The role of C-reactive protein as a risk marker of postoperative delirium in older hip fracture patients: a prospective cohort study.

Purpose: Postoperative delirium (POD) is a common and serious neuropsychiatric syndrome that leads to higher morbidity and mortality. We investigated the association between serum C-reactive protein (CRP) and the occurrence of POD in older hip fracture patients, and whether CRP predicted POD better than a clinical model.

Methods: Patients aged ≥ 75 years admitted for surgical repair of an acute hip fracture were recruited. We compared serum CRP levels between patients with and without POD.

Results: Sixty patients were included, of whom 21 (35%) developed POD. Serum CRP levels were significantly higher in patients who developed delirium (p = 0.011). In a multiple regression model including clinical variables and CRP, cognitive impairment (p = 0.003) and infection (p = 0.001) were the best predictors of POD.

Conclusions: Although higher levels of serum CRP were significantly associated with POD in older hip fracture patients, pre-existing cognitive impairment and infections were the most important risk factors for POD.