High-velocity nasal insufflation with oxygen assist module versus conventional high-velocity nasal insufflation after extubation: an open-label randomized crossover study

Abstract

Background: The current technology of high-velocity nasal insufflation (HVNI) can be equipped with an oxygen assist module (OAM) that continuously monitors and automatically adjusts the inspired oxygen fraction (FiO2) to maintain oxygen saturation by pulse oximetry (SpO2) within the target range. This study aimed to evaluate the use of HVNI with OAM compared to conventional HVNI in patients after endotracheal extubation. Methods: This randomized crossover study enrolled 16 mechanically ventilated subjects who were ready to wean. The subjects were randomized to protocol A (HVNI with OAM for 60 min, followed by conventional HVNI for another 60 min) or protocol B (conventional HVNI for 60 min, followed by HVNI with OAM for another 60 min) after extubation. In HVNI with OAM, the target SpO2 was set at 94% with a range of 92-98%, temperature of 37 °C and flow rate of 40 L/min. In the conventional HVNI group, the attending physician adjusted the FiO2 to maintain an SpO2 of at least 94%. The primary outcome was the time in the SpO2 range between the two groups. The secondary outcomes included FiO2, transcutaneous carbon dioxide pressure (PtcCO2), respiratory rate oxygenation (ROX) index, and hemodynamic variables. Results: HVNI with OAM significantly maintained SpO2 within the target range compared to conventional HVNI [99.4% (97.4-99.8%) vs. 5.3% (1.5-68.1%); P=0.001]. The use of FiO2 was significantly lower and the ROX index was significantly higher at the end of the study in the HVNI with OAM group than in the conventional HVNI group [0.22 (0.21-0.25) vs. 0.40 (0.40-0.40); P=0.001 and 22.26 (15.94-26.46) vs. 13.01 (10.72-14.66); P=0.001, respectively]. No differences in breathing frequency, PtcCO2 or hemodynamic variables were observed between the two groups. Conclusions: HVNI with OAM can maintain SpO2 within the target range while using a lower FiO2 and providing a higher ROX index than conventional HVNI in patients after extubation. Trial Registration: This study was registered in the Thai Clinical Trial Registry (TCTR20220801007) before the inclusion of the first patient.