Journal of Clinical Anaesthesiology: Open Access

Purpose: Although laparoscopic surgery is generally considered minimally invasive, some patients have difficulty in postoperative analgesia. This study investigated the possibility of improving postoperative analgesia by intraoperative dexmedetomidine infusion.

Methods: This study was a two-arm, single-blind, randomized, intergroup trial. A total of 64 patients having undergone laparoscopic colorectal surgery were included, which were randomly divided into two: dexmedetomidine administration (DEX group) vs. no-administration (control group), with the former received DEX at 0.5 μg/kg/h. The primary endpoint was the maximum Numerical Rating Scale (NRS) pain score at rest within 4 hours after returning to the High Care Unit (HCU). The secondary endpoints included the NRS pain score at rest on the following morning, the doses of analgesics and antiemetics, The Quality of Recovery (QoR) score, intraoperative circulatory dynamics, and postoperative respiratory status.

Results: DEX group, compared with control group, showed the followings; 1) significantly smaller maximum NRS pain score at rest within 4 hours after returning to the HCU (mean of 2.4 (SD of 2.0) vs. 4.2 (1.7)); 2) significantly smaller NRS pain score at rest on the following morning (1.9 (1.4) vs. 3.1 (1.6)); 3) significantly smaller doses of patient-controlled analgesia (PCA) fentanyl and acetaminophen; 4) smaller doses of pentazocine and flurbiprofen; and 5) more QoR score (86 vs. 80). There was no significant difference in postoperative nausea and vomiting or antiemetic use.

Conclusion: Intraoperative administration of dexmedetomidine significantly improved pain scores at rest within 4 hours after returning to the HCU in the present study population. Intraoperative dexmedetomidine also significantly improved pain scores at rest of the following morning, which played a role of "prophylactic analgesia" beyond expectation.