Hemostasis Inr

Hemostasis Inr. Factor XI activated by factor XIIaIntroduction to Blood Coagulation The ability of the body to control the flow of blood following vascular injury is paramount to continued survival The process of blood clotting and then the subsequent dissolution of the clot following repair of the injured tissue is termed hemostasis Platelet Activation and von Willebrand Factor (vWF) In order for hemostasis to occur platelets must adhere to exposed collagen release the contents of their granules and aggregate Table of the Primary Coagulation Factors Factor Trivial Name(s) Pathway Characteristic Prekallikrein (PK) Fletcher factor Intrinsic Functions with HMWK and factor XII Functional Classification of Clotting Factors Zymogens of Serine Proteases Activities Prothrombin (factor II) modified by vitamin K to contain gla residues activated on surface of activated platelets by prothrombinase complex.

The deficiency in vitamin Kdependent clotting factors (II VII IX and X) in those with cirrhosis results in an elevated international normalized ratio (INR) Although an elevated INR is interpreted as indicating one who is at an increased risk for bleeding it is not the case for patients with cirrhosis and is not as reliable as in someone with normal liver function [ 8 ] Author Brisas Flores Hirsh D Trivedi Simon C Robson Alan BonderCited by Publish Year 2017.

Blood Clotting: International Normalised Ratio (INR) myVMC

CausesTreatmentDefinitionSignificancePathophysiologyResultsInteractionsOverviewUsageBenefitsPreparationRisksIssuesNormally clotting only occurs when there is blood loss from a damaged blood vessel However there are several conditions that can cause blood clots to form in the absence of active bleeding When this occurs a person may be at an increased risk of thromboembolic disease In thromboembolic disease fragments of blood clots dislodge and circulate in the blood potentially obstructing blood vessels in the lungs and causing pulmonary embolism or vessels in the heart and causing heart attack or in the brain and causing stroke These conditions are all potentially fatal Therefore when a person is at high risk of one of the above conditions (eg because they have had a stroke or heart attack previously) anticoagulants (medicines which thin the blood and reduce the formation of clots) are used to minimise the risk of blood clots forming People who require longterm anticoagulant therapy are usually given warfarin an anticoagulant that can be taken in the form of a tablet instead of injection This is often referred to as oral anticoagulant therapy The international normalised ratio (INR) is a laboratory measurement of how long it takes blood to form a clot It is used to determine the effects of oral anticoagulants on the clotting system The ISI is a numerical value representing the responsiveness of any given commercial system relative to the international standard It takes into account the variability in results obtained using different commercial systems in calculating the result In this way results from different laboratories and countries can be compared more readily We regularly monitor the INR of people using warfarin in order to balance the risk of excessive bleeding (when the INR is too high meaning that the blood is too thin) against the risk of clotting or thrombosis (when the INR is too low or the blood is too thick) INR values over 45 increase the risk of major haemorrhage (bleeding) and an INR less than 2 increases the risk of thromboembolism (formation of blood clots within the blood vessels) and associated conditions such as heart attack and stroke Evidence suggests that more frequent testing will result in more time within the desired INR target range For example studies suggest that the desired results are achieved 50% of the time with monthly monitoring compared to 85% of the time with weekly monitoring Many medications foods and even concurrent illness are known to interact with warfarin and therefore interfere with the INR These affect the way warfarin is processed by the body Therefore you should consult your doctor if you Portable devices introduced in the 1990s allow you your doctor or another health practitioner (eg pharmacist or nurse) to obtain blood test results on the spot using a drop of fingertip blood as the sample The blood drop is placed on a test strip which is inserted into the portable device so that the clotting time can be measured The result as an INR value is then displayed on the devices screen If the device is used for monitoring in a health facility a health practitioner (often a nurse) conducts the blood test and records the result on your behalf In consultation with the doctor prescribing warfarin or based on a computerised algorithm the health practitioner can notify you immediately if any dose adjustments are necessary Benefits have been associated with this testing method In particular obtaining on the spot results enables better management of oral anticoagulation therapy as dose adjustments can be made immediately and discussed with the health practitioner face to face rather than over the phone Some people also prefer not needing to have blood drawn from a vein using a needle with this method Selfmonitoring is considered the gold standard of care as it has been found that individuals using this method remain within therapeutic range over 70% of the time Selftesting has the advantage of being more convenient and making it easier for you to take the correct dose of warfarin at the correct time People who use this method are more likely to monitor their INR more frequently They are also less likely to experience blood clot or bleeding complications Compared to laboratory testing selfmonitoring and selfmanagement are associated with a 50% reduction in thromboembolic events such as stroke and heart attack an overall reduction in death from any cause and a small reduction in major bleeding These reductions may be the result of people who selftest spending more time within the therapeutic range due to more frequent monitoring and more timely dose adjustments On the spot results enable immediate adjustments to the warfarin dose It may also be particularly beneficial for individuals who need to travel long distances to attend a clinic for laboratory blood testing When a portable device is used for home monitoring you usually conduct the test yourself However in some countries health practitioners can visit you in your homes or aged care settings to conduct blood monitoring This enables you to have your INR monitored without the inconvenience of attending a healthcare facility There are however some limitations with this model of INR monitoring It can cause some individuals to become more anxious about their health and in these people without proper support and supervision from a health professional their INR regulation may be poorer Its also important to realise that selfmonitoring is not appropriate for or desirable to all people In one study 68% of people either could not or would not take part in selfmonitoring/selfmanagement of their INR Of those people who did agree and attempted INR selfmonitoring 249% were unable to complete the task The main reasons for this included physical limitations problems attending training sessions failing training assessments and problems with the device.

Hemostasis: Biochemistry of Blood Coagulation The Medical

The process of hemostasis involves four principal stages first the initiation and formation of the platelet plug (also called primary hemostasis) second the coagulation cascade a series of enzymatic actions on proteins leading to clot formation third its termination by antithrombotic control mechanisms and fourth the removal of the clot by fibrinolysis Author Demian Halperin Guido ReberCited by Publish Year 2007.

Hemostasis, bleeding and thrombosis in liver disease

The International Normalised Ratio (INR) is the PT ratio of a test sample compared to a normal PT (derived from the log mean normal prothrombin time (LMNPT) of 20 normal donors) corrected for the sensitivity of the Thromboplastin used in the test.