Why should you avoid drawing from a hematoma?

Drawing blood from a hematoma should be avoided primarily because it can lead to inaccurate test results and patient discomfort. A hematoma is a localized collection of blood outside of blood vessels, usually resulting from bleeding that has occurred due to trauma to the blood vessels. When a blood sample is drawn from a hematoma, the blood is not drawn from a healthy vein, which means that the sample may contain altered components or concentrations that do not accurately reflect the patient’s true physiological state.

In addition, drawing blood from a site with a hematoma can be painful and uncomfortable for the patient, as the site is already compromised and may be sensitive. The presence of the hematoma can also make it difficult to properly visualize or access the vein, potentially complicating the blood draw process. These factors emphasize the importance of selecting a site that is free from complications like hematomas when performing venipuncture.