Changes of Peripheral Venous Tone and Central Transmural Venous Pressure during Immersion in a Thermo-Neutral Bath.

摘要

Pheripheral venous tone, central venous and oesophageal pressures were recorded while the upright sitting subjects were immersed to the neck in a thermoneutral water bath. The central venous pressure rose from 3.4 to 15.2 mm Hg. The transmural pressure, which determines the enddiastolic volume of the heart, increased by 8.0 mm Hg. Plethysographic determinations of peripheral venous tone revealed a relaxation of the peripheral veins; after a quick initial decrease of the volume elasticity coefficient (E'15) from 16.6 to 13.5 mm Hg/ml/100g tissue there is a continuous decline to 11.8 mm Hg/ml/100g tissue after 3 hrs immersion. This relaxation persists for at least 1 hr after termination of immersion. (Author)