I’m participating in a health study and went along this morning for some routine blood tests to see how I’m doing after 12 months of exercise. Last week I visited a nurse who took my blood pressure and had me step up and down for several minutes then took my pulse.
While I watched four whole vials of blood pump out of my arm this morning I was idly scanning the room, and noticed a poster about the best sequence for taking multiple vials of blood. I was surprised by the response to my question about why the sequence matters …
Apparently the different empty vials have been treated with various products before they’re used. The nurse showed me how one contained some kind of powder, and mentioned that others might have, for example, anti-clotting agents.
I guess it makes sense — it had just never occurred to me before.