OxyMask is not superior to a non-rebreathing oxygen mask for oxygen supply in a post-anesthesia care unit in Korea: a comparative study

<strong>Background</strong> OxyMask, a novel concept, has recently been used to administer oxygen to patients postoperatively, who had undergone general anesthesia. This study aimed to evaluate the occurrence of hypoxia in patients under general anesthesia upon arrival at the post-anesthesia care unit (PACU) using arterial blood gas analysis, and to compare the effectiveness of OxyMask with non-rebreathing oxygen mask for oxygen administration. <strong>Methods</strong> We retrospectively investigated anesthesia records based on electronic medical records of 460 patients from April to November in 2021. We analyzed patients aged 20 years or older who had undergone general anesthesia and whose perioperative arterial blood gas analysis results were available upon arrival at PACU. These patients were grouped into the non-rebreathing oxygen mask (n=223) and OxyMask groups (n=237), and statistical analysis was performed utilizing their anesthesia records. <strong>Results</strong> No hypoxia occurred upon arrival at the recovery room. The oxygen concentration increased after oxygen administration; its concentration during the recovery room period (Δ₂PaO₂) was 10.7 ± 42.3 and 13.9 ± 38.5 mmHg in the non-rebreathing oxygen mask and OxyMask groups, respectively, with no significant difference between the two groups. Moreover, the arterial oxygen saturation between the end of surgery and upon arrival at the PACU (Δ₁SaO₂) and the arterial oxygen saturation 20 min after oxygen administration at the PACU (Δ₂SaO₂) did not significantly differ between the groups. <strong>Conclusion</strong> OxyMask is not superior to the non-rebreathing oxygen mask in terms of the effectiveness of oxygen supply.