Early postoperative pain trajectories in a real-world surgical cohort: a prospective observational study

Acute postoperative pain remains a major challenge in perioperative medicine and is associated with delayed recovery and an increased risk of chronic postsurgical pain. Although numerous demographic, clinical, surgical, and psychosocial factors have been proposed as predictors of postoperative pain, their predictive value remains inconsistent across heterogeneous surgical populations. This prospective observational study included 105 adult surgical patients treated at the Emergency Center of the University Clinical Center of Serbia. Pain intensity was assessed using the Numeric Rating Scale (NRS) at admission to the postanesthesia care unit (PACU), at PACU discharge, and 24 h after surgery. Demographic, socioeconomic, clinical, surgical, anesthetic, and analgesic variables were analyzed. Exploratory analyses included univariate comparisons, logistic regression, pain reduction (ΔNRS), and correlation analyses. Mean NRS pain scores decreased from 3.54 ± 1.13 at PACU admission to 1.90 ± 0.62 at 24 h after surgery ( P < 0.001). Multimodal analgesia based on tramadol and nonsteroidal anti-inflammatory drugs was the most frequently administered postoperative analgesic regimen (68.6%). Clinically significant postoperative pain (NRS ≥ 3) was present in 14 of 98 patients (14.3%) with available 24-h assessments. No consistent associations were observed between 24-h pain outcomes and the demographic, socioeconomic, clinical, surgical, anesthetic, or analgesic variables examined. Given the limited number of outcome events, the exploratory regression analysis was not sufficiently powered to establish reliable independent predictors of postoperative pain. Acute postoperative pain was generally mild and decreased significantly during the first postoperative day. Within this heterogeneous single-center cohort, no independent predictors of clinically significant postoperative pain could be reliably identified among the variables examined. These findings should be interpreted in the context of the limited number of outcome events, clinical heterogeneity, and the absence of several established preoperative pain-related and psychosocial predictors. Larger, adequately powered studies incorporating procedure-specific and broader biopsychosocial factors are needed to improve postoperative pain risk assessment.