How the nurse would demonstrate how to mix insulins?

The nurse should wipe the insulin bottles with an alcohol swab before each use to eliminate contamination. Then the nurse should inject 12 units of air into the NPH vial, without touching the insulin. Next, the nurse should insert 6 units of air into the fast-acting insulin and draw up the insulin into the syringe. Fast- or rapid-acting insulin should be drawn into the syringe first to avoid the risk of mixing the long-acting insulin into the vial and delaying the onset of action of the regular insulin in an emergency. Lastly, the nurse should draw 12 units of nph (intermediate- or long-acting insulin) into the syringe.