Effros Richard M, Pornsuriyasak Prapaporn, Porszasz Janos, Casaburi Richard
Los Angeles Biomedical Institute at Harbor-UCLA Medical Center, 1124 West Carson St., Torrance, CA 90502, USA.
Am J Physiol Lung Cell Mol Physiol. 2008 Jun;294(6):L1023-31. doi: 10.1152/ajplung.00533.2007. Epub 2008 Mar 21.
Since they were introduced more than five decades ago, a variety of single-pass indicator, thermal, and osmotic dilution approaches have been developed for detecting and measuring excess fluid in the lungs. This brief review discusses why studies of the extravascular lung water (EVLW) continue to intrigue physiologists and clinicians and the likelihood that they will become sufficiently reliable for more widespread use. Emphasis is placed on the basic assumptions that underlie these measurements and limitations imposed by the nature of the data that are collected. A distinction is made between approaches that are based on compartmental models of solute and water exchange and those that represent extensions of more conventional washout procedures, which have been utilized extensively for measurements of gas volumes in the lungs. Although the compartmental approach has been used to simplify indicator dilution studies by eliminating the need for a vascular indicator, it is based on assumptions that may not be realistic. Early recirculation inevitably limits the period in which observations can be made and impairs detection of those portions of the lungs with decreased perfusion. These general principles are also used to develop a new method of analyzing osmotic transient studies. A short account is given of EVLW observations that have been made in animals and humans. Both the sensitivity and specificity of EVLW measurements in humans are uncertain, and the normal clinical range of EVLW remains in doubt.
自从五十多年前被引入以来，已经开发出了多种单通道指示剂、热稀释和渗透稀释方法来检测和测量肺内的多余液体。本简要综述讨论了为什么血管外肺水（EVLW）研究继续引起生理学家和临床医生的兴趣，以及它们变得足够可靠以更广泛应用的可能性。重点放在这些测量所基于的基本假设以及所收集数据的性质所带来的局限性上。区分了基于溶质和水交换的房室模型的方法和那些代表更传统洗脱程序扩展的方法，后者已被广泛用于测量肺内气体容积。尽管房室方法已被用于通过消除对血管指示剂的需求来简化指示剂稀释研究，但它基于的假设可能不现实。早期再循环不可避免地限制了可以进行观察的时间段，并损害了对灌注减少的肺部分的检测。这些一般原则也被用于开发一种分析渗透瞬变研究的新方法。简要介绍了在动物和人类中进行的EVLW观察。EVLW测量在人类中的敏感性和特异性都不确定，EVLW的正常临床范围也仍有疑问。
