Ventilation During Flexible Bronchoscopy and Endobronchial Ultrasound Study (VEBUS)

SESSION TITLE: Bronchoscopy Poster Discussions SESSION TYPE: Original Investigation Poster Discussion PRESENTED ON: Wednesday, October 28, 2015 at 11:00 AM - 12:15 PM PURPOSE: Bronchoscopy with endobronchial ultrasound guided biopsy (EBUS) is an evolving diagnostic modality which may impact ventilation more significantly than does tradition flexible bronchoscopy. There are currently no studies looking at monitoring of ventilation during EBUS to guide monitoring choices. Our study questions whether bronchoscopy utilizing EBUS is associated with significant hypercapnea and whether the addition of capnography monitoring is warranted. METHODS: An IRB approved, semi-blinded prospective observational study was performed in subjects undergoing bronchoscopy with EBUS in the pulmonary clinic at our academic teaching institution. We measured capnography, collected all monitoring data and drew blood gases before and after procedures. Estimated nadir pH calculations were made using capnography values and a Henderson-Hasselbalch derived equation. Logistic regression was used for predictors of hypercarbia. RESULTS: During an 11 month period, data was collected on 29 subjects. All subjects developed a PCO2 >45 during EBUS (median 56, IQR 52.1-62). A significant difference in highest PCO2 (p=0.03) was observed in the subject groups with anesthesia support, an airway device placed and general anesthesia. Mode of ventilation and procedure duration were also significant predictors of highest PCO2 (p=0.01 and p=0.02). Estimated nadir pH values calculated from capnography indicated that during EBUS procedures 72.4% of subjects had a nadir pH<7.3, 31% a pH<7.2 and 10.3% a pH<7.1. There were adverse events in 4 subjects that were related to hypoventilation or consequent acidemia during our study (2 unplanned admissions, an intraprocedural change in airway device and unblinding of blood gas results due to severe hypercapnea (PCO2>80). CONCLUSIONS: Our study found that EBUS is associated with hypercapnea. All 29 subjects developed hypercapnea during their procedures. While, we do not currently know the ubiquity of hypercapnea in EBUS at other centers, clinicians should be made aware of the risk of hypercapnea in these patients Awaiting further study, we recommend consideratiion for capnography monitoring during EBUS procedures. CLINICAL IMPLICATIONS: Even given the small size of this study, all of our subjects developed hypercapnea. Clinicians should be made aware of the risk of hypercapnea in these patients. DISCLOSURE: The following authors have nothing to disclose: Leslie Wood, Jonathan Sosnov, Damon Forbes, David Bell, Kevin Chung, Edward McCann No Product/Research Disclosure Information