Lidocaine Infusion or Quadratus Lumborum Block and Intrathecal Morphine, Versus Intrathecal Morphine Alone

Systemic administration of intravenous lidocaine has a number of observed and theoretical advantages in the perioperative period. Systematic review of perioperative lidocaine infusions has shown a reduction in early post-operative pain scores in patients undergoing abdominal surgery, positive effects for GI recovery, reduction in post-operative opioid requirements, reduction in the incidence of post-operative nausea and vomiting, and decreased length of hospital stay. They have been shown to modulate the surgery-induced stress response in colorectal surgery and abdominal hysterectomy. Thoracic epidural analgesia was better as compared to intravenous lidocaine in a RCT of patients undergoing laparoscopic colorectal surgery as part of an enhanced recovery program, though there was similar impact on recovery of bowel function.

Truncal regional anesthesia has been utilized in open and closed abdominal operations with various levels of efficacy. A statistically significant, though marginal clinical analgesic benefit, by recorded opioid consumption, has been concluded by meta-analysis in patients undergoing abdominal laparotomy, laparoscopy, or cesarean delivery after US-guided TAP block. There was not found to be any additional benefit of TAP block in patients who received a spinal anesthetic that included a long-acting opioid. The interpretation of results was noted to be limited by the heterogeneity of the included studies and analysis, though. The conclusions of one study of open prostatectomy, as part of an ERP, was that neither systemic lidocaine nor TAP block improved post-operative analgesia. Both IV lidocaine and TAP block groups showed a reduction in post-operative opioid consumption, though to an insignificant degree. It was noted as a possibility that the other interventions as part of the ERP, such as scheduled administration of IV acetaminophen, could have resulted in the non-significant decrease in post-operative opioid requirement. A recent review of the use of TAP blocks in major gynecological, non-obstetric, surgery, including total abdominal hysterectomy, concluded that TAP blocks may contribute to early post-operative analgesia, with marginal additional benefit if multimodal analgesic regimens including NSAIDs and acetaminophen are added. It was hypothesized by the authors that some of the limited benefit might be due to the fact that US-guided TAP blocks are primarily useful for somatic pain, but that major gynecologic surgery has a large visceral pain component. There are limited randomized studies involving Quadratus Lumborum block (QL) at this time. QL block has shown improved analgesia in abdominal operations as compared to TAP block and is thought to have potentially greater relief of visceral pain. There is a case report of motor weakness following anterior, lateral QL block for gynecologic laparoscopy, thought to be related to spread of the block to affect the L2 dermatome on one side. It has not been determined if this is a common occurrence or may be affected by the type of QL block performed.

Prior to this study, truncal regional anesthesia was used in the UAB Gynecology-Oncology Surgery Enhanced Recovery Program as an analgesic alternative for those who were not good candidates for intrathecal opioid injection. A comparison of QL block versus systemic lidocaine infusion or whether either of these interventions has utility over intrathecal opioid administration alone has yet to be described.