P249 Effect of anesthetic technique on chronic pain in patients undergoing breast cancer surgery: follow-up data from an RCT

<h3></h3> <b>Please confirm that an ethics committee approval has been applied for or granted</b>: Yes: I’m uploading the Ethics Committee Approval as a PDF file with this abstract submission <h3>Background and Aims</h3> Acute perioperative pain, if not managed adequately, can result in chronic pain. Opioid-free anesthesia (OFA) is a combination of multimodal analgesia without the use of opioids. Chronic postsurgical pain may lead to functional limitations and psychological trauma for patients. In our study; we aimed to assess the efficacy of erector spinae block (ESP) without opioids versus opioid-based anesthesia in patients undergoing breast cancer surgery. We followed them up at 6 months to find out if the anesthetic technique made any difference in the development of chronic pain in these patients. <h3>Methods</h3> 100 patients undergoing breast cancer surgery were randomized into two groups in 1:1 ratio. Group O received opioid-based anesthesia and Group N received ultrasound guided ESP block without any opioids intraoperatively. Post-extubation analgesia was managed with a patient-controlled analgesia pump containing morphine. Our primary outcome was 24-hour morphine consumption. Secondary outcomes included NRS at various time points postoperatively (1,2,6,24 hour) and at 6 months. <h3>Results</h3> There was no statistical difference in the total 24-hour postoperative morphine consumption (p=0.13). The NRS at 6 months differed significantly, with group N having a lower score (4.72±2.2 vs 2.56± 1.41; p&lt;0.05). NRS at rest and on movement at various time points postoperatively did not differ significantly (p&gt;0.05). <h3>Conclusions</h3> Our follow-up data found that Opioid free was associated with decreased chronic pain at 6 months and can be considered as a technique of choice in oncology surgeries.