Systemic and Local Effects of Warm Oxygen Exposure to the Lower Extremities in Healthy Volunteers.

INTRODUCTION: Warmth to the extremity is known to improve the cutaneous blood flow and tissue perfusion. Oxygen is essential for healing of chronic wounds. Topical oxygen therapy has become standard therapy in management of lower extremity wounds. A combination of local heat and oxygen is likely to be beneficial in many clinical scenarios of non-healing wounds without any systemic effects.

AIM: To evaluate the local and systemic effects of the exposure of extremity to warm oxygen in healthy volunteers.

MATERIALS AND METHODS: Thirty one volunteers were included in the study. The index foot was exposed to oxygen 7l/min, 93%-95% concentration at temperature of 43(o)C for 90 minutes with the device. The following parameters such as basal and periprocedural blood pressure, body temperature, heart rate, 24 lead ECG, temperatures at foot and plethysmographic waveforms from the index foot were measured. A NRS-11 questionnaire was asked to the patient to rate his or her pain from 0 to 10 and documented by health care worker at the end of the session.

RESULTS: The skin temperature of index foot reached to 34(o)C from 32.9(o)C, (p=0.011). The average pulse amplitude changed from 39.8 mV to 79.8 mV over the duration of the experiment (p< 0.001). Overall heart rate and core body temperature decreased and not much change in blood pressure.

CONCLUSION: The result of the study can be extrapolated to the healing of chronic non healing wounds using warm oxygen therapy. Further studies are required on patient population to prove benefits in clinical settings.