During a return demonstration, a nursing student prepares to mix NPH and Regular insulin. Which sequence of steps indicates correct technique?

Rationale: A. When mixing NPH (intermediate-acting) and Regular (short-acting) insulin, air must first be injected into the NPH vial, then into the Regular vial, before drawing up the insulin. Drawing up the Regular insulin first ensures the short-acting insulin remains uncontaminated by NPH, which could alter its onset and peak. After the Regular insulin is drawn, the NPH dose is drawn, maintaining proper concentrations and ensuring safe, accurate administration. B. Injecting air into Regular first and drawing Regular before NPH can result in contamination of the short-acting insulin with intermediate-acting insulin. This could affect the insulin’s onset, peak, and duration. Using the wrong sequence increases the risk of improper glucose control. C. Drawing NPH before Regular increases the risk of contaminating the Regular insulin. Contamination can alter the pharmacokinetics of the short-acting insulin, making blood glucose management unpredictable. This sequence does not follow safe mixing guidelines. D. Not injecting air into both vials before drawing the insulin can create a vacuum, making it difficult to withdraw the correct doses. This increases the chance of dosing errors and reduces the accuracy of the insulin administered.