The Diagnosis of Circulatory Shunts by the Nitrous Oxide Test
Improvements in Technic and Methods for Quantification of the Shunt
The nitrous oxide test for the detection and localization of left-to-right shunts has previously been studied clinically. Further experience with the method has shown that a higher N2O concentration and an earlier sampling period result in a larger arteriovenous N2O difference that increases the sensitivity of the test and further minimizes the importance of possible analytic errors. In addition, a method is described of determining the magnitude of the shunt from the results of a N2O test. The results of 150 N2O tests performed with the improved technic are presented, and compared to the results obtained with the O2 method in a group of patients on whom both tests were carried out.
- © 1958 American Heart Association, Inc.