一秒率による簡単な肺機能鑑別診断方法について

Simple method for differentiation of the ventilatory defect by Tiffeneau's test

いとぐち

　肺機能不全が肺実質障害によるか，換気に対する抵抗増加によるかを知る為に従来Gaenslerの気速指数（Air Velocity Index）^1）すなわち

　気速指数＝実測MBCの標準値に対する％／実測肺活量の標準値に対する％

Although Air Velocity Index (Gaensler) is used to determine functionally whether the ventila-tory disturbance is due to the increased resistance of air-flow or the loss of lung tissues, one may be erronously impressed especially when this index is in the vicinity of 1. For this disadvantage the following method was considered.

(VC/pred. VC-1)×100(%) and Volume Expiratoire Maximum Seconde (Tiffeneau)/VC×100(%) were plotted on the ordinate and the abscissa, respectively. On such coordinates 149 subjects with broncial asthma, chronic pulmonary emphysema, pulmonary tuberculosis, postoperative conditions (pulmonary resection, thoracoplasty), etc. were plotted to find the limited localization peculiar to each disease.

Conclusively, the increased resistance of air-flow and the loss of lung tissues were statistically divided into 2 groups, and severe chronic pulmonary emphysema showed characteristic deviation from other pulmonary conditions. Therefore this simple method was thought to be useful both to analyze functionally the character of ventilatory disturbances and to know the grade of severity in chronic pulmonary emphysema.