The two most common problems encountered in samples to be evaluated for clinical chemistry are:

The two most common problems encountered in samples to be evaluated for clinical chemistry are:

• A. Coagulation and separation
• B. Dilution and concentration
• C. EDTA and heparin
• D. Hemolysis and Lipemia

Answer: (D)

Hemolysis and lipemia are the most impactful preanalytic problems in clinical chemistry because they directly disturb the sample in ways that many tests rely on. Hemolysis occurs when red blood cells break open, releasing hemoglobin and intracellular ions and enzymes into the serum or plasma. This can falsely raise substances like potassium and certain enzymes, and it also changes the sample’s color, which interferes with color-based assays. Lipemia, the presence of excess lipids, makes the sample appear milky and cloudy. That turbidity scatters light and can bias spectrophotometric measurements and other assays, leading to inaccurate results across a wide range of tests. While other issues—such as clotting problems or the use of certain anticoagulants—can affect specific tests, they don’t broadly compromise as many chemistry results as hemolysis and lipemia do. To reduce these problems, ensure proper venipuncture technique and gentle handling to minimize hemolysis, and obtain fasting samples when lipemia is likely, or apply appropriate methods if a lipemic sample must be tested.

Hemolysis and lipemia are the most impactful preanalytic problems in clinical chemistry because they directly disturb the sample in ways that many tests rely on. Hemolysis occurs when red blood cells break open, releasing hemoglobin and intracellular ions and enzymes into the serum or plasma. This can falsely raise substances like potassium and certain enzymes, and it also changes the sample’s color, which interferes with color-based assays. Lipemia, the presence of excess lipids, makes the sample appear milky and cloudy. That turbidity scatters light and can bias spectrophotometric measurements and other assays, leading to inaccurate results across a wide range of tests.

While other issues—such as clotting problems or the use of certain anticoagulants—can affect specific tests, they don’t broadly compromise as many chemistry results as hemolysis and lipemia do. To reduce these problems, ensure proper venipuncture technique and gentle handling to minimize hemolysis, and obtain fasting samples when lipemia is likely, or apply appropriate methods if a lipemic sample must be tested.