Final answer:
Sites that may disqualify for capillary puncture include those with edema, scarring or thickened skin, infection or inflammation, visible sores, a previous mastectomy on the same side, and sites with a vascular shunt or cannula, as these conditions can affect the safety and accuracy of the procedure.
Step-by-step explanation:
A site may be disqualified for capillary puncture for several reasons, which include the presence of physical conditions or complications that could interfere with the safety or accuracy of the procedure. Some reasons include edema, which is the swelling of tissue due to excess fluid that can dilute the blood sample; scarring or thickening of the skin, making puncture difficult; infection or inflammation at the puncture site, which could lead to contamination or further complication; visible infection or open wounds, which carry a high risk of infection transfer; or a previous mastectomy on the side considered for puncture as lymphocytosis can affect blood flow and sample validity.
Additionally, areas with a vascular shunt or cannula for dialysis should not be used, as puncturing these could cause complications. Each of these conditions could potentially compromise test results or pose a risk to the patient's health, leading to their disqualification as sites for capillary blood collection.