Ultrasound-guided quadratus lumborum block versus ultrasound-guided erector spinae block for perioperative analgesia in laparoscopic colorectal cancer resection: a prospective randomized controlled study

Interventions: Ultrasound-guided quadratus lumborum block group (QLB group):Before general anesthesia, bilateral ultrasound-guided quadratus lumborum block was performed, and 25ml of 0.375% ropivacaine was used on each side, for a total of 50ml;Ultrasound-guided erector spinae block group (ESPB group):Before general anesthesia, bilateral ultrasound-guided erector spinae block was performed, using 25ml of 0.375% ropivacaine on each side, for a total of 50ml Primary outcome(s): The dose of opioid analgesics consumed by the patient Study Design: Case-Control study