Acute postoperative pain trajectories during the first 72 hours after abdominal surgery in patients aged 60 years or older

BACKGROUND Postoperative pain in older adults undergoing abdominal surgery is dynamic rather than static, and patients with similar pain scores at a single time point may follow markedly different subsequent courses.Pain trajectories have been described in broad surgical populations, but longitudinal data confined to patients aged 60 years or older undergoing heterogeneous abdominal procedures are scarce, and the clinical and psychosocial factors that accompany trajectory membership, together with its relation to later pain and recovery, remain uncharacterized in this population.AIM To identify acute postoperative pain trajectories during the first 72 hours after abdominal surgery in patients aged 60 years or older, to examine the clinical and psychosocial factors associated with trajectory membership, and to relate membership to pain and quality of recovery at 1 and 3 months.METHODS This single-center retrospective longitudinal cohort study analyzed 326 consecutive patients aged 60 years or older who underwent abdominal surgery between October 2025 and February 2026 and were recorded in the institutional perioperative pain database.Pain was abstracted from routine nursing records using the 11-point Numerical Rating Scale (NRS) before surgery, at 6, 24, 48 and 72 hours after surgery, and at 1 and 3 months.Latent class growth analysis with a linear growth factor was fitted to the four acute NRS measurements, and one-through four-class solutions were compared using information criteria, entropy, the bootstrap likelihood-ratio test, class size and clinical interpretability.Correlates of membership were examined by 4 / 54 multinomial and binary logistic regression, with multiple imputation as a sensitivity analysis. RESULTSThree classes were retained: Mild pain with rapid resolution (n = 220, 67.5%), moderateto-mild pain (n = 85, 26.1%) and severe-to-moderate pain (n = 21, 6.4%); entropy was 0.917.Surgery type differed across classes (P < 0.001): Hepatobiliary-pancreatic procedures accounted for 88.2%, 61.2% and 33.3%, gastrointestinal procedures for 9.1%, 37.6% and 66.7%.After adjustment, surgery type [odds ratio (OR) = 7.57], an open approach (OR = 10.63) and blood loss (OR = 3.91 per 100 mL) characterized the severeto-moderate class, and surgical duration (OR = 1.47 per 30 minutes) the moderate-tomild class.Pain at 1 and 3 months increased across classes, but trajectory class was not independently associated with the 1-month 15-item Quality of Recovery score after adjustment. CONCLUSIONThree acute pain trajectories were distinguishable within 72 hours of abdominal surgery, and membership was graded with respect to pain and quality of recovery at 1 and 3 months, although the recovery gradient was not independent of operative burden.Surgery type and greater operative burden, namely an open approach, longer surgery and greater blood loss, accompanied the less favorable trajectories, whereas preoperative sleep quality, anxiety and depressive symptoms and social support did not.These single-center retrospective findings are hypothesis-generating and require multicenter, procedure-specific prospective confirmation.