Heparin-Induced Thrombocytopenia at the Emergency Department Due to Intermittent Heparin Flush in a Patient Undergoing Stem Cell Transplant.

Heparin-induced thrombocytopenia (HIT) is an adverse reaction to heparin products, but not warfarin. HIT usually occurs 5‒10 days after exposure to heparin. Here, we report a case of HIT with multiple thrombotic events and severe thrombocytopenia resulting from intermittent intravenous heparin flushes for maintenance of a newly placed subclavian central venous catheter (CVC) for stem cell transplant. The patient is a woman in her forties with multiple myeloma who presented to the emergency department (ED) with dyspnea, pleuritic-type chest pain, hemoptysis, and worsening left-leg swelling. Heparin had been used to flush the CVC. Her platelet count began dropping approximately one week after insertion. The patient was receiving other medications known to cause thrombocytopenia. She had undergone multiple platelet transfusions. In the ED, her lab results showed thrombocytopenia), anemia; renal insufficiency; and elevated troponin, prothrombin time, and D-dimer levels. Because of the hemoptysis and thrombocytopenia, she initially received platelet transfusion and oxygen. She was found to have deep vein thrombosis of the lower extremity and started a referral to interventional radiology for inferior vena cava (IVC) filter placement. However, further review and consultation of the Benign Hematology service, discussion about the timing of decreased platelet count shortly after CVC placement and heparin administration, and the presence of thrombosis, suggested a high pre-test probability of HIT. Anticoagulation with argatroban was initiated, and IVC filter insertion was canceled. Further workup confirmed HIT diagnosis and saddle pulmonary embolism. During the patient's hospitalization, her platelets continued to improve and reached baseline upon discharge. She was transitioned to fondaparinux at the time of discharge. A few weeks later, she had successful stem cell transplantation. Emergency physicians treating patients with thrombocytopenia receiving heparin, even in small amounts, should consider the possibility of HIT and be familiar with its management.

Once daily versus twice daily enoxaparin for acute pulmonary embolism in cancer patients.

BACKGROUND: Venous thromboembolism (VTE) is a condition in which a thrombus occludes the vasculature. The incidence of VTE in cancer patients is three times higher than that of the general population. Enoxaparin 1 mg/kg subcutaneously (SC) twice daily and enoxaparin 1.5 mg/kg SC once daily are both FDA-approved dosing regimens for the treatment of pulmonary embolism (PE). The objectives of this study were to assess outcomes of cancer patients treated with once or twice daily enoxaparin for acute PE. Primary outcomes included recurrent or worsening PE and secondary outcomes included mortality or signs of clinically overt, major bleeding. METHODS: This study was a retrospective chart review of adult cancer patients treated at The University of Texas MD Anderson Cancer Center from 2011 to 2013 who received either 1 mg/kg twice daily or 1.5 mg/kg once daily enoxaparin for acute PE upon discharge. RESULTS: Among 48 patients in each the twice daily and once daily group, six recurrent PEs occurred. The incidence of recurrent PE was higher in the once daily group (n = 4) versus twice daily group (n = 2). More major bleeding events occurred in the once daily group than the twice daily group (15% vs. 6%). Mortality at 6 months was higher in the twice daily group versus once daily group (13% vs. 6%). CONCLUSION: Cancer patients receiving once daily enoxaparin for the treatment of acute PE may be at increased risk of recurrent PE and clinically overt bleeding. Larger randomized trials are needed to confirm the results of this study.