What is the preferred site for capillary puncture in adults and children?

The preferred site for capillary puncture in adults and children is the middle or ring finger of the non-dominant hand. This choice is based on several factors that ensure both accuracy and patient comfort during the procedure.

The middle and ring fingers have adequate blood supply and are typically less sensitive than the thumb, making them suitable for obtaining capillary blood specimens. Additionally, using the non-dominant hand helps to minimize discomfort and allows the dominant hand to remain free for other tasks or support during the procedure.

Capillary puncture aims to obtain a small sample of blood with minimal trauma to the surrounding tissues. Choosing the right finger site reduces the risk of injury to nerves or blood vessels, which can occur if the puncture is performed on more sensitive or overly used fingers like the thumb.

Other choices may not provide the same level of comfort or may increase the likelihood of complications. For example, puncturing the thumb can be problematic because it is often more sensitive and may be involved in multiple activities throughout the day, potentially leading to inaccurate results due to increased muscle activity or trauma. Similarly, opting for any finger on the dominant hand could similarly increase discomfort and disrupt typical hand function.

Thus, selecting the middle or ring finger of the non-d