Postoperative delirium (POD) is the most common postoperative complication in older adults undergoing surgery, with an estimated incidence of 15-25% for all inpatient procedures. POD is associated with increased mortality, an increased risk of discharge to institutional care and long-term cognitive decline. Whilst 30% - 40% of cases of POD are thought to be preventable, identifying those at greatest risk remains a significant challenge.
Acute delirium is associated with identifiable changes on the electroencephalogram (EEG), including changes in brain connectivity. Reductions in brain connectivity have also been proposed as the neurophysiological basis of a delirium-vulnerable brain phenotype. Anaesthesia and surgery have been described as a ‘stress-test’ for the brain, and a vulnerable brain phenotype may become more apparent under general anaesthesia.
The aim of this project is to identify EEG-derived biomarkers that are associated with the subsequent development of POD. We will utilise multi-channel EEG collection and analysis of spatio-temporal brain dynamics to develop biomarkers that we hypothesise will outperform current POD risk stratification methods. It is hoped that such analyses will not only provide a clinically useful marker of brain vulnerability and POD risk, but will also further our understanding of the pathophysiology of POD.
Dr Steven McGuigan, Dr Andre Peterson, Professor David Scott, St Vincent’s Hospital, Melbourne, Professor Jamie Sleigh, Waikato Clinical School, University of Auckland, New Zealand.
The project was awarded A$70,000 funding through the ANZCA research grants program for 2026.