Objective:To discuss the treatment and clinical characteristics of hyponatremia after brain trauma.Methods:238 patients with complicated hyponatremia after brain injury were enrolled in this retrospective study.According to treatment

all patients were divided into two groups:hypertonic saline solution injecting group(HSSI group) and control group.500 ml of 3% sodium chloride was injected per-day in 107 patients of HSSI group when serum sodium were lower than 135 mmol/L

and routine fluid infusion according to physiological requirement was performed in 131 patients of control group.Recovery rate and recurrence of hyponatremia were measured to be compared between two groups.Results:Recovery rate of serum sodium in HSSI group was significantly higher than that in control group.Conclusion:HSSI had a significant therapeutic effect on patients with complicated hyponatremia after traumatic brain injury;moreover

it did not increase the incidence of SIADH.