Efficacy of local infiltration tramadol (transversus abdominis plane block technique) versus preemptive intravenous tramadol on postoperative pain after open appendectomy: a prospective randomized controlled trial

Background: Acute postoperative pain, if mismanaged, leads to increased morbidity and mortality. Effective perioperative analgesia is crucial to prevent persistent pain. In abdominal surgeries, endogenous opioids are released, and tramadol, a weak synthetic opioid, has demonstrated effective analgesic properties. Recent studies suggest tramadol's mechanism involves blocking voltage-dependent sodium channels, which increases extracellular calcium and affects peripheral nerves. This suggests tramadol has both systemic and local anesthetic effects. Methods: A prospective, randomized, double-blind study was conducted on 32 patients (ages 18–60) diagnosed with acute appendicitis who underwent open appendectomy under general anesthesia. Participants were randomly assigned to two groups: group 1 received normal saline with tramadol infiltration for transversus abdominis plane (TAP) block (n=16), and group 2 received preemptive intravenous tramadol with TAP normal saline infiltration (n=16). Pain was assessed using the visual analogue scale (VAS) at various postoperative intervals. Opioid consumption was monitored through patient-controlled analgesia (PCA), and intraoperative data, complications, and hospital stay were recorded. Results: Demographic data were similar between groups. The primary outcome showed a significant reduction in postoperative pain (VAS score) at 0 hours (p=0.031) for the tramadol TAP group, with a 1-point reduction in pain over 24 hours compared to the intravenous group. Secondary outcomes indicated reduced opioid consumption, with no significant differences in complications (nausea/vomiting, infection, hospital stay). Conclusions: Local tramadol combined with TAP block is an effective alternative for postoperative pain relief after open appendectomy, reducing opioid consumption without additional complications.