Regional Limb Perfusion
Regional limb perfusion (RLP) is a technique which provides a high concentration of an antibiotic to the soft tissues, joints, and bones of the limbs. The antibiotic used would be very expensive if given at a dose appropriate for the entire horse but the cost of the drug is more affordable since it is delivered into a superficial leg vein below the level of a tourniquet, and the benefits great. Drug concentrations achieved generally exceed that required to kill many types of bacteria and persist locally in the tissues for an extended period of time. This makes RLP a practical adjunctive treatment for septic conditions affecting the extremities (the knee and hock and below).
To perform, the horse is lightly sedated and the tourniquet is applied above the level of the injury. Once the skin over the distended vein is cleaned, the drug, diluted in saline, is slowly injected, via an IV catheter, into the vein. The tourniquet is left in place for an additional 20 minutes, which prevents the antibiotic from quickly leaving the affected area. Once the tourniquet and the catheter are removed, the injection site is temporarily bandaged. The procedure may be performed daily, alternating the type of antibiotic, or every other day using the same antibiotic. Drug selection and frequency of delivery are determined by the clinician based on the results of the bacterial culture and drug sensitivity patterns.
This radiograph of the foot shows a horse which stepped on a nail. Radio-opaque contrast material was injected into the puncture wound which was located in the medial sulcus (inner side) of the foot. The contrast material fills the navicular bursa (arrow) confirming that the nail tract had communicated with the bursa. The horse responded positively to navicular bursoscopy and administration of systemic and regional limb perfusion antibiotic therapy.