Epidural Lidocaine, Nalbuphine, and Lidocaine–Nalbuphine Combination in Donkeys

• Nalbuphine epidural analgesia was compared with of lidocaine and lidocaine–nalbuphine.
• Epidural nalbuphine alone resulted in long duration of analgesia but of slow onset.
• Epidural lidocaine resulted in rapid onset of analgesia but of short duration.
• Lidocaine–nalbuphine combination resulted in rapid and prolonged analgesia.
• Lidocaine–nalbuphine may be useful for long and effective epidural analgesia.

Nalbuphine is a lipophilic semisynthetic κ-agonist/μ-antagonist opioid that has been used for epidural anesthesia in humans and dogs but not in donkeys. The purpose of the present study was to report the effect of epidural nalbuphine either alone or in combination with lidocaine compared with lidocaine alone. Six adult clinically healthy Baladi Egyptian donkeys were used. All donkeys were allocated into one of the three groups with a 2-week washout period using a Latin Square design. Group 1 injected with lidocaine hydrochloride 2% at a dose of 0.22 mg/kg. Group 2 injected with nalbuphine hydrochloride 2% at a dose of 0.4 mg/kg, and Group 3 injected with a combination of lidocaine hydrochloride 2% at a dose of 0.11 mg/kg and nalbuphine hydrochloride at a dose of 0.2 mg/kg. Epidural nalbuphine alone resulted in analgesia of significant (P < .05) long duration (198.3 ± 12.6 minutes) but of significant (P < .05) slow onset (14.3 ± 1.8 minutes). The combination of lidocaine–nalbuphine resulted in rapid onset (6.7 ± 1.2 minutes) and prolonged duration (147 ± 5.6 minutes) of analgesia. Rapid and intense analgesia was produced with lidocaine–nalbuphine combination when compared with lidocaine or nalbuphine alone. Mild ataxia was reported only in lidocaine and lidocaine–nalbuphine groups. Mild sedation was achieved after administration of nalbuphine groups either alone or in combination with lidocaine. The obtained results suggest that lidocaine–nalbuphine combination could be used efficiently for performing surgical interventions required long duration and effective analgesia.