Which patient is most likely to develop heparin-induced thrombocytopenia?

Heparin-induced thrombocytopenia (HIT) is a serious and potentially life-threatening complication associated with the use of heparin. This condition is characterized by a decrease in platelet count that occurs 5 to 14 days after exposure to heparin, although it can occur earlier in patients who have been previously exposed to heparin.

In this case, the patient who is 5 days post-CABG whose platelet count has decreased by 60% fits the profile for developing HIT. A significant drop in platelet count, especially by 50% or more, is a key indicator for the condition. The timing is also critical; the patient is within the window of time (5 days post heparin exposure) when HIT is most likely to occur.

In contrast, the other options either indicate insufficient time since heparin administration or insufficient reduction in platelet count to suggest HIT. For example, a decrease of only 20% in platelet count, as mentioned in one of the alternatives, is not significant enough to trigger suspicion of HIT. Similarly, a patient who is just a few hours post-CABG is still too early to assess the risk for HIT, particularly with a normal platelet count. Therefore, the option