Sakai T, Yoshida H, Endoh E, Kimura K, Takaori M
Department of Anesthesiology, Kawasaki Medical School.
Kokyu To Junkan. 1990 May;38(5):451-5.
Airway resistance was measured by an interrupter technique in anesthetized and paralyzed dogs. Bronchoconstriction was then induced by the inhalation of methacholine hydrochloride at a concentration of 25 or 50 mg . ml-1 for ten minutes. Airway resistance was measured again immediately after the inhalation of methacholine and 50 minutes later. Under normal conditions, airway resistance increased with a linear relationship to the expiratory airflow as expressed by a function of Y = K1 + K2X. K1 and K2 were calculated by a least square method. As a result, K1 increased markedly immediately after the inhalation of methacholine and returned to the control level thereafter. However, it was still higher than the control 50 minutes later. On the other hand, no statistically significant changes were observed because the changes in K2 were variable. In some cases, K2 increased, while in others it was unchanged. K2 decreased in more cases, however, and a negative value was often seen. This inverse correlation between flow and resistance was supposed to reflect the occurrence of small airway obstructions during the end expiratory phase. Therefore, it was considered that this method is capable of detecting small airway abnormalities which could not be detected by %FEV1.0.
采用阻断法在麻醉和麻痹的犬身上测量气道阻力。然后通过吸入浓度为25或50mg·ml-1的盐酸乙酰甲胆碱10分钟来诱发支气管收缩。吸入乙酰甲胆碱后立即及50分钟后再次测量气道阻力。在正常情况下，气道阻力与呼气气流呈线性关系增加，用Y = K1 + K2X函数表示。K1和K2通过最小二乘法计算。结果，吸入乙酰甲胆碱后K1立即显著增加，此后恢复到对照水平。然而，50分钟后它仍高于对照。另一方面，由于K2的变化是可变的，未观察到统计学上的显著变化。在某些情况下，K2增加，而在其他情况下它不变。然而，更多情况下K2下降，且常出现负值。这种流量与阻力之间的负相关被认为反映了呼气末期小气道阻塞的发生。因此，认为该方法能够检测到%FEV1.0无法检测到的小气道异常。
