DiRocco Joseph D, Carney David E, Nieman Gary F
Department of Surgery, Upstate Medical University, 750 E Adams Street, 13210, Syracuse, NY, USA.
Intensive Care Med. 2007 Jul;33(7):1204-1211. doi: 10.1007/s00134-007-0629-8. Epub 2007 May 25.
To determine whether individual alveolar recruitment/derecruitment (R/D) is correlated with the lower and upper inflections points on the inflation and deflation limb of the whole-lung pressure-volume (P-V) curve.
Prospective experimental study in an animal research laboratory.
Five anesthetized rats subjected to saline-lavage lung injury.
Subpleural alveoli were filmed continuously using an in vivo microscope during the generation of a whole-lung P-V curve using the super syringe technique. Alveolar R/D was correlated to the calculated inflection points on both limbs of the P-V curve.
There was continual alveolar recruitment along the entire inflation limb in all animals. There was some correlation (R2=0.898) between the pressure below which microscopic derecruitment was observed and the upper inflection point on the deflation limb. No correlation was observed between this pressure and the lower inflection point on the inflation limb.
In this physiological experiment in lungs with pure surfactant deactivation we found that individual alveolar recruitment measured by direct visualization was not correlated with the lower inflection point on inflation whereas alveolar derecruitment was correlated with alveolar derecruitment on deflation. These data suggest that inflection points on the P-V curve do not always represent a change in alveolar number.
确定单个肺泡的复张/萎陷（R/D）是否与全肺压力-容积（P-V）曲线充气和放气支上的下拐点和上拐点相关。
在动物研究实验室进行的前瞻性实验研究。
五只接受盐水灌洗肺损伤的麻醉大鼠。
在使用超级注射器技术生成全肺P-V曲线的过程中，使用体内显微镜连续拍摄胸膜下肺泡。肺泡R/D与P-V曲线两支上计算出的拐点相关。
所有动物在整个充气支上均持续出现肺泡复张。观察到微观萎陷的压力与放气支上的上拐点之间存在一定相关性（R2 = 0.898）。该压力与充气支上的下拐点之间未观察到相关性。
在这个单纯表面活性剂失活的肺的生理实验中，我们发现通过直接观察测量的单个肺泡复张与充气时的下拐点不相关，而肺泡萎陷与放气时的肺泡萎陷相关。这些数据表明，P-V曲线上的拐点并不总是代表肺泡数量的变化。
