Background: A repetitive graphic display of the single-breath data for the expired gas flow rate and pulmonary gas exchange can indicate changes in cardiac and pulmonary function observed with clinical events. We have
used this noninvasive approach with anesthesia and critical care for many years to monitor airway obstruction, bronchospasm, and impaired oxygen uptake.
Case Report: To demonstrate the clinical application of this noninvasive breath-by-breath pulmonary monitoring system we present selected breath profiles from the monitoring of a 9.7 kg patient during anesthesia and pre-and postcardiac bypass for an atrioventricular septal defect repair.
Conclusions: Using standard monitoring equipment with computer display we present a noninvasive system for early and rapid recognition of conditions that may lead to adverse events in anesthesia and critical care. This
continuous monitoring enhances patient safety and also provides an indication for the effects of therapy.

Keywords: Pulmonary Gas Exchange, computer monitoring, pediatric cardiac bypass