Dexmedetomidine Preemptive Analgesia on Intra- and Postoperative Pain in Noncardiac Surgery: A Randomized, Double-Blind, Controlled Study

BACKGROUND: Inadequate pain management affects over half of the 230 million major surgeries performed annually. Preemptive analgesia aims to prevent peripheral and central sensitization. Dexmedetomidine (DEX) offers non-opioid analgesia and opioid-sparing effects. This study evaluated the efficacy of preemptive DEX using the nociception index (NOX) for objective intraoperative monitoring and assessed its impact on perioperative outcomes. METHODS: In this single-center, double-blind, randomized controlled trial, 220 eligible patients were assigned to receive either intravenous DEX (1.5 µg·kg -1 ·h -1 ) (DEX group) or placebo (normal saline) (PO group) from 15 minutes before anesthesia induction until 15 minutes post-induction. The co-primary outcomes were the intraoperative NOX compliance rate (mean NOX ≤60 during nociceptive stimulation) and the incidence of moderate-to-severe postoperative pain (pNRS > 3) at 0, 24, 48 hours, and 7 days. Secondary outcomes included hemodynamic parameters, postoperative nausea and vomiting (mPONV), dizziness, analgesic consumption, and safety events. RESULTS: The DEX group demonstrated a significantly higher NOX compliance rate compared to the placebo group (98/108, 90.7% vs 14/112, 12.5%; P < .001). The incidence of NRS>3 was significantly lower in the DEX group at all postoperative time points (3/108, 2.8% vs 29/112, 25.9% at 0 hour; 6/108, 5.6% vs 33/112, 29.5% at 24 hours; 1/108, 0.9% vs 19/112, 17% at 48 hours; 0/108, 0% vs 6/112, 5.4% at 7 d; P = .000). DEX also reduced rescue opioid consumption ( z = -2.428, P = .004), decreased mPONV ( z = -4.901, P = .001), and improved hemodynamic stability. Safety profiles were favorable in DEX group. CONCLUSION: Preemptive analgesia with DEX significantly improves both intraoperative nociceptive control as objectively measured by the NOX and postoperative pain control. It validates the role in optimizing perioperative analgesia and enhancing recovery.