Perioperative Factors Associated with 48-Hour Postoperative Oxycodone Requirement After Gastrointestinal Surgery: A Single-Center Retrospective Cohort Study

Background/Objectives: Postoperative opioid requirements vary substantially after gastrointestinal surgery. Oxycodone-based patient-controlled intravenous analgesia (PCIA) is used for postoperative pain control, but perioperative factors associated with early postoperative oxycodone requirement remain insufficiently defined. This study investigated factors associated with 48 h oxycodone consumption after gastrointestinal surgery. Methods: This single-center retrospective cohort study included 493 adults who underwent elective gastrointestinal surgery and received oxycodone-based PCIA between January and December 2025. The primary outcome was cumulative oxycodone consumption within 48 h after surgery. Multivariable linear regression was used for the primary continuous-outcome analysis. An exploratory analgesia-adjusted model additionally included regional block, incisional local infiltration, and routine postoperative non-opioid analgesic use. High consumption, defined as a 48 h dose >38 mg, was evaluated using exploratory logistic regression models. Results: The median 48 h oxycodone consumption was 34 mg (interquartile range, 27–38 mg), and 105 patients (21.3%) had high consumption. In the prespecified clinical continuous-outcome model, gastric surgery, rectal surgery, open surgery, converted-to-open surgery, radical resection, and longer operation time were associated with higher 48 h oxycodone consumption, whereas older age was associated with lower consumption. After adjustment for available analgesia-related variables, the main associations remained broadly stable, although the association for converted-to-open surgery was attenuated. Regional block and incisional local infiltration were associated with lower 48 h oxycodone consumption in the analgesia-adjusted model. In the exploratory logistic models, younger age, rectal surgery, open or converted-to-open surgery, radical resection, and longer operation time were associated with high consumption. Body mass index (BMI) was not independently associated with oxycodone requirement. Conclusions: Age and procedure-related characteristics were associated with 48 h oxycodone requirement after gastrointestinal surgery. These routinely available perioperative factors may help identify patients who warrant earlier postoperative pain reassessment, closer acute pain service follow-up, and individualized multimodal analgesic planning. Prospective multicenter validation is required before formal risk-stratified analgesic protocols can be recommended.