Total Intravenous Versus Inhalational Anesthesia- A Geriatric Anesthesia Study

Aim 1: Determine the effects of intravenous vs. inhalational anesthesia on incidence of postoperative delirium and postoperative cognitive dysfunction in older adults undergoing non-cardiac surgery. Hypothesis: Intravenous anesthesia is associated with a lower incidence of POD and POCD compared to inhalational anesthesia. Primary outcomes: Incidence of postoperative delirium and postoperative cognitive dysfunction Secondary outcomes: delirium severity, delirium duration Aim 2: Determine the effects of intravenous vs. inhalational anesthesia on incidence of postoperative functional decline and patient-reported outcomes in older adults undergoing non-cardiac surgery. Hypothesis: Intravenous anesthesia is associated with a lower incidence of postoperative functional decline and improved patient-reported outcomes (PROs) compared to inhalational anesthesia. Primary outcomes: Incidence of postoperative functional decline; patient-reported outcome scores Aim 3: Determine the effects of intravenous vs. inhalational anesthesia on blood phosphorylated tau 181 (p-tau181) and other blood biomarkers in older adults undergoing non-cardiac surgery. Hypothesis 1: Elevated preop blood p-tau181 is associated with increased POD and POCD; Hypothesis 2: Postoperative increase in blood p-tau181 is greater with GAS relative to IV; Hypothesis 3: Postop increases in blood biomarkers of neuroinflammation and AD pathology are greater with GAS relative to IV. Primary outcomes: preoperative levels of blood p-tau181 and change in levels from preoperative baseline to postoperative. Secondary outcomes: Other candidate biomarkers include those previously implicated in POD or POCD: p-tau217, Aβ,54 NF-L,55 High mobility group box protein 1 (HMGB1),60 S100β,76 interleukin (IL)-6,58 IL-1β,22 IL-10,46 tumor necrosis factor (TNF)-α,22 CCL2,62 and glial fibrillary acidic protein (GFAP).77