To obtain the best capillary specimen using the finger, align the puncture device perpendicular (horizontal) to the whorls of the fingerprint. This cross-cut of the fingerprint whorls
causes the blood to bead at the puncture site
, allowing the phlebotomist to efficiently collect the drops of blood into the container.
Why is it important to puncture across fingerprint lines and reach capillary beds?
This will provide the best
possible drop and blood flow
. If the cut is made along the fingerprint lines, the blood will follow the lines of the fingerprint and will not form the best drop for collection, therefore it should be avoided.
What happens if we puncture parallel to the fingerprint?
A puncture parallel to or along the lines of the fingerprint will
cause blood to run down the finger rather than form a rounded drop
, which makes collection difficult. … The index finger is more calloused and, therefore harder to penetrate.
Do not puncture parallel to the grooves of fingerprints Why?
The puncture should be made just off center and perpendicular to the fingerprint ridges. (A puncture parallel to the ridges tends to make the
blood run
down the ridges and hamper collection.)
What is the purpose of capillary puncture?
Capillary blood sampling is becoming a common
way to minimize the amount of blood drawn from a patient
. The 10 or 20 microliters can be used to look for anemia, check blood sugar or even to evaluate thyroid function. The procedure is easier and less painful than traditional venipuncture which draws blood from a vein.
Why is it important to wipe the first drop of blood?
The first drop of blood from a lancing site contains
a greater volume of platelets
, which could make the lancing site seal up before enough blood was obtained for the test, and the dual wipe ensured a longer, larger flow of blood.
What is the purpose of wiping away the first drop of blood during skin puncture?
Wipe away the first drop of blood
because it may be contaminated with tissue fluid or debris (sloughing skin)
. Avoid squeezing the finger or heel too tightly because this dilutes the specimen with tissue fluid (plasma) and increases the probability of haemolysis (60).
What is the most common location for a skin puncture?
The distal end of the third or fourth finger
is the most commonly used site. The very tip of the finger should not be punctured because there is a greater chance of puncturing bone as the bone is close to the skin surface.
Why do you warm a site for skin puncture?
Skin puncture blood is a mixture of undetermined proportions of blood from arterioles, venules, capillaries, and interstitial and intracellular fluids.
The arterial portion can be increased by warming the site prior to collection
. This increases the blood flow as much as sevenfold.
How do you puncture a finger for blood?
Hold the finger in an upward position and lance the palm-side surface of the finger with proper-size lancet (adult/child).
Press firmly on the finger when making the puncture
. Doing so will help you to obtain the amount of blood you need. Cap the Microtainer® and gently invert it 10 times to prevent clots from forming.
Why is it important to wipe the puncture site with alcohol beforehand quizlet?
Why is it important to wipe the puncture site with alcohol beforehand?
It kills microorganisms and minimizes the risk of infection
. … -Aseptic technique is used to remove microorganisms and prevent infection. What type of blood is collected during a skin puncture?
What is the order of draw?
- Blood Culture Tubes or Vials.
- Coagulation Tubes (Blue-Top Tubes)
- Serum Tubes without Clot Activator or Gel (Red-Top tubes)
- Serum Tubes with Clot Activator or Gel (Gold or Tiger Top Tubes)
- Heparin Tubes (Green-Top Tubes)
- EDTA Tubes (Lavender-Top Tubes)
What part of the finger should be punctured?
The puncture must be on
the palm-up surface of the distal segment (fingertip) of the middle or ring finger
(a). The puncture should be made across the fingerprint, not parallel to it (b). The puncture must be performed on the side of the fingertip where tissue depth is sufficient to prevent bone injury.
What finger is not allowed in capillary collection?
The thumb (1) is
to be avoided because it has a pulse. The index finger (2) tends to be more calloused, which would make collection of the specimen more difficult. This area is also more sensitive for the patient. The pinky finger (5) does not have sufficient tissue depth to prevent injury.
What is the ideal depth of skin puncture?
The lancet must make a sufficiently deep puncture to ensure an adequate flow of blood. A penetration depth of
1.85 to 2.25 mm
is recommended for adults, depending on the thickness of the skin. For children aged less than 8 years, the penetration depth should not exceed 1.5 mm.
Why is the order of collection so important?
Order of draw is
essential in avoiding cross contamination from additives of one tube to the next
. Cross contamination, depending on the tests ordered, could cause seriously erroneous results, improper patient treatment and possibly death. While most blood collections (straight venipuncture vs.
