Dirty Wintrobe tubes or capillary pipets can decrease the rate.
Tubes should be placed free from vibration or disturbance.
d. Normal View.
Males: Zero to nine mm per hour.
Females: Zero to 20 mm per hour.
Children: Zero to 13 mm per hour.
DETERMINATION OF SEDIMENTATION RATE
a. Principle. Well-mixed, whole blood is diluted with 0.85 percent sodium
chloride placed in a Westergren pipet, and allowed to stand for exactly one hour. The
number of millimeters the red cells fall during this tie period constitutes the ESR result.
(1) Mix the whole blood and the anticoagulant by gently inverting the tube
several times or by placing on a rotator for two minutes.
Place 0.5 ml of 0.85 percent sodium chloride in a plain 13X 100 mm test
Add 2.0 ml of well-mixed whole blood to the test tube.
Mix the tube for two minutes.
Make certain that the Westergren ESR rack is exactly level.
(6) Fill the Westergren pipet to exactly the "0" mark, making certain there
are no air bubbles in the blood.
(7) Place the pipet in the rack. Be certain the pipet fits snugly and evenly
into the grooves provided for it.
Allow the pipet to stand for exactly 60 minutes.
(9) At the end of 60 minutes, record the number of millimeters that the red
cells have fallen. This result is the erythrocyte sedimentation rate in millimeters per
c. Sources of Error. See para 6-4c.