how is hit diagnosed

How is HIT Syndrome diagnosed?

The criteria for diagnosis of HIT include: normal platelet count before the commencement of heparin. thrombocytopenia defined as a drop in platelet count by 30% to <100×109/l or a drop of >50% from the patient's baseline platelet count.

Which lab value is used in the diagnosis of HIT?

HIT Laboratory Testing Immunoassays detect the presence of PF4-heparin antibody in the patient's serum. The solid phase ELISA is the gold standard and is the most widely used test to evaluate HIT. This test is performed at UC Davis Medical Center as the screening test.

How do you diagnose and manage hits?

When HIT is strongly suspected, standard practice includes substituting heparin with an alternative anticoagulant; the 2 US-approved agents are the direct thrombin inhibitors (DTIs) lepirudin and argatroban, which are "niche" agents used only to manage HIT.

How do you investigate heparin induced thrombocytopenia?

Diagnosis requires the combination of a compatible clinical picture and laboratory confirmation of the presence of heparin-dependent platelet-activating HIT antibodies. The Warkentin (4Ts) Probability Scale score is commonly used to determine the clinical probability of HIT.

How do you know if heparin induced thrombocytopenia?

HIT can often be diagnosed by measuring the platelet count and PF4 antibody level in the blood. Symptoms of new blood clot formation may suggest HIT. Symptoms of deep vein thrombosis include pain or tenderness, sudden swelling, discoloration, visibly large veins, and skin that is warm to the touch.

What are the symptoms of heparin induced thrombocytopenia?

What Are the Symptoms of HIT?Skin tenderness.Swelling.Skin that's warm to the touch.Shortness of breath.Change in heart rate.Sharp pain in your chest.Dizziness.Anxiety.More items...•

What is the treatment for HIT?

Treatment of HIT entails immediate withdrawal of all heparin, including heparin-containing flushes and catheters. Heparin cessation alone, however, is often insufficient to prevent thrombosis.

What is the antidote for heparin?

To date, protamine sulphate (PS), a cationic polypeptide is the only clinically approved antidote for unfractionated heparin.

When does heparin-induced thrombocytopenia occur?

When Does HIT Occur? Immune-mediated HIT usually occurs between 5 to 14 days after first beginning heparin therapy. However, there are exceptions, with HIT developing infrequently either early (after a recent previous exposure to heparin) or late after heparin exposure.

What lab do you check for heparin?

When assessing therapeutic levels of unfractionated Heparin, two laboratory tests are available; the Activated Partial Thromboplastin Time (aPTT) and the Anti-Factor Xa Assay. The aPTT has been the gold standard for monitoring IV heparin for more than 50 years. It is cost-effective and familiar to most personnel.

What is the test for heparin?

Heparin anti-Xa tests are sometimes used to monitor and adjust standard heparin (unfractionated heparin, UFH) therapy, though the primary monitoring tool for UFH is currently the PTT test.

What is functional assay for HIT?

Diagnostic tests for HIT consist of immunoassays and functional assays. Immunoassays identify antibodies against heparin/platelet factor 4 (PF4) complexes. Functional assays measure the platelet-activating capacity of PF4/heparin-antibody complexes.

How do you measure thrombocytopenia?

A complete blood count (CBC) measures the levels of red blood cells, white blood cells, and platelets in your blood. For this test, a small amount of blood is drawn from a blood vessel, usually in your arm. If you have thrombocytopenia, the results of this test will show that your platelet count is low.