[Validity of thermodilution cardiac output determination in the presence of pulmonary insufficiency (author's transl)].

The thermodilution (TD) technique can be considered as the most useful method for cardiac output (CO) determinations in clinical routine. However, surgical procedures for pulmonary stenosis or atresia frequently induce pulmonary insufficiency (PI) of various degree; due to abnormal flow conditions, this may interfere with the validity of transvenous CO-determinations. This experimental study shows that the TD technique is accurate even in the presence of PI. This observation may be explained by the fact that PI results, on the one hand, in a higher distribution volume and, on the other hand, in an increased transit time of the indicator; both of these factors have opposite effects on CO calculations, thus possibly leading to a balance of either error.