Presurgical cognitive impairment is associated with postoperative delirium and postoperative cognitive dysfunction

BACKGROUND: Presurgical cognitive impairment (PreCI) is frequently seen in older age, but the influence on postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) remains unclear. The present study sought to determine the association between PreCI, POD and POCD with special focus to different PreCI domains. METHODS: We analyzed 934 patients with complete baseline neurocognitive assessment. PreCI was determined as cognitive performance of at least two standard deviation (SD) below the mean performance of non-surgical controls. POD was assessed according to the Diagnostic and Statistical Manual of Mental Disorders 4 (DSM-4). POCD at three months follow-up was calculated by the reliable change index (RCI). Associations between PreCI and POD or POCD were assessed using multivariable logistic regression models adjusted for age, sex, randomization, ASA status, type of anesthesia, and type of surgery. RESULTS: PreCI was significantly associated with POD [OR 1.936 (95%CI 1.119 to 3.348); P=0.015] and POCD [OR 3.091 (95%CI 1.287 to 7.426); P=0.012]. Patients with coincident PreCI and POD were significantly more likely to develop POCD [OR 6.131 (95%CI 1.476 to 22.364); P=0.007]. Differentiation between no PreCI, amnestic and non-amnestic PreCI revealed a sole influence of amnestic PreCI on POD and POCD. CONCLUSIONS: Patients ≥ 60 years with PreCI were more likely to develop POD and POCD, respectively. The odds for POCD were highest in patients with PreCI whom also suffered from POD. Amnestic rather than non-amnestic PreCI might play a key role in the development of POD and POCD. These results warrant further pathophysiological investigations and demand preventive strategies.