Question 37

The needle gauge that corresponds to the smallest lumen is 27.

The gauge system for needles states that as the gauge number increases, the diameter of the lumen decreases. Therefore, a gauge of 27 indicates the smallest lumen among the provided options.

A) 13

Option A is incorrect because a 13 gauge needle is one of the largest gauges listed. It has a larger lumen compared to the other options, making it unsuitable for identifying the smallest lumen.

B) 18

Option B is also incorrect as an 18 gauge needle is larger than both the 20 and 27 gauge needles. It has a significant lumen size which does not align with the requirement for the smallest lumen.

C) 20

Option C is not correct since a 20 gauge needle still has a larger lumen than a 27 gauge needle. While it is smaller than 18 and 13 gauges, it does not represent the smallest lumen among the choices provided.

D) 27

Option D is correct because a 27 gauge needle has the smallest lumen among the options listed. It is the highest gauge number provided, which indicates a narrower diameter compared to all other choices.

Conclusion

The 27 gauge needle is definitively the smallest in terms of lumen size due to its high gauge number, which signifies a narrower diameter. In contrast, the other options (13, 18, and 20) represent larger gauges with wider lumens, disqualifying them from being the correct answer.