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.