Nevertheless, the Marx 20/10 protocol has now been studied and found to be effective with randomised prospective studies in at least 3 areas of head and neck post-radiation surgery, bone graft reconstruction, soft tissue vascular flaps and tooth removal. Therefore, it is presently the definitive protocol whenever any elective surgery or wounding is performed within irradiated tissues. Transcutaneous pulse oximetry is a simple, reliable, non-invasive diagnostic technique that provides an objective assessment of local tissue oxygenation. It can be used for serial assessment of the soft tissue envelope surrounding problem wounds. Uses of transcutaneous pulse oximetry in the problem wound includes the assessment of healing potential, selection of amputation level and patient selection for hyperbaric medicine.