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 mu g/kg bolus followed by 0.4 mu g/kg/h infusion (group Dex) or saline placebo (group Con). During the operation, an additional dose of remifentanil 0.05-0.25 mu g/ 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] mu g; 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.