Hip fracture post-operation dysnatremia and Na+-courses in different cognitive and functional patient groups

The aim of the study was to investigate Na+-course of hip fracture patients in relation to demographic and clinical parameters. Data on 155 older hip fracture patients were analyzed retrospectively. Clinical parameters and serum Na+ on admission (Na1), during 24 h pre-op. (Na2), during 24 h post-op. (Na3), and pre-discharge (Na4) were recorded. Hyponatremia and hypernatremia rates pre- and post-operation were 26.5%, 2.6%, 24.5% and 5.8%. Higher Na3 (138.76 ± 4.4 mEq/l) vs. Na1 (137.69 ± 4.5 mEq/l) (p = 0.004) and correlation between age and Na3 (p = 0.021) was found. Mean serum Na+ of impaired mental status (IMS) vs. normal patients and of partially/independent vs. dependent patients were higher (p < 0.05). More complications occurred in IMS patients tending to higher Na3 in patients with complications. No differences in Na+-courses were found according to sex or co-morbidities. Dysnatremia is highly prevalent in older hip fracture patients. A distinct post-operative increase in serum Na+ was found, higher in the cognitively and functionally impaired patients. It seems that the Na+ increase characterizes more IMS patients who suffer more complications, but does not necessarily indicate complications. We recommend surveillance of serum Na+, particularly in cognitively and functionally impaired older patients in whom the risk of hypernatremia and complications is higher.