Heparin induced thrombocytopenia hit is a serious adverse reaction that is caused by plateletactivating antiplatelet factor 4 pf4 heparin antibodies and leads to an. Heparin induced thrombocytopenia adult inpatient clinical. Heparininduced thrombocytopenia hit immune complexes heparinpf4igg cause platelet activation via the platelet fc. In the group of 70 patients with a history of prior heparin therapy, seven 10% had thrombocytopenia.
The role of a bone marrow biopsy is to rule out other causes of thrombocytopenia or an underlying lymphoproliferative disorder. Heparininduced thrombocytopenia what you need to know. Heparininduced thrombocytopenia history and exam bmj. Do not send hit antibody testing elisa or serotonin release assay sra 4. Treatment involves prompt cessation of heparin and treatment with argatroban or offlabel fondaparinux.
In summary, hit is an immunemediated reaction to heparin therapy that results in decreased platelet counts and hypercoagulability and requires clinicopathologic correlation for accurate diagnosis. Heparininduced thrombocytopenia hit is an adverse reaction to the drug heparin resulting in an abnormally low amount of platelets thrombocytopenia. Heparin induced thrombocytopenia heparin induced thrombocytopenia hit can be defined as a decrease in platelet count that can occur during or shortly after exposure to heparin. Heparin induced thrombocytopenia hit is an immune complication of heparin therapy caused by antibodies to complexes of platelet factor 4 pf4 and heparin. Heparin therapy may sometimes be seriously complicated by heparin induced thrombocytopenia hit. Our understanding of the pathophysiology of this immunemediated condition has improved in recent years, with heparin. Haemodialysisrelatedheparininduced thrombocytopenia revista. Heparininduced thrombocytopenia hit is a potentially life threatening complication. This complication of heparin is often confusing because in hit, heparin. Heparininduced thrombocytopenia in critically ill patients. This algorithm has been developed for md anderson using a multidisciplinary approach considering. List of heparininduced thrombocytopenia medications. Heparin induced thrombocytopenia hit is an immunemediated hypercoagulable disorder caused by antibodies to platelet factor 4 pf4 and heparin.
Riia thrombocytopenia high risk of thrombosis occurs in 50% of untreated cases may be venous dvt, pe or arterial limb ischemia, stroke, mi thrombotic complications can be fatal. Heparininduced thrombocytopenia shaikh n j emerg trauma shock. Usually, heparin administered at or near surgery is the most immunizing situation i. Target population adult patients with suspicion or diagnosis of heparin induced thrombocytopenia key practice recommendations screening for hit 1. Heparininduced thrombocytopenia hit is an immune igg mediated condition that occurs secondary to heparin exposure. Sometimes, these antibodies strongly activate platelets and coagulation, thereby causing the prothrombotic disorder, heparin induced thrombocytopenia. Heparin induced thrombocytopenia hit treatment page 1. Heparininduced thrombocytopenia, fifthedition although first reported in 1973, immune heparin induced thrombocytopenia hit remains one of the most frequent and devastating. The pretest probability of heparin induced thrombocytopenia. Itp is a diagnosis of exclusion without an absolute confirmatory test. Guidelines for the investigation and management of idiopathic.
Diagnosing postoperative heparin induced thrombocytopenia hit in cardiothoracic surgical patients is complicated because of the profound thrombocytopenia that occurs with cardiopulmonary bypass cpb. Heparin induced thrombocytopenia hit is considered the most common form of drug induced thrombocytopenia as well as one of the common causes of thrombocytopenia in hospitalized patients. Heparin induced thrombocytopenia in the cardiovascular patient. Society for haematology and idiopathic thrombocytopenic purpura. May 03, 2012 heparin induced thrombocytopenia hit is an adverse reaction to the drug heparin resulting in an abnormally low amount of platelets thrombocytopenia. Heparininduced thrombocytopenia is a profoundly dangerous, potentially lethal, immunologically mediated adverse drug reaction to unfractionated heparin or, less commonly, to lowmolecular weight heparin. Hit is the most common type of drug induced, immunemediated thrombocytopenia and is associated with high morbidity and mortality if undiagnosed. Understanding the misunderstood disease of heparin. Treatment and prevention of heparininduced thrombocytopenia.
The result is venous and occasionally arterial thrombosis. Heparin induced thrombocytopenia hit heparin induced thrombocytopenia hit is a potentially lethal, immunologically induced complication to unfractionated heparin therapy and to a smaller degree, low molecular weight heparin. This algorithm has been developed for md anderson using a multidisciplinary approach considering circumstances particular to md andersons specific patient population, services and structure, and clinical information. Hit may also be associated with low molecular weight heparin use. Heparininduced thrombocytopenia hit is the development of thrombocytopenia a low platelet count, due to the administration of various forms of heparin, an anticoagulant.
Heparin induced thrombocytopenia hit is an immunemediated complication of heparin therapy. We describe a 58yearold nulliparous obese woman who developed severe. However, these patients are likely to require anticoagulation therapy at some point in the future. Feb 03, 2020 heparin induced thrombocytopenia hit is a condition that causes a decrease of platelets in the blood. Heparin induced thrombocytopenia hit is a lifethreatening complication of exposure to heparin eg, unfractionated heparin, low molecular weight lmw heparin that occurs in a small percentage of patients exposed, regardless of the dose, schedule, or route of administration. The most commonly used intravenous anticoagulant is heparin. Cpb predisposes patients to develop a frequent incidence of antibodies directed against platelet factor 4 pf4 heparin. Overview test information additional resources heparininduced thrombocytopenia hit is a complication of heparin therapy. Heparin induced thrombocytopenia hit treatment page 1 of 7. Ticagrelor causes falsenegative functional tests for. Pathogenesis and management heparin induced thrombocytopenia hit is a transient.
Research over the last 20 years has vastly expanded knowledge, awareness and management of this condition. Its diagnosis is based on a medical condition compatible with this syndrome and. Hit is considered to be the most important and most frequent drug induced type of thrombocytopenia. Hit usually occurs after you are treated with heparin. Heparininduced thrombocytopenia, fifth edition fundamental and clinical cardiology warkentin, theodore e. Heparininduced thrombocytopenia hit is an immunemediated hypercoagulable disorder caused by antibodies to platelet factor 4 pf4 and heparin. Heparin induced thrombocytopenia hit is a prothrombotic state associated with antiplatelet factor 4 pf4 heparin antibodies, which cause platelet activation. A severe drug reaction to heparin that can lead to life and limbthreatening venous andor arterial thromboembolism. The management of patients with heparin induced thrombocytopenia who require anticoagulant therapy kathryn hassell, md for patients with heparin induced thrombocytopenia hit, reexposure to heparin is generally not recommended. Hit develops in temporal association with heparin therapy and manifests either as an unexplained thrombocytopenia or thrombocytopenia complicated by thrombosis. Recent data show that up to 8% of heparinized patients will develop the antibody associated with hit and that approximately 15% of patients on heparin will progress to develop hit with thrombocytopenia. This is the case of a patient with heparin induced thrombocytopenia hit, a syndrome that can be potentially fatal. Putting the brakes on bleeding by clicking on the pdf icon above.
The use of heparin to flush some vascular access devices makes hit a concern for. Pubmed comprises more than 26 million citations for biomedical literature from medline, life science journals, and online books. Heparininduced thrombocytopenia, fifth edition fundamental. Laboratory testing reveals a platelet count of 86,000 per cubic. Heparininduced thrombocytopenia hit is a potentially serious complication of heparin therapy and is being encountered more frequently in patients with cardiovascular disease as use of anticoagulant therapy becomes more widespread. Hit predisposes to thrombosis and, when identified, the condition is then called heparin induced thrombocytopenia and thrombosis hitt. Heparin induced thrombocytopenia hit is a lifethreatening complication of exposure to heparin ie, unfractionated heparin, low molecular weight lmw heparin that occurs in up to 5 percent of patients exposed, regardless of the dose, schedule, or route of administration. Heparin induced thrombocytopenia is a clinicopathologic syndrome that can be associated with severe complications and significant mortality. The following guideline is intended to guide the diagnosis and management of heparin induced thrombocytopenia. A 63yearold man with coronary artery disease who has recently undergone bypass surgery presents with dyspnea. Impact of bovine versus porcine heparin in hit pathogenesis.
Start anticoagulation with no heparin based compound such as a direct thrombin inhibitor. The multiple causes and myriad presentations of thrombocytopenia. Heparininduced thrombocytopenia and thrombosis syndrome hitts is an immunemediated response to the administration of heparin that results in lifethreatening thrombosis. Heparin induced thrombocytopenia is a serious immunemediated, drug adverse effect. This article discusses the pathogenesis, diagnosis, and treatment of patients with heparin induced thrombocytopenia. Heparininduced thrombocytopenia retrospective analysis. Heparininduced thrombocytopenia and thrombosis syndrome. Heparin induced thrombocytopenia hit is a complication of heparin therapy and is characterized by two types. An iv or central line that is flushed with heparin or coated with heparin. Halting heparininduced thrombocytopenia american nurse. Heparininduced thrombocytopenia hit arup laboratories. Riia on platelets and monocytes to propagate a hypercoagulable state culminating in lifethreatening thrombosis.
Sample case 64 yo woman with endocarditis platelet count decreases from 161k on day 7 to 60k on day 9 been receiving low molecular weight heparin. Heparin induced thrombocytopenia hit is an antibodymediated adverse drug reaction that can lead to devastating thromboembolic complications, including pulmonary embolism, ischemic. Heparininduced thrombocytopenia hit is an immune complication of heparin therapy caused by antibodies to complexes of platelet factor 4 pf4 and heparin. Prospective evaluation of the 4ts score and particle gel immunoassay specific to heparin pf4 for the diagnosis of heparin induced thrombocytopenia. Heparin induced thrombocytopenia hit treatment page 1 of 7 disclaimer. Persistent heparininduced thrombocytopenia treated with ivig. A diagnosis of heparininduced thrombocytopenia with.
The pathophysiology of heparin induced thrombocytopenia includes an immunemediated reaction to heparin that activates platelets and results in an acquired hypercoagulability. Target population adult patients with suspicion or diagnosis of heparin induced thrombocytopenia. The pathophysiology of hitts remains controversial. Heparin induced thrombocytopenia hit is an antibodymediated adverse drug reaction that can lead to devastating thromboembolic complications, including pulmonary. Hit is usually an immune response which typically occurs 410 days after exposure to heparin. If the platelet count falls by 30% or more andor the patient develops new thrombosis or skin allergy or any of the other rarer manifestations of heparin. Heparininduced thrombocytopenia hit is by far the most relevant pathological association of it encountered by clinicians. Evans may have developed deep vein thrombosis or a complex coagulopathy, such as heparin induced thrombocytopenia hit. Hit is characterized by a 3050% drop in platelet count 5 to 10 days after heparin. Heparininduced thrombocytopenia investigations bmj best. Heparininduced thrombocytopenia is the most important of the immunemediated, drug induced thrombocytopenias.
Heparininduced thrombocytopenia in acute coronary syndrome. Heparininduced thrombocytopenia hit is a lifethreatening complication of exposure to heparin ie, unfractionated heparin, low molecular weight lmw heparin that occurs in up to 5 percent of patients exposed, regardless of the dose, schedule, or route of administration. Heparininduced thrombocytopenia genetic and rare diseases. Heparininduced thrombocytopenia and cardiac surgery the. Laboratory testing for the antibodies that cause heparin induced thrombocytopenia.
Unfractionated heparin given during cardiopulmonary bypass is remarkably immunogenic, as 25% to 50% of postcardiac surgery patients develop heparin dependent antibodies during the next 5 to 10 days. Heparin induced thrombocytopenia kettering health network. When drugs or medications are the causes of a low platelet count, it is called drug induced thrombocytope. Heparininduced thrombocytopenia hit is an immune complication of heparin. Thrombocytopenia is any disorder in which there are not enough platelets. In a prospective study of 142 patients receiving intravenous heparin of bovine lung origin, thrombocytopenia developed in nine 6% patients. Clinical picture of heparin induced thrombocytopenia hit and its differentiation from nonhit thrombocytopenia.
Heparininduced thrombocytopenia hit is a lifethreatening immune response to heparin and its derivatives that is associated with a high risk of thromboembolic complications. Each case had confounding features that delayed recognition of the problem. May 18 issue1 identified a difference in outcome favoring the use of lowmolecularweight heparin. This cardiology patient page focuses on heparin induced thrombocytopenia hit, a complication of heparin therapy. The onset of clinical symptoms and laboratory changes is usually delayed 12 weeks after exposure to heparin. Heparininduced thrombocytopenia heparininduced thrombocytopenia hit is characterized by a decrease in the platelet count of more than 50% from the highest platelet count value after the start of heparin, an onset 5 to 10 days after the start of heparin, hypercoagulability, and the presence of heparindependent, plateletactivating igg. Smock, md associate professor of pathology, medical director, arup hemostasisthrombosis. Moser, md heparin induced thrombocytopenia hit is a complication seen in approximately 1%3% of patients treated with unfractionated heparin therapy. None of the newer anticoagulants, whether oral or parenteral, combine. Heparin induced thrombocytopenia hit occurs in two major forms type i, which is non immunologic and associated with mild transient thrombocytopenia, and type ii, caused by an. Im going to reveal to you the secret method that allows you to get the equivalent exercise of 45 minutes at the gym, in just a few minutes per day.
Heparin use for treatment and prevention of thromboembolism is more common in the elderly and that may be the reason why hit is reported more frequently in this group of patients. Antiplateletantibodies are not thought to be sufficiently sensitive or specific to rule in or out itp. Negatively charged heparin forms a complex with positively charged platelet factor 4 pf4 1. The propensity for thrombosis distinguishes hit from other common drug induced. Guidelines on the diagnosis and management of heparin. Two clinical forms of hit are generally recognized. Treatment of heparininduced thrombocytopenia involves discontinuing heparin and starting a non heparin anticoagulant. The following guideline is intended to guide the management of heparin induced thrombocytopenia and includes recommendations for diagnosis and treatment agents. Key clinical pointsheparininduced thrombocytopenia heparininduced thrombocytopenia hit is characterized by a decrease in the platelet count of more than 50% from the highest platelet. Heparin induced thrombocytopenia is the development of thrombocytopenia due to the administration of heparin.
Thrombocytopenia is the most common sign of heparin induced thrombocytopenia hit. Patients with heparininduced thrombocytopenia present with mild thrombocytopenia. Hit results from an autoantibody directed against platelet factor 4. Key clinical pointsheparininduced thrombocytopenia heparininduced thrombocytopenia hit is characterized by a decrease in the platelet count of more than 50% from the highest platelet count valu. Based on the ethical guidelines for medical and health research involving human.
Heparin cessation and alternative anticoagulation are the key interventions in patients with hit. Heparin induced thrombocytopenia diagnosis and management theodore e. A case of heparininduced thrombocytopenia hit triggered by. Heparininduced thrombocytopenia hit is a condition that causes a decrease of platelets in the blood. Hit is an immunologic drug reaction mediated by the igg antibodies against the heparin platelet factor 4 pf4 complex. Diagnosis of heparin induced thrombocytopenia karen a. Key clinical pointsheparin induced thrombocytopenia heparin induced thrombocytopenia hit is characterized by a decrease in the platelet count of more than 50% from the highest platelet count valu. Pathogenic antibodies to pf4heparin bind and activate cellular fc.
Heparin induced thrombocytopenia hit is an immunemediated syndrome of thrombocytopenia and thrombosis as a result of heparin exposure. Citations may include links to fulltext content from pubmed central and publisher web sites. Complications of hit are venousarterial thrombosis, skin gangrene, and acute platelet activation syndrome. Heparin induced thrombocytopenia was defined as a decrease in the platelet count below 150,000 per cubic millimeter that began five or more days after the start of heparin therapy, and a positive. Heparininduced thrombocytopenia clinical presentation. Heparin induced thrombocytopenia mild to moderate thrombocytopenia or a 50 percent reduction after exposure to heparin or lowmolecularweight heparin arterial and venous thrombosis. Because the platelet count normalizes even with continued heparin therapy, it is not associated with increased thrombotic risk.
Heparininduced thrombocytopenia article nursingcenter. Hit occurs in up to 5% of patients receiving unfractionated heparin ufh, and in sep 08, 2010 gym guru exposes fat burning secret. Hit results from an autoantibody directed against endogenous. Warkentin, md h eparin induced thrombocytopenia hit is an adverse drug reaction characterized by thrombocytopenia and a high risk for venous or arterial thrombosis. Heparin induced thrombocytopenia is an antibodymediated adverse drug reaction to heparin therapy with potentially lifethreatening complications. Heparin induced thrombocytopenia hit is a common and often severe complication of heparin therapy.
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