BackgroundPatients are administered supplemental oxygen upon emergence from general anesthesia against the risk of hypoxia. However, few studies have assessed the weaning from supplemental oxygen therapy. This study investigated the frequency and risk factors of failure to discontinue supplemental oxygen at a postanesthesia care unit (PACU).MethodsThis retrospective cohort study was conducted in a tertiary hospital. We reviewed the medical records of adult patients admitted to the PACU after general anesthesia for elective surgery between January 2022 and November 2022. The primary endpoint was the frequency of failed weaning from supplemental oxygen therapy at PACU. A failed weaning was defined as oxygen saturation (SpO2) < 92% after discontinuing oxygen administration. The rate of failed discontinuation of supplemental oxygen at the PACU was assessed. Demographics, intraoperative, and postoperative factors were explored to determine potential associations with failed weaning from supplemental oxygen therapy using logistic regression analysis.ResultsWe analyzed 12,109 patients. We identified 842 cases of failed weaning from supplemental oxygen therapy, with a frequency of 1:14 (95% confidence interval [CI], 1:15–1:13). Risk factors that showed the strongest associations with failed weaning included postoperative hypothermia (odds ratio [OR], 5.42; 95% CI, 4.40–6.68;P< 0.001), major abdominal surgery (OR, 4.04; 95% CI, 3.29–4.99;P< 0.001), and preoperative SpO2< 92% in room air (OR, 3.15; 95% CI, 2.09–4.64;P< 0.001).ConclusionIn the analysis of more than 12,000 general anesthetics, an overall risk of failed weaning from supplemental oxygen therapy of 1:14 was observed. The identified risk factors may help determine the discontinuation of supplemental oxygen administration at PACU.Trial registrationNot applicable.