BACKGROUND: Advanced bronchoscopic procedures have become a widely prevalent evaluation and treatment modality. These procedures require appropriate sedation and respiratory support. This study directly compares three respiratory support methods during advanced bronchoscopy. METHODS: This three-arm, prospective, block randomised trial included 60 consenting adult patients that were referred for advanced bronchoscopy involving endobronchial ultrasound (EBUS) with transbronchial needle aspiration and met inclusion/exclusion criteria. Patients were randomised to undergo bronchoscopy through a laryngeal mask airway (LMA) or with a high-flow nasal cannula (HFNC) or low-flow nasal cannula (NC), with bronchoscopy performed through a bite block. Demographic, procedural and clinical parameters were compared between the three groups, including complications, oxygenation, ventilation and need for intervention. RESULTS: Analysis according to intention to treat was made for the 20 patients in each arm. There were no significant differences in demographic parameters, pre-morbidities and procedure type and duration between groups. Hypoxia was significantly more common in the NC group (90%) compared with the LMA (45%) and HFNC (26%) groups (p<
0.01). The need for interventions and their number were also lower in the LMA (40%) and HFNC (52.6%) groups compared with the NC group (90%, p<
0.01). A multivariate analysis confirmed both HFNC and LMA as independent predictors of a lower rate of recurrent desaturation events and fewer complications in general compared with NC. CONCLUSION: In this prospective randomised trial, we demonstrated the advantages of using LMA or HFNC over NC during advanced bronchoscopy with EBUS.