The Impact of High-flow Nasal Cannula vs Other Oxygen Delivery Devices during Bronchoscopy under Sedation: A Systematic Review and Meta-analyses

The widespread diagnostic and therapeutic application of bronchoscopy is often associated with complications like desaturation. This systematic review and meta-analysis intend to scrutinize whether the high-flow nasal cannula (HFNC) is advantageous for providing respiratory support during bronchoscopic procedures under sedation, in comparison with other conventional modalities for oxygen therapy. Materials and methods: A thorough screening of electronic databases was done till 31st December 2021 after obtaining registration in PROSPERO (CRD42021245420). Randomized controlled trials (RCT), evaluating the impact of HFNC and standard/any other oxygen-delivery devices during bronchoscopy were included in this meta-analysis. Results: We retrieved in nine RCTs, with a total of 1306 patients, the application of HFNC during bronchoscopy led to decreased number of desaturation spells [relative risk (RR) 0.34, 95% confidence interval (CI) 0.27-0.44, I 2 = 23%], higher nadir value of SpO 2 [Mean difference (MD) 4.30, 95% CI 2.41-6.19, I 2 = 96%], and improved PaO 2 from baseline (MD 21.77, 95% CI 2.8-40.74, I 2 = 99%), along with similar PaCO 2 values (MD -0.34, 95% CI -1.82 to 1.13, I 2 = 58%) just after the procedure. However, apart from desaturation spell, the findings are significantly heterogeneous. In subgroup analysis, HFNC had significantly lesser desaturation spells and better oxygenation than low-flow devices, but in comparison to noninvasive ventilation (NIV) had a lower nadir value of SpO 2 with no other significant difference. Conclusion: High-flow nasal cannula led to greater oxygenation and prevented desaturation spells more effectively in comparison with lowflow devices like nasal cannula, venturi mask, etc., and may be considered as an alternative to NIV during bronchoscopy in certain high-risk patients.