The effects on skin blood flow of immersing the ischemic legs of patients with peripheral arterial disease into artificially carbonated water

Abstract

It is known that carbon dioxide causes vasodilatation. Therefore, immersing the extremities into carbonated water would be expected to increase skin blood flow, given that carbon dioxide can permeate through the skin surface. We immersed the ischemic legs of patients with peripheral arterial disease (PAD) into water artificially carbonated by a new device. Sixteen Fontaine grade II PAD patients were randomly divided into two groups: eight patients whose legs were immersed into artificially carbonated water (CO₂ group), and eight patients whose legs were immersed into tap water as a control (CTL group). The water temperature was set at 35°C, and the immersion (10 min) was repeated daily for 3 weeks in both groups. During immersion, the average percent skin blood flow increase was larger in the CO₂ group than in the CTL group (426 vs. 173%, p < 0.001), and increased gradually with each immersion in the CO₂ group (272% at the first immersion, 343% after 2 weeks, and 359% after 3 weeks, p < 0.01). Leg symptoms at rest, such as a sensation of cold and/or numbness, were significantly alleviated in the CO₂ group compared to the CTL group (2.5 points, CO₂ group vs. 8.7 points, CTL group after 3-weeks based on a 10-point relative scale, p < 0.01). Immersion into artificially carbonated water appears to be a convenient treatment option for treating limb ischemia.