Perioperative nutrition for gastrointestinal surgery: On the cutting edge

Evidence on perioperative nutrition interventions in gastrointestinal surgery is rapidly evolving. We conducted a narrative review of various aspects of nutrition support, including formula choice and route of administration, as well as duration and timing of nutrition support therapy. Studies have demonstrated that nutrition support is associated with improved clinical outcomes in malnourished patients and those at nutrition risk, emphasizing the importance of nutrition assessment, for which several validated nutrition risk assessment tools exist. The assessment of serum albumin levels has fallen out of favor, as it is an unreliable marker of nutrition status, whereas imaging evidence of sarcopenia has prognostic value and may emerge as a standard component of nutrition assessment. Preoperatively, evidence supports limiting fasting to reduce insulin resistance and improve oral tolerance. Benefits to preoperative carbohydrate loading remain unclear, whereas literature suggests preoperative parenteral nutrition (PN) may reduce postoperative complications in high-risk patients with malnutrition or sarcopenia. Postoperatively, early oral feeding is safe with benefits in time to return of bowel function and reduced hospital stay. There is a signal for potential benefit to early postoperative PN in critically ill patients, though evidence is sparse. There has also been a recent emergence in randomized studies evaluating the use of ω-3 fatty acids, amino acids, and immunonutrition. Meta-analyses have reported favorable outcomes for these supplements, though individual studies are small and with significant methodological limitations and risk of bias, emphasizing the need for high-quality randomized studies to guide clinical practice.