A nurse is teaching a client how to draw up regular insulin and NPH insulin into the same syringe. Which of the following instructions should the nurse include?

Choice A rationale Drawing up NPH insulin into the syringe first is incorrect and goes against standard safety protocols for mixing insulin. The correct procedure is to draw the clear, regular insulin first, followed by the cloudy NPH insulin. This "clear to cloudy" sequence prevents the contamination of the short-acting regular insulin vial with the longer-acting NPH insulin. Contamination could alter the onset and peak action of the regular insulin, leading to unpredictable blood glucose levels for the patient. Choice B rationale Shaking a vial of NPH insulin is discouraged because it can create bubbles in the solution, which leads to inaccurate dosing when drawing the medication into the syringe. Additionally, vigorous shaking can potentially break down the protein molecules in the insulin, reducing its effectiveness. Instead, the nurse should gently roll the vial between the palms of the hands to resuspend the insulin particles without compromising the integrity of the medication or creating problematic air bubbles. Choice C rationale Regular insulin is a short-acting, clear solution. If a vial of regular insulin appears cloudy, it has been contaminated or has undergone a chemical change and must be discarded immediately. While this is a true statement about insulin safety, it is not an instruction for the process of drawing up both types into one syringe. The question asks for the specific steps in the mixing process, and discarding bad medication is a general prerequisite rather than a mixing step. Choice D rationale When mixing insulin, the nurse must first inject air into both vials to prevent creating a vacuum. The correct sequence starts with injecting air into the NPH insulin vial without the needle touching the solution, followed by injecting air into the regular insulin vial. After injecting air into the regular insulin, the nurse keeps the needle in place to withdraw the regular insulin dose first. This ensures proper pressure and maintains the purity of the regular insulin during the process.