Effect of Dexmedetomidine as an adjuvant in quadratus lumborum block in patient undergoing caesarean section – A randomised controlled study

This study was conducted to evaluate the effect of Dexmedetomidine as an adjuvant in quadratus lumborum block (QLB) for postoperative pain relief at rest in patients undergoing caesarean section (CS). The primary objective was to compare the time to the first request of rescue analgesia. Secondary objectives were to compare the amount of rescue analgesia, patient satisfaction, Numeric rating scale (NRS), and Ramsay sedation score (RSS) during the first 24 h. A randomised, double-blinded study. The study was conducted at AIIMS Bhubaneswar from December 2019 to February 2021in the Operating Theatre complex (for the immediate postoperative follow-up) and in the Obstetric Ward (for follow-up at the later time points). A total of 70 patients were enrolled with singleton term pregnancies scheduled for CS under spinal anaesthesia after written informed consent. Bilateral QLB was given in the recovery area. Group A received 30 ml of 0.25% Bupivacaine and group B received 30 ml 0.25% bupivacaine with Dexmedetomidine 1 μg/kg. They received inj. Paracetamol 15 mg/kg intravenously TDS and Inj. Tramadol 1 mg/kg as rescue analgesia (if Numeric rating scale (NRS) Score ≥ 4). We also compared the rescue analgesia in the first 24 h, patient satisfaction scores, Ramsay sedation score (RSS), and NRS scores at 2, 4, 6, 8, 12, 18, and 24 h. The time to request the first rescue analgesia was significantly prolonged in group B [Mean ± SD (95% CI)] 880 ± 351 (720–1040) min. vs group A 439 ± 208 (368–510) min., p < 0.001). There was a significant decrease in the amount of rescue analgesia [(Inj. Tramadol (1 mg/ kg)] used in the group with dexmedetomidine [group B Mean ± SD (95% CI) (57 ± 18 (49–65) mg. vs group A - 81 ± 25 (73–90)] mg., p < 0.001]. A significant difference was seen in patient satisfaction scores and pain scores between the groups up to 18 h. ( p < 0.05) but not in RSS. Dexmedetomidine can be considered an effective adjuvant for QLB in CS in the absence of intrathecal morphine. • Regional blocks are important component of multimodal analgesia for postoperative pain relief after caesarean section. • Ultrasound-guided QL block using Bupivacaine with Dexmedetomidine prolong analgesia in the absence of intrathecal morphine. • The same provides decreased rescue analgesic dose and better patient satisfaction scores upto 18 hours post-operatively.