Comparison of the effectiveness of postoperative analgesia methods: bilateral transversus abdominis plane block versus quadratus lumborum block in women after cesarean section: a single-center, prospective, randomized study

BACKGROUND: The mixed nature of pain (visceral and somatic components) after cesarean section and the use of interfascial blocks have substantially influenced the effectiveness of postoperative analgesia. However, because of the variety of regional analgesia techniques, the superiority of the quadratus lumborum block over the transversus abdominis plane block remains a subject of debate.

AIM: This study aimed to compare the analgesic effectiveness of the transversus abdominis plane block and the quadratus lumborum block in the early postoperative period after cesarean section.

METHODS: This prospective, randomized study was based on the analysis of analgesic effectiveness in 78 women who underwent cesarean section and received analgesia using two methods: transversus abdominis plane block and quadratus lumborum block. Patients were randomized into two groups: group 1 consisted of 39 patients who received the transversus abdominis plane block as postoperative analgesia; group 2 included 39 patients who received the quadratus lumborum block. The quality of analgesia, its analgesia, overall need for additional analgesia, pain intensity before block placement, and the impact of the block on postoperative analgesia quality were assessed. Pain was evaluated using the visual analog scale at rest at the following time points: before analgesia, at 6 hours, at 12 hours, and 12 hours after transfer to the postpartum ward. The need for additional analgesia was also recorded.

RESULTS: Pain intensity before analgesia varied considerably between groups; however, intergroup differences in frequency distributions of visual analog scale scores were not significant (p = 0.061). Pain intensity at 6 and 12 hours after the block did not differ significantly between the groups. No statistically or clinically significant difference in the frequency of additional analgesia was observed (p = 0.062). These data indicate comparable analgesic effectiveness of both methods. The analysis of analgesia quality after cesarean section prior to block administration revealed a significant difference in analgesia satisfaction curves between the studied groups. Specifically, in the transversus abdominis plane block group, a nerve block was required substantially earlier after surgery compared with the quadratus lumborum block group (p = 0.0012).

CONCLUSIONS: The use of interfascial blocks (transversus abdominis plane block and quadratus lumborum block) provided a comparable analgesic effect in the early postoperative period after cesarean section.