A useful way to think about the whole routine is to sort every decision into two piles: the ones made at the bench, and the ones made in advance. The goal is to make the first pile as small as possible.
Decisions that belong in advance:
- The diluent volume, and therefore the concentration.
- The dose in milligrams, and the unit count that corresponds to it on this vial.
- Which syringe, and therefore which barrel you will be reading.
- Which site is next in the rotation.
- Whether this is the week a planned change happens.
Decisions that unavoidably happen at the bench:
- Whether the solution looks right.
- Whether the draw came out clean, and whether to redraw.
That is the whole list. Anything else showing up at the bench means something upstream was left open, and open questions get answered badly when you are holding a syringe and mildly impatient.
The practical implementation is boring: the numbers on the vial, the site on the log, the syringes in a tray. None of it is clever. What it buys is that injection becomes execution rather than decision making, and execution is where mistakes are rare.
I do the advance pile once a week, at the same time as I mix or restock, working out anything numerical in the Peptide Tracker & Calculator and writing the results where I will see them. It takes a few minutes and it removes almost all the ways this goes wrong.