Transversus abdominis plane block versus local anaesthetic wound infiltration for analgesia after caesarean section: A systematic review and meta-analysis with trial sequential analysis.

Background: Transversus abdominis plane (TAP) block and local anaesthetic wound infiltration are used to relieve pain after caesarean section. Objectives: To determine whether TAP block or local anaesthetic wound infiltration is the better analgesic option after caesarean section.

Design: Systematic review and meta-analysis with trial sequential analysis. Data sources: MEDLINE, Embase, Cochrane Central Register of Controlled Clinical Trials, Web of Science up to June 2020. Eligibility criteria: We retrieved randomised controlled trials comparing TAP block with wound infiltration after caesarean section. Primary outcome was pain score during rest (analogue scale, 0 to 10) at 2 h postoperatively, analysed according to the TAP block technique (ultrasound-guided/landmark-guided), anaesthetic strategy (spinal/general), intrathecal fentanyl (yes/no) and multimodal analgesia (yes/no). Secondary pain-related outcomes included pain scores during rest at 12 and 24 h, and total intravenous morphine consumption at 2, 12 and 24 h. We sought rates of block complications, including postoperative infection, haematoma, visceral injury and local anaesthetic systemic toxicity.

Results: Seven trials, totalling 475 patients, were identified. There was no difference in pain score during rest at 2 h between groups. Subgroup analyses revealed no differences related to TAP block technique (P = 0.64), anaesthetic strategy (P = 0.53), administration of intrathecal fentanyl (P = 0.59) or presence of multimodal analgesia (P = 0.57). Pain score during rest at 12 h and intravenous morphine consumption at 2 and 12 h were identical in both groups. Data were insufficient to compare block complications. Overall quality of evidence was moderate.

Conclusion: There is moderate level evidence that TAP block and wound infiltration provide similar postoperative analgesia after caesarean section. Trial registry number: PROSPERO CRD42020208046.