Purpose: We examined the effects of foot baths containing artificial carbon dioxide (CO₂) on peripheral circulation. Our goal was to obtain quantitative results bearing on the treatment and preservation of refractory leg ulcers and gangrene, which would occur in arteriosclerosis obliterans (ASO) and diabetic peripheral circulation disorders.
Procedures: The lower legs of six healthy volunteers were placed for 10min into a 42°C bath of 10l in which 45g of artificial CO₂ “BUB” was dissolved. A laser Doppler blood-flowmeter was firmly attached. The measurements of blood flow were taken before, during, and 5, 15, 25, and 35min after each subject took a foot bath. Next, in order to examine the effects of peripheral blood flow on the whole body during the foot baths, each laser Doppler blood-flowmeters was attached on the subject's right arm, 10cm above the wrist joint.
Results: The blood flow increased during the foot bath and decreased after the bath was removed; during in a 10min bath, the flow was 264±135 (%) (p<0.05) of the flow before the feet were placed into the bath. 5min after the bath was removed, the flow was 256±174 (%) of the original pre-bath rate. 15min later it was 146±60 (%), 25min later it was 112±23 (%), and 35min later it was 107±24 (%), as low as the flow before the feet were placed in the bath. The arm blood flow also increased during the foot bath and decreased after the bath was removed. During a 10min bath, the flow was 119±49 (%) of the rate before the feet were placed in the bath. 5min after the bath was removed, the flow was 120±66 (%) of the original pre-bath rate. 15min later it was 113±28 (%), 25min later it was 109±16 (%), and 35min later it was 95±14 (%), essentially the same as the flow before the feet were placed in the bath.
Discussion: Our work demonstrates an increase in blood flow, by 2.6X, by using a foot bath containing artificial CO₂. The increase was maintained for 5min after removed of the foot from the bath. However, the blood flow decreased 15min after the baths were removed. We hope that this simple and effective foot bath will be used both at home and elderly care service stations. Its use could see prevention from refractory leg ulcers or gangrene, particularly as average life span continues to increase in Japan.