Abstract: Due to large trauma after oral cancer resection repaired with free flaps reconstruction, patients often experience severe pain after surgery. Opioids are the most powerful analgesics used for postoperative pain alleviation, but they also have adverse effects such as respiratory depression, postoperative nausea and vomiting. In addition, factors including the relatively extensive surgical resection, expected postoperative edema, and accumulation of secretions may contribute to increased airway complications in these patients. On the other hand, vomiting can lead to postoperative bleeding and wound infection. Thus, there is a necessity to find an analgesic strategy with high safety, good analgesic effect and few side effects. To address this dilemma, ultrasound-guided regional nerve block technology, as a part of multimodal analgesia, has been developed in recent years, which can significantly reduce opioids requirement and their side effects. This paper described the anatomy of commonly used free flaps, the researches and operational procedures of ultrasound-guided nerve block, in order to provide reference for the application of this technology in oral cancer resection with free flaps reconstruction.

Key words: Oral cancer, Postoperative pain, Nerve block, Opioids