Ordering tests for bleeding coagulopathic patients

Knowing how to manage bleeding in coagulopathic patients is a crucial skill. But to devise an effective management plan, you first need to know the cause of the coagulopathy. In this video from our Hematology and Coagulation Essentials course, we'll cover a thorough diagnostic approach to figuring out why your patient is bleeding and by ordering the appropriate tests.

Demystify hematology and coagulation with our fascinating Hematology and Coagulation Essentials course. Hematological and coagulation disorders can be difficult to diagnose. Under the expert guidance of Dr Amer Wahed–Associate Professor in the Department of Pathology at the University of Texas–you’ll learn how to order tests, interpret results, and diagnose disorders with ease.

[00:00:00] The management of bleeding in coagulopathic patients is clinically important. Broadly speaking, a patient may demonstrate bleeding either due to surgery or due to coagulopathy. So, what are the causes? Coagulopathy may arise from platelet issues such as thrombocytopenia or thrombocytopathia. Coagulopathy may also result from clotting factor deficiencies or presence of anticoagulants.

[00:00:30] Example of such anticoagulants are heparin and direct thrombin inhibitors. Primary fibrinolysis is another unusual cause of bleeding. Normally, when there is a clot formation, the clot is lysed, this is secondary fibrinolysis. In some individuals, the fibrinogen is lysed without clot formation and that is known as primary fibrinolysis. These patients may bleed. How can we test for these underlying causes?

[00:01:00] Our diagnostic approach should start with the CBC. If the patient has thrombocytopenia, this will be evident from the complete blood count. Several tests are available to establish thrombocytopathia or platelet dysfunction. One common screening test for thrombocytopathia is platelet function analyzer or PFA 100. PFA 100 is discussed in greater detail in another lesson. Platelet aggregometry

[00:01:30] is another test for thrombocytopathia. It is the gold standard test, however, it takes long to perform and is not practical for the management of bleeding patients. In platelet aggregometry, light passes through a suspension of platelet-rich plasma. Various agonists are added to the test media, which results in the platelets clumping and settling to the bottom. This will result in more light passing out through the test media and this light that is being passed out

[00:02:00] is measured on to a graph paper. Thromboelastography or TEG is a test for primary and secondary hemostasis. Platelet issues such as thrombocytopenia and thrombocytopathia are picked up by the value of MA. When values of MA are low, it implies thrombocytopenia or thrombocytopathia. Thromboelastograph can also pick up clotting factor deficiencies, this is manifested by

[00:02:30] a prolonged R-value. TEG is also capable of detecting primary fibrinolysis. This is manifested by increased LY30 time. Thromboelastography or TEG is discussed in detail in another section. Another test we can employ for detection of coagulopathy in bleeding patients is a DIC screen. This screen includes five tests, the first of which is PT,

[00:03:00] the second test is PTT, the third is the thrombin time, fibrinogen level, and levels of D-dimer. If the PT or PTT are prolonged, it indicates deficiency in one or more clotting factors. If the thrombin time is prolonged, this usually means presence of anticoagulants such as heparin or low levels of fibrinogen. If the fibrinogen level is low with increased levels

[00:03:30] of D-dimer, this usually implies fibrinolysis. And just to remind you, fibrinolysis is two types: one is primary fibrinolysis, which I've explained, these are cause of increased bleeding, and the other is secondary fibrinolysis, which happens after normal clotting.