screening test of haemostatic system

7/29/2019 Screening Test of Haemostatic System

1/24

Screening tests of

Haemostatic system


2/24

1. Tourniquet Test

2. Bleeding Time

3. Bedside Clotting Time*


3/24

1.Tourniquet Test

= Capillary Resistance Test.

= Rumple Leede Test = Hesss Test


4/24

Principle :

This test measures the ability of the

capillaries to resist pressure.

In health, the capillaries of the arm will

resist a pressure of 100 mmHg.

If the capillaries can not resist, they will

break or rupture, tiny spot will then appear.

These spots are hemorrhages orptechiae.


5/24

Purpose

To evaluate the capillary resistance

Equipments Sphygmomanometer

Stethoscope

Stopwatch Markerpen


6/24

Procedure :

Draw with marker pen a circle (5 cm in

diameter) in the volar surface of the

forearm, about 5 cm below the elbow.

Put on a sphygmomanometer cuff in the

upper arm, determine a systolic and

diastolic pressures.


7/24

Procedure (cont.)

Then deflate to a pressure midway

between the systolic and diastolic

Leave the inflated cuff in place for 5

minutes.

Remove the cuff, let for 5 min.


8/24

Interpretation

Inspect the circle for ptechiae. Normal : < 10 ptechiae.

Discussion : (Tourniquet test)

- Explain about principle of the test!

- Positive results can be found in some

diseases, such as.

- What are further tests that should be

done?


9/24

BLEEDING TIME (Dukes Method)

Principle :

When the skin is incised, haemostatic

ability of the body (vascular and plateletsystem) will make platelet plug to stop the

bleeding.

The time needed until there's no bleed

seen, is Bleeding Time


10/24

Purpose :

To evaluate platelet and vascular ability inperforming platelet plug.

Equipments Blood lancet.

Cotton ball soaked in alcohol 70%.

Circular filter paper.

Stop watch


11/24

Procedure

The lobe of the ear is cleaned with alcohol 70%

and let dry

Use a blood lancet to puncture the earlobe with

depth of 3 mm. Start the stop watch.

At half minute intervals, gently apply edge of

small disc of filter paper to absorb the drop of

blood do not touch skin. Use a fresh edge of

filter paper disc for each half-minute blotting.


12/24

Interpretation

Time in minutes equals number of blots

divided by 2.

Reference value : 1-3 minutes.


13/24

Note :

The size of the blood spot about 1 cm in

diameter is desirable, but becomes larger in

some cases. However bleeding usually

stops for several minutes regardless of thesize.

Dont wipe off the blood. Gently touch. Note

so as not to touch the wound.


14/24

When the blood spot becomes 1 mm or smaller,

stop the stop watch.

When bleeding is not stop even for 10 min.,

discontinue the test. Indicate the result as 10

min or longer.

Make the patient cover the wound with a sterile

gauze for a while, hemostasis should be

confirmed, after which the patient may leave.


15/24

DISCUSSION : (Bleeding Time Duke`s)

When the result is > 3 min, it is said as..

What is the difference between Duke's

method and Ivy's method?

What further tests would you perform

when the result is prolonged?


16/24

BEDSIDE CLOTTING TIME

PRINCIPLE :

To record time interval since blood contact

with glass surface, until fibrin networkperformed at the room temperature.


17/24

Sample : Capillary blood

Equipments :

1. Clean, oil free, dry and smooth object glass2. Stop watch

3. Needle

4. Sterile blood lancet

5. Cotton ball soaked in alcohol 70 %.


18/24

PROCEDURE

1. Clean the finger tip with alcohol 70 %, let dry.2. Puncture with blood lancet, 3 mm in depth.

3. Wipe the blood drop with dry cotton.

4. Drop the next blood drop onto the object glass(4-5 mm in diameter) and start stopwatch

immediately as the blood touch glass surface.

5. Put the second drop beside the first one withsame size in diameter.


19/24

6. Watch the fibrin thread formed in the second

drop of blood by tilt it with a needle every 30sec

7. When the fibrin was performed, do the same

step to the first blood drop and stop thestopwatch if the fibrin was seen in the first drop

8. Record the time (in minute).


20/24

DISCUSSION : (Bedside clotting time)

What are the differences between this

method with Lee & White method?

Which is better, this method or Lee &

White method? Why?

In this method, can we assess vascular

function?


21/24

*** CLOT RETRACTION

Principle When whole blood is allowed to clot

spontaneously, the initial coagulum is

composed of all elements of the blood.With time, the coagulum reduces in mass,

and fluid serum is expressed from the clot,

and its volume stated in %. This is due toan action of platelets on the fibrin network

formation.


22/24

*** Sample : 5 ml blood obtained fromperipheral vein

Instruments :

1. A set of devices for drawing the blood

from peripheral vein

2. Centrifuge glass test tube

3. Wooden stick4. Centrifuge


23/24

***Procedure :

Obtained 5 mL of venous blood

Put off the needle and transfer blood intothe test tube. Put the tube on the rack.Place the wooden stick vertically on the

blood. Leave at room temperature for about 1.5

- 2 hours.

After 2 hours, separated blood clot fromthe test tubes wall carefully, placed theblood clot into another test tube.


24/24

***

5. Centrifuge the serum for about 5

min/1000 rpm.

6. Measure the amount (mL) of serum

which was performed and compute its

percentage

screening test of haemostatic system

Documents