Which of the following actions is likely to cause an accidental arterial puncture during blood collection?

Probing to find a vein can lead to an accidental arterial puncture during blood collection because it involves repeatedly inserting and adjusting the needle within the vein. This action increases the risk of penetrating through the vein and into an adjacent artery, especially if the anatomy is not clearly understood or visible. Arteries are often located near veins, so if a practitioner is unsure of the precise location of the vein or if the vein is difficult to access, probing can inadvertently cause injury to an artery.

The other scenarios may contribute to various complications during blood collection, but they do not directly lead to the same risk of arterial puncture. For example, using a too-small needle can lead to difficulties in obtaining a blood sample, but it doesn't inherently increase the chances of puncturing an artery. Similarly, inserting the needle near the basilic vein may pose risks for nerve injury or hematoma formation but is not specifically associated with arterial puncture. Using a tightly applied tourniquet can complicate venous filling and may make veins more prominent, yet it doesn't inherently cause an arterial puncture. Understanding these nuances is essential in ensuring safe and effective blood collection practices.