Nalbuphine Combined with Ropivacaine for Epidural Labour Analgesia

Abstract

Background: The addition of a small amount of opioids during epidural labour analgesia can enhance the local analgesic effect, reduce the amount of local anaesthetics required, and prevent motor blockade as much as possible. The use of nalbuphine, a κ-opioid receptor agonist, in epidural labour analgesia has not yet been reported. Methods: This clinical trial applied a prospective, randomized, double-blind, parallel-controlled, multicentre experimental design and was carried out in six tertiary hospitals in different regions of China. We included parturients aged 20 years or older,with a singleton pregnancy cephalic presentation, and who requested labor pain relief. Recruited parturients were randomly divided into two groups: the nalbuphine group (Group N) and the sufentanil group (Group S). Epidural puncture was performed at the L2-3 space. After successful catheterization, the drug was administered in the supine position. Medication regimen:(1) Group N received an epidural injection (5 mL mixture) of 0·1% ropivacaine, 0·3 mg/mL nalbuphine, and 1:400,000 epinephrine. A 10-mL mixture of 0·1% ropivacaine and 0·3 mg/mL nalbuphine was injected; subsequently, the drug was administered by patient-controlled epidural analgesia (PCEA). The background dosage was 6 mL/h, the patient-controlled analgesia (PCA) dose was 6 mL, and the lock-out period was 15 min. (2) Except that nalbuphine was replaced with 0·3 μg/mL sufentanil; all other drug administration and analgesia procedures in Group S were the same as those in Group N. The primary outcome was the time to the first PCA dose. Secondary outcomes included the ropivacaine dose per hour. Findings: Between November 2018 and February 2019,180 parturients were recruited for the study. Compared to the time to the first PCA dose in Group S (131·2 (89·9) min), the time to the first PCA dose in Group N (101·8 (76·7) min) was not significantly extended (P=0·050). The ropivacaine dose per hour in Group N (9·3 (2·4) mg) was significantly greater than that in Group S (8·4 (2·5) mg) (P=0·024). adverse drug reactions or serious adverse events directly associated with analgesics were noted during the study. Interpretation: The combinations of 0·3 mg/mL nalbuphine with ropivacaine and 0·3 μg/mL sufentanil with ropivacaine have comparable effects for labour epidurals. Both combinations are safe, effective, and suitable for labour epidurals, with few adverse reactions. Trial Registration: This study was registered at the Chinese Clinical Trial Registration Center (registration number: ChiCTR1800018810). Funding Statement: The authors stated: No funding received. Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: This study was approved by the ethics committee of the Obstetrics & Gynecology Hospital Affiliated of Fudan University (approval number: Obstetrics and Gynecology ethics review 2018-52). Informed consent was obtained from all participating parturients.