Hematocrit hema

Question 1

Volume of packed red blood cells that occupies a given volume of
whole blood after centrifugation of a blood sample
Also known as ____ or ____
Reported either as ___,___,___,___

Answer 1

Hematocrit
- Packed Cell Volume (PCV) or Erythrocyte Volume Fraction (EVF)
-percentage(%), cell volume percent (CV%), volume percent (Vol%) or in liters per liter (L/L)

Question 2

Plasma

Answer 2

water, nutrients proteins hormones

Question 3

Buffy coat

Answer 3

wbc, platelets

Question 4

Hematocrit

Answer 4

RBC

Question 5

Normal blood

Answer 5

37-47% hct female
42-52% hct male

Question 6

depressed hct %

Answer 6

Anemia

Question 7

elevated hct %

Answer 7

Polycythemia

Question 8

HEMATOCRIT
DETERMINATION

Answer 8

Macro method ( Wintrobe method) & micro method (Adam’s Microhematocrit)

Question 9

Adam’s Microhematocrit method
Procedure:
1. Fill two plain capillary tubes approximately three-quarters (3/4) full with blood anticoagulated with ___
> 2/3 filled, ____, filled portion ___
Length:___
Bore: ___
____ - for blood collected on anticoagulated tube
____ - for blood from skin puncture

Answer 9

• EDTA/heparin
  -0.05 ml blood
• 5 cm
• 7-7.5 cm
• 1.2 mm
• Non-heparinized (blue ring) capillary tube
• Heparinized (red ring) capillary tube

Question 10

Seal the end of the tube with the colored ring using___
> Seal by placing the dry end into the tray with sealing compound at a __.
> Rotate the tube slightly and remove it from the tray
> The plug should be at least___ long

Answer 10

nonabsorbent sealing clay
90-degree angle
4 mm

Question 11

Balance the tubes in a
microhematocrit centrifuge with the clay ends facing ___ , touching the rubber gasket

Answer 11

outside away from the center

Question 12

Tighten the head cover on the
centrifuge and close the top. Centrifuge the tubes at ___ for ___.

Answer 12

10,000g to 15,000 g for 4-5 minutes

Question 13

Determine the hematocrit by using a ___

Answer 13

microhematocrit reading device

Question 14

The values of duplicate hematocrits
should agree within ___

Answer 14

1% (0.1 L/L)

Question 15

HCT Reference Values
Conventional Unit:

Answer 15

Male: 40-54%
Female: 35-49%

Question 16

HCT Reference Values
SI Unit:

Answer 16

Male: 0.40-0.54 L/L
Female: 0.35-0.49 L/L

Question 17

Estimation of __ and ___ is possible on the basis of the hematocrit value under normal circumstances.
1% hematocrit - ___ Hemoglobin or ___ RBC/cumm

Answer 17

hemoglobin and red blood cell count
- 0.34 g/dL
- 107,000

Question 18

INCREASED HCT

Answer 18

1. the specimen was not mixed properly
2. Insufficient centrifugation or a delay in reading results after
   centrifugation
3. The buffy coat of the specimen should not be included in the hematocrit reading because this falsely elevates the result
4. microhematocrit reader is
   not used properly
5. The fluid loss associated with dehydration causes a decrease in plasma volume and falsely increases the hematocrit reading

Question 19

DECREASED HCT

Answer 19

1. Improper sealing of the capillary tube as a result of leakage of blood during centrifugation
2. An increased concentration of anticoagulant (short draw in an
   evacuated tube)
3. the specimen was not mixed properly
4. microhematocrit reader is
   not used properly
5. A temporarily low hematocrit reading may result immediately after a blood loss because plasma is replaced faster than are the RBCs
6. Proper specimen collection is an important consideration. The
   introduction of interstitial fluid from a skin puncture or the improper flushing of an intravenous catheter causes decreased hematocrit readings

Question 20

Many disorders, such as __,__,__,__,__,___ may cause plasma to be trapped in the RBC layer even if the procedure is performed properly

Answer 20

sickle cell anemia, macrocytic anemias, hypochromic
anemias, spherocytosis, and thalassemia,

Question 21

____: amount of plasma that still remains in the RBC portion after the microhematocrit has been spun.

Answer 21

Trapped Plasma

Question 22

Trapping of the plasma causes the microhematocrit to be ___ to ____ higher than the value obtained using automated instruments that calculate the hematocrit and are unaffected by the trapped plasma

Answer 22

1% to 3% (0.01 to 0.03 L/L)

Question 23

Automated Methods
1
2

Answer 23

( Coulter Counter, Autoanalyzer)

Question 24

Hematocrit = __

Answer 24

RBC x MCV

Question 25

This method utilizes the Wintrobe
tube
Length:___
Bore: ___
Has 2 calibrations
0-10 (Red) is used for ___
10-0 (White) used for __
Anticoagulant of choice: __

Answer 25

Wintrobe Method
11.5 cm
3 mm
Erythrocyte Sedimentation Rate (ESR)
hematocrit
Double oxalate

Question 26

Procedure
1. Fill the Wintrobe tube with blood using a Pasteur pipette
2. Centrifuge the tube at___
3.Read the volume of packed red blood cells
4.Compute for the hematocrit level using the formula: ____

Answer 26

Wintrobe Method
3000 rpm for 30 minutes
Hematocrit = (height of packed RBC / height of whole blood used) x 100

Question 27

Rule of Three
> This rule only applies to specimens that have __,___

Answer 27

RBC x 3 = Hgb
Hgb x 3 = Hct +/-3
- normocytic normochromic
RBCs