The nurse is caring for a client who has a new prescription for a continuous heparin infusion. Prior to starting the medication, what data will be obtained?

Choice A rationale While vital signs (e.g., blood pressure, heart rate) are essential baseline data for all clients, and are important for monitoring for internal bleeding (hypotension, tachycardia) during heparin therapy, they are not the primary data point required for calculating and initiating a weight-based continuous heparin infusion protocol. Choice B rationale Heparin is commonly dosed and titrated based on the client's current weight in kilograms for both the initial bolus and the continuous infusion rate. Obtaining the client's most current weight is absolutely essential prior to starting the medication to ensure accurate, safe, and therapeutically effective dosing, thus preventing under- or over-anticoagulation. Choice C rationale The PT/INR level is primarily used to monitor warfarin, not continuous unfractionated heparin, though a baseline PT/INR and aPTT are usually drawn. The aPTT is the test used for monitoring heparin's effect. While a baseline aPTT is needed, the weight is critical for the initial dosing calculation. Choice D rationale A 12-lead EKG report provides a snapshot of the electrical activity of the heart. While the client may have an EKG as part of their evaluation for conditions like acute coronary syndrome, for which heparin is indicated, this report is not necessary data for the practical calculation or initiation of a continuous heparin infusion.