Nonintubated bronchoscopic interventions with high-flow nasal oxygen A retrospective observational study

To determine the feasibility on maintaining oxygenation of high-flow nasal oxygenation (HFNO) with bispectral index-guided intravenous anesthesia for nonintubated interventional bronchoscopy (NIIB). If desaturation happens, the factors influencing intraprocedural desaturation were also analyzed. This is a single-center retrospective study on patients receiving NIIB with HFNO and intravenous anesthesia guided by bispectral index levels to the depth of general anesthesia, which were between 40 and 60. Intraprocedural desaturation (SPO2 < 90%) and complications (bleeding, delayed discharge, unexpected admission) were collected. Factors affecting desaturation and complications were analyzed including patients' factors (age, American Society of Anesthesiologists classification, body mass index [BMI]), procedural factors (procedural time, with or without use of cryoprobe), and setting (outpatient or hospitalized). Records of 223 patients receiving NIIB were collected. The NIIB procedures time was 56.1 +/- 26.8 minute. Sixty patients (26.9%) presented desaturation events. Higher BMI, but not procedure time or setting, was significantly associated with desaturation. The desaturation were resolved after relieving upper airway obstruction but 1 patient required bag-valve-mask ventilation to restore oxygenation. Accidental massive bleeding and intraprocedural desaturation during tracheal and bronchial recannulation with cryoprobes happened in 2 patients and 1 of them was admitted to intensive care unit. HFNO is feasible to maintain oxygenation during NIIB only if there is effective upper airway management especially for patients with higher BMI. Longer procedural time and different setting did not affect the desaturation rate. Complications and unexpected admission were associated with the use of cryoprobes.