The following information was provided by the State via e-mail (State text in quotes):
At 2 PM on March 17, 2005, the Swedish Medical Center, Radiation Safety Officer reported that an incident occurred at 12 PM, March 17, due to a clogged filter in the i.v. tubing used to administer an Iodine 131 radioisotope. The clog occurred during the procedure and prevented the administration of the total prescribed dose.
The dosimetric protocol of the I-131 administration requires a 'cold' infusion of AntiB Antibody prior to radioisotope administration. This cold administration needs to pass through a 0.22 micron filter. The manufacturer's protocol states that the radioisotope should also be administered through the filter. The protocol further indicates that if the filter clogs, that the remainder of the radioisotope is administered without the presence of the filter.
When the filter clogged, the nuclear medicine technologist first attempted to flush the clog with saline and then bypass the filter to complete the administration. After the administration it was determined by dose calibrator that 43.7 MBq (1.18 mCi) of I-131 was trapped in the tubing behind the filter. The actual administered activity was about 146.2 MBq (3.95 mCi) of the prescribed 185 MBq (5 mCi) dose.
Corrective Actions: Since the preliminary investigation indicates the cause of the misadministration was due to clogging of the filter, the Radiation Safety Officer has recommended immediately bypassing the filter during administration instead of attempting to unclog it. The
RSO plans to contact the vendor to get a protocol clarification and will include that information in the formal written report.