実験的肺水腫犬におけるラ音の検討—肺性不連続性ラ音の発生機序に関連して

Rales in experimentally induced edematous lung in dogs

はじめに

　われわれはこれまでに臨床的および数学的モデルによる理論的検討から^1,2），肺性不連続性ラ音（rales）^3）は発生機序の上から少なくとも2種類のラ音に分類され，一つは破裂音であるbubblingであり，もう一つは共鳴音であるcracklesであることを報告し，破裂音は気道内分泌液中にある気泡が空気相に出る時に破裂することによって生じ，水泡性ラ音が含まれること，一方，共鳴音は硬化した末梢肺組織の気腔壁が振動することによって生じ，捻髪音やベルクロ・ラ音^4）が含まれることを報告した。今回はこのことを更に確認する目的で，この2種類の音を実験的に犬に作成し，組織形態学的所見とラ音分析所見との比較検討を行った。

From the clinical and theoretical investigation, we have reported that the pulmonary discontinuous sounds or rales might be classified into two main groups with different occurrence mechanisms. One is bubbling with acoustically explosive character produced by the explosion of the bubbles in the airways, and another is crackles which contain crep-itation and Velcro rale with acoustically resonant character produced in the certain condition where the movement of surrounded tissue wall is limited. To ascertain these events, correlative morphologic and acoustic investigations on experimentally induc-ed edematous lung in canines were done.

As a result, it was noted that the sounds record-ed in early stage of the experiment were resonant sound or crepitation and the histologic examination at that time revealed lung congestion with peri-vascular cuffing and alveolar wall thickening with-out intraalveolar and airway's fluid fiilling, and that the sounds recorded in late stage of the lung edema were mainly explosive sound or bubbling and the histologic findings at this time revealed not only marked alveloar wall thickening but also fluid-filling into intraalveolar spaces and airways.

These results suggest that our postulation men-tioned above would be well acceptable.