Individualizing Perioperative Analgesia: Patient-Specific Determinants of Postoperative Pain and Opioid-Related...

Background and Objectives: Postoperative pain and opioid requirements can vary widely, even among patients undergoing similar procedures. This narrative review examines how biological sex, age, frailty, chronic pain, preoperative opioid exposure, and psychological factors may affect postoperative pain, opioid response, and recovery. Materials and Methods: PubMed and Google Scholar were searched from database inception through 18 June 2026. Relevant systematic reviews, meta-analyses, clinical guidelines, randomized trials, and observational studies involving adult surgical patients were included, with a focus on postoperative pain, opioid use, adverse effects, persistent pain, and functional recovery. Human perioperative evidence was prioritized, while experimental and preclinical evidence was used selectively to explain relevant biological mechanisms. Results: The available evidence was heterogeneous across patient populations, surgical procedures, analgesic techniques, and outcome definitions. No single patient characteristic consistently predicts postoperative pain or opioid requirements. Female sex is associated with a greater risk of postoperative nausea and vomiting, but reported differences in pain and opioid efficacy are inconsistent. Older and frail patients may be more susceptible to sedation, respiratory depression, delirium, and other opioid-related adverse effects. Patients with chronic pain or prior opioid exposure often have more difficult postoperative pain control because of tolerance, dependence, or possible opioid-induced hyperalgesia. Anxiety, depression, and pain catastrophizing may also contribute to greater pain and poorer recovery, although their relationship with opioid consumption is less consistent. Conclusions: Perioperative analgesia should be based on the patient's overall clinical picture rather than any single risk factor. The proposed framework is conceptual and has not been clinically validated. Considering these characteristics together may help clinicians select appropriate multimodal treatments, anticipate analgesic needs, monitor for adverse effects, and support recovery.