Kofi, a 58-year-old man, was started on IV heparin three days ago for a newly diagnosed pulmonary embolism after a long transatlantic flight. His morning labs show a platelet count of 78,000/mm3, down from 210,000/mm3 on admission. He has no visible bleeding, but the nurse notes his left IV site looks slightly bruised and he reports mild calf tenderness on the same leg where his heparin infusion runs. What should the nurse suspect is causing this platelet trend?
- Heparin-induced thrombocytopenia (HIT), an immune reaction that paradoxically increases clot risk
- Expected hemodilution from IV fluids running concurrently with the heparin infusion
- Bone marrow suppression from the anticoagulant itself, similar to chemotherapy-induced thrombocytopenia
- A normal, transient drop that resolves without any change in therapy once heparin reaches steady state