Effect of Bupivacaine Liposomes or Bupivacaine for Ultrasound-guided CMB on Postoperative Analgesia in Laparoscopic Hepatobiliary Pancreatic Surgery: a Prospective, Single Blind, Completely Randomized, Active Controlled Clinical Trial

Numerous studies have confirmed that regional analgesia using peripheral nerve block has great potential for perioperative analgesia in abdominal surgery. Ultrasound guided costal margin block (CMB) is a new regional anesthesia technique that has been proven to compensate for the analgesic effects of regional analgesia techniques such as transverse abdominal muscle plane (TAP) and rectus abdominis sheath (RSB) on mid abdominal incisions, but it is difficult to meet the analgesic needs of anterior and outer abdominal wall incisions. According to relevant anatomy and research, the application of local anesthetics along the rib margin under the rectus abdominis muscle or under the external oblique muscle on the rib surface can block the lateral and anterior cutaneous branches of the thoracoabdominal nerve, known as CMB. Ultrasound guided CMB requires the injection of local anesthetics onto the surface of the rib along the plane below the rectus abdominis and oblique muscles, covering most of the upper abdominal incision pain. However, there are few reports on other types of upper abdominal surgeries such as liver, gallbladder, and pancreas surgeries.

Bupivacaine liposomes are an important innovation, which encapsulate bupivacaine in polycystic liposomes using DepoFoam technology to achieve slow drug release and effectively prolong pain relief time by up to 72 hours. This ultra long acting local anesthetic has significant advantages in reducing opioid use, improving analgesic satisfaction, reducing complications, and shortening hospital stays, and has been applied in the ERAS concept.

The investigators designed a prospective, single blind, randomized, active controlled clinical trial to investigate the effect of bupivacaine liposomes in combination with bupivacaine mixture or bupivacaine alone for ultrasound-guided bilateral CMB on postoperative analgesia in patients undergoing laparoscopic hepatobiliary pancreatic surgery. Our main hypothesis is that the use of bupivacaine liposomes and a mixture of bupivacaine for ultrasound-guided CMB in a multimodal analgesia regimen can more effectively reduce the dosage of intravenous patient-controlled analgesia (PCA) opiates within 72 hours after laparoscopic hepatobiliary pancreatic surgery compared to using bupivacaine alone. Secondary outcomes include the dosage of PCA opiates within 24-48 hours, pain score values, patient satisfaction, adverse reactions, and complications.