A Trial Comparing Quadratus Lumborum Block (QLB) and Paravertebral Block (PVTB) for Postoperative Analgesia in Hepatectomy

Pain after hepatectomy can interfere with the patients' recovery and may contribute to developing long term pain. Opioids, e.g. morphine, fentanyl, sufentanil, works well for postoperative analgesia, but have several side effects such as nausea, vomiting and itching which may be severe enough to affect patients' recovery. In some cases, opioids may cause constipation and urinary retention within the first 24 hours after surgery. Thus, several ultrasound-guided nerve block procedures have been applied to provide postoperative analgesia. Ultrasound-guided thoracic paravertebral block (TPVB) is one of the most used nerve block methods using for post-hepatectomy analgesia. However, in some cases, ultrasound-guided TPVB can cause pneumothorax, hemopneumothorax, and higher block level. The quadratus lumborum block (QLB) is a new developed nerve block which can provide a widespread analgesic effect from T7 to L1. Therefore, this study is to determine whether QLB or TPVB have a better pain control with fewer side effects and complications after laparoscopic and open hepatectomy. The adequate pain control will be assessed by their visual analogue score (VAS) and the postoperative quality of recovery scale (QoR-15, Chinese Version). Additionally, the side effect and complications profile of these two nerve block techniques will also be recorded and compared.