A nurse is caring for a client who has a prescription for NPH insulin 10 units and regular insulin 15 units subcutaneously. After injecting 10 units of air into the NPH insulin vial, which of the following actions should the nurse take next?

A) Inject 15 units of air into the regular insulin vial: When drawing insulin from both NPH (a long-acting insulin) and regular insulin (a short-acting insulin), the nurse should first inject air into the NPH insulin vial (which is the intermediate-acting insulin) and then inject air into the regular insulin vial. This technique helps to prevent contamination of the regular insulin vial with NPH insulin. After injecting air into the regular insulin vial, the nurse would then withdraw the regular insulin first and then the NPH insulin to avoid contamination of the regular insulin with the NPH insulin. B) Withdraw 10 units of NPH insulin: This action is premature, as the nurse has not yet injected air into the regular insulin vial. The correct sequence involves injecting air into both vials before withdrawing any insulin. Therefore, withdrawing NPH insulin at this stage is not the correct next step. C) Verify the dosage with another nurse: While verifying the insulin dosage with another nurse is a good practice for ensuring medication safety, this action is not the immediate next step after injecting air into the NPH insulin vial. The priority is to follow the correct sequence of air injection into the vials before withdrawing the insulin. Verification can occur after the insulin is drawn. D) Place the cap over the needle: Placing the cap over the needle is a safety step that is generally performed after withdrawing the insulin and preparing the injection. However, this is not the next step in the process of mixing or drawing insulin, so it is not the correct action to take at this point.