[Resorption of depot cortisone after its submucosal injection in the nasal concha]

Injections of "depot" steroid preparations in the nasal mucosa are frequently used for allergic disorders. We felt it would be interesting to study the fate of these injections. Indeed, a microscopic section through the nasal concha shows a tremendous amount of large vessels and it seems possible that a quantity of the injection enters the general blood stream. The difficulties in obraining radioactive cortisone made us choose the red blood cell as a tracer. They have the same dimensions as the cortisone crystals used in the depot preparations, and are a much used tool in a department of nuclear medicine. Mostly they are marked with radioactive chromium. We modified the technique used for the determination of the blood volume by a dilution method. In this technique radioactive blood is injected and the dilution allows for calculation of the whole blood mass. We injected the radioactive blood into the nasal concha and we searched for these radioactive erythrocytes in the circulation. This gave us an idea of the total amount that escaped from the concha. Blood was taken from a patient and marked by the department of nuclear medicine; it was then injected in the concha in the way a depository cortisone preparation is injected, and after several moments blood was taken from an arm vein and the radioactivity measured. Relying upon a normal blood volume in our patient, we were able to calculate the amount that went into the circulation. As the chart shows, there is a very fast increase and after 15 minutes, practically everything was in the blood stream. Thus we conclude: 1. Intra-nasal injections of cortisone are no more useful than intra-muscular ones. 2. Some reactions after this intranasal injections could be explained by the enmasse embolisation of the crystal suspension.