A Survey of Electronic Health Record (EHR) Variables Associated with Postoperative Delirium: A Systematic Review

IntroductionDelirium is a common post-operative complication in critically ill patients, displaying transient changes in consciousness, inattention, awareness, and organized thought. Not a lot is known about the specific causes of this condition, as it is a complex physiologic state that is currently being unraveled to determine any correlation with imbalances in homeostasis. ObjectiveThe aim of this systematic review is to report on and summarize risk factors associated with the development of postoperative delirium in critically ill adult patients. MethodsThis systematic review assessed studies reporting on risk factors for postoperative delirium in critically ill patients. PubMed, PsycINFO, and CINAHL databases were searched for studies. Observational or interventional studies reviewing predictors for postoperative delirium in delirious versus non-delirious patients were included. ResultsFifty potential risk factors were identified and divided into eight subgroups. The significance of a specific risk factor for postoperative delirium was found to depend on the patient population in question, but consistently cited significant risk factors across cohorts included high mortality risk, abnormal laboratory values, and use of vasopressors, analgesics, thiopentones, propofol, and benzodiazepines. There was not enough evidence found to definitively state the significance of type of surgery being performed or cognitive impairment on development of this condition. ConclusionSeveral risk factors were found to be significantly associated with the development of postoperative delirium, including high risk of mortality, specific medication use, and abnormal laboratory values. Further research needs to be performed to fully define the importance of these individual risk factors across broad critical care population.