Millqvist E, Bake B, Bengtsson U, Löwhagen O
Asthma and Allergy Centre, University of Göteborg, Sahlgrenska Hospital, Sweden.
Allergy. 1995 Mar;50(3):225-8. doi: 10.1111/j.1398-9995.1995.tb01138.x.
In order to devise a protective aid against bronchial obstruction induced by cold air, we have tested a breathing filter with heat and moisture exchanging properties. Nine asthma patients, who all had a history of cold-induced asthma, took part in exercise tests on an ergometer bicycle at a temperature of approximately -10 degrees C, without and with a breathing filter. Without a breathing filter, the maximum reduction in FEV1 was, on average, 36%. With the breathing filter, the maximum reduction in FEV1 was, on average, 11%. The difference was clearly significant (P < 0.001). A further five cold-sensitive asthmatics performed similar exercise tests at -10 degrees C on three occasions: 1) without and 2) with a breathing filter as above, and 3) with two breathing filters connected in parallel: one for inspiration and the other for expiration. Thus, no heat-moisture exchange could take place. The fall in FEV1 after provocation without a breathing filter and with parallel breathing filters was similar but attenuated when rebreathing took place through the breathing filter. The results confirm the theory that in cold/exercise-induced asthma, it is indeed the heat and/or water loss from the airways that triggers airway narrowing, and that a heat and moisture exchanging filter has a considerable protective effect and can be of value in the treatment of asthma.
为了设计一种针对冷空气诱发支气管阻塞的防护辅助装置，我们测试了一种具有热湿交换特性的呼吸过滤器。九名均有冷空气诱发哮喘病史的哮喘患者，在温度约为-10摄氏度的测力计自行车上进行了运动测试，测试时分别使用和不使用呼吸过滤器。不使用呼吸过滤器时，第一秒用力呼气量（FEV1）的最大降幅平均为36%。使用呼吸过滤器时，FEV1的最大降幅平均为11%。差异非常显著（P < 0.001）。另外五名对寒冷敏感的哮喘患者在-10摄氏度下进行了三次类似的运动测试：1）不使用呼吸过滤器；2）使用上述呼吸过滤器；3）使用两个并联的呼吸过滤器：一个用于吸气，另一个用于呼气。因此，无法进行热湿交换。不使用呼吸过滤器和平行使用呼吸过滤器激发后FEV1的下降情况相似，但通过呼吸过滤器进行再呼吸时下降幅度减弱。结果证实了以下理论：在寒冷/运动诱发的哮喘中，确实是气道的热量和/或水分流失引发了气道狭窄，并且热湿交换过滤器具有相当大的保护作用，在哮喘治疗中可能具有价值。
