Canadian Society for Medical Laboratory Science (CSMLS) Practice Exam

What is the common cause of hemolysis in blood samples?

1. Poor technique during venipuncture

2. Using the wrong type of tube

3. Delayed transportation

4. Inadequate centrifugation

The correct answer is: Poor technique during venipuncture

The most common cause of hemolysis in blood samples is poor technique during venipuncture. Proper technique is essential to minimize trauma to the red blood cells. If the venipuncture is performed too forcefully or if a needle that is too small is used, it can cause mechanical damage to the red blood cells, leading to their rupture or hemolysis. This can significantly affect the quality of laboratory results, particularly in tests that measure analytes sensitive to hemolysis, such as potassium or liver enzymes. Other factors may contribute to hemolysis, but they are generally less frequent causes. Choosing the right tube is necessary for ensuring appropriate additive content but is typically not the leading cause. Delayed transportation of samples can lead to changes in sample integrity, though it is less directly linked to hemolysis compared to techniques used during blood draw. Inadequate centrifugation may lead to serum/plasma not being separated correctly, but it usually occurs after the initial sample collection and is therefore less commonly a cause of hemolysis itself.