Canadian Society for Medical Laboratory Science (CSMLS) Practice Exam

How should specimens for arterial blood gases determination be transported to the laboratory?

1. At body temperature

2. In a freezer

3. On ice

4. Stab cell amount

The correct answer is: On ice

Specimens for arterial blood gases (ABG) determination must be transported on ice to ensure the most accurate results. When blood samples are exposed to room temperature, the metabolism of the cells continues, which can affect the levels of carbon dioxide and oxygen in the sample. This cellular metabolism can lead to a decrease in pH, increased carbon dioxide levels, and decreased oxygen levels, resulting in potentially misleading test results. Transporting the specimens on ice slows the metabolic process significantly. This chilled environment helps preserve the sample's integrity by minimizing changes in gas tensions, ultimately allowing for a more reliable assessment of respiratory and metabolic function. Other transportation methods, such as at body temperature or in a freezer, are unsuitable because body temperature can still lead to metabolic activity that alters the sample, while freezing can cause hemolysis or the formation of ice crystals that compromise the quality of the sample and the reliability of the results. Therefore, keeping the specimens on ice is the best practice for accurate ABG analysis.