谷口 信行, 福井 順一, 伊東 紘一, 鈴木 修, 中村 みちる, 川井 夫規子

Nobuyuki TANIGUCHI, Junichi FUKUI, Kouichi ITOH, Osamu SUZUKI, Michiru NAKAMURA, Fukiko KAWAI

自治医科大学臨床病理学教室

Department of Clinical Pathology, Jichi Medical School

キーワード : Diaphragm, Respiration, Measurement, Ultrasonic Studies, Position

We examined respiratory as well as positional changes in diaphragm thickness by measuring it at the costal part using a 10-MHz ultrasonic transducer in 31 healthy young men without respiratory diseases.
The thickness in the supine position was 4.8±1.1 mm (mean±S. D.) at the TLC level, 1.8±0.2 mm at the FRC level, and 1.7±0.2 at the RV level. In the upright position, the thickness was 5.3±1.2 mm at the TLC level, 2.0±0.3 mm at the FRC level, and 1.9±0.2 mm at the RV level. The mean thickness in the upright position was significantly greater than that in the supine position at all respiratory levels, corresponding to an increase in VC and FRC in the upright position. The thickness at the TLC level was significantly greater than that at the FRC and RV levels (P The correlation between the diaphragm thickness and respiratory function was not significant except for the one between the thickness at the TLC level and the VC in the supine position (p This poor correlation may be due to the fact that, as it contracts toward the TLC level, the diaphragm becomes less efficient in generating negative pressure to expand the lungs. Or the costal part might have been an inappropriate site of measurement because the crural part has been reported to be more important in maximal inhalation.