Effect of emptying the vasculature before performing regional limb perfusion with amikacin in horses

Emptying the vasculature with an Esmarch bandage before i.v. regional anaesthesia is commonly performed in human patients to prevent leakage of the solution under the tourniquet but there is no evidence for its efficacy in horses for antimicrobial i.v. regional limb perfusion (IV-RLP).

To determine the effect on synovial fluid concentration of amikacin of emptying the vasculature before performing IV-RLP.

Crossover experiment.

Eight clinically healthy horses underwent 2 IV-RLP with amikacin in a randomised, crossover design. Horses received an IV-RLP with amikacin with or without exsanguination before applying a pneumatic tourniquet at the level of the forearm. Blood was collected from the jugular vein (before tourniquet removal) and synovial fluid from the radiocarpal and metacarpophalangeal joints (5 min after tourniquet removal and at 24 h) for amikacin determination. The procedure was video recorded to assess horse movement.

There was no difference in amikacin concentrations in the plasma or synovial fluid from the radiocarpal joint between groups. There was a higher concentration of amikacin in the synovial fluid from the metacarpophalangeal joint immediately after tourniquet removal in the group with exsanguination of the limb prior to IV-RLP (mean ± s.d.: no exsanguination 49.7 ± 53.7 μg/ml, exsanguination 257.4 ± 149.7 μg/ml, P = 0.04). Horse movement did not differ significantly between groups.

Emptying the vasculature with an Esmarch bandage before IV-RLP can improve amikacin concentrations in the metacarpophalangeal joint of horses with no effect on the levels of amikacin in the radiocarpal joint.