Biomarkers of postoperative delirium and cognitive dysfunction

Abstract

Elderly surgical patients frequently experience postoperative delirium (POD) and the subsequent development of postoperative cognitive dysfunction (POCD). Clinical features include deterioration in cognition, disturbance in attention and reduced awareness of the environment and result in higher morbidity, mortality and greater utilization of social financial assistance. The aging Western societies can expect an increase in the incidence of POD and POCD. The underlying pathophysiological mechanisms have been studied on the molecular level albeit with unsatisfying small research efforts given their societal burden. Here, we review the known physiological and immunological changes and genetic risk factors, identify candidates for further studies and integrate the information into a draft network for exploration on a systems level. The pathogenesis of these postoperative cognitive impairments is multifactorial; application of integrated systems biology has the potential to reconstruct the underlying network of molecular mechanisms and help in the identification of prognostic and diagnostic biomarkers.

Diabetes, but Not Hypertension and Obesity, Is Associated with Postoperative Cognitive Dysfunction

“…Here, patients with diabetes (even if not exposed to surgery) may have simply declined at steeper rates during follow-up compared with non-diabetics. OCTOPUS also reported an incidence rate of POCD of around one-third of patients at 12-month follow-up, which is high relative to previous studies [61]. Post-surgery stroke was considered as “POCD” in OCTOPUS and DECS, which complicates the interpretation of findings on POCD as a form of impairment as opposed to overt cerebrovascular disease.…”

Patients prone for postoperative delirium

“…Considering that nearly half of the elderly will require surgery after the age of 65 years [47], and almost half of hip fracture patients are occurring among the 'oldest old' with an increasing trend [37], POD will be a more frequent devastating complication in the future [48]. Consequently, monitoring of POD has already become a quality marker in some health care policies [49].…”

Effects of alfentanil or fentanyl added to propofol for sedation in colonoscopy on cognitive functions: Randomized controlled trial

“…These include advanced age, existing mental dysfunction, systemic diseases, alcohol abuse, electrolyte imbalance, long and complicated surgical interventions, genetic factors, hemodynamic changes, hormone levels, psychoactive medications, postoperative infection, respiratory complications, prolonged sedation, and pain (14). Sedation during endoscopic procedures facilitates the procedure and allows patients a fast and pain-free return to daily life.…”