Gouezel C, et al. - This study tested the postulation that use of intravascular microdialysis incorporated in a central venous catheter would be interchangeable with the reference blood gas technique to monitor changes in blood lactate during high-risk cardiac surgery. It appeared that reliable absolute blood lactate values were obtained using microdialysis with a central venous catheter. Findings also showed that despite an excellent concordance rate shown by alterations in blood lactate measurements, changes between the two methods were poorly interchangeable with the trend interchangeability method (TIM).