Stability of radiopharmaceuticals during administration to the intensive care patient

Nuclear medicine can provide useful data when monitoring the organ function of patients undergoing intensive care. Test procedures involve the administration of radiopharmaceuticals and external monitoring using gamma cameras or nuclear probes. The radiopharmaceuticals required may be given at lower doses than normally used in routine nuclear medicine imaging, are ideally available 24 h a day and are preferably administered via indwelling cannulae and giving sets. Three radiopharmaceuticals have been studied; a renal function agent, a hepatobiliary function agent and a product used for in vivo labelling of protein for lung permeability studies. Under conditions of storage, dilution and passage through giving sets (simulating conditions found during administration in the intensive care setting), some instability can be demonstrated in each product, which could result in the tests giving rise to wrong or misleading data. It is recommended that radiopharmaceuticals are not diluted excessively, and that where possible, parenterally-administered products are given by direct intravenous injection and not through giving sets.