Anti-nociceptive Effects of Dexmedetomidine Infusion Plus Modified Intercostal Nerve Block During Single-port Thoracoscopic Lobectomy: A Double-blind, Randomized Controlled Trial.

BACKGROUND Multimodal general anesthesia based on modified intercostal nerve block (MINB) has been found as a novel method to achieve an intraoperative opioid-sparing effect. However, there is little information about the effective method to inhibit visceral nociceptive stress during single-port thoracoscopic surgery. OBJECTIVE To investigate whether a low-dose dexmedetomidine infusion followed by MINB might be an alternative method to blunt visceral stress effectively. STUDY DESIGN Double-blind, randomized control trial. SETTING Affiliated hospital from March 2020 through September 2020. METHODS Fifty-four patients were randomized (1:1), 45 patients were included to receive dexmedetomidine with a 0.4 microgram/kg bolus followed by 0.4 microgram/kg/h infusion (group Dex) or saline placebo (group Con). During the operation, an additional dose of remifentanil 0.05-0.25 microgram/kg/min was used to keep mean arterial pressure (MAP) or heart rate (HR) values around 20% below baseline values. The primary outcome was to evaluate remifentanil consumption. Secondary outcomes included intraoperative hemodynamics, the first time to press an analgesia pump, and adverse effects. RESULTS Remifentanil consumption during surgery was markedly decreased in the Dex group than in the Con group (0 [0-0] versus 560.0 [337.5-965.0] microgram; P = 0.00). MAP and HR in the Con group during the first 5 minutes after visceral exploration was significantly higher than in the Dex group (P < 0.05). Time to first opioid demand was significantly prolonged (P = 0.04) and postoperative length of stay was shortened slightly in the Dex group (P = 0.05). LIMITATIONS This study was limited by the measurement of nociception. CONCLUSIONS This study demonstrates that low-dose dexmedetomidine infusion combined with MINB might be an effective alternative method to blunt visceral stress in patients undergoing single-port thoracoscopic lobectomy. Furthermore, the analgesic effect of MINB was significantly prolonged after dexmedetomidine infusion.