Anticoagulation fundamentals for EMS
Maintaining our internal oxygen transportation system is essential to life and the red blood cells are the carriers. Excessive red blood cell loss can produce organ system damage or death.
It's as simple as this: kill enough cells, kill the organ; kill enough organs or the right organ, kill the organism. Fortunately, we have an internal leak management system comprised of circulating platelets and coagulation factors that can provide a seal.
The initial event in clot formation is the development of a platelet plug. As the plug develops it stimulates the coagulation cascade to spin a fibrin web thorough out the gathered (aggregated) platelets to trap red blood cells (RBCs).
Most of these coagulation pathway factors are made in the liver, so it is not surprising that the patient with severe liver failure can have bleeding problems due to an inadequate supply of these factors. We can therapeutically decrease the supply or effectiveness of coagulation factors to prevent or treat abnormal clot formation in certain conditions. Although the bleeding risks naturally increases with anti-clot medication, it is administered in a controlled manner and the therapeutic effect outweighs the risk for most patients. It is important to understand how anticoagulant medications work and how to monitor patients who use them.
Anticoagulants For our discussion, the most important factors that antithrombin III inhibits are thrombin and Factor X (Figure 2).
Heparin comes in two flavors, unfractionated and fractionated. Unfractionated heparin contains both long chains and short chains of heparin molecules, each with a different action. When the long chains combine with antithrombin III they increase thrombin inactivation, and when the short chains combine with antithrombin III they increase inactivation of Factor X. Fractionated heparin contains only the short chains thus primarily inactivates Factor X5 (Figure 2).
Heparin cannot be administered orally because the heparin chains are not absorbed, thus we give heparin by subcutaneous (SC) injection or intravenously (IV). There has been work on developing a carrier molecule to bind with heparin to facilitate absorption in the gastrointestinal tract,6 but I am not aware of a commercially available product at this time. We don't give heparin intramuscularly because of the higher number of blood vessels in muscle versus SC tissue and the potential for bleeding in the muscle.
Platelet Plug Formation - News
Fortunately, we have an internal leak management system comprised of circulating platelets and coagulation factors that can provide a seal. The initial event in clot formation is the development of a platelet plug. As the plug develops it stimulates
Hemostasis: Understanding the Platelet Plug - Blogger
A clinician needs to think about them differently. Let's explore platelet plug formation.Now, there are two main problems with platelets, either 1) a decreased number or 2) bad (broken) platelets that have poor function. There are two tests that we need to evaluate for platelet functionne is the platelet count as seen on the red blood cell count. So, we are looking at the absolute number, or we are looking at a test called the bleeding time. When a platelet count is decreased, this is known as thrombocytopenia. This is seen if there is a problem in the bone marrow such as decreased production of platelets which you can see in some malignancies, most commonly seen in chemotherapy that suppresses bone marrow, increased destruction such as a hyperactive spleen where the only potential solution to this is to have a splenectomy, or from idiopathic thrombocytopenia which is typically a child after a viral syndrome where the treatment is steroid removal immunoglobulin or spleen removal. When I was in my pediatric rotation, I remember seeing a young child for a well child visit, and this was actually my first rotation as a physician assistant student. When the physician came in, the child clearly responded adversely to the pediatrician who was a bit older with a beard, and the mom said that he looked kind Mens MBT Karani Shoes of like his father. The child was really kind of frightful of the physician. When he looked over the child, the child had a number of bruises especially on his lower legs. I believed this child was being abused by his father. The doctor sent him off for blood work, and I was quite upset with the physician which I talked about wondering how he could not see how apparent abuse was. Well, when the blood work came back, this child had idiopathic thrombocytopenia, and it was not child abuse.Sepsis, in the setting of a low platelet count, is a red flag for a patient requiring intensive care. Platelet counts lower than 50,000, you can get increased bleeding status post trauma. If you have platelet counts of less than 20,000, you can have increased spontaneous bleeding. When I used to cover the hematology/ oncology floor, we would transfuse patients when they got below 10,000.To test platelet function, we need a bleeding time. The bleeding time is basically a small incision in the skin that by spring-loaded apparatus, it gives us a very uniform little abrasion, and the lab will blot that area until the bleeding stops.
Platelet Plug Formation - Bookshelf
Platelets
Stages in Platelet Plug Formation Platelet activation can be divided into three overlapping stages: initiation, extension, and perpetuation (Fig. 16-1). ...Introduction to the human body, the essentials of anatomy and physiology
Platelet Plug Formation When platelets come into contact with parts of a damaged blood vessel, their characteristics change drastically and they quickly ...Fibroids, Menstruation, Childbirth, and Evolution, The Fascinating Story of Uterine Blood Vessels
Therefore, NSAIDs interfere with platelet plug formation by blocking TxA2 formation. In endothelial tissue, but not in platelets, COX-2 converts arachidonic ...Principles of anatomy and physiology
Platelet Plug Formation In their unstimulated state, platelets are disc-shaped. ... In the first phase of platelet plug formation, platelets contact and ...Clinically Oriented Pharmacology
Atherosclerosis can lead to narrowing of lumen, there may be rupture of the plaque and subsequent platelet plug formation, aneurysm etc. rupture of the ...Everyday News Directory
platelet plug formation - definition of platelet plug ...
Definition of platelet plug formation in the Online Dictionary. Meaning of platelet plug formation. Pronunciation of platelet plug formation. ...
Platelet - Wikipedia, the free encyclopedia
This is achieved primarily by the formation of thrombi, when damage to the endothelium of ... Aggregation and adhesion act together to form the platelet plug. ...
Hemostasis
2. Formation of a Platelet Plug. Platelets, also called thrombocytes, ... Platelet aggregation results in the formation of a platelet plug which acts to ...
Platelet Research Laboratory
The Platelet Research Laboratory is a center for the study of the basic mechanisms involved in alterations of hemostasis and the pathogenesis of thrombosis, ...
City of Long Beach, CA - Platelet Function
... secondary hemostasis process culminates in the formation of strands of fibrin that are woven through the loose platelet plug, cross-linked to form a ...