Page 695 - Clinical Hematology_ Theory _ Procedures ( PDFDrive )

CHAPTER 32 ■ Laboratory Manual: Manual Procedures in Hematology 679

HEMATOLOGY PROCEDURES (continued)

erythrocytes, an an angle o even 3 egrees rom the vertical 3. Place the tip o the pipette (f lle with bloo ) into the

can accelerate se imentation by as much as 30%. Wintrobe tube until the tip touches the bottom o the tube.

4. Gently begin to press the pipette bulb an slowly move
Clinical Applications the pipette tip up rom the bottom o the tube. Continuous

he ESR is irectly proportional to the weight o the pressure must be kept on the pipette bulb while the pipette

cell aggregate an inversely proportional to the sur ace tip is moved up from the bottom of the tube. T e pipette

area. Microcytes se iment more slowly than macrocytes. tip must be in continuous motion to avoi intro ucing air

Erythrocytes with abnormal or irregular shapes, such as bubbles into the column o bloo .

sickle cells or spherocytes, hin er rouleaux ormation an 5. T e Wintrobe tube must be f lle to the zero mark.

lower the ESR. T e removal o f brinogen by ef brination 6. Place the tube into a Wintrobe tube hol er that has been

also pro uces a ecrease ESR. a juste to a per ectly level position.

An increase ESR value can be seen owing to various 7. Allow the tube to stan or 1 hour at room temperature in

abnormal bloo con itions: rouleaux, increase f brinogen a ra - ree room.

levels, a relative increase o plasma globulins cause by the 8. Rea the tube rom the bottom o the plasma meniscus to

loss o plasma albumin, an an absolute increase o plasma the top o the se imente erythrocytes. Each line on the

globulins. Clinical con itions associate with increase tube represents 1 mm.

ESR values inclu e anemia, in ections, in ammation, tis-

sue necrosis (such as myocar ial in arction), pregnancy, an Reporting Results

some types o hemolytic anemia. T e patient’s value is reporte in millimeters per hour. T e

re erence value is 0 to 20 mm/h or women an 0 to 9 mm/h

or men.
BIBLIOGRAPHY

Procedure Notes

Provi e on this book’s companion Web site at http://thepoint. One o the major rawbacks o this proce ure is that the 100-

lww.com/ urgeon6e.
mm tube length an the narrow bore o the tube limit rea ings

in excess o 60 mm/h. Care must be taken to avoi intro ucing
SEDIMENTATION RATE OF ERYTHROCYTES: air bubbles into the column an to f ll the tube to the zero mark.

WINTROBE METHOD

Sources of Error
Principle

See Principle at the Westergren Metho (above) or etails. Falsely increased results can be pro uce by

1. Positioning the tube at an incline rather than in a vertical
Specimen position

Fresh bloo collecte in ED A anticoagulant may be use . A 2. Allowing the tube to stan or longer than 1 hour

minimum o 2 mL o whole bloo is nee e . T e specimen 3. A room temperature above normal

must be well mixe , an the proce ure must be per orme 4. Falsely decreased results can be pro uce by

within 2 hours o bloo collection. 5. An improper concentration o anticoagulant-whole bloo

ratio
Reagents, Supplies, and Equipment

1. Wintrobe se rate tubes: these tubes are available in either 6. Anticoagulate bloo that is more than 2 hours ol
7. Allowing the tube to stan or less than 1 hour
reusable glass or isposable orm. Depen ing on the type 8. Re rigerate bloo or a ecrease room temperature

o Wintrobe rack use , the choice o tube inclu es gra u-

ate or plain. Clinical Applications

2. Wintrobe se imentation rack (gra uate or plain). Re er to the Westergren Metho above.

3. Pasteur pipette (long-tippe ) an rubber pipette bulb.

Procedure BIBLIOGRAPHY

1. Gently an thoroughly mix the anticoagulate bloo .

2. Draw as much bloo as possible into the Pasteur pipette Provi e on this book’s companion Web site at http://thepoint.

with the attache pipette bulb. lww.com/ urgeon6e.