A randomised controlled trial comparing erector spinae and transversus abdominis plane blocks for postoperative analgesia after elective caesarean section

Abstract

Background Peripheral abdominal nerve blocks contribute to multimodal postoperative analgesia that enhances early recovery after caesarean sections. The transversus abdominis plane (TAP) block is an established technique that offers somatic abdominal analgesia. The erector spinae plane (ESP) block is a novel fascial plane block that may offer additional visceral analgesic effects. This study aimed to compare the postoperative analgesic efficacy of bilateral ultrasound-guided TAP blocks to ESP blocks in women undergoing caesarean sections under spinal anaesthesia Methods Sixty-six ASA grade 1-3 (≥18 years) patients undergoing elective caesarean section under spinal anaesthesia were randomly allocated to receive either TAP blocks (n =33) or ESP blocks at the T9 vertebral level (n =33). The primary outcome measure was 24-hour cumulative morphine consumption. The secondary outcomes included the time taken to perform blocks, numeric rating scale (NRS) pain scores at 6- and 24-hours, effect of pain on activities of daily living (ADLs) and care for the newborn, time to first analgesic request, severity of opioid-related side effects, and patient satisfaction. Results There was no statistically significant difference in mean (SD) 24-hour cumulative morphine consumption between the ESP blocks and TAP blocks: 27 mg (14) vs 32 mg (15) (p=0.185). ESP blocks took longer to perform: 10.7 minutes (2.2) vs 9.0 minutes (2.5) (p<0.01). There were no significant differences in the other secondary outcomes. Conclusion The TAP block and ESP block were equally effective for postoperative analgesia after elective caesarean section under spinal anaesthesia. The ESP block did not demonstrate significant additional visceral analgesic effects.