Ultrasound-guided celiac plexus block increases intestinal motility in normal horses

To describe a technique for ultrasound-guided celiac plexus block in horses and characterize its effect on intestinal motility in healthy horses.

This study was conducted from January 2022 through June 2022. In phase 1 (dye study), an ultrasound-guided technique was optimized, and dye deposition around the celiac plexus branches was evaluated via postmortem dissection in 6 horses. In phase 2 (experimental study), 6 healthy horses were fasted and sedated with 0.6 mg/kg xylazine, IV (experiment 1). After a washout period, the ultrasound-guided celiac plexus block with lidocaine 1% (1.3 mg/kg) was performed after sedation (experiment 2). In both experiments, intestinal motility was recorded via transcutaneous ultrasound before sedation, after sedation (15, 30, and 45 minutes and 1, 2, 3, 4, and 6 hours), and 1 hour after refeeding. Ultrasound video recordings were blinded of horse identity, day, and time; randomly arranged; and scored using a specifically designed motility scoring system.

Postmortem dissection confirmed dye deposition over the celiac plexus branches. In phase 2, a significant increase in intestinal motility was detected after the celiac plexus block compared to sedation alone, with a peak between 1 and 3 hours postblock (13.58 ± 2.8 vs 3.75 ± 2.4 at baseline); motility remained increased up to 6 hours. The only side effect observed was a transient hindlimb ataxia in 1 horse.

Ultrasound-guided celiac plexus block is feasible and induces an increase in intestinal motility in healthy horses without significant complications.

This technique can be considered in multimodal management of colic and paralytic ileus.