437: Postoperative Movement-evoked Pain Trajectories in Abdominal Surgery Patients: A Retrospective Study

Topic: Clinical Science
Subtopic: Pain category (ICD-11), Acute postsurgical pain, Assessment and Measurement of Pain/Nociception

Background and Aims: Movement-evoked pain (MEP) is often more severe than rest pain and correlates directly with functional recovery.
Current pain assessments often rely on single time-point measurements, overlooking the dynamic changes of pain over time.
Opioid-free anesthesia (OFA) is trending, but its impact on postoperative MEP trajectories remains controversial.
We aim to identify distinct trajectories of early postoperative MEP in patients undergoing major abdominal surgery, and to determine the perioperative factors associated with these trajectory patterns.

Methods: Study Design: Single-center, retrospective analysis (2022-2023).
Participants: 268 patients undergoing major abdominal surgery.
Data Collection:
Time Points: PACU, Postoperative days (POD) 1, 2, and 3.
Instrument: Electronic medical records and the DoCare Anesthesia Clinical Information System.
Key Variables: MEP scores, Opioid consumption (Intraoperative, PACU, PCA), Surgery type, ASA, Peripheral nerve block, Side effect, Length of hospital stay, and Demographics.
Statistical Analysis: Longitudinal Latent Profile Analysis (LPA) to identify patient subgroups. Ordinal logistic regression to identify predictors.

Results: Finding 1: Three Distinct MEP Trajectories Identified
Using LPA, patients were classified into three latent classes:
Class 1: Moderate-to-severe pain (25%) - Consistently high pain intensity.
Class 2: Mild pain (42%) - Stable, mild pain.
Class 3: No pain (33%) - Consistently low pain.

Finding 2: Predictors of Better MEP Control (Membership in No Pain Class)
Higher opioid consumption in the early phase was associated with better pain outcomes (Class 3):
Intraoperative Opioids: Consumption ≥ 40 mg (OR: 2.616, P=.001)
PACU Opioids: Consumption ≥ 2.5 mg (OR: 1.699, P=.048)
PCA Consumption: Lower consumption was associated with membership in the No Pain trajectory (OR=0.994, P=.039)

Conclusions: Conclusions
Postoperative MEP allows for dynamic heterogeneity, categorized into three distinct trajectories.
Adequate intraoperative and PACU opioid consumption predicts a favorable No Pain trajectory without increasing adverse effects.
Implications for Practice
Strategically optimizing opioid use during surgery is crucial for blunting nociceptive input.
Proactive management in the early recovery period and guiding analgesic dosing during care transitions are vital to prevent moderate-to-severe pain trajectories.

References: Bayman EO, Oleson JJ, Rabbitts JA. AAAPT: assessment of the acute pain trajectory. Pain Med. 2021;22(3):533–547.
Chapman CR, Donaldson GW, Davis JJ, Bradshaw DH. Improving individual measurement of postoperative pain: the pain trajectory. J Pain. 2011;12(2):257–262.
Mercado LASC, Liu R, Bharadwaj KM, et al. Association of intraoperative opioid administration with postoperative pain and opioid use. JAMA Surg. 2023;158(8):854–864.

Presenting Author: ZIHAO XUE
Submitting Author: ZIHAO XUE

Senior Author: ZIHAO XUE

IASP 2026 Global Year theme of Neuropathic Pain: No