Capillary Fragility Test (Tourniquet Test - Rumple Leede Method)

Prothrombin Time (PT) Test

• The prothrombin time (PT) test is used to monitor the extrinsic and common coagulation pathways.
• The PT test especially monitors the factor VII.
• Factor VII is initiated by tissue thromboplastin in the PT test.
• Thrombin converts fibrinogen into fibrin in the PT test.

Activated Partial Thromboplastin Time (aPTT)

• The aPTT is a measure of the intrinsic and common coagulation pathways.

Anticoagulant Therapy

• The PT test is used to measure the effect of anticoagulant therapy.

Tourniquet Test (Rumple Leede Method)

• The tourniquet test is used to assess capillary fragility.
• The test involves inflating a blood pressure cuff to midway between the systolic and diastolic pressures for 5-10 minutes.
• The number of petechiae (small hemorrhages) that appear on the forearm indicates capillary fragility.
• '4+' petechiae indicate severe capillary fragility.
• Petechiae formation during the tourniquet test indicates increased capillary fragility.
• A positive tourniquet test indicates increased capillary fragility.
• There is an inverse relationship between platelet count and capillary fragility based on the tourniquet test.

Blood Pressure Cuff Test

• The purpose of examining the forearm, hands, and fingers for petechiae after the blood pressure cuff test is to assess capillary fragility.

Clot Retraction Test (Macfarlane Method)

• A normal clot retraction time is associated with a condition like idiopathic thrombocytopenic purpura.
• A small clot with increased red cell fallout is observed in conditions like thrombocytopenia.
• A small and ragged clot appearance indicates a defect in platelet function.
• A high red cell count within the clot can lead to a limited degree of clot retraction.
• Normal clot retraction requires platelet aggregation, thromboxane A2, and a stable clot structure.