Ischaemic preconditioning and pharmacological preconditioning with dexmedetomidine in an equine model of small intestinal ischaemia-reperfusion.
Authors: König Kathrin S, Verhaar Nicole, Hopster Klaus, Pfarrer Christiane, Neudeck Stephan, Rohn Karl, Kästner Sabine B R
Journal: PloS one
Summary
# Editorial Summary Small intestinal strangulation remains a devastating surgical emergency in equine practice, with ischaemia-reperfusion injury (IRI) driving progressive tissue damage even after blood flow is restored. König and colleagues tested whether two preconditioning strategies—ischaemic preconditioning (IPC) via brief cycles of clamping and release, and pharmacological preconditioning (PPC) using dexmedetomidine infusion—could mitigate mucosal injury in an anaesthetised equine model involving 90 minutes of jejunal ischaemia followed by 30 minutes of reperfusion. Both interventions successfully arrested further mucosal deterioration during the reperfusion phase, whereas untreated controls showed progressive injury; dexmedetomidine additionally reduced apoptotic cell death (TUNEL-positive cells) and neutrophil infiltration, though IPC paradoxically increased inflammatory cell markers despite protective effects on tissue architecture. Whilst these laboratory findings are encouraging, the practical applicability to clinical colic remains uncertain—questions persist regarding whether preconditioning protocols could be safely implemented intraoperatively in field-compromised horses, whether the 30-minute reperfusion window adequately models the more prolonged post-operative period, and whether dexmedetomidine's cardiopulmonary effects during general anaesthesia warrant the protective benefit. These results suggest that future clinical investigations targeting pharmacological modulation of reperfusion injury, particularly dexmedetomidine's anti-inflammatory properties, may offer adjunctive support for surgically managed small intestinal strangulation cases.
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Practical Takeaways
- •Dexmedetomidine given prior to colic surgery for small intestinal strangulation may reduce tissue damage and improve outcomes by limiting reperfusion injury.
- •While ischaemic preconditioning protected against mucosal injury, dexmedetomidine showed better control of inflammatory response, potentially offering more complete protection.
- •These findings support investigation of dexmedetomidine as an adjunctive therapy in equine colic cases involving intestinal ischaemia, though clinical validation is still needed.
Key Findings
- •Both ischaemic preconditioning (IPC) and dexmedetomidine preconditioning (DEX) prevented progression of mucosal injury during reperfusion, whereas control group showed continued injury progression.
- •DEX reduced apoptosis (TUNEL-positive cells) and inflammatory cell infiltration (calprotectin-positive cells) compared to control group.
- •IPC prevented mucosal injury progression but paradoxically showed increased calprotectin-positive inflammatory cells compared to control.
- •Pharmacological preconditioning with dexmedetomidine demonstrated superior anti-inflammatory effects compared to ischaemic preconditioning in this equine model.