Comparison of Ultrasound-Guided Anterior, Posterior and Combination of Quadratus Lumborum Block in Laparoscopic Abdominal Surgeries: A Pilot Study.

Abstract

The quadratus lumborum block (QLB) is an effective technique to provide analgesia for upper and lower abdominal surgeries. There are various approaches described in the literature, but the best approach is still to be explored. This study aims to compare the analgesic efficacy of three different approaches of QLBs. Sixty-five patients, aged 18-70 years posted for elective laparoscopic abdominal surgery under general anesthesia were enrolled after taking written informed consent. QLB was given using bupivacaine 0.25% 40 mL with injection dexmedetomidine 1 mcg/kg in all the groups. In Group 1 and Group 2, the drug was injected into the anterior and posterior aspects of the muscle respectively. In Group 3, a combination of the anterior-posterior approach was used. Pain scores at various intervals along with analgesic consumption and complications were observed. The demographic variables, hemodynamic parameters, and complications were comparable among the three groups. There were statistically significant differences between treatment groups in fentanyl requirement as assessed using the Kruskal-Wallis test (P = 0.012). Pairwise post-hoc analysis between block groups showed that the differences between Group 1 & Group 2 and Group 2 & Group 3 were significant (P = 0.0098 and P = 0.013). The tramadol requirement was comparable in all the groups (P = 0.75). Patient satisfaction was significantly higher in Group 3 compared to other groups (P = 0.024). Further studies can be planned to evaluate the best approach for QLB in terms of perioperative analgesia, which remains a dilemma in this pilot study. The anterior, posterior, and combined anterior-posterior QLB approaches appear equally efficacious as a component of multimodal analgesia in laparoscopic abdominal surgeries.