Coagulation Screen
   HOME

TheInfoList



OR:

A coagulation screen is a combination of screening laboratory tests, designed to provide rapid non-specific information, which allows an initial broad categorization of haemostatic problems. __TOC__


Process

The basic screen consists of: *
platelet Platelets or thrombocytes () are a part of blood whose function (along with the coagulation#Coagulation factors, coagulation factors) is to react to bleeding from blood vessel injury by clumping to form a thrombus, blood clot. Platelets have no ...
count *
bleeding time Bleeding time is a medical test done to assess the function of a person's platelets. It involves making a patient bleed, then timing how long it takes for them to stop bleeding using a stopwatch or other suitable devices. The term template bleedi ...
for platelet function * PR (
prothrombin Prothrombin (coagulation factor II) is encoded in the human by the F2-gene. It is proteolytically cleaved during the clotting process by the prothrombinase enzyme complex to form thrombin. Thrombin (Factor IIa) (, fibrose, thrombase, throm ...
ratio) for the tissue factor pathway (extrinsic pathway) *
aPTT The partial thromboplastin time (PTT), also known as the activated partial thromboplastin time (aPTT or APTT), is a blood test that characterizes coagulation of the blood. A historical name for this measure is the Kaolin-cephalin clotting time ...
(Activated Partial Thromboplastin time) for the
contact activation pathway In the contact activation system or CAS, three proteins in the blood, factor XII (FXII), prekallikrein (PK) and kininogen, high molecular weight kininogen (HK), bind to a surface and cause blood coagulation and inflammation. FXII and PK are protea ...
(intrinsic pathway) * TCT or
fibrinogen Fibrinogen (coagulation factor I) is a glycoprotein protein complex, complex, produced in the liver, that circulates in the blood of all vertebrates. During tissue and vascular injury, it is converted Enzyme, enzymatically by thrombin to fibrin ...
assay for final common pathway (THROMBIN TIME) Two other tests are regularly performed at the same time: *
blood count A complete blood count (CBC), also known as a full blood count (FBC) or full haemogram (FHG), is a set of medical laboratory tests that provide cytometry, information about the cells in a person's blood. The CBC indicates the counts of white blo ...
, to detect other hematological abnormalities *
liver function tests Liver function tests (LFTs or LFs), also referred to as a hepatic panel or liver panel, are groups of blood tests that provide information about the state of a patient's liver. These tests include prothrombin time (PT/INR), activated partial ...
to exclude
liver disease Liver disease, or hepatic disease, is any of many diseases of the liver. If long-lasting it is termed chronic liver disease. Although the diseases differ in detail, liver diseases often have features in common. Liver diseases File:Ground gla ...
as a cause of
coagulation factor Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a blood clot. It results in hemostasis, the cessation of blood loss from a damaged vessel, followed by repair. The process of coagulation ...
deficiency These tests may miss mild abnormalities but they will detect major disorders. The results of these screening tests, in conjunction with the
clinical history The medical history, case history, or anamnesis (from Greek: ἀνά, ''aná'', "open", and μνήσις, ''mnesis'', "memory") of a patient is a set of information the physicians collect over medical interviews. It involves the patient, and even ...
(especially
bleeding Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethr ...
history), will then direct the selection of further, more detailed and specific coagulation tests, such as: * specific factor assays, like
fibrin degradation product Fibrin degradation products (FDPs), also known as fibrin split products, are components of the blood produced by clot degeneration. Clotting, also called coagulation, at the wound site produces a mass of fibrin threads called a net that remains in ...
s,
D-dimer D-dimer (or D dimer) is a dimer that is a fibrin degradation product (FDP), a small protein fragment present in the blood after a blood clot is degraded by fibrinolysis. It is so named because it contains two D fragments of the fibrin protein ...
,
thrombin time The thrombin time (TT), also known as the thrombin clotting time (TCT), is a blood test that measures the time it takes for a clot to form in the plasma of a blood sample containing anticoagulant, after an excess of thrombin has been added. It is ...
,
platelet aggregation Platelets or thrombocytes () are a part of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping to form a blood clot. Platelets have no cell nucleus; they are fragments of cytop ...
, or * specific factor inhibitor assays, like
Protein C Protein C, also known as autoprothrombin IIA and blood coagulation factor XIV, is a zymogen, that is, an inactive enzyme. The activated form plays an important role in regulating anticoagulation, inflammation, and cell death and maintaini ...
,
TFPI Tissue factor pathway inhibitor (or TFPI) is a single-chain polypeptide which can reversibly inhibit factor Xa (Xa). While Xa is inhibited, the Xa-TFPI complex can subsequently also inhibit the FVIIa-tissue factor complex. TFPI contributes signif ...
,
Antithrombin Antithrombin (AT) is a small glycoprotein that inactivates several enzymes of the coagulation system. It is a 464-amino-acid protein produced by the liver. It contains three disulfide bonds and a total of four possible glycosylation sites. α-An ...
etc.


References

{{Medicine Blood tests