# Analgesic Effect of Dexmedetomidine-Nalbuphine Combination vs. Dexmedetomidine Alone in Donkeys Undergoing Field Castration under Total Intravenous Anesthesia

## TL;DR

Combining dexmedetomidine and nalbuphine before anesthesia improves pain relief and heart function in donkeys undergoing field castration.

## Contribution

The study introduces a new premedication combination for improved analgesia and cardiac stability in field castration of donkeys.

## Key findings

- The dexmedetomidine-nalbuphine combination reduced postoperative pain in donkeys compared to dexmedetomidine alone.
- The combination improved cardiac function and recovery quality during anesthesia and recovery.
- Lower inflammatory cytokine levels were observed in the combination group during surgery and recovery.

## Abstract

Donkey welfare and pain relief are of particular importance in the veterinary field. Therefore, pain management during surgical operations in field settings is mandatory. The current study sheds light on the antinociceptive effect of a combination of dexmedetomidine and nalbuphine premedication prior to total intravenous anesthesia using ketamine-propofol in castration procedures in field conditions. Shortly after castration, the proposed combination of dexmedetomidine and nalbuphine resulted in decreased postoperative pain. In addition, the cardiac function was improved compared to using dexmedetomidine alone during anesthesia. This was demonstrated using established clinicophysiological assessments, serum biochemical markers, and behavioral pain scores for six hours post-recovery. Dexmedetomidine and nalbuphine premedication prior to total intravenous anesthesia using ketamine-propofol showed potential benefits compared to dexmedetomidine alone in providing more analgesia and managing postoperative pain in jacks undergoing castration under field conditions.

This study evaluated the antinociceptive effect of dexmedetomidine-nalbuphine vs. dexmedetomidine alone in jacks undergoing field castration under total intravenous anesthesia. Jacks were premedicated with intravenous (IV) dexmedetomidine (5 µg/kg), either alone (Group D, n = 6) or in combination with 0.3 mg/kg nalbuphine (Group DN, n = 6). IV ketamine (1.5 mg/kg) and propofol (0.5 mg/kg) were used to induce general anesthesia, which was maintained by a continuous propofol (0.2 mg/kg/min) IV infusion. The quality of anesthesia, analgesia, and recovery were evaluated. A simple descriptive scale (SDS) was used to measure pain from the recovery time to 6 h later. The DN group exhibited improvements in analgesic and recovery quality and SDS of pain at 1-, 2-, and 3-h post-recovery. There was an apparent improvement in cardiac status, as evidenced by the enhanced heart rate and electrocardiogram findings compared to group D during surgery and recovery time. The DN group had a lower level of inflammatory cytokines, both during the surgery and shortly after recovery. Therefore, the dexmedetomidine-nalbuphine combination prior to IV anesthesia of ketamine and propofol in jacks undergoing field castration resulted in a stable surgical plane of anesthesia, improved antinociception, less pain postoperatively, and better cardiac stability.