<unk>  <unk>  or TcPO2) is a non-invasive method of measuring the<unk>  level of the tissue below the skin. Since<unk>  is carried by the blood,<unk>  can be used as an indirect measure of blood flow to the tissue. Since blood flow is important for wound healing,<unk>  is often used to gauge the ability of tissue to effectively heal. To perform the test, one set of electrodes are placed on viable tissue (e.g. the chest) as a control and a second set is placed around the tissue in question (e.g. legs or feet). The electrodes may mildly heat the skin to increase blood flow into the area.<unk>  may also be given to the patient to see if that increases<unk>  levels in the tissue. The test takes about 45 minutes. Results are reported either as the absolute values of the tissue in question (in mmHg) or as a ratio of the tissue in question to the control tissue. The normal<unk>  tension in the foot is approximately 60 mmHg, and the normal chest/foot ratio is approximately 0.9. Many factors can limit the accuracy of the test including edema, temperature, inflammation, medications, and stress. In addition for the<unk>  to be normal, all parts of the<unk> ation pathway must be functioning: the lungs must be able to<unk> ate the blood, the heart must be able to pump the blood, and a patent artery must be able to carry blood to the skin. Without comorbitities, wounds are thought to be able to heal if the<unk>  tension is >40 mmHg. In the presence of comorbities, such as diabetes or edema, a higher value is likely needed. Patients with<unk>  tensions <20 mmHg are likely to need revascularization to promote adequate wound healing. The required<unk>  level for adequate wound healing, however, remains controversial.
Transcutaneous oxygen measurement
Arterial blood gas test
Respiratory pressure meter
Hyperoxia test
Pulse oximetry
Hemoximetry
Blood gas test
Structured light plethysmography