Objective  To investigate the influence of nalbuphine assisted by ropivacaine on anesthetic effect of brachial plexus block via ultrasound-guided supraclavicular approach.

  Methods  A total of 114 patients with open reduction and internal fixation for upper limb fractures from June 2019 to June 2020 were finally included as study objects, and they were randomly divided into N₂₀ group (20 mg naborphine), N₁₀ group (10 mg naborphine) and placebo group, with 38 cases in each group. The N₂₀ group were given 100 mg ropivacaine diluted to 18 mL in combination with 2 mL naborphine (10 mg/mL); the N₁₀ group were given 100 mg ropivacaine diluted to 18 mL in combination with 2 mL naborphine (5 mg/mL); the placebo group were given 100 mg ropivacaine diluted to 18 mL in combination with 2 mL 0.9% sodium chloride injection. The systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) of the three groups were compared before nerve block (T₀), 10 minutes after nerve block (T₁) and immediately after operation (T₂). The sensory block (SB) and motor block (MB) at T₁ in the three groups were evaluated, and the onset time of SB, onset time of MB, duration of SB and duration of MB were recorded. Adverse reactions such as dizziness, nausea, vomiting and skin pruritus were recorded during and within 24 hours after operation.

  Results  At T₁, SBP and DBP in the N₂₀ group and the N₁₀ group were significantly lower than those in the placebo group, and SBP in the N₂₀ group was significantly lower than that in the N₁₀ group (P < 0.05). At T₂, there were no significant differences in SBP and DBP among the three groups (P>0.05). There was no significant difference in HR among the three groups at each time point (P>0.05). There were no significant differences in SB score and MB score among the three groups (P>0.05). The onset time of SB and MB in the N₂₀ group and the N₁₀ group were significantly shorter than those in the placebo group, and the duration of SB and MB were significantly longer than those in the placebo group (P < 0.05). The incidence rates of intraoperative hypotension, nausea and dizziness in the N₂₀ group were significantly higher than those in the placebo group, and the incidence rate of dizziness was significantly higher than that in the N₁₀ group (P < 0.05). There were no significant differences in the incidence rates of intraoperative hypotension, nausea and dizziness between the N₁₀ group and the placebo group (P>0.05). There were no significant differences in the incidence rates of vomiting, skin pruritus and respiratory depression among the three groups (P>0.05).

  Conclusion  As an adjuvant drug, 10 mg naborphine can enhance the anesthetic effect of brachial plexus block via ultrasound-guided supraclavicular approach without increasing the incidence of adverse reactions.