Which capillary site should be avoided when performing a puncture?

When performing a capillary puncture, it is crucial to select a suitable site to ensure accurate and reliable test results while minimizing patient discomfort. Edematous sites, scarred tissue, and bruised tissue can all compromise the quality of the sample collected for several reasons.

Edematous sites are swollen areas of tissue that may contain excess fluid. This fluid can dilute the blood sample, leading to potentially inaccurate results, especially in tests that require precise measurements of certain blood components.

Scarred tissue can result from previous punctures or injuries, which may alter blood flow. Scar tissue can also make it more challenging to obtain a sufficient blood sample due to reduced vascularity, potentially leading to inadequate or erroneous results.

Bruised tissue indicates that there has been bleeding beneath the skin, which could affect the composition of the blood in that area. It may also be more painful for the patient and could result in further complications such as hematomas.

Thus, all these sites should be avoided when performing a capillary puncture to ensure the integrity of the sample and the well-being of the patient. This approach ensures that the collected specimens yield reliable laboratory results and improves the overall patient experience.