The Effect of Local Infiltration of Dexmedetomidine as an Adjuvant on Breakthrough Pain During Epidural Labor Analgesia: A Randomized Controlled Trial

PURPOSE: Evaluation of the effectiveness of local dexmedetomidine and ropivacaine administration prior to epidural puncture in reducing breakthrough pain during labor analgesia. METHODS: A total of 267 parturients were enrolled in this study and allocated to three groups: Group C (n=86) received 0 µg/kg (control), Group D1 (n=87) received 0.4 µg/kg, and Group D2 (n=92) received 0.6 µg/kg. Dexmedetomidine combined with 0.5% ropivacaine (3 mL) was applied locally at the epidural puncture site. The primary outcome was the incidence of breakthrough pain during labor. The secondary outcomes included visual analog scale (VAS) score at the puncture site on days 3, 7, and 42 postpartum; the Edinburgh Postnatal Depression Scale (EPDS) score and Pittsburgh Sleep Quality Index score at prenatal, 7-day postpartum, and 42-day postpartum. In addition, the Apgar scores and umbilical artery blood gas status at 1 and 5 minute and the need for neonatal ward admission were also collected. RESULTS: The incidence of breakthrough pain episodes was markedly lower in the Group D1 (23 of 87 [26.4%] vs 43 of 86 [50.0%]; odds ratio [OR], 0.395; 95% confidence interval [CI], 0.190-0.675; p = 0.002) and Group D2 (21 of 92 [22.8%] vs 43 of 86 [50.0%]; OR, 0.296; 95% CI, 0.155-0.564; p < 0.001) than in the Group C. Postpartum analysis revealed significantly lower VAS scores for puncture site pain in Groups D1 and D2 than in Group C at the 3-days postpartum (p < 0.001). Parturients in Group D2 demonstrated a significant reduction in EPDS scores compared to Group C at postpartum day 7. CONCLUSION: Administering local infiltration of 0.4 µg/kg or 0.6 µg/kg dexmedetomidine prior to epidural puncture in parturients undergoing elective labor analgesia has been shown to be effective in decreasing the incidence of breakthrough pain during labor analgesia. TRIAL REGISTRATION: The trial has been registered in the Chinese Clinical Trials Registry (ChiCTR2400083244) https://www.chictr.org.cn/showproj.html?proj=227790.