What is hemolysis, and what are common causes during collection?

• A. The rupture of red cells; caused by a small-gauge needle, excessive turnover, vigorous mixing, or drawing through IV lines.
• B. The clumping of platelets; caused by improper labeling.
• C. The formation of fibrin clots; caused by cold temperature.
• D. The dilution of plasma; caused by IV fluids.

Answer: (A)

Hemolysis is the rupture of red blood cells, releasing hemoglobin into the plasma and often giving the serum a pink or red tint. During collection, mechanical factors can cause this damage. A needle that is too small creates high shear forces as blood is drawn, increasing the risk of red cell rupture. Drawing the sample with excessive force or transferring it too aggressively can physically break cells. Vigorous mixing or shaking of the specimen, or over-inverting the tube, can also damage red cells. Drawing through an IV line introduces fluids or meds and additional shear, which can contribute to hemolysis as the sample passes into the collection tube. These mechanical causes distinguish hemolysis from other issues like platelet clumping, clot formation, or plasma dilution, which involve different processes.