Question

What is the clinical importance of estimating bleeding time and coagulation time? What are the normal levels of bleeding time and coagulation time of different species of animals?

Answer 1

See below.

Explanation:

The tests

Bleeding time is a measurement of the time it takes a person to stop bleeding.

Coagulation time is a measurement of the time it takes for a sample of blood to clot in vitro.

Clinical importance

Diseases that cause prolonged bleeding time include

• von Willebrand disease — a genetic disorder caused by a missing or defective clotting protein
• thrombocytopenia — a deficiency of blood platelets
• disseminated intravascular coagulation(DIC) — widespread formation of blood clots in the small blood vessels throughout the body
• Glanzmann's thrombasthenia — a genetic disorder in which the platelets have a deficient fibrinogen receptor
• hypofibrinogenemia — a partial deficiency of fibrinogen

Diseases that cause prolonged coagulation time include:

• hemophilia — a deficiency of blood clotting proteins
• hypoprothrombinemia — a deficiency of prothrombin
• afibrinogenemia — a lack of fibrinogen
• heparinemia — the presence of heparin in the blood stream

Normal Values

Numbers vary widely, but a normal range for bleeding time is 3 min to 9 min.

The normal ranges for clotting times are

`"Species"color(white)(m)"Time/min"`
`stackrel(————————)("Human" color(white)(mll) 8 - 15)`
`"Sheep"color(white)(mml)6 - 24`
`"Pig"color(white)(mmmll)2 - 5`
`"Rabbit"color(white)(mm)2 - 10`
`"Rat"color(white)(mmmll)1 - 6`