Which patient is most at risk for developing heparin induced thrombocytopenia (HIT) after CABG?

The correct answer is that a patient with a 60% decrease in platelet count post CABG is most at risk for developing heparin-induced thrombocytopenia (HIT).

HIT is an immune-mediated adverse reaction to heparin that results in a significant drop in platelet count, typically more than 50% of the baseline. A reduction of 60% in the platelet count indicates a substantial response to heparin, aligning with the criteria that suggest the development of HIT.

The timing of the decrease is also a key factor; HIT usually occurs five to fourteen days after exposure to heparin, and a dramatic drop in platelets post-operatively, especially in the context of cardiac surgery such as CABG, raises suspicion for this condition. A 60% decrease signifies the body’s immune response to heparin, placing the patient at higher risk for thrombocytopenia and subsequent complications such as thrombosis.

In contrast, a patient with a platelet count of 200,000 four hours post CABG is still within a normal range for platelet count, and thus would not be at risk for HIT. The patient with a platelet count of 100,000 two days post CABG also does not sufficiently indicate