Preconditioning with lidocaine and xylazine in experimental equine jejunal ischaemia.
Authors: Verhaar Nicole, Pfarrer Christiane, Neudeck Stephan, König Kathrin, Rohn Karl, Twele Lara, Kästner Sabine
Journal: Equine veterinary journal
Summary
# Editorial Summary: Pharmacological Preconditioning in Equine Intestinal Ischaemia Ischaemia-reperfusion injury to the equine small intestine remains a significant clinical challenge, yet pharmacological strategies to mitigate this damage remain poorly explored in horses despite promising results in other species. This experimental study investigated whether xylazine or lidocaine could provide a preconditioning effect in anaesthetised horses subjected to controlled jejunal ischaemia followed by reperfusion, comparing outcomes against a historical untreated control group. Xylazine demonstrated potential protection at the cellular level, with significantly fewer caspase-3-positive cells (227% reduction) following ischaemia and markedly reduced calprotectin-positive cell counts in both mucosa and serosa during reperfusion, suggesting suppression of apoptosis and inflammatory responses; lidocaine, however, showed no protective effect across any measured variable. Despite these encouraging immunohistochemical findings, the absence of corresponding improvements in histomorphological injury grading raises questions about clinical relevance, and the researchers acknowledge that isoflurane anaesthesia may have masked additional drug effects whilst the small sample size and historical control group limit the strength of conclusions. Further investigation with larger concurrent controls and different anaesthetic protocols would be warranted before considering xylazine preconditioning as a clinical intervention in surgical colic cases, though the cellular-level protection observed merits continued research into its mechanism and practical application.
Read the full abstract on PubMed
Practical Takeaways
- •Xylazine may offer some cellular-level protection against intestinal ischaemia/reperfusion injury in horses, though clinical benefit remains unproven without visible tissue improvement
- •Lidocaine preconditioning provided no protective effect in this experimental model and cannot be recommended for this indication
- •These findings remain experimental and require larger clinical studies before implementation in colic surgery protocols
Key Findings
- •Xylazine preconditioning significantly reduced caspase-3 positive cells after ischaemia (227% median difference vs control, P=0.01)
- •Xylazine preconditioning significantly reduced calprotectin-positive cell counts after reperfusion in mucosa (6.8 cells/mm² difference, P=0.02) and serosa (44 cells difference, P=0.05)
- •Lidocaine preconditioning showed no protective effect on tested variables
- •No histomorphological differences between xylazine-preconditioned and control groups despite cellular improvements, limiting clinical significance