The incidence of hyponatremia in hospitalized patients due to hip fracture and its effect on mortality

Purpose: Hyponatremia is associated with high morbidity and mortality in elderly patients. This study aimed to investigate the incidence of hyponatremia and its effects on the duration of hospitalization, in-hospital and 1-year mortality in elderly patients admitted to the hospital due to hip fracture. Materials and Methods: After the approval of the ethics committee, patients over the age 65 and had hip surgery between January-December 2020 were retrospectively analyzed. The age, gender, fracture type, current comorbidities, and American Society of Anesthesiology physical status scores of the patients were recorded. Plasma Na, K, and Ca values in admission to hospital were recorded. Patients with hyponatremia and normonatremia were compared in terms of demographic data, comorbidities, duration of hospitalization, in-hospital, and 1-year mortality rates. Results: Of the total 253 patients, 52(%20.5) had hyponatremia at hospital admission. Demographic data were similar in hyponatremic and normonatremic patients. In hyponatremia group mean Na values were 131.13±3.96 mmol/L and significantly lower than normonatremia group (138.73±2.27). In the hyponatremic group, diabetes mellitus was observed in 23 (44%) patients, and congestive heart failure was observed in 9 (17%) patients, which was higher than the normonatremic group. The preoperative and total duration of hospitalization was 5.21±2.68 and 9.92±4.49 days respectively and higher in patients with hyponatremia. In-hospital and 1-year mortality rates were similar between the groups. Conclusion: The incidence of hyponatremia was found to be 20.5% in patients with hip fractures, and both the preoperative and total hospital stays were prolonged in these patients. Although mortality rates were similar in this study, hyponatremia requires careful follow-up and early treatment in these patients, since it is known that the length of hospital stay increases mortality.