Impact of dexmedetomidine-ropivacaine versus sufentanil-ropivacaine combination for epidural labour analgesia on neonatal outcomes: a pilot randomised clinical trial.

Objective: To investigate the impact of dexmedetomidine-ropivacaine combination versus sufentanil-ropivacaine combination for epidural labour analgesia on neonatal and maternal outcomes and test the feasibility of a future large, randomised trial.

Design: A randomised, double-blind, pilot clinical trial from 16 March 2023 to 15 June 2023.

Setting: A tertiary-care hospital in Beijing, China.

Participants: 200 women aged≥18 years who had full-term single pregnancy and were scheduled for vaginal delivery with epidural analgesia.

Interventions: Eligible participants were randomly assigned in a 1:1 ratio to receive self-controlled epidural labour analgesia using ropivacaine supplemented with either dexmedetomidine (0.45 µg/mL for induction and 0.36 µg/mL for maintenance) or sufentanil (0.45 µg/mL for induction and 0.36 µg/mL for maintenance).

Main Outcomes And Measures: The primary endpoint was a composite of neonatal morbidity, including 1- or 5 min Apgar score<7, umbilical artery PH<7.1, requirement for immediate assisted ventilation and admission to neonatal ward or intensive care unit within 24 hours. Secondary and other endpoints included effect of analgesia and occurrence of adverse events. The feasibility of implementing the protocol was evaluated.

Results: All 200 women were included in the intention-to-treat analysis. Composite neonatal morbidity occurred in 14.0% (14/100) of women with dexmedetomidine versus 17.0% (17/100) of women with sufentanil: relative risk 0.82, 95% CI 0.43 to 1.58. Women in the dexmedetomidine group had a comparable area under curve of pain intensity (median difference -2.0 point⋅h, 95% CI -9.9 to 5.9, p=0.638), required more self-controlled boluses (median difference two boluses, 95% CI 0 to 3, p=0.040) and epidural analgesics (median difference 17 mL, 95% CI 4 to 29, p=0.007), and experienced less pruritus (0.0% (0/100) vs 30.0% (30/100), p<0.001) but more lower limb weakness (13.0% (13/100) vs 1.0% (1/100), p<0.001). Recruitment rate was satisfactory (87.7%); the protocol was well accepted by anaesthesiologists and nurses.

Conclusions: Compared with sufentanil-ropivacaine combination, use of dexmedetomidine-ropivacaine combination for epidural labour analgesia was associated with a 18% decrease in composite neonatal endpoint and deserve further investigation. The dexmedetomidine-ropivacaine combination provided comparable analgesia but increased mild motor block. The conduct of a large, randomised trial using same protocol requires careful re-evaluation.

Trial Registration Number: NCT05698407.