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47 terms

Phlebotomy Chapter 10 MTC 110 Dermal Puncture

Dermal Puncture
ancillary blood glucose test
bedside test to determine blood glucose level, performed by dermal puncture
bleeding time test
a test that measures the length of time required for bleeding to stop after an incision is made.
bilirubin, uric acid, phosphorus, and potassium
heel bone
capillary tubes (microhematocrit tubes)
small plastic tubes used primarily for hematocrit tests.
liquid for dilution
microcollection tubes
small tube used to collect dermal puncture samples; "bullet"
micropipets (Caraway or Natelson pipets)
large glass capillary tube
painful inflammation of the bone or cartilage
bone infection
venous thrombosis
formation of a blood clot within a vein
arterial blood gas-tests that determine the concentrations of oxygen and carbon dioxide in arterial blood and the pH of the blood.
bleeding time
bilirubin, uric acid, phosphorus, and potassium
complete blood count
Occupational Safety and Health Administration
Name two sites commonly used for adult capillary collection.
Sites commonly used for adult capillary collection are the palmar surface of the distal segments of the third and fourth fingers or the big toe
Explain why it is best to perform a dermal puncture rather than a venipuncture on children
Dermal puncture is preferred in children because the young child's smaller veins and lower volume make standard venipuncture difficult and potentially dangerous.
List six types of patients, other than infants, in who dermal puncture may be advisable.
Dermal puncture may be advisable for patients undergoing frequent glucose monitoring or frequent blood tests, obese patients, patients with IV's in place, geriatric patient, patients with burns or scars, patients at risk for venous thrombosis restrained patients, and patients at risk anemia, hemorrhage, infection, organ or tissue damage, arteriospasm, or cardiac
Explain why, in a dermal puncture, the first drop of blood is wiped away with clean gauze.
The first drop blood in a dermal punctures is wiped away with clean gauze to prevent contaminating the sample with tissue fluid.
Describe what micropipets are used for.
Micropipets are typically used for the collection of samples for arterial blood gas determination
Describe the Unopette system and what it is used for.
The Unopette system allows you to collect a very small blood sample, which is diluted to the correct volume for analysis in the Unopette reservoir. The system includes a capillary pipet in a holder, a pipet shield, and a sealed reservoir containing diluent. This system is useful for CBC tests when a large sample is not needed for other tests.
What can be used to stimulate blood flow to the capillaries?
Warm washcloths or heel warmers can be used to stimulate blood flow to the capillaries
List six specific areas of the skin to avoid when performing a capillary stick.
Specific areas of the skin to avoid when performing a capillary stick include areas with scars, cuts, bruises, rashes, or edema, and callused, burned, bluish, and infected areas, as well as previous puncture sites.
At what age are heel sticks preferred to finger sticks?
Heel sticks are preferred to finger sticks in children under the age of 1 year.
List four reasons why alcohol must air-dry before a capillary stick.
Unless alcohol air dries before a capillary stick, stinging, hemolysis, and contamination can occur. Alcohol also can interfere with the formation of rounded drops of blood on the skin surface.
Explain why povidone-iodine should not be used for capillary collection procedures.
Povidone-iodine may elevate test results for bilirubin, uric acid, phosphorus, and potassium, and therefore is not recommended for use with dermal puncture
Which fingers are acceptable to use for dermal puncture.
The third and fourth fingers are acceptable to use for dermal punctures.
Describe the order of collection for a dermal puncture.
The order of collection for a dermal puncture is: (1) blood smears; (2) platelet counts, CBCs, and other hematology tests; (3) other tests
Explain the purpose of the bleeding time test.
The bleeding time test measures the length of time required for bleeding to stop after an incision is made. It helps assess the overall integrity of primary hemostasis, involving the vascular system and platelet function
Why should bandages not be placed on young children following a dermal puncture?
Small children may remove bandages and choke on them; therefore, it is not recommended that bandages be used on children younger than 2 years.
Dermal punctures are performed on:
Which of the following has a higher value in capillary blood as opposed to venous blood?
A red-banded microhematocrit tube contains which anticoagulant?
The Unopette system can be used for which kind of tests?
An infant heel-warming device should be applied for approximately:
3 to 5 minutes
The depth of a heel puncture should be more than:
2.0 mm
Which finger is most used for capillary collection?
In performing a dermal puncture, the puncture should be:
perpendicular to the whorls of the fingerprint
The location for heel sticks is the:
medial or lateral borders of the plantar surface.
In a dermal puncture, which test is collected first?
Blood smear
Which test cannot be collected by dermal punctures?
blood cultures
Which medication does not interfere with the bleeding time test?
At what level does the blood pressure cuff remain during a bleeding time test?
40 mm Hg
A normal bleeding time result is:
2 to 10 minutes
How frequently is the blood wicked during a bleeding time test?
every 30 seconds