American Society for Clinical Pathology (ASCP) Histotechnician Certification Practice Exam

When collecting a sample from a patient with difficult-to-palpate veins, which method is most effective?

1. Butterfly needle

2. Syringe

3. Vacutainer

4. Capillary tube

The correct answer is: Syringe

When collecting a sample from a patient with difficult-to-palpate veins, using a syringe can be the most effective method. A syringe allows for greater control over the vacuum applied to the vein. This is particularly useful in situations where veins are hard to locate or when the veins are smaller or more fragile. The ability to draw blood slowly and steadily helps to minimize the risk of collapsing the vein during the procedure, which can often happen with traditional blood draw methods that use a vacuum tube like a Vacutainer. In addition, when using a syringe, a smaller gauge needle can be employed, which is less likely to cause discomfort or complications compared to larger gauge needles used with other methods. This control can significantly help in obtaining blood from difficult veins, as it reduces trauma and enhances the likelihood of a successful draw. While other methods such as using a butterfly needle can also be effective, they typically rely on a consistent vacuum provided by the collection device, which may not be ideal for challenging vein situations. A Vacutainer, while convenient for general blood draws, may not provide the same level of control in delicate situations. Capillary tubes are suitable for different types of sample collection, particularly for quite small blood volumes, but they are not designed for venip