(680) Elevated Serum Sodium in Brain Injury Patients Receiving Vasopressin: A Predictor of Mortality

Introduction: Hypotension in brain injury patients presents a significant clinical challenge, often necessitating the use of vasopressors to maintain adequate cerebral perfusion and prevent secondary brain injury. Vasopressin (VP), a potent vasopressor, is frequently utilized due to its effectiveness in increasing vascular tone and blood pressure. However, VP administration has been associated with alterations in serum sodium (Na) levels, a critical electrolyte whose dysregulation can negatively impact outcomes. The aim of this study is to investigate the effect of VP administration on serum Na levels in brain injury patients, and to compare the Na levels in patients who survived versus those who did not.

Methods: A retrospective analysis was conducted on brain injury patients admitted to the Neuro-ICU who received VP. Serum Na levels were recorded at three key points: before the initiation of VP therapy (Na Pre), during the VP drip (Na V), and after discontinuation of the VP drip (Na post). Data was collected from EHR (EPIC) and APACHE Outcome Database.

Results: A total of 113 brain injury patients were included in the study, with 68 survivors and 45 non-survivors (Mortality 40%). Both groups had similar APACHE IV scores (59 +/- 16 vs 56 +/- 19, p = 0.4), acute physiologic cores (APS: 47 +/- 16 vs 47 +/- 19, p = 1.0), % male (64 % vs 69 %, p = 0.6), time on vasopressor drip (40 +/- 28 vs 46 +/- 43 hours, p = 0.4), and similar proportions treated with hyperosmolar therapy (salt tabs, 2 % saline, 3 % saline or 23.4 % saline: 53 % vs 49 %, p = 0.7). The mean serum Na levels were significantly higher in non-survivors compared to survivors at all three time points (Na Pre: 144 +/- 7 vs 140 +/- 6, p = 0.001; Na V: 144 +/- 7 vs 138 +/- 5, p = 0.001, and Na Post: 148 +/- 10 vs 143 +/- 6, p = 0.001).

Conclusions: Brain injury patients receiving vasopressin for hypotension who did not survive had significantly higher serum sodium levels before, during, and after vasopressin administration compared to those who survived. These findings suggest that elevated serum Na levels may be associated with poorer outcomes in this patient population. Further research is warranted to confirm these findings and to explore the underlying mechanisms and potential therapeutic implications.