Aims: The aim of this study was to investigate association of mortality with the serum sodium level in surgical patients. Methods: The study was a prospective, observational study, conducted on the 167 patients admitted in Surgical ICU over a period of eighteen months (January 2014 ­ June 2015) in Department of Surgery, Mathura Das Mathur Hospital attached to Dr. S. N. Medical College, Jodhpur. Serum sodium values were analysed at admission, at 24 hours, at 72 hours, at the time of shifting to ward in survivors and before death in nonsurvivors. Results: At admission, hyponatremia was present in 8.4%, and hypernatremia in only 0.6% patients. During ICU stay, the prevalence of hypo­ and hypernatremia increased. In nonsurvivors, before death, hyponatremia was seen in 21.5% and hypernatremia in 8.6% patients. Conclusion: In surgical ICU, mortality was shown to have a U­shaped relationship with serum sodium. Both hyponatremia and hypernatremia are independently associated with high mortality in surgical ICU patients. Further studies are needed to find if this association is causal or merely a reflection of differences in severity of illness.

Keywords: Hyponatremia; Hypernatremia; Surgical ICU; Mortality.