Which of the following needles has the widest lumen?

Thegaugeof a needle refers to its diameter, with a lower gauge number indicating a larger diameter. Therefore, a19 gauge needlehas the widest lumen among the options given. It is commonly used for rapid blood transfusions or for drawing viscous fluids.

21 gauge: Smaller lumen than 19 gauge.

22 gauge: Smaller lumen than 21 gauge.

26 gauge: Smallest lumen of the options listed.