Evaluation of a fiberoptic system for airway pressure monitoring

Objective..Our objective was to evaluate the accuracy of a novel fiberoptic system for airway pressure measurement at the carinal end of the endotracheal tube in an in vitro pediatric lung model. Methods. A fiberoptic pressure measuring system was compared to the conventional method of measuring airway pressure with a pneumatic transducer using a test lung model. Pressure measurements were obtained using four endotracheal tubes of various internal diameters (ID) (3 to 6 mm) during simulated spontaneous and mechanical ventilation. Airway pressure was measured using both methods simultaneously and the results were compared by statistical analysis. Results. Airway pressure measured by the fiberoptic system was not significantly different from measurements obtained by the pneumatic transducer except when using the 3-mm and 4-mm ID endotracheal tubes during mechanical ventilation. Conclusions. We conclude that the fiberoptic system provides accurate and precise measurement of airway pressure during spontaneous and mechanical ventilation. Additionally, the statistically significant differences obtained for 3- and 4-mm tubes are not large enough to be clinically significant. The fiberoptic system offers advantages over the pneumatic system for measuring the airway pressure. These advantages include decreased chance of false pressure measurement secondary to occlusion with water or mucous, less chance of kinking, and, possibly, more rapid response to pressure changes due to the mechanical ventilator.