Capillary and Special Collections Flashcards

Which finger is generally preferred for capillary puncture in adults?

Answer: Middle or ring finger

The middle and ring fingers are preferred because they have adequate blood flow and fewer nerve endings compared to the index finger or thumb.

What is the maximum recommended depth for a lancet puncture on an infant's heel?

Answer: 2.0 mm

The maximum safe depth for infant heel puncture is 2.0 mm to avoid reaching the calcaneus bone and causing osteomyelitis.

Which of the following specimens is collected using a cold agglutinin test procedure?

Answer: Specimen kept at 37 degrees C during transport

Cold agglutinin specimens must be kept warm at 37 degrees C during collection and transport to prevent cold-reacting antibodies from attaching to red blood cells at lower temperatures.

When performing a capillary blood gas collection, which of the following is required?

Answer: Warming the site prior to collection

Warming the capillary puncture site increases arterial blood flow to the area, making the capillary blood more closely reflect arterial values.

What is the correct procedure when the first drop of blood appears after a capillary puncture?

Answer: Wipe it away with sterile gauze

The first drop of blood is wiped away because it contains tissue fluid that can dilute the sample and affect test results.

During a glucose tolerance test (GTT), what must the patient do between blood draws?

Answer: Remain fasting and avoid strenuous activity

Patients must remain fasting (except for water) and avoid strenuous activity during a GTT because eating or exercise can affect glucose metabolism and skew results.