von Ungern-Sternberg Britta S, Petak Ferenc, Saudan Sonja, Pellegrini Michel, Erb Thomas O, Habre Walid
Pediatric Anesthesia Unit, Geneva Children's Hospital, Geneva, Switzerland.
J Thorac Cardiovasc Surg. 2007 Nov;134(5):1193-8. doi: 10.1016/j.jtcvs.2007.03.061.
To characterize factors that contribute to lung function impairment after cardiopulmonary bypass, we assessed functional residual capacity and ventilation homogeneity during the perioperative period in children with congenital heart disease who are to undergo surgical repair.
Functional residual capacity and lung clearance index were measured by using a sulfur hexafluoride washout technique in 24 children (aged 0-10 years). Measurements of functional residual capacity and ventilation distribution were performed after induction of anesthesia, at different stages of the surgical procedure, and up to 90 minutes after skin closure. Anesthesia was standardized, and ventilator settings, including the fraction of inspired oxygen, were kept constant throughout the study period.
Sternotomy and retractor insertion led to a significant increase in functional residual capacity (mean [SD], 24% [14%]), followed by a similar percentage decrease in the resting volume after a significant reduction in pulmonary blood flow during cardiopulmonary bypass with aortic clamping. Although reestablishing pulmonary blood flow increased functional residual capacity (10% [6%]), chest closure led to a decrease in functional residual capacity of 36% (14%) that only slightly improved during the first 90 minutes after surgical intervention. Changes in lung clearance index were affected conversely compared with changes in functional residual capacity at all assessment times.
These results confirmed that chest wall condition and pulmonary circulation affect lung volumes and ventilation homogeneity. Although opening of the chest wall improved alveolar recruitment and ventilation homogeneity, blood flow appeared essential for alveolar stability, presumably by exerting a tethering force caused by the filled capillaries on the alveolar walls and therefore contributing to an increase in resting lung volume.
为了明确体外循环后导致肺功能损害的因素，我们评估了先天性心脏病患儿在接受手术修复围手术期的功能残气量和通气均匀性。
采用六氟化硫冲洗技术对24名儿童（年龄0 - 10岁）测量功能残气量和肺清除指数。在麻醉诱导后、手术过程的不同阶段以及皮肤缝合后90分钟内进行功能残气量和通气分布的测量。麻醉标准化，在整个研究期间，包括吸入氧分数在内的呼吸机设置保持不变。
胸骨切开术和插入牵开器导致功能残气量显著增加（均值[标准差]，24%[14%]），随后在体外循环主动脉钳夹期间肺血流量显著减少后，静息容量有类似百分比的下降。尽管恢复肺血流量使功能残气量增加（10%[6%]），但关胸导致功能残气量减少36%（14%），在手术干预后的最初90分钟内仅略有改善。在所有评估时间，肺清除指数的变化与功能残气量的变化相反。
这些结果证实胸壁状况和肺循环会影响肺容量和通气均匀性。尽管胸壁打开改善了肺泡复张和通气均匀性，但血流似乎对肺泡稳定性至关重要，可能是通过对肺泡壁上充盈的毛细血管施加一种束缚力，从而有助于增加静息肺容量。
