Pre- and Post-Operative Dye Dilution Curves in Operations for Intracardiac and Pulmonary Shunts

In order to evaluate the post-operative result after correction of intracardiac and pulmonary shunts, dye dilution curves were recorded pre- and immediately post-operatively in 28 patients. A total of 56 shunts were recorded. Factors influencing the calculation are discussed In the cases where calculation was not possible, the morphology of the dilution curves was found to be clearly indicative of whether closure of the defect was established or whether a residual shunt had to be taken into consideration in the post-operative treatment. Pre-operative shunt calculation or shunt estimation by dye dilution agreed well with shunt calculation by oxymetry, thus indicating the usefulness of dye dilution during anaestesia. Shunt calculation by dye dilution correlated well with oxygen saturation before and after intracardiac repair, just as post-operative dye dilution curves were in agreement with autopsy findings and known residual shunts.