The Influence of Preoperative Risk Factors on Perioperative Neurocognitive Disorders in Patients Scheduled for Non-cardiac Surgery

Perioperative neurocognitive disorders remain an important complication after surgery. After many years of speculating about the etiology of this complication, currently studies are pointing to an inflammatory cascade being set in motion. Following the combination of surgery/ anesthesia, high molecular group box protein 1 (HMGB1) is released. This damage-associated molecular pattern (DAMP) binds to pattern recognition receptors (PRR) on circulating bone marrow-derived monocytes (BM-DMs). Through an intracellular signaling pathway, the transcription factor NF-kappaB passes into the nucleus, is activated and increases expression and release of pro-inflammatory cytokines. These in turn disrupt the blood brain barrier. Within the brain parenchyma the chemokine MCP-1 (also referred to as CCL2) is upregulated and attracts the BM-DMs through binding to its receptor, CCR2. In turn, this activates the resident quiescent microglia. Together, the BM-DMs and activated microglia release HMGB1 and pro-inflammatory cytokines that disrupt long-term potentiation (LTP) thereby blocking synaptic plasticity changes that are required for the cognitive functions of learning and memory.

Unfortunately, treatment currently is lacking, however optimising lifestyle seems to be a promising pathway in a murine population.

This prospective study is designed to examine preoperative lifestyle factors (such as sedentary behavior) associated with postoperative cognitive impairment in a group of patients undergoing non-cardiac surgery.

Prior to surgery, patients will have a baseline MMSE (mini mental state examination) assessment. At the same time, a standardized history form will be completed to document pertinent patient information, with special emphasis on patterns of smoking and ethanol consumption. French IPAQ data will be collected as well as the Geriatric Depression Scale.

Right before the surgery, a peripheral blood sample will be drawn (to analyse IL-6 levels).