The Effect of Perfusate Volume on Amikacin Concentration in the Metacarpophalangeal Joint Following Cephalic Regional Limb Perfusion in Standing Horses.

The research study investigates the impact of three different volumes of perfusate on the concentration of amikacin in the metacarpophalangeal joint in horses. The study found that higher volumes result in a greater concentration of amikacin in the synovial fluid.

Objective

The study aims to determine how varying volumes (30mL, 60mL, 100mL ) of chosen perfusate carrying 2 grams of antibiotic drug called amikacin can influence its concentration within a particular joint (metacarpophalangeal joint) in horses following a procedure called cephalic regional limb perfusion (RLP).

Methodology

• Seven healthy horses were utilized for the study and three different perfusate volumes were tested.
• Each volume, containing 2 grams of amikacin, was used in a procedure called the regional limb perfusion at the cephalic vein (a necessary vein in a horse’s leg). The process was carried out while the horse stood sedated, with a tourniquet placed at the mid antebrachium (forearm region).
• Samples of synovial fluid, which aids joint movement, were collected from the metacarpophalangeal joint before and at intervals of 30 and 120 minutes after perfusion was administered.
• Simultaneously, serum samples from the jugular vein were also collected at the same time points for analysis.
• These samples were then analysed for amikacin concentrations using a statistical method, including ANOVA and least squares difference pairwise comparisons.

Results and Conclusion

• The analysis showed that the concentration of amikacin was significantly higher 30 minutes after perfusion using the 100mL volume of perfusate (579 μg/mL), as compared to the 60mL (227 μg/mL) and 30mL (282 μg/mL) volumes.
• Furthermore, when tested against a threshold of 160 μg/mL, more horses achieved the therapeutic threshold after perfusion with the 100 mL volume (100%) in comparison to those that received 60 mL (43%) and 30 mL (57%).
• The study concludes that using a 100 mL volume for RLP at the cephalic vein in standing horses resulted in a higher concentration of amikacin in the synovial fluid and therefore it is recommended for use in clinical cases where high amikacin concentration in the joint is ideal.