PACKED CELL
VOLUME
(or)HAEMATOCRIT
3/OCTOBER
/2017
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1
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/2017
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/2017
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/2017
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PACKED CELL VOLUME
(or)HAEMATOCRIT
 DEFINED AS THE VOLUME OF PACKED RED CELLS IN A GIVEN
SAMPLE OF BLOOD
 EXPRESSED AS A PERCENTAGE OF THE TOTAL VOLUME OF THE
BLOOD SAMPLE
 PACKING THE RED CELLS IS ACHIEVED BY CENTRIFUGING A
COLUMN OF BLOOD IN A GLASS TUBE
3/OCTOBER
/2017
G.VANI
8
PACKED CELL VOLUME
(or)HAEMATOCRIT
IN ORDER TO STANDARDIZE THE DEGREE OF PACKING DURING
CENTRIFUGATION,
IT IS NECESSARY TO HAVE
(1) OPTIMUM SPEED OF THE CENTRIFUGE
(11) OPTIMUM RADIUS OF THE CENTRIFUGE
(111)OPTIMUM DURATION OF CENTRIFUGING
3/OCTOBER
/2017
G.VANI
9
PACKED CELL VOLUME
(or)HAEMATOCRIT
DETERMINATION OF PCV
SIMPLE
VERY ACCURATE
METHOD OF ESTIMATING THE RED BLOOD CELL MASS IN THE
BLOOD OF TELLING WHETHER THE PATIENT IS NORMAL
ANAEMIC OR INCREASED RBC MASS(POLYCYTHEMIA)
3/OCTOBER
/2017
G.VANI
10
3/OCTOBER
/2017
G.VANI
11
3/OCTOBER
/2017
G.VANI
12
3/OCTOBER
/2017
G.VANI
13
3/OCTOBER
/2017
G.VANI
14
3/OCTOBER
/2017
G.VANI
15
3/OCTOBER
/2017
G.VANI
16
PACKED CELL VOLUME
(or)HAEMATOCRIT
METHODS OF ESTIMATION OF PCV
1.MACRO METHOD USING WINTROBE’S METHOD
2.MICROMETHOD USING CAPILLARY TUBE
3.AUTOMATED ANALYZER
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/2017
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17
PACKED CELL VOLUME
(or)HAEMATOCRIT
ANTICOAGULANTS USED :EDTA SAMPLE ,HEPARIN OR
DOUBLE OXALATE (THE SPECIMEN NEED NOT BE A FASTING
SAMPLE)
PRINCIPLE: WHEN ANTICOAGULATED BLOOD IS CENTRIFUGED
IN A HAEMATOCRIT TUBE AT HIGH SPEED,THE ERYTHROCYTES
SEDIMENT AT THE BOTTOM.THE RED CELL COLUMN IS CALLED
AS PACKED CELL VOLUME(OR) HEMATOCRIT (CELL VOLUME%)
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/2017
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REQUIREMENT
 SPECIMEN
 WINTROBE TUBE
 PASTEUR PIPETTE (OR ) A SYRINGE WITH NEEDLE
 CENTRIFUGE
WINTROBE TUBE
 SPECIALLY THICK WALLED GLASS TUBE
 GLASS TUBE 11 cm LONG
 INTERNAL DIAMETER 3 mm
 FLAT INNER BASE
 CALIBRATED
 HOLDS 1ml OF BLOOD
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/2017
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19
PACKED CELL VOLUME
(or)HAEMATOCRIT
PROCEDURE
MIX THE BLOOD SAMPLE CAREFULLY
LABEL A WINTROBE TUBE
FILL THE TUBE USING PASTEUR PIPETTE OR A SYRINGE UP TO
THE 100 MARK (USE A NEEDLE OF WIDE BORE TO PREVENT
MECHANICAL BREAK DOWN OF RED BLOOD CELLS)
AVOID TRAPPING OF AIR BUBBLES
PLACE THE TUBE IN A CENTRIFUGE CUP(USE ANOTHER EMPTY
WINTROBE TUBE FILLED WITH ANOTHER SPECIMEN)
CENTRIFUGE FOR 30 MINUTES AT 3000 RPM
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/2017
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20
• OBSERVATION
AFTER THE BLOOD IS CENTRIFUGED ,THREE DEFINITE LAYERS
CAN BE EASILY SEEN
UPPER MOST LAYERS – IS PLASMA,PALE YELLOW IN COLOUR

A THIN LAYER OF WBC AND PALTELETS WHICH IS JUST ABOVE
THE RBC,WHICH IS GREYISH IN COLOUR CALLED THE ‘BUFFY
COAT’(BUFFY LAYER -NORMALLY IT IS 0.5 TO 1mm.EACH 0.1ml =
1000 CELLS per cu mm (µl) approximately)
LOWER MOST LAYER OF RED CELLS ARE CLOSELY PACKED
TOGETHER
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/2017
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21
COLOR AND OPACITY OF PLASMA EXPECTED CLINICAL CONDITIONS
YELLOW JAUNDICE
MILKY LIPEMIA
CLOUDY MULTIPLE MYELOMA
REDDISH HEMOLYSIS
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/2017
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22
OTHER USE OF WINTROBE
TUBE
• USED FOR ESR ESTIMATION
• THE WESTERGREN METHOD IS PREFERRED AS IT IS MORE
ACCURATE
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23
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CAPILLARY TUBE
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/2017
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SPECIALLY CONSTRUCTED
CENTRIFUGE
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CAPILLARY TUBE AFTER
CENTRIFUGED
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MICROHEMATOCRIT READER
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TAKEN READING AFTER THE
CENTRIFUGE
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MICROHAEMATOCRIT METHOD
SPECIMENS
• EDTA OR OXALATED SPECIMEN(USE PLAIN CAPILLARY TUBES)
• CAPILLARY BLOOD(USE HEPARINIZED BLOOD)
PRINCIPLE
• BLOOD IS CENTRIFUGED IN A SEALED CAPILLARY TUBE AND PCV IS
DETERMINED BY, A SPECIAL HEMATOCRIT READER
REQUIREMENTS
• HEMATOCRIT CENTRIFUGE
• HEMATOCRIT READER
• CAPILLARY HEMATOCRIT TUBES
• SOFT WAX OR MODELLING CLAY
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/2017
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PROCEDURE
• DRAW THE SPECIMEN INTO AN APPROPRITATE CAPILLARY
TUBE
• FILL IN THE TUBE TO ABOUT 2/3 LENGTH
• SEAL BOTH THE ENDS OF THE TUBE WITH SOFT WAX OR
MODELLING CLAY
• IT IS PLUGGED TO A DEPTH OF ABOUT 1 CENTIMETER
• PLACE THE TUBE WITH ANOTHER SIMILAR TUBE IN THE
RADIAL GROOVES OF THE CENTRIFUGE HEAD EXACTLY
OPPOSITE TO EACH OTHER
• CLOSE THE CENTRIFUGE COVER AND CENTRIFUGE THE TUBES
AT HIGH SPEED 15,000 RPM FOR 5 MINUTES
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• REMOVE THE CAPILLARY TUBE
OBSERVATION
• IT WILL SHOW THREE LAYERS
• 1.CLEAR PLASMA AT THE TOP
• 2.WHITISH- BUFFYCOAT AT THE MIDDLE
• 3.COLUMN OF RED AT THE BOTTOM
READ PCV AS FOLLOWS
• HOLD THE TUBE AGAINST THE HEMATOCRIT SCALE SO THAT THE BOTTOM
OF THE COLUMN OF RED CELLS IS ALIGNED WITH HORIZONTAL ZERO LINE
THE HEIGHT OF CLAY
• MOVE THE TUBE ACROSS THE SCALE UNTIL THE LINE MARKED 1.0 PASSES
THROUGH THE TOP OF THE PLASMA COLUMN
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/2017
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33
• THE LINE THAT PASSES THROUGH THE TOP OR THE COLUMN
OF RED CELLS GIVES THE VALUE OF PCV
SOURCE OF ERROR
• HEMOYSZED SPECIME WILL YIELD FALSE LOW VALUES
• INADEQUATE MIXING OF BLOOD
• INCOMPETENESS OF PACKING MAY LEAD TO ERRONEOUS
RESULTS
• ERROR UNDER OPTIMUM CONDITIONS IS ONLY ± 1%
DISADVATAGES
• IT REQUIRES SPECIAL CENTRIFUGE
• DISPOSABLE CAPILLARY TUBES
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/2017
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ADVANTAGES
AMOUNT OF BLOOD REQUIRED IS VERY SMALL
EASILY BE OBTAINED FROM A FINGER PRICK
EDTA blood
TIME REQUIRED FOR CENTIFUGATION IS MUCH LESS
3/OCTOBER
/2017
G.VANI
35
CLINICAL CONDITIONS
FALL IN HEMATOCRIT
• ANEMIA
• HYDREMIA
• HEMORRHAGE
• CIRRHOSIS
• RENAL DISEASES
• NORMAL PREGNANCY
3/OCTOBER
/2017
G.VANI
36
INCREASEIN HEMATOCRIT
POLYCYTHEMIA
DEHYDRATION
EMPHYSEMA
CONGENITALHEARTDISEASE
EXTREMEPHYSICALEXERCISE
3/OCTOBER
/2017
G.VANI
37
PREVIOUS YEAR QUESTION
PAPER
PCV ( 2MARKS) APRIL 2017
PACKED CELL VOLUME (AUGUST 2010/SEPTEMBER 2014 ) 5
MARKS
WINTROBE,S TUBE (FEB/MARCH 2011) 3 MARKS
BUFFY COAT (AUGUST 2010) 3 MARKS
WHAT IS PCV? NAME THE INSTRUMENT ,ANTICOAGULANT
AND NORMAL VALUES? (SEP/OCT 2008)
PCV TUBE(WINTROB’S TUBE) 3 MARKS (AUGUST 2013)
3/OCTOBER
/2017
G.VANI
38
PACKED CELL VOLUME
NORMAL RANGE
MEN : 42-52 %
WOMEN :36-48%
LATE PREGNANCY : 23-37%
3/OCTOBER
/2017
G.VANI
39
3/OCTOBER
/2017
G.VANI
40

Packed cell volume