Abstract
Objective—To describe and compare the distribution of technetium Tc 99m (99mTc) pertechnate following intraosseous or IV injection (with or without use of a tourniquet) in the distal portion of the forelimb in standing horses.
Animals—4 horses.
Procedure—Each horse received 4 forelimb treatments in random sequence: intraosseous infusion with tourniquet application (IOT), intraosseous infusion without tourniquet application, IV infusion with tourniquet application (IVT), and IV infusion without tourniquet application. Dynamic nuclear scintigraphic imaging of the third metacarpal bone, proximal and middle phalanges, and distal phalanx was performed from the start of each treatment until 1 hour after infusion was completed. Radionuclide activity was compared within and between treatment groups.
Results—Tourniquet application was necessary to maintain high levels of radionuclide activity in the distal portion of the forelimb after intraosseous or IV infusion with 99mTc pertechnate; IVT and IOT treatments resulted in similar radionuclide activity in the proximal and middle phalanges and distal phalanx. Of the 4 treatments, there was significantly higher radionuclide activity in the distal aspect of the third metacarpal bone after the IOT treatment.
Conclusions and Clinical Relevance—By use of a tourniquet, radionuclide administration via the intraosseous or IV routes resulted in effective perfusion of the distal portion of the forelimb and similar distribution of the agent in the phalanges of horses. Further studies are required to ascertain whether these findings apply to delivery of therapeutic agents in infected tissues via IOT or IVT. (Am J Vet Res 2005;66:1267–1272)
