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Background and Aims Inadequately managed post-operative pain is associated with increased morbidity, mortality and could contribute to development of chronic pain. Mechanical temporal summation (MTS) measures nociceptive pain amplification and is negatively associated with acute and chronic pain post-thoracic surgery. We aimed to investigate the association between MTS and acute pain post-hysterectomy, and to determine perioperative risk factors.

Methods This prospective study recruited patients undergoing hysterectomy for benign gynaecological indications from July 2019 to June 2023. The preoperative MTS was assessed as the primary exposure. The difference of MTS scores (difference between 11th and 1st pain scores evoked by von Frey filament), baseline demographics and clinical information were collected. The presence of acute severe pain at 24 hours post-hysterectomy was defined as pain score of 7 or more. Univariate and multivariable analyses were conducted.

Results Out of 197 patients, 25 (12.7%) reported acute severe pain. There was no significant correlation between evoked MTS and acute severe pain post-hysterectomy. However, univariate analysis showed statistically significant association between difference of MTS scores and presence of acute severe pain (p=0.0518). The multivariable model for acute severe pain post-hysterectomy comprised three factors: difference of MTS scores (adjusted OR (aOR) 1.06, 95% CI 1.01-1.12, p=0.0238), marital status being non-married (aOR 3.62, 95%CI 1.40-9.39, p=0.0081), and presence of moderate/severe pain pre-hysterectomy (aOR 3.01, CI 1.32-6.88, p=0.0090). AUC was 0.726 (95%CI 0.599-0.853).

Conclusions This study identified association factors for acute severe pain post-hysterectomy. Future studies could explore early individualised therapies for high-risk patients to optimise post-surgical pain outcomes.