Dobbinson T L, Miller J R
Anaesth Intensive Care. 1981 Nov;9(4):307-13. doi: 10.1177/0310057X8100900401.
The respiratory and haemodynamic effects of incremental levels of positive and expiratory pressure (PEEP) to 9 cm H2O were studied in ten adult patients 3--6 hours after uneventful cardiopulmonary bypass surgery. Functional residual capacity was increased and deadspace-tidal volume ratio tended to fall, the latter approaching significance at +6 and +9 cm PEEP. Thus lung volume was increased and there was a tendency to improved gas distribution to the alveoli. However there was no significant change in PaO2, alveolar-arterial oxygen tension difference or venous admixture. Cardiac index, and left ventricular strokework index were marginally depressed at 6 cm PEEP and further at 9 cm, while right atrial pressure and pulmonary artery occlusion pressure were raised at 9 cm PEEP. It would appear that low levels (3--6 cm) of PEEP do not improve gas exchange in the lungs to any worthwhile degree, and levels (6--9 cm) may impair cardiac performance.
对10例成年患者在经历顺利的体外循环手术后3至6小时，研究了逐步增加呼气末正压（PEEP）至9厘米水柱时的呼吸和血流动力学效应。功能残气量增加，死腔潮气量比趋于下降，在PEEP为+6和+9厘米水柱时，后者接近显著水平。因此肺容积增加，且有改善气体向肺泡分布的趋势。然而，动脉血氧分压、肺泡 - 动脉血氧分压差或静脉血掺杂无显著变化。心脏指数和左心室每搏功指数在PEEP为6厘米水柱时略有下降，在9厘米水柱时进一步下降，而右心房压力和肺动脉闭塞压在PEEP为9厘米水柱时升高。看来低水平（3至6厘米）的PEEP并不能在任何值得的程度上改善肺部气体交换，而高水平（6至9厘米）可能会损害心脏功能。
