What is the gauge size for a 20g catheter in millimeters?

The gauge size for a 20-gauge catheter corresponds to a diameter of approximately 1.1 millimeters. In the system of gauge sizes, a larger numerical gauge size indicates a smaller diameter, and a 20-gauge is considered to be a relatively small catheter, commonly used for intravenous access. Understanding catheter gauge sizes and their corresponding diameters is essential for selecting the appropriate catheter for different clinical scenarios.

For example, a 20-gauge catheter is often chosen when blood transfusions or medication administration are needed, balancing the need for sufficient flow rate while minimizing patient discomfort and potential vessel trauma.

In contrast, other gauge sizes listed in the options correspond to different diameters: 1.3 mm would represent a smaller catheter (typically a lower gauge number), while 1.5 mm and 0.9 mm correspond to even different gauge sizes—indicating that 1.1 mm is indeed the correct measure for a 20-gauge catheter. Recognizing these measurements aids healthcare providers in making informed decisions regarding vascular access.