High-flow nasal cannula for reducing hypoxemic events in patients undergoing bronchoscopy: A systematic review and meta-analysis of randomized trials

BACKGROUND: Patients undergoing bronchoscopic procedures may develop hypoxemia and severe complications. High-flow nasal cannula (HFNC) may prevent hypoxemic events during bronchoscopy. We conducted a systematic review of randomized controlled trials (RCTs) to evaluate the effectiveness of HFNC in these patients. METHODS: We conducted a search in PubMed, Embase, and the Cochrane Library for RCTs published before November 2021. Individual effect sizes were standardized, and a meta-analysis was performed to calculate the pooled effect size using random-effects models. The primary outcome was the incidence of hypoxemic events (oxygen saturation [SpO(2)] < 90%) during bronchoscopy. Secondary outcomes included the incidence of interrupted bronchoscopy due to desaturation, lowest SpO(2) during bronchoscopy, partial pressure of oxygen (PaO(2)), partial pressure of carbon dioxide (PaCO(2)), end-tidal CO(2) (EtCO(2)) at the end of bronchoscopy, and the incidence of intubation after the procedure. RESULTS: Five trials involving 257 patients were reviewed. The incidence of hypoxemic events was lower in the HFNC group than in the conventional oxygen therapy group (risk ratio, 0.25; 95% confidence interval [CI], 0.14–0.42). The lowest SpO(2) during the procedure was significantly higher in the HFNC group than in the conventional oxygen therapy group (weighted mean difference [WMD], 7.12; 95% CI, 5.39–8.84). PaO(2) at the end of the procedure was significantly higher in the HFNC group than in the conventional oxygen therapy group (WMD, 20.36; 95% CI, 0.30–40.42). The incidence of interrupted bronchoscopy due to desaturation, PaCO(2) and EtCO(2) at the end of the procedure, and the incidence of intubation after the procedure were not significantly different between groups. CONCLUSIONS: HFNC may reduce the incidence of hypoxemic events and improve oxygenation in patients undergoing bronchoscopy.