Several key issues must be noted in determining postoperative analgesic efficacy of intercostal nerve block for thoracoscopic surgery.

The letter to the editor was written in response to "The effect of ultrasound-guided intercostal nerve block on postoperative analgesia in thoracoscopic surgery: a randomized, double-blinded, clinical trial", which was recently published by Li et al. (J Cardiothorac Surg 18(1):128, 2023). In this article, Li et al. showed that addition of a preoperative intercostal nerve block to the multimodal analgesic strategy significantly reduced the pain scores within 48 h after surgery. However, we noted several issues in this study that were not well addressed. They were no use of a standard opioid-sparing multimodal analgesic strategy recommended in the current Enhanced Recovery After Surgery protocols for thoracic surgery, the lack of clear description for reasonable selection of rescue analgesics, the interpretion of between-group differences in the postoperative pain scores based on only statistical differences rather than clinically meaningful differences, inclusion of patients who were not blinded to study intervention, not reporting cumulative opioid consumption and complications of intercostal nerve block. We believe that clarification of these issues is not only useful for improving design quality of randomized clinical trials which assess postoperative analgesic efficacy of nerve blocks, but also is helpful for the readers who want to use an opioid-sparing multimodal protocol including a nerve block in patients undergoing thoracoscopic surgery.