Screening for postoperative delirium in patients with acute hip fracture: Assessment of predictive factors.

Abstract

The aim of the present study was to estimate the incidence and risk factors of delirium during the early postoperative period after hip fracture surgery. Furthermore, we investigated the accuracy of the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) for detection and assessment of delirium in orthopedic patients. We consecutively recruited patients aged 65 years or older undergoing hip fracture surgery. The presence of delirium was determined daily by two of the authors according to the CAM-ICU criteria. A further evaluation was made with the reference standard Diagnostic and Statistical Manual of Mental Disorders Fourth Edition criteria for delirium. Their cognitive function was evaluated with the Mini-Mental State Examination, and possible depressive mood with the Beck Depression Inventory. Baseline characteristics, as well as the American Society of Anesthesiologists classification and clinical outcomes, were analyzed for a correlation with accompanying delirium. Among 109 patients, 20 (18.3%) were diagnosed with delirium. The concurrent validity of CAM-ICU was good (kappa = 0.84). Specificity was 98.9%, and sensitivity was 80%. Multivariate regression analysis showed that Mini-Mental State Examination (P = 0.001; odds ratio 0.75, 95% confidence interval 0.65-0.86) and Beck Depression Inventory scores (P = 0.001; odds ratio 1.13, 95% confidence interval 1.05-1.22) correlated with the occurrence of delirium. The present results show that CAM-ICU is highly sensitive and specific to identify delirium in hip fracture patients in the postoperative period. Among all of the risk factors, cognitive impairment and depressive mood were strongly associated with postoperative delirium. We suggest that a preoperative assessment of cognition and depression might be useful for identifying patients with a higher risk of postoperative delirium. Geriatr Gerontol Int 2017; 17: 919-924.