ASCP (American Society for Clinical Pathology) Phlebotomy Technician Certification Practice Exam

When arm veins are not suitable for venipuncture, the preferred alternative sites are generally the veins located on the dorsal side of the hand or wrist. These veins tend to be more accessible and can often accommodate the necessary blood collection when other areas, like the arm veins, cannot be used due to conditions such as scarring, difficulty finding veins, or medical considerations such as a risk of lymphedema.

The dorsal side of the hand and wrist has a good network of superficial veins that are easier to locate and access compared to deeper or more difficult sites. Additionally, using these areas can minimize discomfort for the patient and allow for a successful collection.

In contrast, the other potential sites have their limitations; for example, the forearm may have its own issues with accessibility or patient comfort. Similarly, while the neck and the dorsal side of the foot could theoretically be used, they are less commonly preferred due to risks associated with those areas, such as proximity to major structures in the neck or the nature of veins in the foot that may not provide as straightforward access.