Which step is performed first when preparing a mixed insulin dose?

Which step is performed first when preparing a mixed insulin dose?

• A. Draw up the correct dosage of NPH insulin into the syringe.
• B. Draw up the correct dosage of regular insulin into the syringe.
• C. Inject air equal to the amount of regular insulin prescribed into the vial of regular insulin.
• D. Inject air equal to the amount of NPH insulin prescribed into the vial of NPH insulin.

Answer: (D)

When mixing insulins, you use an air‑injection technique to keep doses accurate and prevent cross‑contamination. You begin by injecting air into the longer‑acting insulin vial (NPH) equal to the NPH dose. This establishes the correct pressure in that vial so you can withdraw the short‑acting insulin next without pulling any of the longer‑acting insulin into the syringe or creating a vacuum that distorts the amounts. After setting that up, you inject air into the regular insulin vial, then draw up the regular insulin, and finally withdraw the NPH insulin. So the first step is to inject air into the NPH vial.

When mixing insulins, you use an air‑injection technique to keep doses accurate and prevent cross‑contamination. You begin by injecting air into the longer‑acting insulin vial (NPH) equal to the NPH dose. This establishes the correct pressure in that vial so you can withdraw the short‑acting insulin next without pulling any of the longer‑acting insulin into the syringe or creating a vacuum that distorts the amounts. After setting that up, you inject air into the regular insulin vial, then draw up the regular insulin, and finally withdraw the NPH insulin. So the first step is to inject air into the NPH vial.