Dexmedetomidine as adjuvant of transversus abdominal plane block for cesarean delivery under multimodal analgesia: a randomized clinical trial.

BACKGROUND

The parturients who have undergone cesarean delivery (CD) often suffer moderate to severe pain. Multimodal analgesia has been implemented to improve postoperative pain management following CD. The role of dexmedetomidine for multimodal analgesia after CD is not well defined. This study aimed to evaluate the efficacy of dexmedetomidine combined with ropivacaine in ultrasound-guided posterior transversus abdominis plane block(TAPB)on postoperative analgesia following CD.

METHODS

A total of 90 parturients scheduled for CD were divided randomly into two groups: The ropivacaine group (Group R), in which parturients were administered bilateral 0.25% ropivacaine 20 ml in posterior TAPB, and the dexmedetomidine group (Group RD), in which parturients were administered bilateral 0.25% ropivacaine and 0.5 µg/kg dexmedetomidine in posterior TAPB. Oral acetaminophen and celecoxib were routinely administered during the postoperative 48 h according to the multimodal analgesia protocol. The primary outcome was opioid consumption during the first 48 postoperative hours, and the secondary outcomes included opioid consumption during the postoperative 0-4,4–12,12–24,24–48 h, pain scores at 4,24,48 h, and time to first opioid administration.

RESULTS

Opioid consumption (morphine equivalents, MEQ) in the postoperative 48 h showed no significant difference in Group R and Group RD (median, 12.54 mg MEQ vs. 13.86 mg MEQ), p = 0.853. The 4 hours’ postoperative opioid consumption (MEQ) (median) was significantly lower in Group RD (median, 0 mg) for Group R (median, 1.32 mg, p = 0.012). Time to first opioid request was significantly prolonged in Group RD, p = 0.002. There was no significant difference in Numerical rating scale (NRS) score at rest and movement between the two groups. But the NRS score at uterine contraction was significantly lower in Group RD than Group R, p = 0.008.

CONCLUSION

Dexmedetomidine as adjuvant of posterior bilateral TAPB in parturients under multimodal analgesia did not decrease the consumption of opioids, but prolonged time to first opioid request and decreased the NRS score at uterine contraction. TRIAL REGISTRATION NUMBER: NCT05700045(the registration date: December 26,2022).