Measurements of Endothelial Function by Means of Peripheral Arterial Tonometry in Diabetic Foot Ulcer Patients Undergoing Hyperbaric Oxygen Therapy.

Measurement and monitoring of endothelial function can be used for prediction of outcome in acute, severe disease. Diabetic patients have a poorer peripheral vascular function measured by peripheral arterial tonometry (PAT) as compared to normals, but the effect of hyperbaric oxygen therapy (HBOT) on endothelial function in these patients is unknown. Measurement of PAT in patients with diabetic foot ulcers undergoing HBOT, may help to improve treatment and changes in the reactive hyperemic index (RHI) might correlate with wound healing in these patients.

Peripheral arterial tonometer (PAT) has been shown to be an easy, fast and standardized method for measuring the peripheral arterial endothelial function. The method is also operator-independent and has a high reproducibility.

The PAT apparatus (ENDOPAT) measures the post-ischemic response to a five-minute blood flow occlusion of the upper arm, and the relationship between the pre-and post-ischemic pulse amplitude is expressed as a reactive hyperemic index (RHI). The normal RHI in young healthy persons is more than 2, while in critically ill patients and patients with diabetes, hypertension or heart disease it is significantly decreased.

The study aims to test whether or not patients treated with HBOT for diabetic foot ulcers will demonstrate an improvement of the endothelial function in the peripheral vessels, i.e. an increase in RHI measured by the PAT. Similarly, essential mediators of angiogenesis and nitric oxide bioavailability will be measured in peripheral blood taken during the PAT measurements which will be performed at the time of inclusion, before HBOT and subsequently for each 10th HBOT session.