Jonzon A, Rondio Z, Sedin G
Br J Anaesth. 1980 Apr;52(4):395-402. doi: 10.1093/bja/52.4.395.
The functional residual capacity (FRC) was measured in cats by the nitrogen washout technique during positive-pressure ventilation. Frequencies of 60 and 100 b.p.m. were used with insufflation periods of 20% and 35% of the ventilatory cycle, without and with a positive end-expiratory pressure. The higher frequency combined with the shorter insufflation period gave FRC close to that obtained during spontaneous breathing. The lower frequency and the longer insufflation period always gave greater FRC values. A further increase in FRC of about 23-27% was obtained after application of a positive end-expiratory pressure of 0.5 kPa. Adequate ventilation was achieved with small intratracheal and intrapleural pressures at all settings used.
在正压通气期间，采用氮气冲洗技术在猫身上测量功能残气量（FRC）。使用60次/分钟和100次/分钟的频率，吸气期分别为呼吸周期的20%和35%，分别在无呼气末正压和有呼气末正压的情况下进行。较高的频率与较短的吸气期相结合，得到的FRC接近自主呼吸时的数值。较低的频率和较长的吸气期总是产生更大的FRC值。施加0.5 kPa的呼气末正压后，FRC进一步增加约23% - 27%。在所有使用的设置下，通过较小的气管内压和胸内压实现了充分通气。
