A nurse is preparing to mix NPH insulin and regular insulin for administration.
Which of the following actions should the nurse take?
A.
Use a tuberculin syringe.
B.
Inject air into each vial.
C.
Withdraw the NPH insulin first.
D.
Shake the regular insulin vial.
The Correct Answer and Explanation is:
The correct answer is B. Inject air into each vial.
When preparing to mix NPH insulin (an intermediate-acting insulin) and regular insulin (a short-acting insulin), it is crucial to follow specific steps to ensure accurate dosing and to prevent contamination. Here’s why B is the correct action and why the other options are less appropriate:
Explanation
Inject Air into Each Vial: This is the correct procedure when mixing insulins. The process involves injecting air into the vials before withdrawing any insulin. This is done to equalize the pressure in the vials, which helps in drawing the insulin more easily and prevents the formation of a vacuum. Here’s the step-by-step process:
- Inject air into the NPH insulin vial: Insert the needle into the NPH insulin vial and inject an amount of air equal to the volume of NPH insulin you plan to withdraw. This prevents the NPH insulin from creating a vacuum in the vial.
- Inject air into the regular insulin vial: Repeat the process for the regular insulin vial.
- Withdraw the regular insulin first: After injecting air into both vials, withdraw the regular insulin before withdrawing the NPH insulin. This step prevents contamination of the short-acting insulin with the longer-acting NPH insulin, ensuring that the regular insulin remains pure.
Why Other Options Are Incorrect:
- A. Use a tuberculin syringe: This is not ideal because a tuberculin syringe is typically used for small-volume injections, not for mixing or administering insulin. The correct syringes for insulin are insulin syringes, which are specifically marked for insulin measurements.
- C. Withdraw the NPH insulin first: This is incorrect because withdrawing NPH insulin first could lead to contamination of the regular insulin vial. The regular insulin is a clear solution, and it should remain free of contamination from the NPH insulin, which is cloudy.
- D. Shake the regular insulin vial: Shaking the insulin vial, especially NPH insulin, is generally discouraged because it can cause bubbles to form and potentially degrade the insulin. Regular insulin should be gently rolled between the hands to mix, not shaken.
By following the correct procedure—injecting air into each vial and withdrawing the regular insulin first—you ensure the correct and safe preparation of insulin for administration.