clotting time test is important before any operation of the body part.
- Introduction of clotting time
- Principle
- Method
- Normal Range
- Specimen
- Requirement
- Procedure
- Additional information
Introduction of clotting time
This method is generally useful in severe clotting disorders.
Principle
Blood is collected in a capillary tube after a finger prick and the stopwatch is started. The formation of fibrin string is noted by breaking the capillary tube at regular intervals. The time is noted at the first appearance of the fibrin string.
Method
- There are two methods used for the estimation of clotting time.
- Capillary method
- Lee and white method
- But In this page discuss about capillary Method
Normal Range
4 to 9 minute .
Specimen
Capillary blood.
Table of Contents
Requirement
1 Sterile lancet
2 Capillary tubes (1.5 mm diameter and 10 to 15 cm length)
3 Cotton
4 Spirit or 70% alcohol
5 Stopwatch
Procedure
- By using a piece of Cotton apply spririt or 70%alcohol To The patient’s fingertip.
- Make a deep (1 mm) incision with a sterile lancet and start the stopwatch.
- Wipe off the first blood drop and collect blood in the capillary up to 2/3 of its length.
- After every half minute, break off about 1 cm of the capillary to find out whether the fibrin string has formed.
- After every half minute, break off about 1 cm of the capillary to find out whether the fibrin string has formed.
Additional information
- Lee-White method is more reliable than the capillary method. Hence, the capillary method should be used, when venous blood can not be obtained.
- The capillary method for clotting time can be advantageously combined with the bleeding time test
Clinical significance
- deficiency of vitamin k
- deficiency of prothrombin and hemophilia
