Continuous measurement of cardiac output by inert gas throughflow: Comparison with thermodilution

Abstract

Objective: The throughflow method is a new technique for continuous and minimally invasive measurement of cardiac output by the Fick principle, which uses ventilation of the 2 lungs with unequal inspired gas concentrations by means of a double-lumen endobronchial tube. It exploits steady-state gas exchange and thus permits rapid repetition of measurement. Design: Comparison of paired measurements by the throughflow method using N2O exchange with bolus thermodilution. Setting: Departments of anesthesiology in 2 university teaching hospitals. Participants: Nine patients undergoing cardiac surgery in the precardiopulmonary bypass period. Interventions: Patients intubated with a double-lumen end..