Technologist in Chemistry Flashcards

Which electrolyte abnormality is most immediately life-threatening and can cause cardiac arrest?

Answer: Hyperkalemia

Hyperkalemia (elevated potassium) can cause fatal cardiac arrhythmias and cardiac arrest.

What is the clinical significance of elevated troponin levels?

Answer: Myocardial injury or infarction

Cardiac troponin is a highly specific biomarker for myocardial injury and the gold standard for diagnosing acute myocardial infarction.

Which specimen handling error would falsely elevate serum potassium results?

Answer: Hemolysis of the specimen

Hemolysis releases intracellular potassium from red blood cells, which contain about 23 times more potassium than plasma.

What does HbA1c measure and over what time period does it reflect glucose control?

Answer: Glycated hemoglobin; past 2-3 months

HbA1c measures the percentage of hemoglobin with glucose attached, reflecting average glucose over 2-3 months (the RBC lifespan).

Which liver enzyme is most specific for liver damage?

Answer: ALT (alanine aminotransferase)

ALT is the most liver-specific enzyme because it is found predominantly in hepatocytes, unlike AST which is also found in heart, muscle, and kidneys.

What specimen type is required for a lipid panel, and what patient preparation is recommended?

Answer: Serum in a red or gold tube after 9-12 hours fasting

A lipid panel traditionally requires serum collected after 9-12 hours fasting for accurate triglyceride levels.