The role of time and pressure on alveolar recruitment
The role of time and pressure on alveolar recruitment
复制标题
DOI：
10.1152/japplphysiol.90735.2008
复制
发表时间：
2009-03-01
影响因子：
3.3
通讯作者：
Nieman, Gary F.
中科院分区：
文献类型：
--
作者：
Albert, Scott P.;DiRocco, Joseph;Nieman, Gary F.
Albert SP，DiRocco J，艾伦GB，Bates JH，Lafollette R，Kubiak BD，Fischer J，Maroney S，Nieman GF.时间和压力对肺泡复张的作用。J Appl Physiol 106：757-765，2009.首次发表于2008年12月12日; doi：10.1152/japplphysiol. 90735.2008.-急性呼吸窘迫综合征患者不适当的机械通气可导致呼吸机相关性肺损伤（VILI），增加发病率和死亡率。重新开放萎陷的肺单位可能会显著减少VILI，但肺复张的机制尚不清楚。因此，我们研究了肺泡水平肺复张的动力学。将大鼠（n = 6）麻醉并机械通气。然后用盐水灌洗肺以模拟急性呼吸窘迫综合征（ARDS）。进行左胸廓切开术，并将体内显微镜置于肺表面。将肺复张至20、30或40 cmH 2 O三种复张压力（RP），持续40 s，同时连续拍摄胸膜下肺泡。在测量显微镜下肺泡复张后，切除肺，并对肉眼可见的大体肺复张进行数字拍摄。通过计算机图像分析定量招募，并使用数学模型解释数据。大部分肺泡复张（78.3 +/- 7.4和84.6 +/- 5.1%）分别发生在应用RP 30和40后的前2秒（T2）。只有51.9 +/- 5.4%的显微镜视野被RP 20的T2招募。在所有RP下，T2至T40的招募有限。大部分大体肺复张也发生在T2，逐渐复张至T40。通过结合压力和时间的影响的数学模型准确地预测了数据。肺泡复张是由复张压力的大小和施加压力的时间长度决定的，这一概念得到了我们的数学模型的支持。当设计临床应用的肺复张操作时，需要考虑肺泡复张的这种时间依赖性。
Albert SP, DiRocco J, Allen GB, Bates JH, Lafollette R, Kubiak BD, Fischer J, Maroney S, Nieman GF. The role of time and pressure on alveolar recruitment. J Appl Physiol 106: 757-765, 2009. First published December 12, 2008; doi:10.1152/japplphysiol. 90735.2008.-Inappropriate mechanical ventilation in patients with acute respiratory distress syndrome can lead to ventilator-induced lung injury (VILI) and increase the morbidity and mortality. Reopening collapsed lung units may significantly reduce VILI, but the mechanisms governing lung recruitment are unclear. We thus investigated the dynamics of lung recruitment at the alveolar level. Rats (n = 6) were anesthetized and mechanically ventilated. The lungs were then lavaged with saline to simulate acute respiratory distress syndrome (ARDS). A left thoracotomy was performed, and an in vivo microscope was placed on the lung surface. The lung was recruited to three recruitment pressures (RP) of 20, 30, or 40 cmH(2)O for 40 s while subpleural alveoli were continuously filmed. Following measurement of microscopic alveolar recruitment, the lungs were excised, and macroscopic gross lung recruitment was digitally filmed. Recruitment was quantified by computer image analysis, and data were interpreted using a mathematical model. The majority of alveolar recruitment (78.3 +/- 7.4 and 84.6 +/- 5.1%) occurred in the first 2 s (T2) following application of RP 30 and 40, respectively. Only 51.9 +/- 5.4% of the microscopic field was recruited by T2 with RP 20. There was limited recruitment from T2 to T40 at all RPs. The majority of gross lung recruitment also occurred by T2 with gradual recruitment to T40. The data were accurately predicted by a mathematical model incorporating the effects of both pressure and time. Alveolar recruitment is determined by the magnitude of recruiting pressure and length of time pressure is applied, a concept supported by our mathematical model. Such a temporal dependence of alveolar recruitment needs to be considered when recruitment maneuvers for clinical application are designed.