[Analysis of empyrical factors for the determination of cardiac output]

With a method by which no recirculation was possible the area of a dilution curve was obtained. On this basis it was searched what percentage represents the forward triangle of the total surface of the curve. The rôle of the V/F of the sampling system on this portion of the curve was studied, surface from which the empirical constants for the estimation of the cardiac output derivates. The data obtained suggest that the forward surface triangle was V/F dependent V/F less than 1 gave smaller forward triangles, the opposite was true with V/F greater than 1. It was also found that V/F greater than 1 subestimate the total surface of the dye curve, which means cardiac outputs higher than the real. The forward surface of the curve was reduced to a minimal percentage of the total curve when a V/F less than 1 was used. Situation that makes this area non useful to obtain from them empirical factors. If an empirical factor is use in order to measure cardiac output it had to be accepted that an important grade of error is introduced.