Addition of dexmedetomidine to anesthesia regimen reduces pain level after endoscopic submucosal dissection: A systematic review and meta analysis.

[INTRODUCTION] Endoscopic submucosal dissection (ESD) is a minimally invasive organ-preserving procedure indicated for the removal of precancerous and cancerous areas in the gastrointestinal (GI) tract. It is highly valuable due to its ability to achieve high en-bloc resection rates and reduced local recurrence. Nevertheless, postoperative pain has been an often-overlooked complication, previous studies found that the incidence of moderate to severe pain after ESD can be as high as 44.9-62.8 %, leading to decreased patient satisfaction. Dexmedetomidine, a selective and potent α2-receptor agonist, has gained recognition in clinical practice for its sedative, analgesic, and anxiolytic properties, with the advantage of not causing respiratory depression as seen with opioids.

[METHODS] Following the PRISMA guidelines, a systematic review and meta-analysis were performed to determine the impact of dexmedetomidine on endoscopic submucosal dissection postoperative pain in adult patients with gastrointestinal neoplasias. Primary outcomes were postoperative pain, sedation time and adverse event rate. Data were analyzed using R version 4.2.2. The risk of bias was assessed by the Robins-I and RoB 2 tool. The quality of evidence was graded using the GRADE scale and Newcastle-Ottawa guidelines.

[RESULTS] Five randomized clinical trials and one observational studies described the postprocedural pain level of dexmedetomidine vs control for gastrointestinal neoplasia dissection, totaling 643 patients. The meta-analysis demonstrated a significant reduction in postoperative pain with dexmedetomidine (RR = 0.50; 95 % CI = [0.35; 0.70]; p < 0.01). No significant difference was found in terms of adverse event rate between -groups (RR = 1.04; 95 % CI = [0.55; 1.98]; p = 0.85). Similarly, regarding sedation time, two randomized clinical trials and one observational study totaling 249 patients showed no significant difference between groups (SMD = 0.27; 95 % CI = [-0.62; 1.17]; p = 0.32). The risk of bias was low with moderate-to-high quality of evidence among the included studies.

[DISCUSSION] Our updated systematic review and meta-analysis demonstrated a significant difference in the postoperative pain level in the group with concomitant dexmedetomidine and midazolam sedation compared to midazolam alone for the endoscopic dissection of superficial gastrointestinal neoplasias. Importantly, our analysis did not include objective data regarding post procedure opioid consumption nor patient satisfaction; these variables would be valuable for future analysis. Further large-scale randomized control trials are warranted currently to help confirm these findings and to explore the optimal dosing regimens and administration protocols for dexmedetomidine in ESD.