A tourniquet test (also known as a Rumpel-Leede capillary-fragility test or simply a capillary fragility test) determines
capillary
A capillary is a small blood vessel from 5 to 10 micrometres (μm) in diameter. Capillaries are composed of only the tunica intima, consisting of a thin wall of simple squamous endothelial cells. They are the smallest blood vessels in the body: ...
fragility. It is a clinical
diagnostic
Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine " cause and effect". In systems engine ...
method to determine a patient's
haemorrhagic tendency. It assesses fragility of capillary walls and is used to identify
thrombocytopenia
Thrombocytopenia is a condition characterized by abnormally low levels of platelets, also known as thrombocytes, in the blood. It is the most common coagulation disorder among intensive care patients and is seen in a fifth of medical patients a ...
(a reduced
platelet
Platelets, also called thrombocytes (from Greek θρόμβος, "clot" and κύτος, "cell"), are a component of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping, thereby i ...
count).
The test is part of the
WHO algorithm for diagnosis of
dengue fever
Dengue fever is a mosquito-borne tropical disease caused by the dengue virus. Symptoms typically begin three to fourteen days after infection. These may include a high fever, headache, vomiting, muscle and joint pains, and a characteristic ...
.
A
blood pressure cuff
A sphygmomanometer ( ), a blood pressure monitor, or blood pressure gauge, is a device used to measure blood pressure, composed of an inflatable cuff to collapse and then release the artery under the cuff in a controlled manner, and a mercury ...
is applied and inflated to the midpoint between the
systolic and
diastolic blood pressure
Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressur ...
s for five minutes. The test is positive if there are more than 10 to 20
petechiae
A petechia () is a small red or purple spot (≤4 mm in diameter) that can appear on the skin, conjunctiva, retina, and mucous membranes which is caused by haemorrhage of capillaries. The word is derived from Italian , 'freckle,' of obscure origi ...
per square inch.
Limitations
Some studies have shown that the tourniquet test may not have high specificity. Interfering factors with this test are women who are premenstrual, postmenstrual and not taking hormones, or those with sun damaged skin, since all will have increased capillary fragility. However many other studies have shown that the tourniquet test has good specificity but a low sensitivity. Therefore, its use as a diagnostic test for dengue is questioned as people who have a negative test may still have dengue. It is no longer used as a classification test for dengue haemorraghic fever in the lates
WHO guidance
See also
*
Hess test
The Hess test or Rumpel-Leede test is a medical test used to assess capillary fragility. It is also called the Tourniquet test.
To perform the test, pressure is applied to the forearm with a blood pressure cuff inflated to between systolic and d ...
References
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Physical examination
Medical tests