Bleeding time

The bleeding time is a parameter that is determined by the number and functionality of the thrombocytes and is therefore a global test for detecting thrombocyte disorders.

The determination of bleeding time is not very well standardized. The basic principle of the method is to measure the time after a defined stab wound, e.g. into the fingertip, until bleeding stops. The normal time is about two to five minutes. The bleeding time is extended at:

• Thrombopenia
• Platelet dysfunction
• von Willebrand syndrome
• Thrombasthenia
• severe fibrinogen deficiency
• high heparin concentrations

If plasmatic coagulation is normal and there is no thrombocytopenia, a prolonged bleeding time indicates disturbed platelet aggregation. In most cases, this is due to medication, less frequently to congenital thrombocyte defects or von Willebrand syndrome.

A variant for determining the bleeding time is the subaqueous bleeding time according to Marx: a puncture wound is made in the fingertip. The finger is immersed in a beaker with 37 degrees Celsius warm water. The time until the blood thread, which sinks to the ground, breaks off is the bleeding time. The normal time in this case is six minutes.

Another variant is the determination according to Ivy. Here the measurement is carried out after applying a congestion cuff with a pressure at 40 mmHg. The escaping blood is dabbed off until the bleeding stops.

Standard value: The standard value is up to 6 to 9 minutes

1. HA Neumann (2014) The coagulation system. ABW-Scientific Publisher GmbH Berlin