Critical Care Medicine-Neurologic Disorders>>>>>Management Strategies (Coagulation, Vasoactive Medications)
Question 2#

A 58-year-old female with diverticulitis developed free air and required intensive care unit admission. In the intensive care unit, she went into persistent atrial fibrillation and the team decided to start her on a heparin drip for stroke prevention. Her preoperative platelet count was 343 000/µL, and on hospital day 5, her platelet count is 86 000/µL. You suspect heparin-induced thrombocytopenia (HIT) but still need to provide anticoagulation.

What is NOT an appropriate drug to administer?

A. Argatroban
B. Bivalirudin
C. Enoxaparin
D. Desirudin
E. Hirudin

Correct Answer is C

Comment:

Correct Answer: C

HIT is a condition that develops after exposure to heparin (both unfractionated or low molecular weight heparin such as enoxaparin) and occurs in 5% to 28% of patients receiving heparin. Type 1 HIT is characterized by a mild decrease in platelet count that occurs within 2 days of exposure and is due to the platelet aggregation which is not clinically significant and not associated with thrombosis. Type 2 HIT usually occurs after more than 5 days of heparin administration (average time onset is 9 days). It is immune mediated, and antibodies bind to the heparin and platelet factor 4 complex to cause endothelial injury and complement activation. These antibody complexes can cause thrombosis and thrombocytopenia; the incidence of thrombotic complications can be 20% with a mortality rate as high as 40%. Diagnosis of HIT can be confirmed through a heparin-induced serotonin release assay or a heparin-induced platelet activation assay. 

References:

  1. Kaplan’s Cardiac Anesthesia. 7th ed. Elsevier; 2016.
  2. Arepally GM. Heparin-induced thrombocytopenia. Blood. 2017;129:2864.