Low Plasma Cholinesterase Activity is Associated With Postoperative Delirium After Noncardiac Surgery in Elderly Patients: A Prospective Observational Study.

BACKGROUND: Postoperative delirium (POD) commonly occurs in elderly patients after noncardiac surgery, resulting in increased morbidity and greater risk of death. However, its pathophysiology is currently unknown. Cholinergic dysfunction has been implicated in delirium pathophysiology, and low plasma cholinesterase activity has been reported as a risk marker of POD. Therefore, the aim of this study was to investigate the link between plasma cholinesterase activity and POD in elderly Han Chinese patients after noncardiac surgery.

METHOD: From January 2014 to January 2016, a cohort of 206 patients aged ≥ 60 years who underwent noncardiac surgery and were transferred to the surgical intensive care unit were enrolled. POD was assessed using the Confusion Assessment Method for Intensive Care Unit. Clinical data including sex, age, general comorbidities, alcohol consumption, Acute Physiology and Chronic Health Evaluation II score, and type of surgery were recorded. Blood was drawn postoperatively to measure cholinesterase activity. Using multiple logistic regression analyses, the associations between cholinesterase activity and POD were examined, adjusting for potential confounding variables.

RESULTS: Delirium incidence was 22.3%. POD was associated with cholinesterase activity, age, and Acute Physiology and Chronic Health Evaluation II score. In multiple logistic regression analyses, lower acetylcholinesterase and butyrylcholinesterase activity was independent risk factors for POD.

CONCLUSION: Plasma cholinesterase activity may be a candidate biomarker for POD after noncardiac surgery in the elderly Chinese Han population.