MEASUREMENT OF CARDIAC OUTPUT BY A CONTINUOUSLY RECORDING CONDUCTIVITY METHOD

Publisher Website
Google Scholar
Abstract
A method for continuous recording of the impedance changes produced in a flowing stream by rapid injn. of a measured amt. of NaCl is described and is shown to afford accurate measurements of vol. flow of a salt soln. or of defibrinated beef blood. When the method was applied to the dog heart-lung prepn. the detd. cardiac output values averaged about 10% higher than the observed output; this is interpreted as indicating not more than a 10% loss of salt on lung passage. The method when applied to the intact dog showed fair agreement with Fick detns., the values ranging from 13% less to 22% greater than the corresponding Fick values in satisfactory expts. Jugular to femoral time in the normal intact anesthetized dogs was 5[long dash]9 secs., averaging 6.7; left ventricle to left ventricle time 7-11 secs., averaging 9.2. In most cases all, or practically all, of a rapid intra-jugular injn. of salt passed a given paint in a femoral artery before discernible recirculation occurred. Circulation time was greatly lengthened and cardiac output decreased in a hypophysectomized-thyroidectomized dog. Repeated detns. may be made at minimum intervals of about 1 min.

This publication has 5 references indexed in Scilit: