Abstract:

Objective

To investigate the postoperative changes in blood sodium levels in patients with severe traumatic brain injury （sTBI） due to secondary hydrocephalus.

Methods

The clinical data of 130 patients with sTBI admitted to Neurosurgery Department of General Hospital of Northern Theater Command of PLA from June 2012 to June 2023 were retrospectively analyzed. The patients were divided into a secondary hydrocephalus group （32 cases） and a non-secondary hydrocephalus group （98 cases）according to whether they developed hydrocephalus after surgery. By comparing the general data of the two groups and the changes of blood sodium level after operation，the combined model of the change rate of blood sodium level and the secondary hydrocephalus group was established. The correlation between postoperative blood sodium changes and cerebrospinal fluid pressure （CSFP） parameters in the secondary hydrocephalus group was analyzed using a stepwise Logistic regression model. Multiple Logistic regression analysis was used to explore the potential risk factors of secondary hydrocephalus after sTBI.The restricted cubic spline model was used to estimate the relationship between sodium levels and postoperative secondary hydrocephalus and the dose-response relationship.

Results

There were significant differences in the head injury site，preoperative and postoperative GCS score，intraventricular hemorrhage，clear structure of the aqueduct and annulus，incidence of postoperative large cerebral infarction，and postoperative intracranial infection rate between 2 groups （P＜0.05）. The serum sodium level in both groups significantly increased on the second day after surgery，and the serum sodium level in the secondary hydrocephalus group was much higher than that in the non-secondary hydrocephalus group from 2 to 28 d after surgery，with statistical significance （P＜0.05）. Stepwise Logistic regression model analysis showed that different serum sodium levels were significantly correlated with soluble Fas （sFas，OR=1.495，95%CI： 1.133-1.967，P=0.009），sFas ligand （sFasL，OR=1.307，95%CI： 1.106-1.748，P=0.011），CSFP （OR=1.608，95%CI： 1.276-2.308，P=0.004） and regression of amplitude and pressure （RAP，OR=1.328，95%CI： 1.025-1.768，P=0.006） in cerebrospinal fluid. Multivariate Logistic regression analysis showed that postoperative intraventricular hemorrhage，postoperative intracranial infection，postoperative large area cerebral infarction，postoperative sFas，sFasL，CSFP，RAP elevation，and serum sodium level ≥149.76 mmol/L 2 d after surgery were all independent risk factors for postoperative secondary hydrocephalus （P＜0.05）. The results of the restricted cubic spline model showed that there was a nonlinear dose-response relationship between the level of blood sodium and the intensity of postoperative secondary hydrocephalus.

Conclusion

The postoperative changes in blood sodium levels in sTBI patients are closely associated with secondary hydrocephalus and have a certain predictive value for postoperative secondary hydrocephalus.

Key words: Severe traumatic brain injury, Blood sodium level, Hydrocephalus, Cerebrospinal fluid