Anesthesia, analgesia, and immunonutrition in perioperative immune homeostasis: a focused mini review

Surgical injury compresses tissue damage, neuroendocrine stress, pain, fasting, microbial exposure, and repair into a brief interval of intense immune activity. Although anesthetic, analgesic, and nutritional care are usually examined separately, each can affect cytokine release, immune-cell trafficking, oxidative stress, macrophage activity, gut barrier integrity, substrate availability, and inflammatory resolution. This mini review examines the mechanistic and clinical evidence linking anesthetic technique, regional and opioid-sparing analgesia, anti-inflammatory adjuncts, and immunonutrition with perioperative immune homeostasis, focusing on major gastrointestinal and cancer surgery. Current evidence indicates that anesthetic and analgesic strategies can alter inflammatory or immune-cell phenotypes, and these changes are most informative when interpreted as surrogate or mechanistic endpoints linked to patient-important outcomes. Immunonutrition has the clearest clinical evidence in gastrointestinal cancer surgery, particularly among nutritionally vulnerable or high-risk patients, although effects vary with formula composition, timing, route, adherence, procedure, and comparator. Direct trials of integrated anesthesia-analgesia-immunonutrition pathways are now needed to connect these mechanistic pathways with recovery outcomes. Risk-stratified studies can use this framework to examine both component-specific effects and interactions across the wider pathway.