CMLA Phlebotomy 5

Question 1

Which complication is most likely if a phlebotomist accidentally punctures the brachial artery during venipuncture?

Accepted Answer

Rapid, bright red blood flow and pulsation in the tube

Answer

Arterial blood is oxygenated (bright red) and flows rapidly under higher pressure, often pulsating into the collection tube.

Question 2

The term 'sclerosed vein' refers to a vein that is:

Accepted Answer

Hardened and fibrotic due to repeated venipuncture or disease

Answer

Sclerosed veins are stiff and cord-like from scar tissue, making successful venipuncture difficult and increasing the risk of hematoma.

Question 3

Why must the first few drops of blood be discarded when performing a capillary puncture for most tests?

Accepted Answer

The first drops contain excess tissue fluid that can dilute and alter the specimen

Answer

The initial drops mix with interstitial fluid from tissue trauma, which can dilute analytes and affect test accuracy.

Question 4

Which gauge needle is most commonly used for routine adult venipuncture?

Accepted Answer

21 gauge

Answer

A 21-gauge needle provides adequate flow for evacuated tube collection without causing excessive hemolysis or vein trauma.

Question 5

A chain of custody procedure is required for specimens collected for:

Accepted Answer

Forensic drug testing and legal/employment toxicology screens

Answer

Chain of custody documents every person who handles a forensic specimen to ensure its integrity is legally defensible in court.

(CMLA) Certified Medical Laboratory Assistant Practice Test