Quadratus Lumborum and Transversus Abdominis Plane Blocks and Their Impact on Acute and Chronic Pain in Patients after Cesarean Section: A Randomized Controlled Study

Background: Severe postoperative pain is a significant problem after cesarean sections. Methods: This study was a randomized, controlled trial of 105 patients conducted in two hospitals. All patients were anesthetized spinally for elective cesarean section. Each participant was randomly allocated to one of three study groups: the quadratus lumborum block (QLB) group, the transversus abdominis plane block (TAPB) group, or the control (CON) group. The primary outcome of this study determined acute pain intensity on the visual analog scale (VAS). The secondary outcomes determined morphine consumption and chronic pain evaluation according to the Neuropathic Pain Symptom Inventory (NPSI) after hospital discharge. Results: At rest, the pain intensity was significantly higher in the CON group than in the QLB and TAPB groups at hours two and eight. Upon activity, the pain in the control subjects was more severe than in the QLB and TAPB groups in three and two of five measurements, respectively. Moreover, morphine consumption was significantly lower in the QLB (9 (5-10)) and TAPB (10 (6-14)) groups than in the CON (16 (11-19)) group. Persistent postoperative pain was significantly lower in the QLB group than in the CON group at months one and six following hospital discharge. Conclusions: Both the QLB and TAPB can improve pain management after cesarean delivery. Moreover, the QLB might reduce the severity of persistent postoperative pain months after cesarean section.