How to Modulate Peripheral and Central Nervous System to Treat Acute Postoperative Pain and Prevent Pain Persistence.

Chronic postoperative pain (CPSP) is a major issue after surgery, which may impact on patient's quality of life. Traditionally, CPSP is believed to rely on maladaptive hyperalgesia and risk factors have been identified that predispose to CPSP, including acute postoperative pain. Despite new models of prediction are emerging, acute pain is still a modifiable factor that can be challenged with perioperative analgesic strategies. In this review we present the issue of CPSP, focusing on molecular mechanism underlying the development of acute and chronic hyperalgesia. Also, we focus on how perioperative strategies can impact directly or indirectly (by reducing postoperative pain intensity) on the development of CPSP.

Opioid-Free Anesthesia and Postoperative Outcomes in Cancer Surgery: A Systematic Review.

BACKGROUND: Surgery is an essential component of the treatment of solid tumors, but the perioperative course can be complicated by different factors (including anesthesia). Opioid-free anesthesia (OFA) may mitigate adverse outcomes of opioid-based anesthesia (OBA), but major questions remain on the actual impact in terms of analgesia and the improvement of surgical outcomes. To address this issue, we present a systematic review to evaluate the efficacy of OFA compared to OBA in the specific subset of cancer patients undergoing surgery. METHODS: following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA), we searched MEDLINE, Embase and the Cochrane CENTRAL Library to include randomized controlled trials (RCTs) on adults undergoing oncological surgery, comparing OFA and OBA up to March 2022. Additional papers were added from the reference lists of identified sources. Papers were manually reviewed by two independent authors to ascertain eligibility and subsequent inclusion in qualitative analysis. RESULTS: only two studies were eligible according to inclusion criteria. It was not possible to perform any meta-analysis. The two studies included patients undergoing prostate and gynecologic surgery on 177 patients, with significant heterogeneity in the outcomes. CONCLUSIONS: randomized controlled trial specifically addressed to cancer patients are lacking. A knowledge gap exists, neither confirming nor rejecting the capacity of OFA to improve early postoperative outcomes in cancer surgery. Long-term consequences on specific oncological outcomes are far from being elucidated. We expect a growing body of literature in the coming years. Further studies are required with homogeneous methodology and endpoints.