An RCT to compare high flow nasal cannula with standard nasal cannula to prevent desaturation in subjects undergoing EBUS-TBNA: HIFLO-EBUS trial

Background and Objective: Oxygen desaturation events occur commonly during Endobronchial endobronchial ultrasound (EBUS) guided-transbronchial needle aspiration (TBNA) performed under conscious sedation. We hypothesized that high-flow nasal cannula (HFNC) would be superior to conventional nasal cannula (NC) in preventing these hypoxemic episodes. Methods: We randomized consecutive subjects ≥18 years undergoing EBUS-TBNA to receive oxygen with HFNC or NC. The primary objective was to compare the proportion of subjects experiencing oxygen desaturation events (defined as SPO 2 < 90% for at least 30 sec) during the EBUS-TBNA procedure between the two study arms. The key secondary outcomes were the number of desaturation events during the procedure and patient comfort on a visual analogue scale (VAS [0 mm-100 mm]). Results: We randomized 300 subjects (150 in each arm). The mean ± SD age of the study population (129 [43%] females) was 46.5 ± 14 years. The proportion of subjects experiencing clinically significant hypoxemic episodes was significantly ( P < 0.0001) higher in NC (42.7% [64/150]) than in the HFNC (20% [30/150]) arm. The median nadir SPO 2 was significantly lower in the NC arm than in HFNC (91% vs. 93%, P < 0.0001). The use of HFNC during EBUS-TBNA resulted in fewer desaturation events (mean difference [95% confidence interval], 0.55 [0.22-0.88]) and better patient comfort (mean difference in VAS, 7.1 [4.3 mm-9.9 mm]). We found no difference in the complication rates. Conclusion: HFNC during EBUS reduced the number of subjects experiencing clinically significant hypoxemia, the number of desaturation events, and improved patient comfort compared to conventional oxygen therapy.