American Medical Technologist (AMT) Practice Exam 2026 – All-in-One Resource to Guarantee Exam Success!

Using a small-bore needle with a large-volume tube for blood collection frequently leads to hemolysis, which is the breakdown of red blood cells. This complication occurs for several reasons. First, the small diameter of the needle can create high shear forces on the blood cells as the blood is drawn into the tube. The turbulence generated during this process can cause the red blood cells to rupture, leading to hemolysis.

In addition, when blood is drawn too quickly through a small-bore needle, it can result in increased pressure and further contribute to the rupture of cells. Hemolysis can cause inaccurate laboratory results, affecting tests that require intact red blood cells, such as certain electrolyte levels and hematology counts.

Other complications like air embolism, infection, and thrombosis, while possible in various contexts of blood collection, are less directly related to the specific combination of using a small-bore needle with a large-volume tube.