Take away message with respect to HIT and Heparin Alternatives
Posted Oct 05 2009 10:03pm
1) Determining the risk for heparin induced thrombocytopenia (HIT) should become part of the perioperative interview. A patient may know if they had a severe prior reaction to heparin (thrombosis or thrombocytopenia). However many Pts will probably not know that they have received heparin. However, pts who have had cardiac bypass, vascular surgery, or an interventional cardiac procedure most likely had heparin exposure and are at risk of heparin related reactions if they received heparin within 90 days of the planned procedure.
2) Be prepared to use alternative anticoagulation regimens for pts with a history of HIT or HITT. In patients with renal failure or significant renal insufficiency argatroban will most likely be the drug of choice. In patients at risk for liver failure or multi-organ failure lepirudin will most likely be used. For cardiac bypass bivalirudin is becoming very popular.
3) The direct thrombin inhibitors are dangerous drugs. There is no reversal except metabolic elimination when given in excess. They require careful monitoring of coagulation for safe titration. In the operating room ACT is the most available monitor for level of anticoagulation.
4) When rFVIIa is used in patients with implanted devices such a LVADS there may be an increased risk of significant thromboembolism. Consider a reduced dose or slow administration to allow earlier recognition of complications.
1) Determining the risk for heparin induced thrombocytopenia (HIT) should become part of the perioperative interview. A patient may know if they had a severe prior reaction to heparin (thrombosis or thrombocytopenia). However many Pts will probably not know that they have received heparin. However, pts who have had cardiac bypass, vascular surgery, or an interventional cardiac procedure most likely had heparin exposure and are at risk of heparin related reactions if they received heparin within 90 days of the planned procedure.
2) Be prepared to use alternative anticoagulation regimens for pts with a history of HIT or HITT. In patients with renal failure or significant renal insufficiency argatroban will most likely be the drug of choice. In patients at risk for liver failure or multi-organ failure lepirudin will most likely be used. For cardiac bypass bivalirudin is becoming very popular.
3) The direct thrombin inhibitors are dangerous drugs. There is no reversal except metabolic elimination when given in excess. They require careful monitoring of coagulation for safe titration. In the operating room ACT is the most available monitor for level of anticoagulation.
4) When rFVIIa is used in patients with implanted devices such a LVADS there may be an increased risk of significant thromboembolism. Consider a reduced dose or slow administration to allow earlier recognition of complications.
David S. Smith, M.D., Ph.D.