Functional bronchoscopy: Development of a new bronchoscopic method for real-time gas exchange assessment of lobes and lung segments

Abstract

Background: There are various imaging methods in use designed to provide information on lung functional status, particularly gas exchange within specific lung segments. These complex imaging methods provide indirect information about volume and local lung function. Objectives: The objective of this research was to develop a simpler and more direct method for the functional assessment of gas exchange in lung segments. Method: We have developed a new bronchoscopic method to sample gas concentrations of oxygen and carbon dioxide at the orifices of segmental bronchi in a breathing patient. Endocapnometry and oximetry curves are displayed in real time and superimposed on the endoscopic video images. Results: The gas exchange mapping of a lung could be achieved in <5 min. We identified typical curve patterns of localized slow and fast clearance regions, and segments with higher or lower oxygen uptake. This method is simple and versatile and the data displayed can help to identify target zones for endoscopic emphysema treatments, e.g. for lowering the risk of resection surgery, or to improve ventilation strategies in ICU patients. Conclusion: This new method enables gas sampling at the lung segment level. The concomitant display of local endocapnometry and endooximetry curves allows for a better identification of target zones for endoscopic emphysema treatments or to improve ventilation strategies for patients on respiratory support.