Tourniquet test

Tourniquet Test

The tourniquet test, also known as the capillary fragility test or Rumpel-Leede test, is a clinical diagnostic tool used to assess capillary fragility and platelet function. It is often employed in the evaluation of dengue fever and other conditions that affect the vascular system.

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A positive tourniquet test showing petechiae formation.

Procedure

The tourniquet test is performed by applying a blood pressure cuff to the upper arm and inflating it to a point midway between the systolic and diastolic blood pressures. The cuff is maintained at this pressure for a specified period, usually 5 minutes. After the cuff is deflated, the forearm is examined for the appearance of petechiae, which are small red or purple spots caused by bleeding into the skin.

Interpretation

A positive tourniquet test is indicated by the presence of 10 or more petechiae per square inch on the forearm. This result suggests increased capillary fragility or a defect in platelet function. A positive test is commonly associated with conditions such as dengue fever, thrombocytopenia, and other coagulation disorders.

Clinical Significance

The tourniquet test is particularly useful in the diagnosis of dengue fever, where it is one of the criteria for clinical diagnosis according to the World Health Organization (WHO). In dengue, the test reflects the increased vascular permeability and capillary fragility that are characteristic of the disease.

Limitations

While the tourniquet test can provide valuable diagnostic information, it is not specific to any single condition and should be interpreted in the context of other clinical findings and laboratory tests. False positives can occur in individuals with naturally fragile capillaries or those taking medications that affect platelet function.

Related Pages

• Dengue fever
• Thrombocytopenia
• Coagulation disorders
• Petechiae