Week 2 Lab: Specimen Collection (Skin Puncture)

Question 1

a technique used to obtain blood specimen when venipuncture or other collection are not appropriate

Answer 1

Skin Puncture

Question 2

Blood sample collected in skin puncture is a mixture of?

Answer 2

1. Capillary blood
2. Arterial blood
3. Venous blood

Question 3

Sites of Skin Puncture?

Answer 3

1. Finger (middle or ring): lateral palmar surface perpendicular to the finger.
2. Earlobe: less free nerve ending, hence less pain and less tissue.
3. < 1 y/o: lateral portion of the plantar surface of the foot.

Question 4

Sites to avoid in skin puncture?

Answer 4

❖ Inflamed and pallor areas
❖ Cold and cyanotic areas
❖ Congested and edematous
❖ Scarred and heavily calloused areas

Question 5

Advantages of Skin Puncture using the Finger?

Answer 5

❖ Easily accessible to the operator
❖ Easy to manipulate
❖ Ideal for peripheral blood smears

Question 6

Disadvantages of Skin Puncture?

Answer 6

❖ Less amount of blood can be obtained
❖ Additional and repeated test cannot be done
❖ Blood obtained by skin puncture hemolyzes easily

Question 7

Depth for skin puncture?

Answer 7

2-3 mm

Question 8

Lancets used for heel puncture in full term newborn must not exceed _________ in length.

Answer 8

2-4 mm

Question 9

Step 1 in skin puncture?

Answer 9

Select the puncture site and warm the puncture site.

Question 10

Step 2 in skin puncture?

Answer 10

Cleanse the puncture site with 70% alcohol using concentric circles.

Question 11

Step 3 in skin puncture?

Answer 11

Grasp the finger and make a quick prick with the use of sterile lancet.

Question 12

Step 4 in skin puncture?

Answer 12

Using sterile dry gauze, wipe away the first drop of blood.

Question 13

Step 5 in skin puncture?

Answer 13

Obtain drops of blood for the desired examination.

Question 14

Step 6 in skin puncture?

Answer 14

Place cotton pad on the puncture site.

Question 15

Step 7 in skin puncture?

Answer 15

Instruct the patient to elevate the puncture site and apply pressure until bleeding has stopped.

Question 16

Order of Draw for Skin Puncture?

Answer 16

1. Tube for blood gas analysis
2. Slides, unless made from specimen in the EDTA (ethylenediaminetetraacetic acid) micro collection tube
3. EDTA micro collection tube
4. Other micro collection tubes with anticoagulants
5. Serum micro collection tubes

Question 17

Which governing body recommends the order of draw for skin puncture?

Answer 17

CLSI (Clinical & Laboratory Standards Institute)