Efficacy of high-flow nasal oxygenation compared with tracheal intubation for oxygenation during laryngeal microsurgery: a randomised non-inferiority study.

BACKGROUND: Oxygenation via a high-flow nasal cannula (HFNC) can be an alternative to tracheal intubation during short apnoeic procedures. This randomised, non-inferiority study assessed the efficacy of HFNC compared with tracheal intubation in laryngeal microsurgery. METHODS: Patients (≥20 yr old) undergoing laryngeal microsurgery under general anaesthesia and neuromuscular blockade were randomised to either the HFNC or tracheal intubation groups. The primary endpoint was lowest pulse oxygen saturation (SpO2) during the first 30 min of surgery. Secondary endpoints included incidence of desaturation (SpO2 <95%), hypercarbia (transcutaneous carbon dioxide [CO2] ≥8.7 kPa), and rescue intervention. RESULTS: Amongst 130 patients randomised, 118 were included in the analysis. The lowest SpO2 was 100 (98-100)% in the HFNC group (n=56) and 100 (100-100)% in the tracheal intubation group (n=62), with a mean difference of -1.4% (95% confidence interval: -2.4% and -0.3%), failing to confirm non-inferiority with a non-inferiority margin of 2%. The peak transcutaneous CO2 and end-tidal CO2 at the end of surgery were higher in the HFNC group compared with the tracheal intubation group. Incidences of desaturation, hypercarbia, and rescue intervention were more frequent in patients receiving HFNC compared with tracheal intubation. CONCLUSIONS: HFNC oxygenation was not non-inferior to tracheal intubation for maintaining oxygen saturation during laryngeal microsurgery. Considering more frequent desaturation, hypercarbia, and requirement for rescue intervention compared with tracheal intubation, HFNC should be used with cautious monitoring even for short duration airway surgery. CLINICAL TRIAL REGISTRATION: NCT03629353.