自然気胸術後の局所換気機能

Regional pulmonary functions of spotaneous pneumothorax in post-thoracotomy stage

　若年者に好発する典型的な自然気胸では，その発症の経過や病態から考えて術前に充分な努力性肺機能は施行し難く，術後の肺機能との比較はあまりなされない。また，比較し得た場合もその切除範囲，侵襲の程度から考えて全肺機能的に臨床上問題となる事は少ない。しかし局所肺機能の立場からすると，このような対象は残存肺が極めて正常であり，肋骨切除などの侵襲がないので，ブレブの切除，縫縮による近傍肺への影響や，開胸それ自体による術側肺及び胸郭への影響を評価する上ではむしろ好都合である。

　このような観点に立ち，著者らは¹³³Xe，^81mKrの2つの放射性不活性ガスを使用し，自然気胸術後患者を対象として術後の局所換気機能及びその時間的推移について検討したので報告する。

Regional pulmonary functions by Xe-133 and Kr-81m were examined in 20 patients (average age 26 years old) with spontaneous pneumothorax in post-thoracotomy stage.

In about a half of cases, washout study by Xe-133 showed delay of washout time in the operated lung or in the apical area of the operated side. The former phenomenon was recognized in 5 cases, in whom all case were examined within 2 weeks after surgery except one case. The latter was recognized in 7 cases examined within 5 months after surgery. In most of cases, unilateral RV/TLC measured by Xe-133 increased in the operated lung. Bolus gas of Kr-81m inhalated at various lung volume level asymmetrically distributed in right and left lung, especially inhalated at RV and high lung volume level, in about 70% of cases examined within 5 months after surgery.

These results suggest that the restriction on ventilation at rest remains in the operated lung for a few weeks and in the apical area for several months after thoracotomy. Maximum expiration and inspiration in the operated lung are restricted for several months after thoracotomy.