[Blood gas changes during treadmill exercise in convalescents from pulmonary tuberculosis. 1. Method of measurement]

With advances in treatment for tuberculosis, pulmonary tuberculosis has become curable. However, chronic respiratory failure has been more often observed in those who have ever had thoracic operation, and were cured with anti-tuberculous chemotherapy in spite of initially severe pulmonary tuberculosis with wide spread lesions in both lungs, particularly in the aged. Therefore it is now necessary to understand accurately the real physio-dynamic situation of respiro-circulatory impairment in these patients. For this purpose, an exercise test was newly designed, and changing curves of blood gas (O2- and CO2-partial pressure, measured transcutaneously) were drawn in 4 healthy persons and 23 recovered patients from pulmonary tuberculosis. The newly designed method was carried out by using Treadmill walk apparatus (Nihon-Denki Sanei Co., Japan), transcutaneous blood gas measurement apparatus (Radio-Meter Co., Copenhagen) and automatic blood pressure measurement apparatus (Kyorin Co., Japan). Treadmill walk exercise test was done through Bruce-Sheffield converted method. The details of this exercise test are written and illustrated in this paper. The results of the test were classified into 4 types by the changes of transcutaneously measured O2 partial pressure curve during the test: 1. unchanged, 2. slightly decreased, 3. moderately decreased, 4. markedly decreased. The significance of these 4 types will be discussed in the next report after examining more convalescents from pulmonary tuberculosis. The reproducibility of this test was examined in 6 patients, and it was almost good. In addition, in 3 out of 27 patients, odd curves contrary to our expectation, that is increase of the value of trans-cutaneously measured O2 partial pressure and/or decrease of the value of trans-cutaneously measured CO2 partial pressure immediately after the initiation of the first test were observed. But in the second test, carried out in the other day, the curve fell into one of the 4 types mentioned above. The odd curve might be due to psychological hyperventilation.