Changes in Oxygen Saturation During Fiberoptic Bronchoscopy: High-Flow Nasal Cannula versus Standard Oxygen Therapy

BACKGROUND: Hypoxemia is a relatively common complication in stable patients during fiberoptic bronchoscopy (FOB). To prevent this complication, high-flow nasal cannula (HFNC) has been described as an alternative to standard oxygen therapy. However, the advantages of HFNC over standard oxygen therapy in acute care patients receiving supplemental oxygen before FOB performed with an oral approach are unknown.

METHODS: We conducted an observational study that involved subjects with a presumptive diagnosis of pneumonia and a clinical indication for a bronchial aspirate sample. The type of oxygen support (standard oxygen therapy vs HFNC) was selected according to availability. The oxygen flow in the HFNC group was 60 L/min. In both groups, the F_IO2 was set at 0.40. Hemodynamic, respiratory dynamics, and gas exchange data were collected at baseline, before, during, and 24 h after FOB.

RESULTS: Forty subjects were included, 20 in each group (HFNC and standard oxygen therapy). The study was performed on day 5 of hospitalization in the HFNC group and on day 4 in the standard oxygen therapy group (P = .10). No significant between-group differences in baseline characteristics were observed. HFNC vs standard oxygen therapy was associated with a smaller decrease in S_pO2 levels during the procedure (94% vs 90%; P = .040, respectively) and with less variation between the last S_pO2 measured before FOB and the lowest S_pO2 during FOB (Δ S_pO2): 2% versus 4.5% (P = .01, respectively).

CONCLUSIONS: In acute subjects who required oxygen support before FOB, the use of HFNC during FOB with an oral approach was associated with a smaller decrease in S_pO2 and lower Δ S_pO2 compared with standard oxygen therapy.