Effect of dexmedetomidine as an adjuvant to bupivacaine in bilateral posterior quadratus lumborum block for postoperative analgesia after cesarean delivery: A prospective randomized double-blinded study

Effective pain control following a cesarean section was crucial. The postoperative discomfort following a cesarean section was treated using intravenous opioids and nonsteroidal anti-inflammatory medications. Currently, postoperative pain is alleviated through the utilization of fascial plane blocks such as the quadratus lumborum block, transversus abdominis plane block (TAP), erector spinae plane (ESP) blocks, and ilioinguinal nerve block. The primary aim of this study was to assess the duration of initial pain relief and time to first rescue analgesia. Secondary objectives were total number of rescue analgesic doses and amount of rescue analgesic consumption and postoperative pain scores. A total of 70 patients scheduled for elective lower segment cesarean sections were randomly assigned to either Group B or Group D. All cesarean sections were performed under spinal anesthesia. Participants in Group B received 0.4 ml/kg of a bupivacaine solution. In contrast, patients in Group D were administered a solution consisting of 0.4 ml/kg of 0.125% bupivacaine combined with 1 μg/kg of dexmedetomidine. The time to initial rescue analgesia was significantly longer in Group D (16.3 hours) compared to Group B (8.3 hours), with a p-value of <0.01. Similarly, the duration of analgesia was extended in Group D (16 hours) compared to Group B (8 hours), showing a statistically significant difference (p < 0.01). Group D required significantly fewer total rescue analgesic doses and fewer individuals required rescue analgesics. The mean total consumption of rescue analgesics, specifically paracetamol and tramadol, was markedly lower in Group D (0.14 gm of paracetamol and 2.8 mg of tramadol) compared to Group B (2.1 gm of paracetamol and 45.7 mg of tramadol), with a p-value of <0.01. Moreover, significant variations in pain scores were observed between 12 and 24 hours, with Group D participants exhibiting considerably lower pain scores than those in Group B. Additionally, from 8 to 24 hours, Group D patients demonstrated significantly reduced heart rates, as well as lower systolic and diastolic blood pressures compared to Group B. The addition of dexmedetomidine to bupivacaine significantly prolongs the time for initial rescue analgesia, duration of analgesia and reduces the number of rescue analgesic doses and pain scores.