Clinical features and prognosis of postoperative hypernatremia in patients with spaceoccupying sellar region lesions

Objective To analyze clinical features and prognosis of postoperative hypernatremia in patients with space-occupying lesions in sellar region. Methods Clinical data about 3 580 patients with sellar region lesions in department of neurosurgery in our hospital from January 2004 to October 2014 were retrospectively analyzed. Hypernatremia was defined as serum sodium greater than or equal to 150 mmol/L. Multivariable logistic regression analysis was used to analyze the contributing factors to the prognosis (death, disturbance of consciousness, and sober). Results The prevalence of hypernatremia in these patients was 5.39%(n=193) and it occurred mainly in craniopharyngioma (n=116, 60.1%), pituitary adenoma (n=31, 16.1%), and germ cell tumors(n=11, 5.7%). Compared with eunatremia patients (n=200), the mortality in hypernatremia was significantly higher with poor prognosis (4.7% vs 1.1%, P< 0.05). Compared with the mild hypernatremia group (n=56, Na< 160 mmol/L), patients with severe hypernatremia (n=41, Na≥160 mmol/L) had a higher proportion of lesion in the third ventricle (94.6%, P=0.006), longer duration of hypernatremia (9.0 d vs 2.5 d, P=0.000) and lower sodium recovery rate at discharge (46.3% vs 69.6%, P=0.021). Compared with narrower sodium fluctuation group (fluctuation< 25 mmol/L), patients in wider sodium fluctuation group (fluctuation≥25 mmol/L)had longer hospital stay (P=0.037) and higher incidence of conscious disturbance (P=0.006). Multivariable logistic regressionanalysis showed that high level of hypernatremia, large tumor size, long time of hypernatremia and wide sodium fluctuation were risk factors of poor prognosis. Conclusion Postoperative hypernatremia in patients with space-occupying lesions of the sellar region mainly occurs in craniopharyngioma, pituitary adenoma and germ cell tumors. Patients with lesion in the third ventricle have higher level of hypernatremia. High level of hypernatremia, large tumor size, long course of hypernatremia and wide sodium fluctuation are the independent risk factors of poor prognosis.