Lec 2: Basic Methods 1 & 2

Question 1

A suspension of red cells, white cells, and platelets in plasma

Answer 1

Blood

Question 2

Blood clots once outside the body within ___.

Answer 2

5 to 8 minutes

Question 3

What is the most important part of specimen collection?

Answer 3

Patient and specimen identification

Question 4

What specimen is usually used for CBC, WBC count, and RBC count?

Answer 4

Whole blood

Question 5

What is the composition of the buffy coat?

Answer 5

White blood cells/leukocytes & platelets

Question 6

1. The blood collected for serum is allowed to clot undisturbed for about ___ (time) at ___ (temperature).
2. When serum is not tested within 30 minutes to 1 hour, store it at ___.
3. Delayed testing

Answer 6

1. 30 min to 1 hour at RT
2. 4° Celsius
3. • store at -20°C for up to 3 months
   • -40°C or lower for long term

Question 7

PRE-COLLECTION

1. Fasting time required when testing for FBS & cholesterol.
2. Effect of smoking
3. Effect of fast walking for 20 minutes
4. Effect of stress

Answer 7

1. • FBS: 6 hours
   • Cholesterol: 12 hours
2. Increases neutrophils
3. Increases platelet count
4. Increases WBC count

Question 8

Causes of misleading results in PRE-COLLECTION

Answer 8

• Meal within 2 hours
• smoking
• physical activity
• stress
• age, gender, and pregnancy

Question 9

Causes of misleading results DURING SPECIMEN COLLECTION

Answer 9

• Diurnal variants
• posture
• hemoconcentration
• excessive negative pressure

Question 10

Hemoconcentration occurs from prolonged tourniquet pressure which increases what substance?

Answer 10

Total CHON

Question 11

It only takes ___ (time) for the blood sample to NOT be used anymore.

Answer 11

2 hours

Question 12

What type of blood sample is necessary for most tests that require anticoagulation?

Answer 12

Venous blood

Question 13

[ TRUE or FALSE ]

Venous Blood

1. There is no variation in blood values if specimens are obtained from different veins.
2. Quite easy in children, obese, and patients in shock
3. You can draw blood from the same extremity that is being used for IV medication
4. Avoid prolonged stasis as it leads to hemoconcentration
5. It has a lengthy procedure and requires more preparation

Answer 13

1. TRUE
2. FALSE
3. FALSE
4. TRUE
5. TRUE

Question 14

[ TRUE or FALSE ]

Capillary Blood

1. Used only in infants less than 1 year old and when it is NOT possible to obtain venous blood
2. Greater likelihood of contamination
3. Carried out using a needle and a syringe

Answer 14

1. TRUE
2. TRUE
3. FALSE

Question 15

The release of hemoglobin from ruptured red cells into the plasma

Answer 15

Hemolysis

Question 16

1. It can suck blood by a predetermined volume of blood by vacuum
2. Usually used for pediatric patients and it uses butterfly wings with plastic tubing
3. It uses the barrel and plunger to control the vacuum

Answer 16

1. ETS
2. Butterfly infusion set
3. Syringe method

Question 17

These are tubes that are designed to fill with a predetermined volume of blood by vacuum

Answer 17

Evacuated collection tubes

Question 18

Tube color - additive - purpose

1. Yellow
2. light blue
3. gold/red
4. green
5. lavender
6. gray

Answer 18

1. Yellow — Sodium Polyanethol Sulfonate — Blood culture
2. light blue — sodium citrate
3. gold/red — none — serum separator
4. green — heparin — gel separator
5. lavender — EDTA
6. gray — sodium fluoride & potassium oxalate — glucose

Question 19

1. How long should the tourniquet be placed?
2. What happens if the tourniquet is placed longer than it should be?
3. It is the large, well anchored, and superficial vein
4. Enumerate the 3 main veins (from least preferred to most preferred)

Answer 19

1. One minute
2. Hemoconcentration
3. Median cubital vein
4. Basilic, cephalic, median

Question 20

1. The site selection of venous blood collection for children older than 2 years
2. The site selection of venous blood collection for children younger than 2 years
3. Can we use deep veins for infants?

Answer 20

1. Antecubital fossa
2. Dorsal hand vein
3. NO

Question 21

This blood is obtained at the time of of the birth of the baby

Answer 21

Cord Blood

Question 22

Cord blood

1. Blood collection method
2. From what vein do we aspirate blood?

Answer 22

1. Syringe
2. Umbilical vein

Question 23

Explain the external jugular vein procedure

Answer 23

• infant is wrapped in a sheet so the arms are immobilized
• infant is placed on the table with the head hanging over the edge
• the head is supported and turned to the side
• area is disinfected
• a butterfly infusion set is inserted into the external jugular vein
• after blood collection, area is treated

Question 24

external jugular vein procedure

1. Who performs the procedure?
2. What Blood collection method is used?

Answer 24

1. Doctor/physician
2. Butterfly mehod

Question 25

Is skin/dermal function a method of choice for collecting blood from infants and children **younger than 2 years**? Why?

Answer 25

Yes. - large and superficial veins are hard to locate - using deep veins is dangerous - should NOT draw excessive blood amount

Question 26

WHEN dermal punctures may be preferable over any puncture in Adult Patients

Answer 26

Patients: - burned, scarred - receiving chemo - with thrombotic tendencies - geriatric - with fragile veins - inaccessible veins - obese - apprehensive - requiring home glucose monitoring - point of care test

Question 27

Composition of capillary blood

Answer 27

- arterial blood - venous blood - small amounts of interstitial and intracellular fluids

Question 28

1. The incision depth should ____ in a device used to perform heel sticks 2. For sufficient blood flow, incision width should be ___. 3. The dermal subcutaneous junction depth

Answer 28

1. NOT exceed 2mm 2. 2.5mm 3. **newborn:** 0.35–1.6 mm below the skin **Adult:** 3mm

Question 29

**Laser Lancets** 1. Available for clinical and home use for ___ (px) 2. Penetration depth 3. Maximum volume collected

Answer 29

1. Adults, children over 5 years 2. 1–2mm 3. 100 uL

Question 30

1. Also known as microhematocrit tubes 2. Red band: 3. Blue band:

Answer 30

1. Capillary tube 2. Heparinized 3. Plain

Question 31

Heel puncture site

Answer 31

Medial and bilateral areas of the plantar

Question 32

[ TRUE or FALSE ] Bandages are not used for children younger than **one year old**

Answer 32

FALSE - 2 years old

Question 33

**DERMAL PUNCTURE** 1. Order of draw 2. Causes if hemolysis

Answer 33

1. - blood smear - platelet count - CBC (lavender) - plasma (green) - serum (red/gold) 2. - failure to wipe away the first drop of blood - milking - capturing of air bubbles

Question 34

Action of the following inhibitors/anticoagulants: 1. Sodium citrate 2. potassium salt of EDTA 3. double oxalate

Answer 34

1. Sodium citrate binds to calcium 2. Potassium salt chelates calcium 3. - Potassium oxalate shrinks the RBC - ammonium oxalate produces swelling of RBC