AUTHOR=Jin Dongcai , Jin Shaofeng , Liu Bingyang , Ding Yi , Zhou Fen , Jin Yuhong 

TITLE=Association between serum sodium and in-hospital mortality among critically ill patients with spontaneous subarachnoid hemorrhage

JOURNAL=Frontiers in Neurology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2022.1025808

DOI=10.3389/fneur.2022.1025808

ISSN=1664-2295

ABSTRACT=Objective: To retrospectively explore the relationship between serum sodium and in-hospital mortality and related factors in critically ill patients with spontaneous subarachnoid hemorrhage(SAH). 
Methods: Data were collected from the Medical Information Mart for Intensive Care IV database. Restricted cubic splines were used to explore the relationship between serum sodium and in-hospital mortality. Receiver operating characteristic analysis was used to calculate the optimal cutoff value of sodium fluctuation and decision curve analysis was plotted to show the net benefit of different models containing serum sodium. 
Results: A total of 295 spontaneous SAH patients were included in the retrospective analysis. The level of sodium on ICU admission and minimum sodium in the ICU had a statistically significant nonlinear relationship with in-hospital mortality (P nonlinear value<0.05, P total value<0.001). Serum sodium on ICU admission, minimum serum sodium during ICU, and sodium fluctuation was independently associated with in-hospital mortality with odds ratios being 1.23 (95% confidence interval(CI): 1.04-1.45, P=0.013),1.35 (95% CI: 1.18-1.55, P<0.001) and 1.07 (95% CI: 1.00-1.14, P=0.047), respectively. The optimal cut-off point was 8.5 mmol/L to identify in-hospital death of spontaneous SAH patients with sodium fluctuation, with an AUC of 0.659 (95% CI 0.573-0.744). 
Conclusions: Among patients with spontaneous SAH, We found a J-shaped association between serum sodium on ICU admission and minimum sodium values during ICU with in-hospital mortality. Sodium fluctuation above 8.5mmol/L was independently associated with in-hospital mortality. These results require being tested in prospective trials.