Guo JG, et al. - In patients undergoing open liver resection with a Mercedes incision, researchers investigated the opioid-sparing effects of the oblique subcostal transversus abdominis plane (OSTAP) blockade with ropivacaine, relative to OSTAP block with isotonic saline. Preoperative and intraoperative parameters, plus intraoperative and postoperative cumulative sufentanil consumption, were recorded. Without obvious side effects, a significant reduction in the perioperative cumulative dosage of analgesics and improved analgesia could be achieved with ultrasound-guided OSTAP block with ropivacaine vs ultrasound-guided OSTAP block with saline.