Efficacy Of Quadratus Lumborum Blocks (QLBs) in Robotic Nephrectomy: A Retrospective Study

Introduction: Abdominal blocks such as quadratus lumborum block (QLB) have been used as an effective analgesic in abdominal surgeries. However, their efficacy in kidney surgery remains unknown. To the best of our knowledge, there are no clinical studies exploring the relationship between QLBs and post-operative opioid consumption in robotic laparoscopic nephrectomy. Objectives: To assess the analgesic efficacy of QLB and its impact on perioperative opioid consumption in robotic laparoscopic nephrectomy. Materials and methods: A retrospective chart review was conducted by querying the electronic medical record system of a 2,200-bed tertiary academic hospital center in New York City. The primary measured outcome was postoperative morphine milligram equivalents (MME) consumption for the first 24 hours. Secondary outcomes include intra-operative MME as well as postoperative pain scores measured on a visual analogue scale (VAS) scale at 2, 6, 12, 18, and 24 hours postoperatively. Results: The mean total postoperative MME in the posterior QLB (pQLB) group was 11 in the QLB group (interquartile range (IQR) 4, 18) and 15 in the control group (IQR 5.6, 28) . There was a significant reduction in intraoperative MME in the QLB group in comparison to the control group. This reduction was not seen in postoperative MME. There was no significant difference in pain scores at any of the measured time points up to 24 hours postoperatively. Conclusion: Our study provides compelling support that ultrasound guided QLB significantly decreased intraoperative opioid requirements but did not have the same effect on postoperative opioid requirements following robotic kidney surgeries in the context of an enhanced recovery after surgery (ERAS) pathway.