Intranasal dexmedetomidine reduces postoperative opioid requirement in patients undergoing total knee arthroplasty under general anesthesia

Abstract Background Total knee arthroplasty (TKA) causes severe pain and strong opioids are commonly used in postoperative analgesia. Dexmedetomidine is a novel alpha-2-adrenoceptor-activating drug indicated for procedural sedation, but previous studies have shown clinically relevant analgesic and antiemetic effects. We evaluated retrospectively the effect of intranasal dexmedetomidine on postoperative opioid requirement in patients undergoing TKA. Methods 150 patients with ASA status 1-2, age between 35 and 80 years and scheduled for unilateral primary TKA under total intravenous anesthesia were included in the study. Half of the patients received 100 μg of intranasal dexmedetomidine after anesthesia induction, while the rest were treated conventionally. Postoperative opioid requirement was calculated as morphine equivalent doses for both groups. The effect of dexmedetomidine on postoperative hemodynamics, length of stay (LOS) and incidence of postoperative nausea and vomiting (PONV), was evaluated. Results The cumulative postoperative opioid consumption was significantly reduced in the dexmedetomidine group compared to the control group (- 28.5 mg, 95% CI 12-47 mg P Conclusion Intraoperatively administered intranasal dexmedetomidine reduces postoperative opioid consumption and may be associated with shorter hospital stay in patients undergoing TKA under general anesthesia.