Hematocrit Determination

Question 1

Volume of packed red blood cells that occupies a given volume of whole blood after centrifugation

Answer 1

Hematocrit

Question 2

Hematocrit is also known as? (2)

Answer 2

1. Packed Cell Volume
2. Erythrocyte Volume Fraction

Question 3

4 Ways to Report Hematocrit

Answer 3

1. Percentage
2. Cell Volume Percent
3. Volume Percent
4. Liters per Liter

Question 4

4 Components of Plasma

Answer 4

1. Water
2. Proteins
3. Nutrients
4. Hormones

Question 5

2 Components of Buffy Coat

Answer 5

1. WBCs
2. Platelets

Question 6

Normal Range of Hematocrit for Females?

Answer 6

35-49%

Question 7

Normal Range of Hematocrit for Males?

Answer 7

40-54%

Question 8

2 Methods of Hematocrit Determination

Answer 8

1. Microhematocrit
2. Macrohematocrit

Question 9

Method used to Microhematocrit?

Answer 9

Adam’s Microhematocrit Method

Question 10

Anticoagulant used for Microhematocrit Method (2)

Answer 10

1. Edta
2. Heparin

Question 11

Fill the capillary tubes with approximately how much blood?

Answer 11

3/4 full / 0.05 ml

Question 12

Length of Capillary Tubes

Answer 12

7-7.5 cm

Question 13

Bore size of Capillary Tubes

Answer 13

1.2 mm

Question 14

Capillary tube for anticoagulated blood

Answer 14

Blue / Non-Heparinized

Question 15

Capillary tube used for skin puncture

Answer 15

Red / Heparinized

Question 16

The seal of the capillary tubes should be atleast ___ long

Answer 16

4 mm

Question 17

While centrifuging the capillary tubes the clay ends should face?

Answer 17

Away from center

Question 18

centrifuge Microhematocrit tubes at ______ to _____ for ____ minutes

Answer 18

10k - 15k for 4-5 mins

Question 19

The value of duplicate hematocrits should agree within?

Answer 19

1% / 0.1 L/L

Question 20

1% hematocrit is equal to?

Answer 20

0.34 g/dl Hgb / 107k RBC/cumm

Question 21

What are the possible errors that causes Decreased Results? (6)

Answer 21

1. Improper Sealing of Capillary Tubes
2. Short draw in evacuated tube
3. Specimen was not mixed properly
4. Microhematocrit Reader is not used properly
5. Interstitial Fluid from skin puncture
6. Improper Flushing of intravenous catheter

Question 22

What are the possible errors that cause increase in hematocrit reading? (3)

Answer 22

1. Buffy coat is included
2. Dehydration
3. Reader is not used Properly

Question 23

5 Disorders that may cause plasma to be trapped in the RBC Layer

Answer 23

1. Sickle Cell Anemia
2. Thalassemia
3. Macrocytic Anemia
4. Spherocytosis
5. Hypochromic Anemia

Question 24

Trapping of plasma causes Microhematocrit to be ____ higher than the value obtained using automated instruments

Answer 24

1-3%

Question 25

Formula for Hematocrit Determination using Automated Methods

Answer 25

Hct = RBC x MCV

Question 26

2 Automated Methods for Hematocrit

Answer 26

1. Coulter Counter 2. Autoanalyzer

Question 27

What causes a decrease in plasma volume but increase in hematocrit reading?

Answer 27

Dehydration

Question 28

Method used for Macrohematocrit?

Answer 28

Wintrobe Method

Question 29

Length of Wintrobe Tube

Answer 29

11.5 cm

Question 30

Bore of Wintrobe Tube

Answer 30

3 mm

Question 31

Calibration used for Hematocrit Determination in Wintrobe Tube?

Answer 31

White / 10-0

Question 32

0-10 or Red Calibration of Wintrobe Tube is used for?

Answer 32

Erythrocyte Sedimentation Rate

Question 33

Anticoagulant of choice for Wintrobe Method?

Answer 33

Double Oxalate

Question 34

Centrifuge the Wintrobe Tube at ___ rpm for how many minutes?

Answer 34

3k for 30 mins

Question 35

Hematocrit Determination Formula for Wintrobe Method?

Answer 35

Hct = (Height of Packed RBC / Height of Whole Blood) x 100

Question 36

The Rule of 3 only applies to specimens that are?

Answer 36

Normocytic Normochromic RBCs