A Randomized Controlled Trial Comparing a Mapleson Circuit with Nasal Trumpet to Standard Oxygen Supplementation during EBUS Bronchoscopy under Monitored Anesthesia Care.

Background: Endobronchial ultrasound (EBUS) procedures tend to be longer than routine bronchoscopies. Increased duration and sedative dosing put patients at increased risk for -hypoxic events.

Objective: To determine whether oxygen supplementation via a nasal trumpet connected to a Mapleson B circuit (NTM) was effective in decreasing hypoxic events when compared with the standard of care, oxygen supplementation with a nasal cannula (NC).

Methods: Patients referred for EBUS-guided transbronchial needle aspiration with monitored anesthesia care (MAC) were randomized 1:1 to NTM or to NC. Hypoxia-related procedural interruptions, the primary endpoint of the study, were documented for all patients. Patients in the NC group who had refractory desaturations were allowed to cross over to the NTM group. Secondary endpoints included: number of crossovers from NC to NTM, sedative dosing, total procedure times, whether procedure goals were achieved, complications apart from hypoxia, patient discharge status.

Results: Fifty-two patients were randomized to NC and 48 to NTM. Baseline characteristics were comparable. The NC group had significantly more interruptions than did the NTM group (p < 0.001). Procedure duration was also significantly (p < 0.03) shorter for the NTM group. Fourteen patients were crossed over from NC to NTM because of hypoxia. Thirteen out of the 14 completed the procedure with no interruptions. All procedures were successfully completed, and all goals were achieved. All patients returned to baseline status prior to discharge. Three minor complications of epistaxis occurred.

Conclusion: For patients undergoing EBUS with MAC, oxygen supplementation with NTM significantly decreased the incidence of hypoxic events when compared with NC. NTM may also be of value for other subsets of patients who are at increased risk for desaturation when undergoing bronchoscopy.