A randomised comparison of transverse abdominal plane block versus thoracic epidural analgesia on postoperative opioid consumption for colorectal enhanced recovery after surgery programme (OPIATE study).

Background: The transverse abdominis plane block is increasingly being used as a less-invasive alternative to thoracic epidural analgesia for effective pain management. This study aimed to compare transverse abdominis plane block with opioid-based thoracic epidural analgesia in terms of postoperative opioid consumption.

Methods: Patients in the thoracic epidural analgesia group received a continuous infusion of 0.1% levobupivacaine with 2mcg/ml of fentanyl, while those in the transverse abdominis plane group received 6-hourly boluses of 0.4ml/kg of 0.25% levobupivacaine. The primary objective was to compare the average fentanyl consumption, measured as intravenous fentanyl equivalents, over 72 hours.

Results: Data of 35 patients were analysed. Fentanyl consumption at the end of 72 hours was significantly lower in the transverse abdominis plane group (median [interquartile range] 495 mcg (255, 750), and mean (95% confidence interval) 717.35mcg (403.54-1031.16)) compared to the thoracic epidural analgesia group (median [interquartile range] 760mcg (750, 760), and mean (95% confidence interval) 787mcg (746.81-827.19)) with a p value of 0.010. Pain scores at rest and during movement were comparable between the groups ( > 0.05). However, the median pain scores during movement were significantly lower in the thoracic epidural analgesia group at 60 and 72 hours ( ⩽ 0.05).

Conclusion: Multimodal analgesia with transverse abdominis plane resulted in lower opioid consumption over 72 hours compared to thoracic epidural analgesia.