What is a distinguishing feature of tunneled catheters?

The distinguishing feature of tunneled catheters is that they are inserted completely under the skin. This design allows the catheter to have a secure exit site, reducing the risk of contamination and infection compared to non-tunneled catheters, which remain exposed. The tunneling involves placing the catheter through a subcutaneous tunnel to create a pathway that keeps the catheter discrete and less vulnerable to external elements. This characteristic not only helps in providing long-term access for patients who may require frequent blood draws or treatments, such as chemotherapy, but also enhances the patient's comfort and hygiene.

In contrast, other options refer to features that do not characterize tunneled catheters. For instance, they are not limited to short-term access; instead, they are designed for prolonged use. They are also suitable for both adults and children, not exclusively for any one group. Lastly, while tunneled catheters may have particular maintenance requirements, they typically do not require frequent needle changes as stand-alone aspects of their care like some other types of access devices do. Understanding these nuances helps clarify why being fully under the skin is a key feature of tunneled catheters.