Needle gauge

Needle Gauge

A needle gauge is a measure used to determine the size of a medical needle. The term "gauge" refers to the diameter of the needle's lumen, or inner opening. The gauge number of a needle is inversely proportional to its diameter; a smaller gauge number indicates a larger diameter, and vice versa.

History

The needle gauge system was first established in the 19th century by the Stubs Iron Wire Gauge system, a standard wire gauge system used in the United Kingdom. This system was later adopted by the medical community for use in sizing medical needles.

Measurement

The gauge of a needle is determined by the diameter of its lumen. This diameter is measured in millimeters. The gauge number is inversely proportional to the diameter of the needle; a smaller gauge number indicates a larger diameter, and vice versa. For example, a 16-gauge needle has a larger diameter than a 25-gauge needle.

Usage

Needle gauges are used in a variety of medical procedures, including intravenous therapy, blood transfusion, and vaccination. The gauge of the needle used depends on the viscosity of the fluid being injected or withdrawn and the size of the vessel into which it is being injected.

Common Sizes

Common needle gauge sizes used in medicine include 16, 18, 20, 22, and 25. Larger gauge numbers (smaller diameters) are typically used for procedures that require the injection of medication into small vessels, such as in pediatric patients or for intradermal injections. Smaller gauge numbers (larger diameters) are typically used for procedures that require the withdrawal of blood or the injection of viscous fluids.

See Also

• Hypodermic needle
• Syringe
• Catheter
• Intravenous therapy
• Blood transfusion