Research for carbon dioxide bathing. III. Basic points for the artificial CO2-bathing and on the effect of CO2 concentration released in the air / 日本温泉気候物理医学会雑誌

It has been well recognized that no known method can produce as strong or as effective a bath as can be given with natural waters.<br>The method of bubbling gas through the bath water is thought to be almost entirely ineffective; the solubility of CO₂-gas in water at 40°C is about 10%, but is much further enhanced about 50% by bubbling through an airstone, making fine bubbles.<br>Tablet form of the CO₂-bath preparation, made from bicarbonate and succinic acid, produces fine CO₂ bubbles so that about 80% of water solubility at 40°C can be obtained.<br>A CO₂-bath preparation, 50g tablet, can produce 100ppm in maximum concentration in a bath of 150 liter at 40°C, maintaining the level of more than 60ppm for 2 hours.<br>In order for the safety to estimate the escaped CO₂, a large quantity of the CO₂-bath preparation, 20 and 50 tablets, was used in a relatively air tight room; CO₂ concentration reached the maximum level of 1.9 and 6.6% respectively with a tendency of rapid falling, so that the critical complications could rarely be happened.

Research for Carbon Dioxide Bathing / 日本温泉気候物理医学会雑誌

It was found that no effect of increase in dermal blood flow depended solely on HCO₃^- or CO₃^2-, but on CO₂ gas dissolved in water.<br>The artificial CO₂ bath was prepared with sodium bicarbonate and citric acid, mixing simply in plain water at 38-40°C.<br>Thermal efficacy was confirmed by a rise in temperature of oral, finger tip and forehead respectively, and by a high transepidermal water loss (TWL) in consequence of increase in dermal blood flow, compared to a plain bathing.<br>A remarkable effect in artificial CO₂ bathing of 400-800ppm has been well-known clinically, however, a substantial increase in dermal blood flow has observed with artificial CO₂-bathing of 59.8ppm or greater in this study, so that a CO₂-bathing using the preparation would be popularized.

Research for Carbon Dioxide Bathing / 日本温泉気候物理医学会雑誌

Increase in dermal blood flow by the artificial CO₂-bathing was confirmed by means of a Thermocouple flow meter and by a Laser doppler velocimeter.<br>The artificial CO₂-bath was prepared with 50g tablet, made from sodium bicarbonate and succinic acid, putting simply in plain water at 38°C.<br>Dermal blood flow was increased nearly 5-fold by the simple bathing, and was further enhanced 1.3-fold by the artificial CO₂-bathing.<br>It has been definitely shown by the artificial CO₂-bathing that an increase in oral, finger tip, and forehead temperature and transepidermal water loss is significant compared to the plain bathing, so that the thermal effect equivalent to carbon-dioxated spring will be obtained.