Fig. 2

Scatter chart of A intraoperative P_tcCO₂ and B postoperative P_ETCO₂. Each line represents a single patient. THRIVE + LM group use orange solid circles and solid lines, while MV + ETT group use blue hollow circles and dotted lines. Five-pointed star represents the last record of the patient. During the intraoperative period, the P_tcCO₂ values increase with time of apneic oxygenation in the THRIVE + LM group. The P_tcCO₂ values are significantly higher in the THRIVE + LM group at 2, 4, 6, 8,10 min after the start of surgery. During the postoperative period, the P_ETCO₂ values are significantly higher in the THRIVE + LM group at the end of the surgery, 5 and 10 min after the arrival of PACU. ETT endotracheal tube, LM laryngeal mask, MV mechanical ventilation, PACU post-anesthesia care unit, P_ETCO₂ end-tidal carbon dioxide pressure, P_tcCO₂ transcutaneous carbon dioxide pressure, THRIVE transnasal humidified rapid insufflation ventilatory exchange