6-esr-bt-ct

Practical Physiology 6th. Lab

Erythrocyte .Sedimentation Rate .Bleeding time .Clotting time

[email protected]

Lab. no. 6: Erythrocyte Sedimentation Rate (ESR) (Westergren method)

Procedure: Under aseptic conditions withdraw (1.6 ml ) of blood from a vein and mix with (0.4 ml) of 3.8% sodium citrate as anticoagulant (4:1), suck this blood into a Westergren tube, adjust the top level at (0 mm) mark. Wipe the blood off its tip and set the tube in a vertical position in the Westergren rack. RBCs settle down leaving a column of clear plasma on the top. After exact one hour read the upper level of the RBC column. The result is expressed in mm/1st hr. hr [email protected]

Lab. no. 6: (ESR)

(Westergren method) Cont…..

-Normal ranges of ESR: Male 0 –15 mm/1st hr. Female 0 –20 mm/1st hr. ESR is i ncre ased p hysiolo gic ally during: 1. Menstrual period. 2. Pregnancy.

ES R has non-specific diagnostic value; that is a

rise in ESR indicates the presence of some organic disease. ES R estimation also has a prognostic value and a fall in ESR after treatment indicates good [email protected]

Lab. no. 6: Bleeding time (Dukeś method)

Procedure: • Clean a finger ball with spirit and with a sterile lancet give at least 2 mm deep prick. Note the time.

• Every 30 sec. blot off the drop of blood by a filter paper until no more blood appears on the puncture site. Note the time at which the bleeding has stopped.

[email protected]

Lab. no. 6: Bleeding time (illustration)

Cont…..

.Every 30 sec

Bleeding time test (Duke’s method) B.T =

no. of blots 2

= ? min.

-Normal bleeding time (B.T) = 3 – 6 min. [email protected]

Lab. no. 6: Bleeding time (Dukeś method)

Cont…..

Estimation of bleeding time is not a reliable test, because the results of this test would vary depending on the site and depth of the puncture. Moreover it is shortened in cold weather, due to capillary constriction, and reverse is the case in hot weather. -It is especially prolonged by lack of platelets (Thrombocytopaenia ). Events in haemostasis (Arrest of bleeding): 1- Vasoconstriction. 2- Platelet aggregation. 3- Formation of platelet plug. 4- Blood coagulation. [email protected]

Lab.no.6: Clotting time (capillary tube method)

Procedure: 6.Clean the finger with spirit and give a deep prick with a sterile lancet, squeeze the finger to obtain a large drop of blood. Note the time (T1). 7.Fill in two plain capillary tubes with blood. 8.After (2 min.), start breaking small pieces of one capillary tube every 30 sec. until a fibrin thread is seen in the interval between the 2 broken equivocal ends. Note the time (T2). 9.The interval between T1 and T2 is the clotting time. [email protected]

Lab.no.6: Clotting time (illustration) Fibrin thread

T2 1

2

3

4

5

6

7

8

.(Clotting time test (capillary tube method .Normal Clotting time (C.T) = 5 – 8 min.It is increased in [email protected]

[email protected]