Which action should be taken to prevent contamination when mixing insulins?

To prevent contamination when mixing insulins, it is essential to follow a specific sequence to maintain the integrity of each insulin type. The correct choice is to inject air into the long-acting insulin after the short-acting insulin. This practice helps to avoid introducing the short-acting insulin into the long-acting vial, which could compromise the potency and functionality of the long-acting insulin.

By injecting air into the vials, you create a positive pressure that allows for easier drawing of the insulin into the syringe. The order matters because if you were to inject air into the long-acting insulin first, then draw from it after mixing with the short-acting insulin, there is a risk of cross-contamination, leading to improper dosing.

Maintaining this sequence is critical in ensuring that each type of insulin remains effective and safe for patient use, as mixing them incorrectly can lead to variations in their pharmacodynamics and therapeutic outcomes. This careful technique is taught to enhance patient safety and medication management in diabetes care.