Perioperative Interventions Based on Fasting Protocols and Carbohydrate Loading in Non-Cardiac Surgery in Older Adults: A Scoping Review

Background and Objectives: Postoperative delirium and postoperative cognitive dysfunction are common complications in older adults undergoing elective non-cardiac surgery, associated with increased morbidity and mortality, functional decline, and prolonged hospital stay. Prolonged preoperative fasting may intensify inflammatory responses and insulin resistance. Preoperative oral carbohydrate loading within ERAS protocols may modulate this response and reduce cognitive risk. Materials and Methods: A scoping review was conducted following the methodological recommendations of Arksey and O’Malley, the Joanna Briggs Institute, and PRISMA-ScR. A systematic search was performed in PubMed and Scopus for studies published up to September 2025. Randomized controlled trials and observational studies including adults ≥ 65 years undergoing elective non-cardiac surgery were included if they evaluated fasting modifications or preoperative carbohydrate loading and reported postoperative delirium or cognitive dysfunction. Results: A total of eight publications were included: four randomized controlled trials, one prospective cohort study, two cross-sectional studies, and one descriptive/correlational study. Populations included older adults undergoing elective abdominal, orthopedic, colorectal, or hip surgery, as well as hospitalized elderly surgical patients. Interventions included oral carbohydrate loading, assessment of preoperative nutritional status, and enteral versus parenteral nutrition. Only four of the eight included studies directly evaluated neurocognitive outcomes. Postoperative delirium was assessed in three studies, using the Confusion Assessment Method in two studies and the Delirium Rating Scale in one study. Postoperative cognitive dysfunction was evaluated in one study using a Mini-Mental State Examination-based cognitive assessment, while the remaining four studies did not assess neurocognitive outcomes and instead focused on metabolic, inflammatory, or perioperative well-being outcomes. Conclusions: Available evidence suggests that perioperative fasting protocols and preoperative carbohydrate loading may influence metabolic and inflammatory responses related to postoperative neurocognitive outcomes in older adults. However, evidence remains limited and heterogeneous. Findings are exploratory and hypothesis-generating, highlighting the need for well-designed trials assessing neurocognitive outcomes in geriatric surgical populations.