Page 694 - Clinical Hematology_ Theory _ Procedures ( PDFDrive )

678 PART 8 ■ Fundamentals of Hematological Analysis

HEMATOLOGY PROCEDURES (continued)

se imente in a special tube that is place perpen icular in
Decreased a rack or 1 hour. T e clinical value o this proce ure is in

Reticulocytes Increased Reticulocytes the iagnosis an monitoring o in ammatory or in ectious

states.
Aplastic anemia Blood loss

Aplastic crises of Crisis associated with Specimen

hemolytic anemia hemolytic anemia Fresh anticoagulate bloo collecte in either so ium citrate

Chemotherapeutic Subsequent to treatment of or ED A may be use . So ium citrate is the pre erre anti-

or radiation-induced pernicious anemia, folic acid coagulant, an the specimen must f ll the entire tube—i an

hypoproliferation de ciency, or iron de ciency evacuate tube is use —to achieve the correct ratio o bloo

Pernicious anemia to anticoagulant. T e ratio is 4 vol o bloo to 1 vol o so ium
citrate. I ED A anticoagulant is use , it must be ilute to the
Decreased erythropoiesis
ratio o 4 vol o bloo to 1 vol o 0.9% so ium chlori e.

Sources of Error Bloo shoul be at room temperature for testing an shoul

A re ractile appearance o erythrocytes shoul not be con- be no more than 2 hours ol . I anticoagulate bloo is re rig-
erate , the test must be set up within 6 hours. Hemolyze
use with reticulocytes. Re ractile bo ies are ue to poor specimens cannot be use .

rying owing to moisture in the air. Filtration o the stain is

essential because precipitate can resemble a reticulocyte. Reagents, Supplies, and Equipment

Erythrocyte inclusions shoul not be mistaken or reticu- 1. Westergren pipettes.

locytes. Howell-Jolly bo ies appear as one or sometimes two, 2. Vertical rack: this special rack is equippe with a leveling

eep-purple, ense structures. Heinz bo ies stain a light blue- bubble evice to ensure that the tubes are hel in a verti-

green an are usually present at the e ge o the erythrocyte. cal position within 1 hour. T e f ttings on the rack shoul

Pappenheimer bo ies are more o en con use with reticulo- be clean an uncracke to prevent leakage o the ilute

cytes an are the most i cult to istinguish. T ese purple- bloo .

staining iron eposits generally appear as several granules in

a small cluster. I Pappenheimer bo ies are suspecte , stain Procedure

with Wright-Giemsa to veri y their presence. 1. Mix the bloo citrate or bloo -ED A-saline mixture

Falsely ecrease reticulocyte counts can result rom thoroughly.

un erstaining the bloo with new methylene blue. High glu- 2. Aspirate a bubble- ree specimen into a clean an ry

cose levels can also cause reticulocytes to stain poorly. Westergren pipette. Fill to the zero mark. Do not pipette

by mouth.
Clinical Applications 3. Place the pipette into the vertical rack at 20°C to 25°C in

Selecte Disor ers Associate with Abnormal Results an area ree rom vibrations, ra s, an irect sunlight.

4. A er 60 minutes, rea the istance in millimeters rom

BIBLIOGRAPHY the bottom o the plasma meniscus to the top o the se i-
mente erythrocytes.

Provi e on this book’s companion Web site at http://thepoint. 5. Recor the value as millimeters in 1 hour.

lww.com/ urgeon6e.
Reporting Results

Te re erence value o this test varies epen ing on age. In per-
SEDIMENTATION RATE OF ERYTHROCYTES: sons younger than 50 years o age, the average re erence values

WESTERGREN METHOD
are up to 10 mm/h in males an 13 mm/h in emales. For per-
T e Westergren metho has been selecte as the metho o sons ol er than 50 years o age, average re erence values are up

choice by the CLSI. to 13 mm/h in males an up to 20 mm/h in emales.

Principle Procedure Notes

Te erythrocyte se imentation rate (ESR), also calle the se Sources of Error

rate, measures the rate o settling o erythrocytes in ilute Numerous sources o error have been cite or the ESR proce-

human plasma. T is phenomenon epen s on an interrela- ure. T e age o the specimen is important, the test shoul be

tionship o variables, such as the plasma protein composition, per orme at 20°C to 25°C, an the bloo shoul be at room

the concentration o erythrocytes, an the shape o the eryth- temperature. Other sources o error inclu e incorrect ratios o

rocytes. T e ESR value is etermine by measuring the is- bloo an anticoagulant, bubbles in the Westergren tube, an

tance rom the sur ace meniscus to the top o the erythrocyte tilting o the ESR tube. ilting o the tube accelerates the all o