THE INFLUENCE OF THE COLLAPSIBILITY OF VEINS ON VENOUS PRESSURE, INCLUDING A NEW PROCEDURE FOR MEASURING TISSUE PRESSURE

Open Access
Publisher Website
Google Scholar
Abstract
In vitro studies of veins and collapsible rubber tubes of varying wall thicknesses show that for each tube there is a range of free volume change in which the internal pressure and external pressure are equal. During flow through tubes within this range of free distensibility, the internal pressure is equal to external pressure and is totally independent of the pressure at distal and central points. The ratio of this freely distensible range to total volume increases as the wall thickness decreases. In vivo studies show that the arm veins are freely collapsible at normal volume flows and that when such veins are collapsed, the pressure within them is equal to the tissue pressure about them and is independent of the venous pressure at any point nearer the heart. When the vein is collapsed at any point between the point of measurement and the auricle, the peripheral venous pressure is a function of the collapsing pressure and may be independent of right auricular pressure. The restrictions which this principle places on the interpretation of peripheral venous pressure are pointed out. The freely collapsible nature of the arm veins may also be utilized for purposes of measuring tissue pressure.

This publication has 3 references indexed in Scilit: