The activated Factor IXa with Factor VIIIa forms the "tenase" complex. This "tenase" complex activates more Factor X, which in turn forms new prothrombinase complexes with Factor Va. Factor Xa is the prime component of the prothrombinase complex which converts large amounts of prothrombin—the "thrombin burst". Each molecule of Factor Xa can generate 1000 molecules of thrombin. This large burst of thrombin is responsible for fibrin polymerization to form a thrombus. Factor Xa also plays a role in other biological processes that are not directly related to coagulation, like wound healing, tissue remodelling, inflammation, angiogenesis and atherosclerosis. Inhibition of the synthesis or activity of Factor X is the mechanism of action for many anticoagulants in use today. Warfarin, a synthetic derivative of coumarin, is the most widely used oral anticoagulant in the US. In some European countries, other coumarin derivatives (phenprocoumon and acenocoumarol) are used. These agents known as vitamin K antagonists (VKA), inhibit the vitamin K-dependent carboxylation of Factors II (prothrombin), VII, IX, X in the hepatocyte. This carboxylation after the translation is essential for the physiological activity.Heparin (unfractionated heparin) and its derivatives low molecular weight heparin (LMWH) bind to a plasma cofactor, antithrombin (AT) to inactivate several coagulation factors IIa, Xa, XIa and XIIa. The affinity of unfractionated heparin and the various LMWHs for Factor Xa varies considerably. The efficacy of heparin-based anticoagulants increases as selectivity for Factor Xa increases.
In medicine, confusion is the quality or state of being bewildered or unclear. The term "acute mental confusion" is often used interchangeably with delirium in the International Statistical Classification of Diseases and Related Health Problems and the Medical Subject Headings publications to describe the pathology. These refer to the loss of orientation, or the ability to place oneself correctly in the world by time, location and personal identity. Mental confusion is sometimes accompanied by disordered consciousness (the loss of linear thinking) and memory loss (the inability to correctly recall previous events or learn new material). Etymology
The word confusion derives from the Latin word, confundo, which means "confuse, mix, blend, pour together, disorder, embroil." Causes
Confusion may result from drug side effects or from a relatively sudden brain dysfunction. Acute confusion is often called delirium (or "acute confusional state"), although delirium often includes a much broader array of disorders than simple confusion. These disorders include the inability to focus attention; various impairments in awareness, and temporal or spatial dis-orientation. Mental confusion can result from chronic organic brain pathologies, such as dementia, as well. Other
Differential diagnosis
The most common causes of drug induced acute confusion are dopaminergic drugs (used for the treatment of Parkinsons disease), diuretics, tricyclic, tetracyclic antidepressants and benzodiazepines or alcohol. The elderly, and especially those with pre-existing dementia, are most at risk for drug induced acute confusional states. New research is finding a link between vitamin D deficiency and cognitive impairment (which includes "foggy brain").