A nurse is preparing to administer 10 units of regular insulin and 20 units of NPH insulin to a client who has diabetes mellitus.
When mixing the two types of insulin, which of the following actions should the nurse take first?
A Replace the needle for withdrawal with a safety needle.
B Inject 20 units of air into the NPH insulin vial.
C Inject 10 units of air into the regular insulin vial.
D Withdraw 10 units of insulin from the regular insulin vial.
The correct answer and Explanation is :
The correct answer is B. Inject 20 units of air into the NPH insulin vial.
Explanation:
When mixing insulin, it’s crucial to follow a specific sequence to ensure that the correct dosage and type of insulin are administered effectively. The proper sequence involves:
- Injecting Air into the Vials:
- Inject Air into NPH Vial First (Option B): Before drawing up any insulin, you should first inject air into the NPH insulin vial. This step is important because it prevents the creation of a vacuum within the vial, which could make it difficult to withdraw the insulin later. To do this, you draw air into the syringe equal to the amount of NPH insulin you plan to withdraw (20 units in this case), and then inject this air into the NPH vial without withdrawing any insulin at this point.
- Inject Air into the Regular Insulin Vial:
- After injecting air into the NPH vial, the next step is to inject air into the regular insulin vial (Option C). This is done to facilitate the withdrawal of the regular insulin by reducing the pressure difference inside the vial.
- Withdraw Regular Insulin:
- Next, you withdraw the prescribed amount of regular insulin from its vial (Option D). This is the clear or short-acting insulin, and it is important to do this before the NPH insulin to avoid contaminating the short-acting insulin with the longer-acting NPH insulin.
- Withdraw NPH Insulin:
- Finally, you should withdraw the NPH insulin (Option A). This step is completed after the regular insulin has been drawn up to ensure that the long-acting insulin does not mix with the short-acting insulin in the vial.
By following this sequence, you avoid the risk of contaminating the regular insulin with NPH insulin, which would reduce the efficacy of the short-acting insulin. Additionally, it ensures that you draw up the correct types and amounts of insulin for accurate administration.