5. Capillary and Heel punctures

What is capillary puncture also known as?

Dermal puncture or skin puncture.

What is the preferred method for obtaining blood from newborns for screening?

Capillary puncture.

When should you consider using a capillary puncture instead of venipuncture?

When access to venipuncture sites may be difficult, such as in obese or geriatric patients.

What type of blood is collected through capillary puncture?

A mixture of arterial and venous blood.

Which analytes are noted to have higher concentrations in capillary blood?

Glucose, hemoglobin, potassium.

What safety features do automatic lancet devices have?

Retractable blades and locks to prevent accidental sticks.

What are microsample containers used for?

Collection of capillary blood and typically contain additives.

What color indicates a tube for hematology tests?

Pink or lavender.

For serum chemistry tests, what tube color is used?

Red or gold.

What should be avoided when selecting a puncture site?

Callused, scarred, burned, or infected skin.

What is the maximum depth for a heel puncture in infants?

2.0 mm.

Why is it important to clean the puncture site with alcohol?

To prevent contamination of the sample with tissue fluid.

What is the role of warming the site before puncture?

To help with blood flow.

Why should the first drop of blood be wiped away?

To prevent contamination with tissue fluid.

How long should pressure be applied after making a puncture?

2 seconds.

What is a key step in preparing to collect a capillary blood sample?

Keep the finger or heel in a downward position to enhance blood flow.

What should not be done while collecting the sample with a microtainer?

Do not scrape the skin.

What must be done immediately after the sample is collected?

Put the lid on the microtainer and invert it.

How is the order of draw for capillary samples determined?

Purple top first, followed by light/dark green, then red/gold top.

What should you do to prevent hemolysis when collecting samples?

Avoid scraping the skin with the container.

What is crucial about the timing of filling the tube after puncturing?

It must be filled within 2 minutes to avoid contamination.

Why should excessive tissue fluid be avoided in samples?

It can lead to contamination and clot formation.

How should the device be aligned when making a puncture?

Across the fingerprint ridges or heel lines.

What can indicate a sample is contaminated?

Excessive tissue fluid present in the tube.

What steps should you take after collecting the sample?

Apply pressure, clean the area, and dispose of equipment properly.

What are capillary tubes primarily used for?

Collection of capillary blood gas samples.

What is a major limitation of capillary puncture in certain patients?

Risk of venous thrombosis.

What is the recommended puncture depth for premature babies?

0.65 to 0.85 mm.

Can the fingertip of patients older than 1 year be used for capillary puncture?

Yes, specifically the palmar surface.

What should be done if the puncture site comes into contact with other surfaces?

Re-clean the site.

How should the blood drop be collected?

Lightly touch the microtainer scoop to the blood drop.

What can happen if the tube is overfilled?

It may indicate improper blood to additive ratio.

What is the significance of labeling the sharps container?

To comply with facility procedures for safety.

What can be used to enhance blood flow during a capillary puncture?

Gentle massage of the finger proximal to the puncture site.

What should be avoided on the earlobes during capillary puncture?

They should never be used as a puncture site.

What materials are typically included in the equipment for capillary puncture?

Lancets, microsample containers, alcohol pads, gauze, etc.

What is the consequence of puncturing too deeply?

Contact with the underlying bone can cause serious injury.

What types of blood tests can capillary punctures be used for?

Neonatal bilirubin tests and glucometer testing.

What aids in the collection of capillary blood in microsample containers?

A fitted plastic capillary tube inside the container.

How should used lancets be disposed of?

In a sharps container.

What features might differ in automatic puncture devices?

Depth options and how they are activated.

Why is it important to notify lab personnel about capillary samples?

To ensure correct interpretation of test results.

What is the purpose of using warming devices when performing a puncture?

To increase blood flow and facilitate sample collection.