analysis and chi-square test were used to analyze the above factors.P<0.05 was statistically significant.Thus to identify the relationship between hyponatremia and the above factors.Results: There was 404 patients in total,90 cases(22.3%)suffered from the delayed hyponatremia after transsphenoidal pituitary adenomas surgery.45 cases were mild hyponatremia,36 cases were moderate hyponatremia,and 9 cases were severe hyponatremia.There were 30 males(17.3%,30/173)and 60 females(25.9%,60/231);34 cases(17.9%,34/189)<50 years old and 56 cases(26.0%,56/215)≥ 50 years old;Adrenocorticotropic adenomas accounted for 14 cases(30.4%,14/46),Prolactinomas 24 cases(24.5%,24/98),growth hormone adenoma 12 cases(14.8%,12/81),nonfunctioning adenomas 25 cases(34.7%,25/72),mixed-cell adenomas 4 cases(10.0%,4/40),Gonadotroph adenoma 11 cases(16.7%,11/66),thyroid stimulating Hormone adenoma 0 cases(0%,0/1);14 cases were microadenomas(13.3%,14/105),54 cases were large adenomas(23.9%,54/226),22 cases were giant adenomas(30.1%,22/73);49 cases were diagnosised invasive adenoma(27.8%,49/176),non-invasive adenoma 41 cases(18.0%,31/228).There were 38 cases(30.6%,38/124)with delayed hyponatremia combined with diabetes insipidus,52 cases(18.6%,52/280)without diabetes insipidus.Chi-square test analysis showed that the gender,tumor size,preoperative invasion,pathological type of tumor,postoperative hypophysis and diabetes insipidus were statistically significant,while age was not significantly correlated with the occurrence of late hyponatremia.Logistic multivariate regression analysis showed that pathological type,postoperative pituitary function and postoperative diabetes insipidus were the risk factors for postoperative delayed hyponatremia(P<0.05).Conclusion: 1.Delayed hyponatremia is a common complication after transsphenoidal pituitary adenoma surgery;2.Pathological type,postoperative pituitary function and postoperative diabetes insipidus were the risk factors for postoperative delayed hyponatremia(P<0.05).Patients with postoperative hypopituitarism are more likely to develop delayed hyponatremia(OR 2.341,P 0.004).Postoperative diabetes insipidus cases are more prone to delayed hyponatremia(OR 2.034,P 0.009)than those without diabetes insipidus;The pathological type of pituitary tumor is correlated with the occurrence of late postoperative hyponatremia(P 0.013),in which the proportion of non-functioning adenomas and ACTH adenomas was higher than other groups.3.There was no significant correlation between age,gender,tumor size,invasiveness and delayed hyponatremia.4.Mild hyponatremia can be supplemented by oral sodium salt,moderate and severe delayed hyponatremia,besides intravenous sodium salt supplement,treatment with hydrocortisone can rapidly improve serum sodium level.