Progressive Care Nursing Certification (PCCN) Practice Exam

A patient transferred to the PCU after CABG surgery develops thrombocytopenia. What is the most likely cause?

1. Platelet dysfunction from the use of the pump

2. Bone marrow suppression

3. Diltiazem used for postoperative care

4. Heparin-induced thrombocytopenia (HIT)

The correct answer is: Heparin-induced thrombocytopenia (HIT)

The most likely cause of thrombocytopenia in a patient who has undergone CABG surgery and is now in the progressive care unit is heparin-induced thrombocytopenia (HIT). HIT is a serious immune-mediated reaction to heparin where antibodies form against complexes of heparin and platelet factor 4, leading to platelet activation and a paradoxical increase in thrombotic events, alongside a decrease in platelet counts. In the context of CABG surgery, patients are often administered heparin both during and after surgery for anticoagulation. The occurrence of thrombocytopenia typically arises within 5 to 14 days after exposure to heparin, especially if the patient has a history of prior heparin exposure. Monitoring platelet levels postoperatively is crucial, and a significant drop in platelets can indicate HIT. While other options may have valid connections to thrombocytopenia, they do not represent the most common or likely cause post-CABG in the presence of heparin. For instance, platelet dysfunction from the use of a pump could contribute to issues but is less likely to specifically account for a significant decrease in platelet count. Bone marrow suppression is a possible cause but not typical following CABG without other contributing