Increasing tourniquet number has no effect on amikacin concentration within the radiocarpal joint in horses undergoing intravenous regional limb perfusion.

The article discusses a study that investigated whether using two wide rubber tourniquets (WRTs) in intravenous regional limb perfusion (IVRLP) in horses would result in a higher concentration of amikacin antibiotic in the radiocarpal joint (RCJ, the wrist equivalent in horses) compared to a single tourniquet. The authors concluded that the use of two tourniquets did not provide any additional benefits compared to a single tourniquet in terms of achieving maximum amikacin concentration.

Study Design

• This study used 7 healthy adult horses. The IVRLP process was carried out while the horses were sedated and standing. The amikacin antibiotic was administered through the cephalic vein (a vein located on the forelimb) and two tourniquet techniques were compared: a single proximal WRT (P) and a proximal with a distal WRT (PD).
• To determine antibiotic concentration, synovial fluid samples were collected from the RCJ at intervals of 5 minutes from 5 minutes up to 30 minutes after IVRLP, while blood samples were collected from the jugular vein at similar time intervals.
• Amikacin concentration in the samples was quantified using fluorescence polarization immunoassay, a sensitive method used to detect the concentration of specific substances in a sample.

Findings

• The study found no significant difference in the peak concentration of amikacin or the time taken to reach maximum concentration (Tmax) between the two tourniquet techniques.
• The median peak amikacin concentration in the RCJ was higher using the single WRT technique (1331.4 μg/mL) compared to the two WRT technique (683.1 μg/mL). Likewise, the median Tmax was 30 minutes using the single WRT technique and 25 minutes using the two WRT technique.

Conclusion

• The researchers concluded that using two WRTs provided no advantage over a single proximal WRT to achieve maximum amikacin concentration in the RCJ when performing IVRLP.
• This means that the simpler approach of using a single tourniquet method is sufficient for treating infections in the joint of horses using the IVRLP technique.