Attenuation of ischaemic injury in the equine jejunum by administration of systemic lidocaine.

This research investigates how the use of systemic lidocaine, a common anesthetic, can help improve the recovery of mucosal tissues in horses afflicted by ischemic injury and reverse the negative effects of flunixin meglumine, a conventional pain relief medicine.

Research Context

• Ischemic injury to the intestinal jejunum mucosa is a common issue in horses undergoing colic surgery. The absorption of endotoxin (a damaging cell component of harmful bacteria) across this damaged tissue is a leading cause of death following the surgical procedure.
• A popular medication, flunixin meglumine, used for analgesia (pain relief) in such circumstances, was found to hamper the healing of the mucosa.
• Lidocaine, usually used in treating post-operative ileus (disruption of normal bowel movement), has been found to have anti-inflammatory properties that might aid the recovery of the mucosa after ischemic injury.

Aim of the Study

• The research aimed to ascertain whether lidocaine can counteract the negative effects of flunixin meglumine on mucosal healing following ischemic injury.

Methods Used

• The horses in the study were subjected to intentional ischaemia of the jejunum (interruption of the blood supply), mimicking the condition found in complicated colic surgeries. They were then treated with one of four treatments: 0.9% saline, flunixin meglumine, lidocaine, or a combination of both flunixin meglumine and lidocaine.
• Each treatment group consisted of 6 horses, assigned randomly.
• Through a series of measurements, including transepithelial electrical resistance (TER) and permeability to lipopolysaccharide (LPS), the researchers objectively evaluated the function of the mucosal barrier.

Findings

• The study found that in the ischaemic-injured jejunum, TER was significantly higher (suggesting better mucosal health) in those treated with saline, lidocaine, or a combination of both lidocaine and flunixin meglumine, compared to those given only flunixin meglumine.
• The permeability for LPS was also significantly increased in the injured jejunum of horses treated solely with flunixin meglumine, suggesting it failed to protect the mucosa from absorbing harmful endotoxins.
• Pain scores after surgery did not significantly increase for groups treated with flunixin meglumine, which suggests this drug was able to control pain effectively despite its negative effect on mucosal repair.

Conclusion

• The study concluded that lidocaine can counteract the inhibitory effects of flunixin meglumine on the recovery of the jejunum mucosal barrier following an ischemic injury.
• The exact mechanism of how lidocaine aids in mucosal repair remains undetermined and necessitates further research.