Randomization and blinding
On the day of surgery, patients were randomly assigned to either the group that received GDHT during the surgery (GDHT group) or the group that received standard care at the discretion of the attending anesthesiologists (control group), with 1:1 allocation based on a randomized computer-generated list, consisting of four and six block sizes. The group allocations were sealed in opaque envelopes by an investigator not involved in the study. Because the anesthesiologists in charge of the operating room managed the patients according to group allocation, blinding the attending anesthesiologists was impossible. However, the investigators who evaluated postoperative outcomes and surgeons were blinded to the group allocation.