Sydow M, Burchardi H, Zinserling J, Ische H, Crozier T A, Weyland W
Zentrum für Anaesthesiologie, Rettungs- und Intensivmedizin, Georg-August-University, Göttingen, FRG.
Intensive Care Med. 1991;17(2):108-14. doi: 10.1007/BF01691433.
A new method for determination the static compliance of the respiratory system is described ("static compliance by automated single steps"--SCASS). In 12 ventilated patients pressure/volume (P/V) curves were determined by automated repetitive occlusion (6 s) at single volume steps and compared to the conventional syringe method (SM). All measurements were corrected for effects of temperature, humidity and pressure (THP). SM was found to be significantly influenced by intrapulmonary gas exchange causing an effective mean volume deficit of 217.4 +/- 65.7 ml (BTPS) at the end of the deflation. In contrast to that, the short duration of occlusion in SCASS minimize the gas exchange effects. The methodical differences between both methods result in overestimation of the inflation compliance in the uncorrected SM (SMuncorr: 83.4 +/- 12.6; SCASS: 76.0 +/- 11.9 ml/cmH2O. p less than 0.01) and underestimation of the deflation compliance resp. (SMuncorr: 58.3 +/- 7.5; SCASS: 79.1 +/- 15.0 ml/cmH2O. p less than 0.005). In contrast to the P/V curves by SM no significant hysteresis was found by SCASS. Gas exchange seems to be the main reason for the hysteresis. Even after correcting gas exchange and THP effects a significant hysteresis remained. The SCASS method avoids these problems and allows furthermore an accurate checking of leaks.
描述了一种测定呼吸系统静态顺应性的新方法（“自动单步静态顺应性”——SCASS）。对12例机械通气患者，通过在单一容积步长下自动重复阻断（6秒）测定压力/容积（P/V）曲线，并与传统注射器法（SM）进行比较。所有测量均针对温度、湿度和压力（THP）的影响进行了校正。发现SM受肺内气体交换的显著影响，在放气结束时导致有效平均容积亏缺217.4±65.7 ml（BTPS）。与此相反，SCASS中较短的阻断时间将气体交换影响降至最低。两种方法之间的方法学差异导致未校正的SM中充气顺应性被高估（未校正的SM：83.4±12.6；SCASS：76.0±11.9 ml/cmH2O，p<0.01），放气顺应性被低估（未校正的SM：58.3±7.5；SCASS：79.1±15.0 ml/cmH2O，p<0.005）。与SM的P/V曲线不同，SCASS未发现明显的滞后现象。气体交换似乎是滞后现象的主要原因。即使校正了气体交换和THP影响后，仍存在明显的滞后现象。SCASS方法避免了这些问题，并且还能准确检查漏气情况。
