Carvalho P, Hilderbrandt J, Charan N B
Pulmonary Research Laboratory, Department of Veterans Affairs Medical Center, Boise, Idaho 83702, USA.
J Appl Physiol (1985). 1996 Oct;81(4):1664-9. doi: 10.1152/jappl.1996.81.4.1664.
We studied the effects of unilateral tension pneumothorax and its release on bronchial and pulmonary arterial blood flow and gas exchange in 10 adult anesthetized and mechanically ventilated sheep with chronically implanted ultrasonic flow probes. Right pleural pressure (Ppl) was increased in two steps from -5 to 10 and 25 cmH2O and then decreased to 10 and -5 cmH2O. Each level of Ppl was maintained for 5 min. Bronchial blood flow, right and left pulmonary arterial flows, cardiac output (QT), hemodynamic measurements, and arterial blood gases were obtained at the end of each period. Pneumothorax resulted in a 66% decrease in QT, bronchial blood flow decreased by 84%, and right pulmonary arterial flow decreased by 80% at Ppl of 25 cmH2O (P < 0.001). At peak Ppl, the majority of QT was due to blood flow through the left pulmonary artery. With resolution of pneumothorax, hemodynamic parameters normalized, although abnormalities in gas exchange persisted for 60-90 min after recovery and were associated with a decrease in total respiratory compliance.
我们使用长期植入超声流量探头，研究了单侧张力性气胸及其解除对10只成年麻醉并机械通气绵羊的支气管和肺动脉血流以及气体交换的影响。右胸膜腔内压（Ppl）分两步从-5 cmH₂O升至10 cmH₂O和25 cmH₂O，然后降至10 cmH₂O和-5 cmH₂O。每个Ppl水平维持5分钟。在每个时间段结束时获取支气管血流、左右肺动脉血流、心输出量（QT）、血流动力学测量值和动脉血气。气胸导致QT降低66%，在Ppl为25 cmH₂O时支气管血流减少84%，右肺动脉血流减少80%（P<0.001）。在Ppl峰值时，大部分QT归因于通过左肺动脉的血流。随着气胸的缓解，血流动力学参数恢复正常，尽管气体交换异常在恢复后持续60 - 90分钟，并与总呼吸顺应性降低有关。
