Measurement of Venous Flow by Continuous Thermodilution and its Application to Measurement of Mammary Blood Flow in the Goat

Abstract

The thermodilution method of Fegler, previously used as a single injection technique to measure the flow in one of the main veins draining the mammary gland of goats, has been adapted to a continuous injection technique. Saline at room temperature is injected at rates of 10 to 50 ml/min for 20 to 60 sec and the blood flow is calculated directly from the fall in blood temperature downstream. The method has been checked in vivo by cannulation of the vessel and shown to be as accurate as the single injection technique and the measurement of mammary flow on the Fick principle. It is particularly valuable for determining rapidly the proportion of the mammary venous flow leaving by each of the two main veins.