Institutional report - Cardiac general screening methods for delirium: Early diagnosis by means of objective quantification of motor activity patterns using wrist-actigraphy

Abstract

Delirium after cardiac surgery is a risk factor for adverse outcome and even death. Disturbance of motor activity is a core feature of delirium, but hypoactive delirium often remains unrecognized. We explored wrist-actigraphy as a tool to objectively quantify postoperative recovery of 24-h rest-activity patterns to improve the early recognition of delirium after surgery. Motor activity was recorded by wristactigraphy after cardiac surgery in 88 patients over 65 years of age. Patients were assessed daily by using the CAM-ICU. Our final analyses were based on 32 non-delirious patients and 38 patients who were delirious on the first day after surgery. The delirious patients showed lower mean activity levels during the first postoperative night (P<0.05), reduced restlessness during the first day (P<0.05), and a lower mean activity of the 5 h with lowest activity within the first 24 h (P=0.01), as compared to the non-delirious patients. Already at a very early stage after cardiac surgery, a difference in motor activity was observed between patients with and without a delirium. As an unobtrusive method, actigraphy has the potential to be a screening method that may lead to early diagnosis and treatment of delirium. © 2009 Published by European Association for Cardio-Thoracic Surgery.