Comparison of intraosseous and intravenous infusion of technetium Tc 99m pertechnate in the distal portion of forelimbs in standing horses by use of scintigraphic imaging.

The research examined and compared the distribution of a radioactive compound, technetium Tc 99m pertechnate, when injected into a horse’s leg bone or vein. It showed that effective perfusion and similar drug distribution could be achieved through both intraosseous and intravenous methods, especially with application of a tourniquet.

Study Methodology

• Four horses were used for the study. Each horse underwent four treatments on their forelimbs, applied in a random order. The treatments consisted of infusion with or without a tourniquet through either intraosseous (into the bone) or intravenous (into the vein) methods.
• Each treatment used an injection of technetium Tc 99m pertechnate, a radioactive compound, facilitating scintigraphic imaging. Scintigraphy, a diagnostic imaging technique, uses a small amount of radioactive material administered to a subject to detect radiation and create images.
• The imaging focused on the third metacarpal bone and the phalanges (finger bones), and was conducted from the start of treatment until an hour after completion of the infusion. The activity level of the radioactive material was compared within and across the four treatment groups.

Findings

• It was discovered that the use of a tourniquet was necessary to maintain high levels of radionuclide activity in the distal portion (far end) of the forelimb following both intraosseous and intravenous infusions.
• The intraosseous infusion with tourniquet application (IOT) and intravenous infusion with tourniquet application (IVT) treatments resulted in similar radionuclide activity in the phalanges and at the far end of the horse’s limb.
• However, the IOT treatment method showed significantly higher radionuclide activity in the distal aspect of the third metacarpal bone (the lower part of the horse’s leg).

Conclusions and Implications

• The results suggest that both intraosseous and intravenous injections can result in effective perfusion (the passage of fluid through blood vessels or lymphatic vessels) and similar distribution of the radioactive agent in the phalanges of horses.
• The findings raise the possibility that these methods might be similarly effective for delivery of therapeutic agents in infected tissues, although further studies are needed to confirm this.