Postoperative delirium following coronary artery bypass grafting on – pump surgery

Abstract

Background: Postoperative delirium (POD) is a frequent complication post-cardiac surgery, often due to impaired cerebral autoregulation during cardiopulmonary bypass (CPB). The aim: This study investigates how cerebral autoregulation impairment affect POD occurrence after on-pump coronary artery bypass grafting (CABG). Materials and methods: A prospective pilot observational study from 2021 to 2023 was approved by the Kaunas Regional Biomedical Research Ethics Committee (No. P1-BE-2- 64/2021, date: 2021-12-15). Delirium was diagnosed using CAM-ICU. Cerebral autoregulation was monitored via transcranial Doppler, and the status index – Mx was recorded in real-time using ICM+ software (Cambridge, U.K.). Results: The study enrolled 104 patients undergoing elective CABG surgery in the Hospital of Lithuanian University of Health Sciences Kaunas Clinics. Patients were divided into nondelirium(n=91) and delirium(n=13) groups. The results revealed that age, education level and sex distribution were not significantly different between the groups (p > 0.05). The delirium group had a significantly longer total duration of cerebral autoregulation impairment events (median: 4783 sec vs. 4204.5 sec, p = 0.047). Additionally, cardiopulmonary bypass time (median: 95 min vs. 83 min, p = 0.036) and aortic cross-clamping time (median: 47 min vs. 40 min, p = 0.021) were significantly longer in the delirium group. Conclusions: Postoperative delirium factors include the longest cerebral autoregulation impairment duration, cardiopulmonary bypass time, and aortic cross-clamping time. Early identification and management of these factors can reduce delirium risk and enhance patient outcomes.