Canadian Society for Medical Laboratory Science (CSMLS) Practice Exam

What is the primary purpose of performing a blood culture?

1. To detect abnormal blood cells

2. To identify pathogens causing infection

3. To measure glucose levels

4. To assess liver functions

The correct answer is: To identify pathogens causing infection

The primary purpose of performing a blood culture is to identify pathogens causing infection. Blood cultures are critical in diagnosing systemic infections such as bacteremia or fungemia. When a patient shows symptoms of an infection, a blood culture helps in isolating and identifying the specific microorganisms (like bacteria or fungi) present in the bloodstream. This information is crucial for determining the appropriate antimicrobial therapy and understanding the severity of the infection. In clinical settings, timely identification of the causative agent enhances treatment efficacy, minimizes the risk of complications, and helps to monitor the effectiveness of therapy. Consequently, this process is a fundamental step in managing infections effectively. Other options focus on different diagnostic purposes. For instance, detecting abnormal blood cells relates to hematology tests and assessing conditions like leukemias or anemias. Measuring glucose levels pertains to managing diabetes and other metabolic conditions, and assessing liver functions is relevant to evaluating liver diseases. Each of these tests serves distinct clinical objectives, but they do not align with the primary intent of blood cultures.