<原著>混合静脈血ガスの非観血的測定法に関する研究

Abstract

The purposes of this study are to analyze the effect of uneven distribution of the ventilation perfusion ratio (V_A/Q) on the estimation of mixed venous carbon dioxide tention (P_<VCO_2>) obtained by the single breath method (Kim, 1966). First, computer simulation was done, then these simulation data was compared with experimental data. Results of our study are follows. 1. Analysis using computer simulation. We used Wagner's data for the modelling of V_A/Q uneven distributions. The procedure of gas exchange calculation referred to Kelman's article. As a result, P_<VCO_2> was underestimated in case that the high V_A/Q space existed. The low V_A/Q space had little effect on the estimation of P_<VCO_2>. 2. Comparison with experimental data. Objects was 4 lung cancer, 1 Kartagener syndrome and 1 Sleep Apnea Syndrome. The dicrepancy between the value obtained by indirect Kim method and the value directly obtained by right heart catheterization was from -7.3 torr to +2.4 torr. The larger the high V_A/Q Space was, the larger the discrepancy became. This result agreed well with our computer analysis.