Anti-inflammatory effects of intravenously administered lidocaine hydrochloride on ischemia-injured jejunum in horses.

The research investigates the anti-inflammatory effects of lidocaine hydrochloride when intravenously administered in horses with ischemia-injured jejunum, drawing a conclusion that lidocaine reduces plasma prostaglandin E(2) metabolite concentration and mucosal COX-2 expression.

Study Design and Methods

• The study involved 24 horses which were grouped into four. Each group received treatments either with saline solution, flunixin meglumine, lidocaine, or both flunixin and lidocaine.
• During the treatment period, each horse had a section of its jejunum (a part of the small intestine) made ischemic (cut off from blood flow) deliberately during surgery to simulate a severe intestinal injury.
• Uninjured and injured sections of the jejunum were collected post the ischemic period and post euthanasia for histological analysis and determination of cyclooxygenase (COX) expression.
• Blood samples of the horses were collected before and after the ischemic period for analysis of prostanoid concentration changes.

Key Findings

• After the ischemic period, horses treated with only lidocaine showed significantly less COX-2 expression than those treated with saline solution or flunixin alone.
• 18 hours post ischemic period, horses treated only with flunixin showed significantly higher neutrophil counts in the intestinal lining than the other treatment groups, which is indicative of an inflammatory response.
• Post-ischemia prostaglandin E(2) metabolite and thromboxane B(2) concentrations increased in horses treated with saline solution and in those treated with saline solution or lidocaine alone, respectively, when compared to baseline concentrations.

Conclusions

• The study concluded that intravenously administered lidocaine has anti-inflammatory effects on horses’ ischemia-injured jejunum by reducing plasma prostaglandin E(2) metabolite concentration and mucosal COX-2 expression. This implies it could be used for managing inflammation in such clinical conditions.
• The study also found that co-administration of lidocaine with flunixin helped in controlling the increase in neutrophil count caused by flunixin alone, suggesting the potential benefit of combining these drugs to control inflammation.