A 66-year-old man hospitalized for pulmonary embolism is started on intravenous unfractionated heparin. On hospital day 6, he develops right leg pain and swelling. Vital signs show BP 138/82, HR 98, RR 18, temp 37.2°C, SpO2 98%. Laboratory studies reveal platelet count decreased from 240,000 to 82,000/mm³, with normal PT and aPTT. He denies recent surgery or trauma. Which of the following is the most likely mechanism underlying his clinical deterioration?

  1. A)Vitamin K depletion due to intestinal flora suppression
  2. B)Direct toxic suppression of megakaryocytes by heparin
  3. C)Antibodies against platelet factor 4 heparin complexes causing platelet activationGABARITO
  4. D)Mechanical destruction of platelets in the spleen
  5. E)Inherited deficiency of antithrombin III

Explicação

Antibodies against platelet factor 4 heparin complexes causing platelet activation is correct. Heparin induced thrombocytopenia is an immune mediated prothrombotic disorder that typically occurs 5 to 10 days after exposure. Platelets are activated rather than ... Ver explicação completa e trilha adaptativa →

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