Question

A patient underwent thrombectomy of femoro popliteal segment with poor outflow and was on heparin infusion. His platelet count dropped from 2 lakhs to 1 lakh/mm$^3$ on 6th day of infusion. Other blood parameters were normal and there was no feature of sepsis/infection.
How will you manage this condition?

Hint:

In HIT, discontinue heparin immediately and use alternatives like direct thrombin inhibitors (e.g., argatroban) for anticoagulation. Monitor for thromboembolic events.

Answer 1

Step 1: Discontinuation of heparin.
The first step in managing HIT is to immediately discontinue all heparin products, including heparin flushes or low molecular weight heparin (LMWH), as they will continue to trigger the immune response.

Step 2: Anticoagulation alternatives.
1. Direct thrombin inhibitors (DTIs): Medications such as argatroban or bivalirudin are preferred as alternatives to heparin. These drugs directly inhibit thrombin and are not cross-reactive with HIT antibodies.
2. Fondaparinux: This is another alternative that can be used, as it has minimal cross-reactivity with HIT antibodies. However, caution is advised in patients with renal impairment.

Step 3: Monitoring and supportive care.
- Monitoring platelet count: Regular monitoring of the platelet count is important to ensure the resolution of thrombocytopenia.
- Managing thromboembolic events: If a thromboembolic event has occurred, the patient may need additional therapies such as thrombolytics or mechanical thrombectomy, depending on the severity and location of the clot.

Step 4: Conclusion.
Management involves stopping heparin, using alternative anticoagulation, and carefully monitoring for thromboembolic events. It is crucial to treat both the thrombocytopenia and the pro-thrombotic state.