125: ASSOCIATION BETWEEN INTRAOPERATIVE ANESTHETIC DEPTH VARIABILITY AND ACUTE POSTOP PAIN PHENOTYPES

Topic: Basic Science
Subtopic: Pain category (ICD-11), Acute postsurgical pain, , , , , , , , , , Pharmacological interventions, Assessment and Measurement of Pain/Nociception, Neurocircuit modulation (could include opto, DREADDs)

Background and Aims: Acute postoperative pain differs widely among patients, even when similar anesthetic techniques are used. The reasons for this variation are not fully clear. Fluctuations in anesthetic depth during surgery may influence postoperative pain outcomes. However, limited data exist on how intraoperative anesthetic depth variability relates to different postoperative pain phenotypes. This study aimed to examine the association between anesthetic depth variability during surgery and acute postoperative pain patterns.

Methods: We conducted a retrospective analysis of routinely collected perioperative data from adult patients undergoing elective non-cardiac surgery under general anesthesia at tertiary hospitals of Sindh between January 2023 and March 2025. The dataset was fully de-identified before analysis; therefore, formal ethical approval was not required under institutional policy. Anesthetic depth was assessed using processed EEG indices. Variability measures were calculated, and postoperative pain scores and opioid use within 48 hours were recorded. Multivariable analysis was performed to evaluate associations.

Results: A total of 612 patients were included. Greater variability in anesthetic depth was associated with higher postoperative pain scores and increased opioid consumption. Patients in the highest variability group were more likely to belong to the high-pain and high-pain/high-opioid phenotypes. Time spent in lighter-than-target anesthetic ranges showed a significant association with increased pain intensity. These findings remained significant after adjusting for demographic and surgical factors.

Conclusions: Intraoperative anesthetic depth variability was associated with distinct acute postoperative pain phenotypes in patients treated at tertiary hospitals in Sindh. Maintaining more stable anesthetic depth during surgery may help reduce postoperative pain severity. Further prospective studies are needed to confirm these findings.

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Presenting Author: Dr.sonia latif, dr mahma khursheed, dr mehwish, dr marukh
Submitting Author: Sonia Latif

Senior Author: Dr.Sonia latif

IASP 2026 Global Year theme of Neuropathic Pain: No