Burwen D R, Watson J, Brown R, Josa M, Slutsky A S
J Appl Physiol (1985). 1986 Mar;60(3):965-71. doi: 10.1152/jappl.1986.60.3.965.
In a previous study using tracheal insufflation of O2 (TRIO) at a rate of 2 l/min, we showed that anesthetized paralyzed dogs could be adequately oxygenated for up to 5 h, albeit with hypercapnia (mean arterial PCO2 approximately 160 Torr). To examine the contribution of cardiogenic oscillations in producing this gas exchange, we studied seven anesthetized paralyzed dogs weighing between 19.6 and 25.5 kg and quantified gas transport by analyzing continuous N2-washout curves in vivo and postmortem. We found that cardiogenic oscillations increase gas mixing roughly fourfold and that this value was independent of insufflation flow rate (0.2-10.0 l/min). Our results lend indirect evidence that, with regard to gas exchange, there are two mechanistically different zones in the lung during TRIO. One zone, located in the more peripheral areas of the lung, is dominated by the effects of cardiac oscillations and molecular diffusion and accounts for the increase in gas mixing found in the alive vs. dead dog. A second zone, close to the insufflated jet of O2, uses convective streaming to produce greater gas mixing at higher flows.
在之前一项以2升/分钟的速率进行气管内吹入氧气（TRIO）的研究中，我们发现，麻醉瘫痪的犬类能够充分氧合长达5小时，尽管存在高碳酸血症（平均动脉血PCO2约为160托）。为了研究心源性振荡在产生这种气体交换中的作用，我们对7只体重在19.6至25.5千克之间的麻醉瘫痪犬进行了研究，并通过分析体内和死后连续的氮气洗脱曲线来量化气体传输。我们发现，心源性振荡使气体混合增加约四倍，且该值与吹入流速（0.2 - 10.0升/分钟）无关。我们的结果间接证明，在TRIO过程中，就气体交换而言，肺内存在两个机制不同的区域。一个区域位于肺的更外周区域，受心脏振荡和分子扩散的影响主导，这解释了在活体与死体犬中发现的气体混合增加现象。第二个区域靠近吹入的氧气射流，利用对流来在更高流速下产生更大的气体混合。
