A nurse is reviewing the medical record of a client who is to undergo open heart surgery. Which of the following findings should the nurse report to the provider as a contraindication to receiving heparin?

Heparin is an anticoagulant commonly used during open heart surgery to prevent clot formation in the cardiopulmonary bypass circuit. Because it inhibits clotting factors, it increases the risk of bleeding. Before administration, nurses must assess for conditions that significantly elevate bleeding risk or impair platelet function. Identifying contraindications is essential to prevent life-threatening hemorrhage during and after surgery. A. Thrombocytopenia is a contraindication to heparin use because it involves a decreased platelet count, which impairs normal blood clot formation. Since heparin further inhibits coagulation, administering it to a client with low platelets significantly increases the risk of severe bleeding, including intraoperative and postoperative hemorrhage. B. Thalassemia is a hereditary blood disorder affecting hemoglobin synthesis and red blood cell structure, but it does not directly contraindicate the use of heparin. While clients with thalassemia may have anemia-related complications, platelet function and coagulation are not inherently impaired in a way that prohibits heparin use. C. COPD (chronic obstructive pulmonary disease) is a respiratory condition and does not directly affect coagulation or platelet function. Although COPD increases perioperative risk due to impaired lung function, it is not a contraindication to anticoagulant therapy such as heparin. D. Rheumatoid arthritis is an autoimmune inflammatory condition that affects joints and connective tissue but is not a contraindication to heparin use. While some clients may be on medications that affect clotting, rheumatoid arthritis itself does not significantly impair coagulation to the extent that heparin would be contraindicated.