In which situation would a butterfly needle be most useful?

A butterfly needle is specifically designed for venipuncture in small or fragile veins, making it particularly useful in situations where standard needles may cause trauma or fail to obtain a sample. The design of the butterfly needle includes flexible "wings" that allow for better stabilization during the drawing process, which is crucial when working with smaller or more delicate veins that could easily collapse or roll away during insertion.

When considering other situations, a butterfly needle may not be the best choice. For blood donations, larger gauge needles are preferred to facilitate the rapid flow of blood from more substantial veins. Similarly, large veins typically accommodate standard or larger bore needles more effectively without the need for the specialized design of a butterfly needle. In routine blood tests, phlebotomy technicians often opt for standard needles unless there are specific concerns regarding the patient's vein condition. Therefore, using a butterfly needle is a strategic choice when handling small or fragile veins, ensuring both patient comfort and the integrity of the sample obtained.