Bleeding time
You don't need to be Editor-In-Chief to add or edit content to WikiDoc. You can begin to add to or edit text on this WikiDoc page by clicking on the edit button at the top of this page. Next enter or edit the information that you would like to appear here. Once you are done editing, scroll down and click the Save page button at the bottom of the page.
|
WikiDoc Resources for Bleeding time | |
|
Articles | |
|---|---|
|
Most recent articles on Bleeding time Most cited articles on Bleeding time | |
|
Media | |
|
Powerpoint slides on Bleeding time | |
|
Evidence Based Medicine | |
|
Clinical Trials | |
|
Ongoing Trials on Bleeding time at Clinical Trials.gov Trial results on Bleeding time Clinical Trials on Bleeding time at Google
| |
|
Guidelines / Policies / Govt | |
|
US National Guidelines Clearinghouse on Bleeding time NICE Guidance on Bleeding time
| |
|
Books | |
|
News | |
|
Commentary | |
|
Definitions | |
|
Patient Resources / Community | |
|
Patient resources on Bleeding time Discussion groups on Bleeding time Patient Handouts on Bleeding time Directions to Hospitals Treating Bleeding time Risk calculators and risk factors for Bleeding time
| |
|
Healthcare Provider Resources | |
|
Causes & Risk Factors for Bleeding time | |
|
Continuing Medical Education (CME) | |
|
International | |
|
| |
|
Businness | |
|
Experimental / Informatics | |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Phone:617-525-6884
Please Take Over This Page and Apply to be Editor-In-Chief for this topic: There can be one or more than one Editor-In-Chief. You may also apply to be an Associate Editor-In-Chief of one of the subtopics below. Please mail us [2] to indicate your interest in serving either as an Editor-In-Chief of the entire topic or as an Associate Editor-In-Chief for a subtopic. Please be sure to attach your CV and or biographical sketch.
Overview
Bleeding time is a medical test done on someone to assess their platelet function.
It involves cutting the underside of the subject's forearm, in an area where there is no hair or visible veins. The cut is of a standardized width and depth, and is done quickly by an automatic device.
A blood pressure cuff is used above the wound, to maintain venous pressure at a special value. The time it takes for bleeding to stop (as thus the time it takes for a platelet plug to form) is measured. Cessation of bleeding can be determined by blotting away the blood every several seconds until the site looks 'glassy'.
Bleeding time is affected by platelet function, certain vascular disorders and von Willebrand Disease--not by other coagulation factors such as haemophilia. Diseases that cause prolonged bleeding time include thrombocytopenia and disseminated intravascular coagulation (DIC).
Aspirin and other cyclooxygenase inhibitors can prolong bleeding time significantly. While warfarin and heparin have their major effects on coagulation factors, an increased bleeding time is sometimes seen with use of these medications as well.
People with von Willebrand disease usually experience increased bleeding time, as von Willebrand factor is a platelet agglutination protein, but this is not considered an effective diagnostic test for this condition.
Normal values fall between 2 - 9 minutes depending on the method used.
Ivy method
The Ivy method is the traditional format for this test. In the Ivy method, a blood pressure cuff is placed on the upper arm and inflated to 40 mmHg. A lancet or scalpel blade is used to make a stab wound on the underside of the forearm.
A standard-sized cut is made (usually using an automatic blade.) The time from when the stab wound is made until all bleeding has stopped is measured and is called the bleeding time. Every 30 seconds, filter paper or a paper towel is used to draw off the blood.
The test is finished when bleeding has stopped completely.
Differential Diagnosis
Increased Bleeding Time
- Bernard-Soulier Disease
- Capillary wall abnormalities
- Disseminated Intravascular Coagulation (DIC)
- Drugs
- Glanzmann's Disease
- Thrombocytopenia
- Von Willenbrand's Disease
External links
MedlinePlus Medical Encyclopedia
Acknowledgement and Attribution Regarding Sources of Content
Some of the initial content on this page may be incorporated in part from copyleft sources in the public domain including wikis such as Wikipedia and AskDrWiki. Drug information for patients came from the The National Library of Medicine. Infectious disease information may have come from the Centers for Disease Control (CDC). Differential Diagnoses are drawn from clinicians as well as an amalgamation of 3 sources: 1.The Disease Database; 2. Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:3; 3. Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:7 .
