Ryu H G, Bahk J H, Lee H J, Im J G
Department of Anesthesiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
Anaesth Intensive Care. 2008 Nov;36(6):792-7. doi: 10.1177/0310057X0803600607.
The mechanism of oxygenation improvement after recruitment manoeuvres or prone positioning in acute lung injury or acute respiratory distress syndrome is still unclear. We tried to determine the mechanism responsible for the effects of recruitment manoeuvres or prone positioning on lung aeration using a whole lung computed tomography scan in an oleic acid induced acute lung injury canine model. Twelve adult mongrel dogs were allocated into either the supine group (n=6) or the prone group (n=6). After the establishment of acute lung injury, three recruitment manoeuvres were performed at one-hour intervals. Haemodynamic and ventilatory variables, arterial blood gas analyses and CT scans of the whole lung were obtained 90 minutes after oleic acid injection and five minutes before and after each recruitment manoeuvre. Recruitment manoeuvres in the supine position improved oxygenation (P=0.025) that correlated with increase of the poorly- and well-aerated dorsal (dependent) lung volume (r=0.436, P=0.016). Prone positioning increased oxygenation (P=0.004) that also correlated with increase of the poorly- and well-aerated dorsal (nondependent) lung volume (r=0.787, P<0.001). However, the recruitment manoeuvre in the prone position had no effect on oxygenation despite an increase in ventral (dependent) lung volume. The increase in PaO2 after recruitment manoeuvres in the supine position or after prone positioning is related to the increase of the poorly- and well-aerated dorsal lung.
在急性肺损伤或急性呼吸窘迫综合征中，复张手法或俯卧位通气后氧合改善的机制仍不清楚。我们试图在油酸诱导的急性肺损伤犬模型中，通过全肺计算机断层扫描来确定复张手法或俯卧位通气对肺通气影响的机制。将12只成年杂种犬分为仰卧组（n = 6）和俯卧组（n = 6）。在建立急性肺损伤后，每隔1小时进行3次复张手法。在注射油酸后90分钟以及每次复张手法前后5分钟，获取血流动力学和通气变量、动脉血气分析及全肺CT扫描结果。仰卧位的复张手法改善了氧合（P = 0.025），这与通气不良和通气良好的背部（下垂部位）肺容积增加相关（r = 0.436，P = 0.016）。俯卧位通气增加了氧合（P = 0.004），这也与通气不良和通气良好的背部（非下垂部位）肺容积增加相关（r = 0.787，P < 0.001）。然而，尽管腹侧（下垂部位）肺容积增加，但俯卧位的复张手法对氧合没有影响。仰卧位复张手法或俯卧位通气后PaO₂的升高与通气不良和通气良好的背部肺容积增加有关。
