Clercx C, Gustin P, Landser F J, Van de Woestijne K P
Clinique Médicale des Petits Animaux, Faculté de Médecine Vétérinaire, Université de Liège, Sart Tilman, Belgium.
Vet Res Commun. 1993;17(3):227-39. doi: 10.1007/BF01839171.
The resistance (Rrs) and reactance (Xrs) of the total respiratory system were determined at various frequencies in 14 healthy conscious beagle dogs. A pseudorandom noise pressure wave was produced at the nostrils of the animals by means of a loudspeaker adapted to the nose by a tightly fitting mask. A Fourier analysis of the pressure and flow signals yielded mean Rrs and Xrs, over 16 s, at frequencies from 2 to 26 Hz. The influence of the posture of the dog, the position of its head, the linearity of the respiratory system, the reproducibility of the method and the effects of upper and lower airway obstructions were studied. In sitting and standing healthy dogs with the head in the extended position, Rrs values increased progressively with frequency from 5.4 +/- 0.4 (SEM) cmH2O L-1s at 6 Hz up to 8.8 +/- 0.7 cmH2O L-1s at 26 Hz, the mean resonant frequency being 6.1 +/- 0.5 Hz. No significant differences were observed between measurements performed with the head in the normal or the extended position. In a recumbent posture, all Rrs values were increased but Rrs was still dependent on the frequency in the same way (7.1 +/- 0.7 cmH2O L-1s at 6Hz up to 10.0 +/- 0.5 cmH2O L-1s at 26 Hz). Tracheal compression also induced higher Rrs values without changes in the frequency dependence or in the resonant frequency. In anaesthetized dogs, airway obstruction was induced by inhalation of histamine (4 mg/ml for 5 min; the Rrs values tended to decrease with increasing frequency, and the resonant frequency was markedly increased.
在14只清醒健康的比格犬身上，于不同频率下测定了整个呼吸系统的阻力（Rrs）和电抗（Xrs）。通过一个经紧密贴合面罩适配于鼻部的扬声器，在动物鼻孔处产生伪随机噪声压力波。对压力和流量信号进行傅里叶分析，得出在2至26赫兹频率范围内16秒的平均Rrs和Xrs。研究了犬的姿势、头部位置、呼吸系统的线性度、该方法的可重复性以及上、下气道阻塞的影响。在头部伸展位的坐姿和站姿健康犬中，Rrs值随频率逐渐增加，从6赫兹时的5.4±0.4（标准误）厘米水柱·升⁻¹·秒增至26赫兹时的8.8±0.7厘米水柱·升⁻¹·秒，平均共振频率为6.1±0.5赫兹。头部处于正常或伸展位置时进行的测量之间未观察到显著差异。在仰卧姿势下，所有Rrs值均升高，但Rrs仍以相同方式依赖于频率（6赫兹时为7.1±0.7厘米水柱·升⁻¹·秒，至26赫兹时为10.0±0.5厘米水柱·升⁻¹·秒）。气管压迫也导致Rrs值升高，但频率依赖性和共振频率无变化。在麻醉犬中，通过吸入组胺（4毫克/毫升，持续5分钟）诱导气道阻塞；Rrs值倾向于随频率增加而降低，且共振频率显著增加。
