Surgery within 48 hours in hip fractures in elderly patients exerts a positive effect on post-operative hyponatremia

This study investigated the prevalence of hyponatremia during the hospital stay, in a cohort of elderly patients with hip fractures who underwent surgery within 48 h from admission. Records data were retrieved from the database of the San Giovanni di Dio e Ruggi d'Aragona Hospital of Salerno, Italy. All elderly patients (≥65 years old) with a documented hip fracture that underwent surgery within 48 h from admission, between 2016 and 2018, were included and divided in 4 subgroups according to their sex and type of fracture. Serum sodium concentration were monitored during the hospital stay and collected at admission, before surgery, after surgery and at discharge. The overall prevalence of hyponatremia was 23.99% (n=71/295), (24.3%, n=57/234 for female patients and 22.9%, n=14/61 for male patients). The percentage of hyponatremic patients with an intracapsular hip fracture was 27.17% (n=25/92), and 22.66% (n=46/203) in patients with an extracapsular hip fracture. The highest value of mean serum sodium concentration (139.2 mmol/L±4.4 SD) was found at the hospital discharge phase, and the lowest value (138.4 mmol/L±4.3 SD) was found during the pre-surgery phase. The lowest mean value of serum sodium was found before surgery, while the highest was after surgery. This could suggest that the early operative treatment and the accurate in-hospital monitoring are effective to treat or prevent this condition.