11/35. Off-pump right atrial thrombectomy for heparin-induced thrombocytopenia with thrombosis.This report describes a 72-year-old woman with atrial fibrillation who presented with lower extremity ischemia secondary to thromboembolism. After lower extremity thrombectomy, the patient developed heparin-induced thrombocytopenia with thrombosis (HITT). Her postoperative course was complicated by recurrent supraventricular and ventricular tachycardia, secondary to a mobile thrombus in the right atrium extending into the right ventricle. Because administration of heparin was contraindicated, the patient underwent off-pump right atrial thrombectomy during a brief period of inflow occlusion. Postoperatively, she was placed on lepirudin. Her platelet count normalized without any further thrombotic episodes, and she was discharged on warfarin.- - - - - - - - - - ranking = 1keywords = thromboembolism (Clic here for more details about this article) |
12/35. thrombocytopenia due to acute venous thromboembolism and its role in expanding the differential diagnosis of heparin-induced thrombocytopenia.thrombocytopenia is an uncommon but serious consequence of heparin administration. Occasionally patients with massive acute venous thromboembolism (VTE) will develop thrombocytopenia. As heparin or some thrombin inhibitor is strongly indicated in acute VTE, it is important to distinguish this event from heparin-induced thrombocytopenia (HIT). Four patients are presented who developed thrombocytopenia so early in their course of VTE and/or therapy with heparin that HIT was considered unlikely. The mean nadir platelet count for these four patients was 60,000/microl occurring at a mean time of 18 hr after the initiation of heparin therapy. Because of strong indications to continue heparin for their acute VTE in the face of a very low likelihood that they did have HIT, heparin was continued with excellent results and resolution of the thrombocytopenia. The literature of this subject is reviewed. thrombocytopenia following VTE is actually rather common, but it is usually milder than in these four cases. In some cases such as these four, the thrombocytopenia can be sudden and rather severe causing diagnostic confusion with HIT.- - - - - - - - - - ranking = 16.022870911025keywords = venous thromboembolism, thromboembolism (Clic here for more details about this article) |
13/35. Heparin-induced thrombocytopenia and thrombosis in a patient with polycythemia vera.A 75-year-old Japanese woman with polycythemia vera was admitted to our hospital in January 2003 with suspected pulmonary thromboembolism. After administration of heparin, platelet count decreased from 1,694 x 10(9)/l on admission to 60 x 10(9)/l on hospital day 14. The patient developed acute limb embolism and transient cerebral ischemic attack on days 17 and 25, respectively. signs and symptoms mimicked those of disseminated intravascular coagulation. antibodies against heparin and platelet factor 4 complexes were detected in serum, and a diagnosis of heparin-induced thrombocytopenia and thrombosis was made. Argatroban treatment improved thrombocytopenia and hypercoagulable state.- - - - - - - - - - ranking = 1keywords = thromboembolism (Clic here for more details about this article) |
14/35. Treatment of patients with a history of heparin-induced thrombocytopenia and anti-lepirudin antibodies with argatroban.patients with heparin-induced thrombocytopenia (HIT) type II require anticoagulation with non-heparin immediate acting anticoagulants. Danaparoid may cross react with HIT-antibodies and lepirudin may generate anti-lepirudin antibodies influencing anticoagulation. We hypothesised, that the synthetic small molecular thrombin inhibitor argatroban does not induce immunoglobulins reacting towards lepirudin in patients with anti-lepirudin antibodies in the history and that titration of the anticoagulation may be easier with argatroban.We report on the treatment of four patients of a study, which was terminated prematurely due to official warnings for a repeated use of lepirudin. Two patients each received argatroban and lepirudin intravenously. A blinded assessor adjusted the doses of the anticoagulants to 1.5-3.0 fold prolongation of the aPTT. Ecarin clotting time (ECT), concentrations of lepirudin (ELISA) and of argatroban (gas-chromatography with mass spectrometry), and the generation of lepirudin antibodies (ELISA) were measured. APTT-adjusted dosages for argatroban was 2.0-2.6 microg/kg.min and for lepirudin 48-149 microg/kg.h. ECT was prolonged 2.1 to 4.5-fold with lepirudin and 4 to 7-fold with argatroban. The concentration of lepirudin ranged between 750 and 1500 ng/ml and of argatroban between 400 and 1100 ng/ml. patients on argatroban did not generate immunoglobulin IgG reacting towards lepirudin in contrast to both patients on lepirudin who developed anti-lepirudin antibodies. Both treatments were well tolerated.Despite the low number of patients argatroban seems to lead to a more stable anticoagulant response than lepirudin resulting in a lower variability of the dosage for prophylaxis or treatment of thromboembolism of patients with a history of HIT and lepirudin antibodies.- - - - - - - - - - ranking = 1keywords = thromboembolism (Clic here for more details about this article) |
15/35. Hirudin-based anticoagulant strategy during isolated limb perfusion in a patient with heparin-induced thrombocytopenia.Heparin-induced thrombocytopenia (HIT) is a rare but potentially fatal complication of heparin therapy. The administration of heparin in patients with HIT causes platelet aggregation, thromboembolism and thrombocytopenia. Therefore, an alternative anticoagulant is recommended in these patients. We describe the use of recombinant hirudin (r-hirudin; Refludan, Pharmion germany GmbH, Hamburg, germany) as an anticoagulant in a patient with HIT requiring isolated limb perfusion (ILP) for in-transit metastases of malignant melanoma of the leg; r-hirudin was used in both the extracorporeal and systemic circuits. The coagulation monitoring included the activated partial thromboplastin time (aPTT) and ecarin clotting time (ECT). There were no thrombotic or bleeding complications. The dosage regimen and the strategy of monitoring of the anticoagulant activity are described. It can be concluded that ILP in patients with suspected or confirmed HIT can be safely performed with the use of r-hirudin in both the extracorporeal and systemic circuits. Monitoring of the anticoagulation effect is necessary and should preferably be performed using ECT.- - - - - - - - - - ranking = 1keywords = thromboembolism (Clic here for more details about this article) |
16/35. Heparin-induced thrombocytopenia: clinical manifestations and management strategies.thrombocytopenia is a relatively frequent and usually benign clinical complication of heparin therapy. However, some patients receiving heparin and heparin-based products experience an immune-mediated reaction due to the development of heparin-induced antibodies. This reaction leads to a highly specific and paradoxical form of thrombocytopenia, known as type II heparin-induced thrombocytopenia (HIT). Unlike other types of drug-induced thrombocytopenia, HIT promotes thrombosis rather than bleeding; therefore HIT should be suspected in patients who experience thrombotic events despite adequate anticoagulation therapy. Early identification and treatment of HIT can prevent more serious complications associated with this disorder (e.g., exacerbation of venous thromboembolism, limb gangrene, and skin necrosis). Both arterial and venous thrombosis can arise from a single episode of HIT. Routine assessment of platelet counts is necessary with heparin therapy, as a decreased platelet level is usually the only indication of HIT. Although compared with unfractionated heparin, low-molecular-weight heparin therapy is less likely to result in HIT, the use of these agents is contraindicated in HIT patients. Concomitant warfarin therapy is not contraindicated in such patients but must be carefully monitored. Treatment with a direct thrombin inhibitor, such as lepirudin or argatroban, is an effective strategy in reversing the thrombocytopenia associated with HIT and reducing its complications. This article discusses the clinical syndrome of HIT, including pathophysiology, diagnostic criteria, clinical presentations, and current available management strategies in the context of 2 case studies.- - - - - - - - - - ranking = 3.204574182205keywords = venous thromboembolism, thromboembolism (Clic here for more details about this article) |
17/35. Delayed-onset heparin-induced thrombocytopenia and thrombosis after intraoperative heparin anticoagulation-four case reports.Delayed-onset heparin-induced thrombocytopenia (HIT) is a rare and only recently described condition. The authors report 4 cases of delayed-onset HIT, each of which presented with thrombotic complications 8-18 days after receiving heparin for coronary artery bypass grafting. Delayed-onset HIT should be suspected in any patient presenting with arterial or venous thromboembolism after heparin therapy, even 1 to 3 weeks after heparin exposure.- - - - - - - - - - ranking = 3.204574182205keywords = venous thromboembolism, thromboembolism (Clic here for more details about this article) |
18/35. Heparin-induced thrombocytopenia in a pediatric patient receiving extracorporeal support and treated with argatroban.INTRODUCTION: Heparin-induced thrombocytopenia (HIT) is rare in the pediatric population, with a majority occurring in the pediatric intensive care unit setting. All reported cases have been associated with the use of unfractionated heparin. Because unfractionated heparin is the anticoagulant of choice for extracorporeal life support, the development of HIT in these patients can be devastating. We report a case of HIT with evidence of small-vessel arterial thromboembolism in a 17-month-old child receiving extracorporeal membrane oxygenation and continuous renal replacement therapy successfully treated with argatroban. CASE: The patient was a 17-month-old boy with severe respiratory failure secondary to asthma and mucus plugging that failed conventional and unconventional ventilation. Venovenous extracorporeal membrane oxygenation was initiated, and within 24 hrs, there was a precipitous decrease in the platelet count, with the development of cutaneous ischemia involving his lower limbs. Heparin-associated antibodies were positive. Argatroban was started, and the child maintained on extracorporeal membrane oxygenation and continuous renal replacement therapy, with resolution of the cutaneous ischemia and rebound of the thrombocytopenia. DISCUSSION: HIT is rare in the pediatric population. Recognition of HIT is vital because withdrawal of heparin is the first and most important therapy. For patients on extracorporeal membrane oxygenation or continuous renal replacement therapy who develop HIT, synthetic thrombin inhibitors (hirulogs) have been reported as an alternative. However, little information on their use in extracorporeal life support has been published, particularly in the pediatric population. CONCLUSION: This report documents a pediatric case of HIT successfully treated with argatroban, allowing continuation of the venovenous extracorporeal membrane oxygenation and continuous renal replacement therapy, with resolution of the thromboembolic ischemia and thrombocytopenia.- - - - - - - - - - ranking = 1keywords = thromboembolism (Clic here for more details about this article) |
19/35. Surgical management of heparin-associated thrombocytopenia. Strategies in the treatment of venous and arterial thromboembolism.We report the vascular surgical strategies and results in 13 patients with heparin-associated thrombocytopenia and describe useful in vitro techniques for the evaluation of anticoagulant therapy. Thirteen of 40 patients with heparin-associated thrombocytopenia had 18 cardiovascular procedures done to save life or limb. Greenfield filters were placed in eight patients to prevent pulmonary embolism. Eight patients had 10 arterial procedures, with alternative anticoagulation that used dextran or warfarin in five cases. In three cases iloprost, a derivative of prostacyclin and a potent platelet inhibitor, was infused intraoperatively and heparin was given. Both the use of alternative anticoagulants and platelet suppression by iloprost were clinically effective strategies. The concurrent measurement of plasma levels of beta-thromboglobulin and fibrinopeptide a in two patients confirmed that both approaches can successfully prevent activation of platelets and plasma coagulation during arterial surgery. One operative death occurred; all vascular reconstructions remained patent at 3 to 6 months. In two patients who received heparin alone for arterial surgery, both procedures resulted in thrombosis and limb loss. When major venous thromboembolism is complicated by heparin-associated thrombocytopenia, insertion of a Greenfield vena cava filter should be considered if there is significant risk of pulmonary embolism. When necessary, arterial surgery is feasible in patients with heparin-associated thrombocytopenia if alternative anticoagulation or adequate suppression of platelet reactivity can be achieved.- - - - - - - - - - ranking = 7.204574182205keywords = venous thromboembolism, thromboembolism (Clic here for more details about this article) |
20/35. Heparin-induced thrombocytopenia and thromboembolism in the postoperative period.The heparin-induced thrombocytopenia and thrombosis (HITT) syndrome is associated with hemorrhage as well as development of systemic thrombosis. A case is presented in which a posthepatectomy patient had probable heparin-induced thrombocytopenia complicated by venous thrombosis and pulmonary emboli after receiving low doses of heparin as line flushes. HITT is reviewed and factors related to its successful management in this postoperative patient are analyzed in detail.- - - - - - - - - - ranking = 4keywords = thromboembolism (Clic here for more details about this article) |
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