Just my thoughts- hopefully others will suggest other ways:

Option 1: If you noticed at the point of entering onto the LIMS then you could call this “not tested” due to availability of a current sample.

Option 2: Seems ok too if your staff or LIMS has not identified that a suitable previous suitable is available.

Option 3- Possibly time consuming for staff. If you have already issued blood then why make more work, potential for confusion and increase risk ?

Of course, if you start looking at exact timing of samples and the time ( is this set in minutes, hours etc?) range of acceptability- then we can discuss forever. No system is perfect, though a more intelligent LIMS may help- are there any out there?

bw