Department of Intensive Care Medicine, Leiden University Medical Center, The Netherlands.
Curr Opin Crit Care. 2010 Jun;16(3):231-6. doi: 10.1097/MCC.0b013e3283378185.
The physiology of the venous part of the human circulation seems to be a forgotten component of the circulation in critical care medicine. One of the main reasons, probably, is that measures of right atrial pressure (Pra) do not seem to be directly linked to blood flow. This perception is primarily due to an inability to measure the pressure gradient for venous return. The upstream pressure for venous return is mean systemic filling pressure (Pmsf) and it does not lend itself easily to be measured. Recent clinical studies now demonstrate the basic principles underpinning the measure of Pmsf at the bedside.
Using routinely available minimally invasive monitoring of continuous cardiac output and Pra, one can accurately construct venous return curves by performing a series of end-inspiratory hold maneuvers, in ventilator-dependent patients. From these venous return curves, the clinician can now finally obtain at the bedside not only Pmsf but also the derived parameters: resistance to venous return, systemic compliance and stressed volume.
Measurement of Pmsf is essential to describe the control of vascular capacitance. It is the key to distinguish between passive and active mechanisms of blood volume redistribution and partitioning total blood volume in stressed and unstressed volume.
人体循环的静脉部分生理学似乎是重症医学中循环生理学的一个被遗忘的组成部分。其中一个主要原因可能是右心房压（Pra）的测量似乎与血流量没有直接联系。这种看法主要是由于无法测量静脉回流的压力梯度。静脉回流的上游压力是平均系统充盈压（Pmsf），它不容易测量。最近的临床研究现在证明了在床边测量 Pmsf 的基本原理。
在依赖呼吸机的患者中，使用常规的连续心输出量和 Pra 的微创监测，可以通过进行一系列吸气末保持操作，准确地构建静脉回流曲线。从这些静脉回流曲线中，临床医生现在终于可以在床边获得不仅是 Pmsf，还有衍生参数：静脉回流阻力、全身顺应性和应激容积。
测量 Pmsf 对于描述血管容量控制至关重要。它是区分血容量再分布的被动和主动机制以及区分应激和非应激容积中总血容量的关键。
