Correlation of Preoperative Olfactory Identification Function With Preoperative Frailty and With Postoperative Complications and Mortality Following Elective Surgery

Olfactory impairment increases with age, affecting more than 50% of the population aged between 65 and 80 years old. Recently, many studies have demonstrated a strong association between olfactory impairment and overall mortality risk. At the moment, the underlying physiopathology linking olfactory impairment to mortality remains unknown and only putative mechanisms are suggested.

Among them, accelerated physiological brain aging seems to be involved, making olfactory decline a possible marker of frailty. To date, only a few studies (mostly using subjective olfactory assessment) investigated the potential relationship between olfactory impairment and frailty. Surgery, and more broadly the perioperative period, remains a major source of morbidity and mortality. Meanwhile, the average age of the surgical population continues to rise, making preoperative risk assessment an essential step in order to detect the most vulnerable patients. Yet, it is well-known that frailty is associated with worse perioperative outcome. The first objective of this research project is thus to evaluate olfactory identification function of preoperative older surgical patients in light of an assessment of their frailty status. Frailty will be tested with the Edmonton Frail Scale and handgrip strength, which are both validated tools. The second objective is to correlate postoperative morbidity and mortality with preoperative olfactory function. Hopefully, this research project will address the misunderstood link between olfactory impairment and mortality, focusing on frailty assessment and using surgery as a heavy stressor for the older patient.