入浴中の組織ガス分圧の変動

抄録

We examined Tissue Partial Pressure of O₂ (PO₂) and CO₂ (PCO₂), changes of Pulse Rate (P. R.) and Blood Pressure (B. P.) in a bath at different temperature using rabbit. Expeilmental method;
A rabbit about 2kg body weight is taken a bath at each temperature of 37°C, 40°C, and 43°C for 30 minutes by means of constant-temperature water bath method under the anesthesia of venous drip of NEMBUTAL® (Pentobarbital Sodium).
Teflon catheters for tissue gas analyses are inserted to the Cranial tibial muscle and the over-lying subcutaneous tissue. Tissue PO₂ and PCO₂ in a bath are measured by Medical Mass Spectrometry (MEDSPECT II, Chemetron, U. S. A.). The changes of B. P. and P. R. are recorded simultaneously.
Results and Discussion;
1, In a bath at 37°C, there are no changes on both B. P. and P. R., but the elevation of PO₂ is a little, leading to an insignificant effect.
2, In a bath at 40°C, subcutaneous tissue PO₂ and muscular tissue PO₂ are found elevated by 74% and 53% respectively. P. R. is found increased by 34%, and B. P. is found reduced by 8%. This reduce of B. P. is due possibly to the peripheral vasodilatation. From the standpoint of a peripheral circulation, bath temperature of 40°C is thought to be efficient in washing out metabolites, leading to recovery from fatigue.
3, In a bath at 43°C, subcutaneous tissue PO₂ and muscular tissue PO₂ are found elevated by 74% and by 53% respectively. And tissue PCO₂ are found elevated by 65% in subcutaneous tissue and by 64% in muscular one; 13% up from those found in a bath at 40°C, leading to some fatigue. B. P. is elevated by 16% and P. R. is increased by 69% respectively in a bath at 43°C. Arrhythmia occurs sometimes. It is, therefore, assumed that the man who has a handicap on the circulation system and the elder who has arteriosclerosis in his base should not take a bath at high temperature and/or for a long time.