This single-center, prospective pilot study will examine dietary fat consumption and its relationship with inflammatory markers before surgery and the incidence of perioperative neurocognitive disorders in older surgical patients. The study will assess the feasibility getting diet-related information in a surgical setting and will establish baseline dietary patterns in older adults. It will also measure the incidence of postoperative cognitive impairment (POCI) in patients with high fat consumption and gather patient perspectives to inform future nutrition-focused interventions for older surgical candidates.

This single-center, prospective pilot study will evaluate dietary fat intake and its association with preoperative inflammatory markers and perioperative neurocognitive disorders in older surgical patients. The study will assess the feasibility of obtaining detailed dietary information in a surgical population and will establish baseline dietary information in older adults.

Participants will complete diet assessments prior to surgery, provide blood samples totaling up to 32 mL (with up to 16 mL collected before surgery and up to 16 mL collected the morning after surgery), and-when available-have up to 1 mL of cerebrospinal fluid collected during their clinically indicated spinal anesthesia procedure. Blood and cerebrospinal fluid samples will be analyzed for inflammatory markers.

Cognitive assessments will be performed to evaluate perioperative neurocognitive disorders. Participants will complete a baseline preoperative telephone cognitive assessment to determine cognitive status. Delirium assessments will be conducted twice daily from immediately after surgery until discharge, supplemented by chart review. At three months after surgery, the telephone cognitive assessment will be repeated and compared with the baseline score to estimate persistent neurocognitive disorder.

Inclusion Criteria:

1. ≥ 60 years of age or older
2. Capable and willing to consent
3. English speaking
4. Anticipated ASA physical status I-III
5. Scheduled to undergo major abdominal or pelvic surgery, or total hip or knee joint arthroplasty under general anesthesia with planned spinal anesthetic/analgesic.

Exclusion Criteria:

1. Illiterate
2. ASA physical status V, VI
3. Active Axis I or II psychiatric disorders including bipolar disorder, schizophrenia, dementia, alcohol, or drug abuse.
4. Preoperative benzodiazepine administration (i.e. Midazolam, Diazepam)
5. Past medical history of any inflammatory autoimmune disease processes (rheumatic arthritis (RA), systemic lupus erythematosus (SLE), autoinflamatory syndrome, etc.)

Obese or normal weight patients over the age of 60 scheduled to undergo a major abdominal or pelvic surgery, or total hip or knee joint arthroplasty at OSUWMC and complete the study.