OBJECTIVE: Preoperative cognitive impairment has been identified as a major risk factor for postoperative delirium in older people. The aim of this study was to evaluate whether a validated and rapid screening cognitive test - COgnitive Disorder EXamination (CODEX) - performed preoperatively before proximal femoral fracture repair, was associated with a risk of postoperative delirium.
STUDY DESIGN: We performed an observational prospective cohort study in orthopedic surgery department of a French hospital.
PATIENTS: We included patients aged 70years or older undergoing proximal femoral fracture repair and who were free of known dementia and delirium at the preoperative phase.
METHODS: Before surgery, the anesthesiologist realized the CODEX based on three-word recall test, simplified clock drawing and if one of these tasks was abnormal, spatial orientation was assessed. Delirium was routinely sought on postoperative day 3 (D3) using the Confusion Assessment Method by the geriatrician.
RESULTS: Among the 52 included patients, seven (13.5%) had delirium on D3. All seven patients were among the 25 patients with abnormal CODEX results. None of the 27 patients with normal CODEX results had postoperative delirium. Abnormal CODEX was significantly associated with the risk of postoperative delirium in univariate analysis and after adjustment for age (odds ratio [OR]: 13.33; 95% confidence interval, [95%CI]: 1.85±∞; P<0.003).
CONCLUSION: Abnormal preoperative rapid screening test CODEX is independently associated with postoperative delirium in older people undergoing hip fracture surgery and free of known dementia.