Jorfeldt L, Wranne B
Clin Physiol. 1982 Apr;2(2):97-104. doi: 10.1111/j.1475-097x.1982.tb00012.x.
The hypothesis was raised that an increased end-expiratory lung volume when switching over from normal to hyperventilation (positive delta FRC) can be used as a criterion of early obstructive lung disease. In 20 normal subjects and in 24 patients with suspect or manifest lung disease delta FRC at breathing frequencies of 40, 60 and 80 min-1, forced expiratory volume in one second (FEV1), vital capacity (VC), maximal expiratory flow at 50 and 25% of VC (MEF50 and MEF25) and closing volume (CV) were determined. FEV% (FEV1 X VC-1 X 100) and CV% (CV X VC-1 X 100) were calculated. delta FRC40 correlated negatively with FEV%, MEF50 and MEF25 for normals and patients separately with no difference between the groups. The residual standard deviation of delta FRC40 on FEV% was significantly reduced when MEF50 and MEF25 was included. delta FRC40 did not correlate with CV or CV%. delta FRC60 and delta FRC80 did not correlate with MEF50 and MEF25. The reproducibility of delta FRC40 was of the same order as the other variables studied. A delta FRC40 of +0.31 corresponded to MEF50 and MEF25 values 2 SD below the reference value. This suggests that a positive delta FRC40 of more than 0.31 indicates airway obstruction.
从正常呼吸转换为过度通气时呼气末肺容积增加（FRC正增量）可作为早期阻塞性肺病的一项标准。对20名正常受试者以及24名疑似或确诊患有肺病的患者，测定了呼吸频率为40、60和80次/分钟时的FRC增量、一秒用力呼气容积（FEV1）、肺活量（VC）、肺活量50%和25%时的最大呼气流量（MEF50和MEF25）以及闭合容积（CV）。计算了FEV%（FEV1×VC-1×100）和CV%（CV×VC-1×100）。正常人和患者的FRC增量40分别与FEV%、MEF50和MEF25呈负相关，两组之间无差异。当纳入MEF50和MEF25时，FRC增量40对FEV%的剩余标准差显著降低。FRC增量40与CV或CV%无相关性。FRC增量60和FRC增量80与MEF50和MEF25无相关性。FRC增量40的可重复性与所研究的其他变量处于同一水平。FRC增量40为+0.31时对应的MEF50和MEF25值比参考值低2个标准差。这表明FRC增量40大于0.31提示气道阻塞。
