Actual changes in tissue partial pressures of each gas and tissue perfusion with serial artificial CO₂ bathing were evaluated by means of medical mass spectrometry using 5 rabbits.
An artificial CO₂ bath was prepared by adding “BUB”-KAO, a 50g sodium hydrogencarbonate and succinic acid tablet producing fine CO₂ bubbles in water of constant temperature 20-litre tub at 36-37°C.
Regional tissue perfusion volume was determined on the basis of a clearance curve for Argon tissue partial pressure which was monitored by an on-line computer system with mass spectrometry.
Increase in subcutaneous tissue PCO₂ changed from 27% to 10%, and in PO₂ from 12% to 5% on average by serial bathing every day for 4 weeks, on the other hand tissue perfusion volume was increased in 3 out of 5 cases; from 20.85±3.56 (X±SE) ml/100g/min, SD=6.71, p<0.05 to 25.23±8.00 (X±SE) ml/100g/min, SD=6.96, p<0.05.
CO₂ has been shown to be locally absorbed through the skin resulting in the elevation of subcutaneous tissue CO₂ partial pessure which decreases depending on the tissue perfusion irrespective of metabolic processes. It is, therefore, assumed that the elimination of absorbed constituents by serial bathings is not caused by a decrease in the percutaneous absorption rate but an increase in washing out rate by the improved tissue perfusion.

Artificial CO₂-bath was prepared with a tablet (50g): made from sodium bicarbonate and succinic acid, putting simply in plain water bath tub of 100-200 litre at 40C.
The effect of artificial CO₂-bath was studied in relation to the change in blood lactic acid which is thought to be indicative of the physical fatigue.
It has been clearly demonstrated experimentally using rats that the blood lactic acid after exercise is significantly reduced as compared both to a plain and an artificial Na₂ SO₄-NaHCO₃ bathing.
A favorable effect of the artificial CO₂-bath was also confirmed clinically by a relief from the stiff pain following maximal abdominal muscle exercise.

Anti-inflammation effect of artificial CO₂-bathing was confirmed on carrageenin induced edema experimentally using rats.
Artificial CO₂-bath was prepared with carbonated water by high pressure CO₂ bubbling and with a 50g tablet, made from sodium bicarbonate and succinic acid, putting simply in plain water.
Carrageenin induced edema was suppressed by plain water bathing, and was further enhanced at lower temperature.
It has been definitely shown that the edema is significantly suppressed with CO₂-bathing as compared to plain bathing due possibly to improved tissue perfusion.