Räsänen Jukka, Gavriely Noam
Department of Anesthesiology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
Intensive Care Med. 2005 Oct;31(10):1434-41. doi: 10.1007/s00134-005-2745-7. Epub 2005 Sep 10.
To evaluate the effect of positive end-expiratory pressure on the sound filtering characteristics of injured lungs.
Prospective experimental study in the animal laboratory in an academic medical center.
Six 35- to 45-kg anesthetized, intubated pigs.
Acute lung injury with intravenous oleic acid.
We injected a multifrequency broad-band sound signal into the airway while recording transmitted sound at three locations bilaterally on the chest wall. Oleic acid injections effected a severe pulmonary edema predominantly in the dependent lung regions, with an average increase in venous admixture from 16+/-14% to 57+/-13% and a reduction in static respiratory system compliance from 31+/-6 to 16+/-3 ml/cm H(2)O. A significant concomitant increase in sound transfer function amplitude was seen in the dependent and lateral lung regions; little change occurred in the nondependent areas. The application of PEEP resulted in a decrease in venous admixture, increase in respiratory system compliance, and return of the sound transmission to preinjury levels.
Acute lung injury causes regional acoustic transmission abnormalities that are reversed during alveolar recruitment with PEEP.
评估呼气末正压对损伤肺脏声音过滤特性的影响。
在一所学术医疗中心的动物实验室进行的前瞻性实验研究。
6头体重35至45千克、麻醉后插管的猪。
静脉注射油酸致急性肺损伤。
我们在气道内注入多频宽带声音信号，同时在胸壁双侧的三个位置记录传输声音。注射油酸主要在肺下垂部位引起严重肺水肿，静脉混合血平均从16±14%增至57±13%，静态呼吸系统顺应性从31±6降至16±3毫升/厘米水柱。在肺下垂和外侧区域，声音传递函数幅度显著增加；非下垂区域变化不大。应用呼气末正压导致静脉混合血减少、呼吸系统顺应性增加，声音传输恢复至损伤前水平。
急性肺损伤导致区域声学传输异常，在呼气末正压进行肺泡复张时可逆转。
