Relationship between preoperative pain assessment to standard stimulus and intraoperative dose of fentanyl

Objective. To assess the feasibility of determining intraoperative fentanyl dosage considering preoperative evaluation of pain sensitivity to standardized stimuli. Material and methods. A prospective single-center pilot study enrolled 44 patients (ASA II-III) undergoing elective thoracic and abdominal surgeries. A standardized anesthesia protocol (propofol, fentanyl, sevoflurane) with multimodal analgesia (ibuprofen, paracetamol) was employed. Pain sensitivity was assessed during venous catheter insertion using a numerical rating scale (NRS) (0-10). Intraoperative fentanyl requirements were adjusted according to the qNOX index (target range 40-60). Postoperative evaluation included pain intensity (NRS at 8 time points), cortisol and cognitive function (MOCA, TMT, MMSE). Results. Ther was a strong correlation between preoperative pain sensitivity and intraoperative fentanyl requirements (Spearman’s correlation coefficient 0.7, p<0.05). Furthermore, when patients were divided into three groups depending on pain following standard stimulus, we found significant differences in intraoperative fentanyl requirements (Kruskal-Wallis test, p=0.0011). Cognitive impairments were minimal and rapidly regressed. Cortisol demonstrated no correlation with preoperative pain sensitivity. Conclusion. Preoperative pain sensitivity may be a predictor of intraoperative analgesic requirements. This personalized approach reduces postoperative pain and cognitive dysfunction, as well as demonstrates clinical potential.