Thank you for your comments about anticoagulation management in HIT. Argatroban and danaparoid would be appropriate anticoagulants to use in this setting. Lepirudin is no longer available, having been recently withdrawn from Europe. Fondaparinux would not be suitable at this stage as it is contraindicated in severe renal impairment (CrCl <30ml/min) and this patient continues to require CVVH. As you will all no doubt be aware all exposure to heparin must be stopped: this includes heparin line flushes and LMWH with which HIT antibodies are likely to cross-react.
Back to the case…in response to the positive HIT test, heparin is stopped and an argatroban infusion is started. Unfortunately, the argatroban is interrupted several times for placement of arterial and venous lines and it takes almost 48 hours to reach therapeutic levels. In the meantime he develops leg swelling on the same side as a femoral venous line. USS confirms a proximal DVT.
QUESTIONS FOR THE TEAM:
What do you do next? How long should he remain anticoagulated for? What are your options for ongoing anticoagulant therapy as he recovers from his surgery?