Effect of enriched oxygen inhalation on lower limb skin temperatures in diabetic and healthy humans: a pilot study.

Introduction: Measurement of skin temperature with infrared thermometry has been utilised for assessing metabolic activity and may be useful in identifying patients with ulcers suitable for hyperbaric oxygen treatment and monitoring their treatment progress. Since oxygen promotes vasoconstriction in the peripheral circulation, we hypothesised that oxygen administration may lower skin temperature and complicate the interpretation of temperatures obtained. This pilot study investigated the effect of oxygen administration on lower limb skin temperature in healthy subjects and diabetic patients.

Methods: Volunteers were recruited from healthy staff members (n = 10) and from patients with diabetic foot ulcers (n = 10) at our facility. Foot skin surface temperatures were measured by infra-red thermometry while breathing three different concentrations of oxygen (21%, 50% and 100%).

Results: Skin temperature changes were observed with increasing partial pressure of oxygen in both groups. The mean (SD) foot temperatures of diabetic patients and healthy controls at air-breathing baseline were 30.1°C (3.6) versus 29.0°C (3.7) respectively, at FiO₂ 0.5 were 30.1°C (3.6) versus 28.5°C (4.1) and at FiO₂ 1.0 were 28.3°C (3.2) versus 29.2°C (4.3). None of these differences between groups were statistically significant.

Conclusions: Data from this small study may indicate a difference in thermal responses between healthy subjects and diabetic patients when inhaling oxygen; however, none of the results were statistically significant. Further investigations on a larger scale are warranted in order to draw firm conclusions.