Risk Factors for Postoperative Hypoxemia in Pediatric OSAHS Patients Undergoing Adenotonsillectomy: A Retrospective Study

Risk Factors for Postoperative Hypoxemia in Pediatric OSAHS Patients Undergoing Adenotonsillectomy: A Retrospective Study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Risk Factors for Postoperative Hypoxemia in Pediatric OSAHS Patients Undergoing Adenotonsillectomy: A Retrospective Study Yan Li, Shenghua Yu, Jingjie Cai, Xueting Yang, Rong Wei, Yan Jiang, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7906867/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 7 You are reading this latest preprint version Abstract Baclground : This study aimed to identify risk factors for perioperative respiratory adverse events in children with obstructive sleep apnea hypopnea syndrome (OSAHS) undergoing tonsillectomy under general anesthesia without supplemental oxygen in the post-anesthesia care unit (PACU), in order to provide clinical practice and improve management strategies. Methods A retrospective analysis was conducted on OSAHS pediatric patients admitted to the PACU without oxygen supplementation after surgery at our hospital between February and June 2023. Patients were categorized into hypoxemia and non-hypoxemia groups based on their PACU oxygen saturation levels. Binary logistic regression analysis was employed to identify independent risk factors for hypoxemia. Results A total of 660 pediatric patients were reviewed, of which 631 met the inclusion criteria. Among these, 146 children (23.1%) developed hypoxemia in the PACU. Preoperative abnormalities on chest X-ray findings (such as increased and blurred lung markings) and the COVID-19 Anit-IgG in blood tests showed statistically significant differences between the hypoxemia and non-hypoxemia groups. The sufentanil dose used intraoperatively was significantly higher in the hypoxemia group compared to the non-hypoxemia group (2.9 ± 1.4 µg vs. 2.5 ± 1.2 µg, P < 0.001). Notably, children who had a cough within one week prior to surgery were higher risk of developing hypoxemia in the PACU (61.6% vs. 16.0%). Among these patients, 28.3% required a chin lift, 7.1% required an oropharyngeal airway, and 5.1% needed bag-mask ventilation. Binary logistic regression analysis identified abnormal chest X-ray findings, recent preoperative cough, COVID-19 Anti-IgG positive, and higher intraoperative sufentanil dosage as independent risk factors for hypoxemia in the PACU. Conclusions Postoperative hypoxemia in pediatric OSAHS patients is significantly associated with preoperative cough, abnormal chest X-ray, and sufentanil dosage. Enhanced perioperative monitoring and tailored management strategies are recommended for high-risk patients. Obstructive sleep apnea hypopnea syndrome post anesthesia care unit hypoxemia perioperative complications risk factors pediatrics Figures Figure 2 1. Introduction Pediatric surgical patients have a relatively high incidence of perioperative respiratory adverse events, with the most common being oxygen desaturation( 1 ). Upper respiratory tract infections are a known risk factor for these complications. In children presenting with severe symptoms—such as wheezing, purulent nasal discharge, fever over 38.5°C, or lethargy—elective surgery should typically be postponed for at least 15 days. However, for those with mild symptoms like a runny nose, sneezing, or a mild cough, careful evaluation and management by an experienced pediatric anesthesiologist may allow surgery to proceed safely( 2 , 3 ). Preoperative risk assessment is crucial for reducing the incidence of perioperative respiratory adverse events. Studies have shown that the colds score can effectively help lower the occurrence of such events in pediatric patients, indicating that early identification of high-risk children and timely, targeted interventions can significantly reduce the risk of severe complications and mortality.( 1 , 2 , 4 ). Children with respiratory symptoms or OSAHS are particularly prone to hypoxemia following the use of opioids, such as sufentanil and remifentanil, and muscle relaxants, such as rocuronium and atracurium( 3 , 5 – 7 ). Numerous factors contribute to postoperative hypoxemia in OSAHS patients. This study aims to identify high-risk pediatric patients with OSAHS more likely to experience postoperative hypoxemia so that enhanced monitoring and preventive measures can be implemented following extubation and transfer to the PACU, ultimately reducing respiratory complications and facilitating smoother perioperative recovery. 2. Materials and Method 2.1 Object This retrospective study analyzed pediatric patients with OSAHS who underwent tonsillectomy and adenoidectomy under general anesthesia between February and June 2023 at a specialized children's hospital in Shanghai. Following extubation, these patients were transferred to the PACU without supplemental oxygen. The study obtained informed consent from the guardians and was approved by the Clinical Trial Ethics Committee of Shanghai Children's Hospital (Approval No. 2024R032-E01). Inclusion criteria: ( 1 ) Pediatric patients diagnosed with OSAHS were evaluated and confirmed by otolaryngologists based on nasal endoscopy findings in the outpatient clinic and scheduled for surgery under general anesthesia. ( 2 ) American Society of Anesthesiologists (ASA) physical status classification I or II. ( 3 ) Patients extubated at the end of surgery and transferred to the PACU without receiving oxygen via face mask. ( 4 ) Patients under 18 years of age. ( 5 ) Availability of complete and detailed medical records. Exclusion criteria: ( 1 ) Preoperative SpO₂ < 95% without supplemental oxygen. ( 2 ) History of chronic or severe anemia. ( 3 ) Presence of comorbidities such as congenital heart disease, liver dysfunction, or renal dysfunction. ( 4 ) Cases in which surgery was canceled due to other factors or patients who required resuscitation during the procedure. 2.2 Date collection and management This study collected basic patient information from the hospital’s inpatient system, including sex, age, height, weight, and presence of cough within one week prior to surgery, as well as laboratory and imaging results such as white blood cell count, COVID-19 IgG antibody levels, and chest X-ray findings. Surgical and anesthetic data—including intraoperative administration of sufentanil, remifentanil, midazolam, dexmedetomidine, and duration of surgery—were obtained from the anesthesia information system. The study also recorded any episodes of oxygen desaturation in the PACU and evaluated whether normal SpO₂ levels could be restored using interventions such as face mask oxygen supplementation, jaw support, or the use of an oropharyngeal airway or bag-mask ventilation. 2.3 Anesthetic Management All children fasted for 8 hours for solids and 2 hours for clear liquids before surgery. Upon arrival in the anesthesia preparation room, oral midazolam (0.5 mg/kg, up to a maximum of 15 mg) was administered for preoperative sedation. After entering the operating room, standard monitoring was initiated, including pulse oximetry, noninvasive blood pressure, and electrocardiography. Once all medications and equipment were fully prepared, anesthesia induction began. Sufentanil (0–0.2 µg/kg) and/or remifentanil (0–2 µg/kg) were administered, along with rocuronium (0.6 mg/kg) or cisatracurium besylate (0.1 mg/kg), and propofol (3 mg/kg). Atropine (0.01 mg/kg) was routinely given to reduce oral and airway secretions. Mask-assisted ventilation was performed, followed by endotracheal intubation under video laryngoscope guidance. Mechanical ventilation was initiated using pressure control mode with a tidal volume of 6–8 mL/kg and a respiratory rate of 15–22 breaths/min, maintaining pressure of end-expiratory carbon dioxide (Et CO₂) between 35 ~ 45 mmHg. Anesthesia was maintained with sevoflurane inhalation, targeting a minimum alveolar concentration (MAC) of approximately 1.2. At the end of the surgey, sevoflurane was discontinued, and the airway and oral secretions were cleared. Once the child regained spontaneous respiration, neostigmine (0.04–0.07 mg/kg) was administered to reverse muscle relaxation. The endotracheal tube was removed when a tidal volume of at least 5 mL/kg was achieved, and face mask oxygen was provided as needed. After confirming oxygen saturation had reached 100%, the child was transferred to the PACU under the supervision of an anesthesiologist. In the PACU, vital signs were continuously monitored, and supplemental oxygen was administered as needed. 2.4 Study groups Patients were divided into two groups based on the occurrence of hypoxemia in the PACU: the hypoxemia group and the non-hypoxemia group. In the hypoxemia group, patients required interventions such as face mask oxygen supplementation and jaw thrust to restore normal oxygen saturation. If these measures failed to correct hypoxemia, positive pressure ventilation via face mask or endotracheal intubation was performed to re-establish airway control and normalize oxygen saturation levels. 2.5 Diagnostic Criteria for Hypoxemia and recent cough In the PACU, if a patient who is not receiving supplemental oxygen has a continuously monitored SpO2 < 91% for more than 30 seconds, it can be determined that the patient is experiencing hypoxemia( 1 , 8 , 9 ). A recent cough was defined as a distinct and persistent coughing episode lasting more than 5 seconds, occurring within one week prior to hospital admission( 1 ). 2.6 Statistical Analysis Statistical analysis was performed using SPSS version 26.0. For normally distributed continuous data, results were expressed as mean ± standard deviation, and comparisons between groups were conducted using the independent samples t-test. Non-normally distributed continuous data were presented as median, and comparisons were made using the non-parametric Mann–Whitney U test. Categorical variables were expressed as number (percentage) [n(%)] and compared using the chi-square test. Baseline clinical characteristics and preoperative laboratory results were compared between the two groups. Variables with statistically significant differences in univariate analysis were further analyzed using univariate logistic regression. Variables with P < 0.05 in the univariate logistic regression were included in a multivariate logistic regression model to identify independent risk factors for postoperative hypoxemia in children with OSAHS. A P-value < 0.05 was considered statistically significant. 3. Result 3.1 Comparison of general information between the two groups The study included 660 pediatric cases of OSAHS. Thirteen cases were excluded due to incomplete medical records, and 16 due to additional concurrent surgeries, resulting in 631 eligible cases. Among these, 146 children developed hypoxemia, while 485 did not, as shown in the flowchart (Fig. 1). No significant differences were found between the two groups in terms of gender, age, height, weight, BMI, or white blood cell count. General clinical data for both groups are presented in Table 1. In the hypoxemia group, 41.1% of the children tested negative for COVID-19 Anti-IgG before surgery, 85.6% had normal chest X-rays with no blurred lung markings, and 58.9% had no preoperative cough. Anesthetic use, including remifentanil, midazolam, and dexmedetomidine hydrochloride, as well as the duration of surgery, did not differ significantly between the groups. However, intraoperative sufentanil dosage was notably higher in the hypoxemia group compared to the non-hypoxemia group (2.9±1.4 µg vs. 2.5±1.2µg), (Table 1). No special interventions were needed in the non-hypoxemia group. Additionally, neither group had any cases requiring re-intubation or tracheostomy. 3.2 Incidence of Hypoxemia During PACU This study included 631 children with OSAHS who underwent tonsillectomy and adenoidectomy under general anesthesia and were admitted to the PACU without supplemental oxygen. Among these patients, 146 experienced hypoxemia, with an incidence rate of 23.1%. 3.3 Logistic Regression Analysis of Risk Factors for Hypoxemia During PACU The risk of hypoxemia in OSAHS children upon admission to the PACU was assessed as follows: hypoxemia present = 1, hypoxemia absent = 0. Significant factors identified in Table 1 were assigned the following values: COVID-19 Anti-IgG positive = 1, abnormal preoperative chest X-ray = 1, and presence of cough in the week before surgery = 1. A binary logistic regression analysis of risk factors for postoperative hypoxemia in OSAHS patients in the PACU indicated that recent cough, abnormal chest X-ray findings, COVID-19 Anti-IgG status, and sufentanil dosage were independent risk factors. Children with abnormal preoperative chest X-rays were found to have a 13.4 times higher risk of hypoxemia, and those with a recent cough had a 4.6 times higher risk compared to children with normal X-rays and no recent cough (Fig. 2). 3.4 Management of hypoxemia in children with preoperative cough Among the 631 children in the study, 99 had a history of preoperative cough. Of these, 61 children (61.6%) required supplemental oxygen via a face mask to address oxygen desaturation. Additionally, 28 children (28.3%) needed jaw support, 7 children (7.1%) required an oropharyngeal airway, and 5 children (5.1%) needed positive pressure oxygen via bag-mask ventilation to restore normal SpO 2 levels (Table 2). 4. Discussion Our previous research indicated that children with OSAS undergoing adenoidectomy or tonsillectomy are at a higher risk of experiencing postoperative hypoxemia ( 10 ). This study further examined hypoxemia rates among children with OSAHS in the PACU without supplemental oxygen, finding an incidence of 23.1%. Independent risk factors included the presence of a cough within one week prior to surgery, increased and blurred lung markings on preoperative chest X-rays, and the intraoperative dosage of sufentanil. Respiratory complications during hospitalization are closely associated with hypoventilation in the PACU. Identified risk factors include OSAHS, preoperative use of extended-release opioids, higher intraoperative opioid administration, isoflurane-based anesthesia, and prolonged surgical duration ( 11 , 12 ). In our study, however, the total dose of sufentanil was relatively low in both the hypoxemia and non-hypoxemia groups (2.9 ± 1.4 µg vs. 2.5 ± 1.2 µg), yet respiratory adverse events still occurred postoperatively. This may suggest that pediatric patients with OSAHS are inherently more sensitive to opioids, such that even small doses can contribute to respiratory depression. Further research is warranted to clarify this association. Laporta et al. noted that a considerable amount of opioid-induced apnea occurs within the first few hours post-PACU discharge, often signaling early deterioration( 11 ). Patients with OSAHS often experience chronic hypoxia due to obstructed airway ventilation, which may increase their sensitivity to opioids. As a result, even low doses of opioids can pose a risk of respiratory depression or apnea in these patients. Excessive use of opioids is known to increase the risk of respiratory depression and apnea. Studies have recommended reducing opioid dosages during pediatric adenotonsillectomy and advocating for individualized analgesic regimens based on patient-specific needs( 13 ). However, in our study, even a relatively low dose of sufentanil (approximately 0.1–0.13 µg/kg) was associated with an increased risk of perioperative respiratory adverse events. This may be partially attributed to a synergistic effect with midazolam, which was used as premedication in some patients. Previous research comparing midazolam and dexmedetomidine in pediatric tonsillectomy found no significant differences in extubation time or length of stay in the PACU between the two groups( 14 ). However, dexmedetomidine demonstrated superior efficacy in postoperative pain control, suggesting that it may offer analgesic benefits without increasing the risk of respiratory compromise. Current PACU discharge criteria do not include systematic assessment of respiratory drive, particularly in patients receiving mask oxygen, which can delay the detection of early respiratory decline( 15 ). Gail et al. reported that patients experiencing apnea or oxygen desaturation in the PACU face a 33% risk of respiratory complications during their hospital stay, while those without such episodes have a risk of ≤ 2%( 16 ). In our study, we did not quantify hypoxemia rates in children who received mask oxygen; however, most patients in the PACU were placed on oxygen supplementation immediately upon arrival. This suggests that even patients with normal SpO 2 levels might still be at risk for hypoxemia. Preoperative symptoms such as coughing and abnormal chest X-ray findings—such as increased or blurred pulmonary markings—may indicate airway hypersensitivity or underlying pathological changes. These conditions can predispose children to postoperative hypoxemia, particularly when supplemental oxygen is not administered in the PACU. Sanz et al. investigated the association between mild pneumonia and hypoxemia, identifying chronic pulmonary disease, bilateral chest X-ray involvement, and hypoalbuminemia as contributing factors( 17 ). Given the retrospective nature of this study and the limited number of patients with preoperative cough, we did not perform a stratified analysis based on the severity of cough or chest X-ray abnormalities. For children requiring surgery who have had a recent upper respiratory tract infection, it is generally recommended to delay surgery for at least two weeks after symptom resolution. A normal preoperative chest X-ray may help reduce the risk of perioperative respiratory complications( 3 ). A prospective study on children undergoing inguinal hernia repair revealed that the presence of respiratory symptoms and exposure to passive smoking are significant risk factors for perioperative respiratory adverse events. For children with respiratory symptoms, postponing surgery by 15 days may be insufficient, as these patients tend to experience a higher incidence of complications compared to those without such symptoms( 2 ). The results of this study showed that children with preoperative chest X-rays indicating increased or blurred pulmonary markings had a 13.4-fold higher risk of developing postoperative hypoxemia compared to those with normal chest X-ray findings. Similarly, children with a preoperative cough had a 4.6-fold higher risk of hypoxemia than those without cough symptoms. A recent study on the use of high-flow nasal oxygen after extubation in gynecological surgeries indicated that compared to traditional oxygen therapy strategies, providing 2 hours of high-flow nasal oxygen after extubation can improve oxygen exchange and reduce atelectasis( 18 ). However, not all research findings are consistent. One study comparing the use of nasal cannula oxygen (2–4 L/min) to air during the transfer from the operating room to the PACU found that the incidence of mild hypoxemia (SpO 2 ≤ 92%) was 6% in the oxygen group and 20% in the air group, while the incidence of moderate hypoxemia (SpO 2 ≤ 90%) was 2% and 10% respectively ( 19 ). Mild hypoxemia is relatively common during the transfer from the operating room to the PACU, however, its incidence and severity could be decreased by administration of supplemental oxygen. It remains unclear whether short-term exposure to mild to moderate hypoxemia is harmful to patients, eventually each event of mild to moderate hypoxemia should be avoided. On the other hand, routine supplemental oxygen may risk exposing patients to hyperoxia( 8 , 20 ). Therefore, in clinical anesthesia practice, real-time monitoring of patient SpO 2 and adjusting the oxygen concentration based on actual conditions may be a more effective approach. In this study, several essential preoperative tests were required for pediatric patients due to various factors. These tests included complete blood count, coagulation profile, liver and renal function tests, and electrolyte levels to assess the patients' internal environment prior to surgery. Additionally, preoperative chest X-rays and electrocardiograms were performed to evaluate cardiopulmonary function, ensuring the safe administration of surgical procedures and anesthetic agents. Given the high prevalence of OSAHS in the local population and cultural factors influencing families' decisions, some guardians still requested surgery for patients exhibiting recent cough or mild pulmonary infections. Consequently, a number of patients with abnormal chest X-ray findings underwent surgery in this study. The current research aims to evaluate the risk of postoperative hypoxemia in children with preoperative abnormal chest X-rays, thereby providing valuable insights for subsequent treatment considerations. This study is a retrospective analysis, and its limited sample size may constrain the ability to include additional relevant factors in the statistical analysis. These factors include the use of antibiotics in the 1–2 weeks prior to surgery, the experience level of the surgeon, the anesthesiologist overseeing the case, neuromuscular blockade recovery, the timing and frequency of hypoxemia episodes in the PACU, and the length of stay in the recovery room. Each of these factors could potentially impact the outcomes observed. Furthermore, SpO 2 was not monitored during the transfer from the operating room to the PACU, which may have resulted in undetected hypoxemia in some patients. Finally, there was no follow-up on the OSAHS children to assess the incidence of respiratory-related events, such as respiratory depression and hypoxemia, after PACU discharge, which could provide additional insights into final outcomes. This identifies an important direction for future research aimed at enhancing post-PACU monitoring strategies for high-risk patients predisposed to hypoxemia. 5. Conclusion During the early stages of anesthesia recovery, it is crucial to monitor all patients for signs of respiratory depression. For children with OSAS undergoing adenotonsillectomy, those who had a cough within the week before surgery, abnormal chest X-ray findings such as increased or blurred lung markings, or a recent COVID-19 infection, close postoperative monitoring is especially important. Additionally, the intraoperative dose of sufentanil is an independent risk factor for hypoxemia in children with OSAHS, underscoring the need for careful observation in these high-risk cases. Abbreviations ASA American Society of Anesthesiologists, BMI body mass index, OSAHS obstructive sleep apnea hypopnea syndrome, PACU post-anesthesia care unit, SpO₂ peripheral capillary oxygen saturation, WBC white blood cell count. Declarations Acknowledgments This study was supported by department of Anesthesiology, Shanghai Children’s Hospital. The authors would like to thank the patients who participated in this trial. Author Contributions YSH and WR designed the study, conducted the study, acquired the data and revised the manuscript. CJJ acquired the data, analyzed the data, prepared figures and tables, wrote the manuscript and modified the language. YXT and LY acquired the data and analyzed the data. JY analyzed the data and wrote the manuscript. LY and ZTX revised the manuscript and modified the language. All authors read and approved the final version of the manuscript. Data availability The datasets used and/or analyzed during the current study is available from the corresponding author on reasonable request. Funding and Conflict of Interest The study was funded by the Clinical Research Training Program of Shanghai Children's Hospital (2023YLY08). No competing interests or funding declared. Ethics approval The study protocol was in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines and approved by Ethics Committee of Shanghai Children’s Hospital (2024R032-E01). 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Br J Anaesth (2023), 131(6): e186-e7. doi:10.1016/j.bja.2023.09.009 Tables Table 1 Comparison of Demographic information Between the Two Groups Variables Hypoxemia Group（n=146） Non-Hypoxemia Group（n=485） P Age, (years) 5.3±2.0 5.5±2.2 0.252 Sex，n M F 93 (63.7%) 53 (36.3%) 296 (61.0%) 189 (39.0%) 0.628 Height (cm) 116.1±14.4 118.7±15.2 0.069 Weight (kg) 23.2±9.0 24.5±9.8 0.157 BMI, kg/m 2 16.7±2.7 16.8±2.9 0.791 Duration of surgery (min) 20.9±7.4 21.1±6.9 0.729 WBC count (x 10 9 /L) 7.3±1.7 7.2±1.8 0.634 COVID-19 Anti-ig G, (Positive/ %) 86（58.9%） 161（33.2%） 0.000 Chest X-ray, (Abnormal/%) 21（14.4%） 3（0.6%） 0.000 Cough, (Y/%) 61（41.8%） 49（10.1%） 0.000 Sufentanil（mg） 2.9±1.4 2.5±1.2 0.001 Remifentanil（mg） 22.3±11.4 20.9±11.6 0.201 Midazolam（Y/%） 132（90.4%） 449（92.6%） 0.471 Dexmedetomidine（Y/%） 78（53.4%） 242（49.9%） 0.606 Note: BMI, Body Mass Index. WBC count, White Blood Cell count. Y, Yes. Table 2 Management of hypoxemia in children with cough between the two groups Table 2 Management of hypoxemia in children with cough between the two groups Measures cough（n=99） Non-cough（n=532） P Oxygen via face mask YES NO 61 38 86 446 0.000 Jaw support YES NO 28 71 41 491 0.000 Oropharyngeal airway YES NO 7 92 6 526 0.001 Bag-mask ventilation YES NO 5 94 1 531 0.000 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 20 Dec, 2025 Reviewers agreed at journal 20 Dec, 2025 Reviewers invited by journal 12 Dec, 2025 Editor invited by journal 14 Nov, 2025 Editor assigned by journal 28 Oct, 2025 Submission checks completed at journal 27 Oct, 2025 First submitted to journal 27 Oct, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7906867","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":560241105,"identity":"36724b31-6610-4146-9c06-c15a82d7eda2","order_by":0,"name":"Yan Li","email":"","orcid":"","institution":"Shanghai Children's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yan","middleName":"","lastName":"Li","suffix":""},{"id":560241106,"identity":"3e5bc0ab-1867-44d6-aec6-e24a74c43000","order_by":1,"name":"Shenghua Yu","email":"","orcid":"","institution":"Shanghai Children's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Shenghua","middleName":"","lastName":"Yu","suffix":""},{"id":560241107,"identity":"455b10a6-ce0f-4660-959f-de63acad3350","order_by":2,"name":"Jingjie Cai","email":"","orcid":"","institution":"Shanghai Children's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jingjie","middleName":"","lastName":"Cai","suffix":""},{"id":560241108,"identity":"f0cc193f-255e-4b9f-b3e3-44b63d42fd7a","order_by":3,"name":"Xueting Yang","email":"","orcid":"","institution":"Shanghai Children's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Xueting","middleName":"","lastName":"Yang","suffix":""},{"id":560241109,"identity":"aacfaf53-cc0d-45e9-a492-aec4a60f76c4","order_by":4,"name":"Rong Wei","email":"","orcid":"","institution":"Shanghai Children's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Rong","middleName":"","lastName":"Wei","suffix":""},{"id":560241110,"identity":"87b61308-9d93-4c90-83aa-023df7a9f8eb","order_by":5,"name":"Yan Jiang","email":"","orcid":"","institution":"Shanghai Children's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yan","middleName":"","lastName":"Jiang","suffix":""},{"id":560241111,"identity":"7a5bc4f9-4423-42b6-a2a2-9baeeb8b63b3","order_by":6,"name":"Tianxiao Zou","email":"data:image/png;base64,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","orcid":"","institution":"Shanghai Children's Hospital","correspondingAuthor":true,"prefix":"","firstName":"Tianxiao","middleName":"","lastName":"Zou","suffix":""}],"badges":[],"createdAt":"2025-10-20 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08:58:22","extension":"xml","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":91378,"visible":true,"origin":"","legend":"","description":"","filename":"3b8228ea391040c3b20a0d1a47d9cbbb1structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7906867/v1/7d63eae25d6d5515d6a7f28b.xml"},{"id":98748876,"identity":"662cd2b0-bb27-4e5a-97e7-008787d18870","added_by":"auto","created_at":"2025-12-22 08:58:22","extension":"html","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":101461,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7906867/v1/fdcb977189a62dbd2b366c9b.html"},{"id":98748860,"identity":"8a8df9e2-14d7-4015-9956-7fa7f9518f6f","added_by":"auto","created_at":"2025-12-22 08:58:22","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":96460,"visible":true,"origin":"","legend":"\u003cp\u003eThe risk factors for hypoxemia in OSAHS children in the PACU\u003c/p\u003e","description":"","filename":"Fig2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7906867/v1/6cc855b82b796a75bd716fe8.jpg"},{"id":98783567,"identity":"a7b1e75e-830e-4c88-9b52-282a4125e718","added_by":"auto","created_at":"2025-12-22 12:42:14","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":765890,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7906867/v1/ea5a4c23-aa22-4f87-bd9d-7555ba1de3fd.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Risk Factors for Postoperative Hypoxemia in Pediatric OSAHS Patients Undergoing Adenotonsillectomy: A Retrospective Study","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003ePediatric surgical patients have a relatively high incidence of perioperative respiratory adverse events, with the most common being oxygen desaturation(\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Upper respiratory tract infections are a known risk factor for these complications. In children presenting with severe symptoms\u0026mdash;such as wheezing, purulent nasal discharge, fever over 38.5\u0026deg;C, or lethargy\u0026mdash;elective surgery should typically be postponed for at least 15 days. However, for those with mild symptoms like a runny nose, sneezing, or a mild cough, careful evaluation and management by an experienced pediatric anesthesiologist may allow surgery to proceed safely(\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). Preoperative risk assessment is crucial for reducing the incidence of perioperative respiratory adverse events. Studies have shown that the colds score can effectively help lower the occurrence of such events in pediatric patients, indicating that early identification of high-risk children and timely, targeted interventions can significantly reduce the risk of severe complications and mortality.(\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eChildren with respiratory symptoms or OSAHS are particularly prone to hypoxemia following the use of opioids, such as sufentanil and remifentanil, and muscle relaxants, such as rocuronium and atracurium(\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan additionalcitationids=\"CR6\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). Numerous factors contribute to postoperative hypoxemia in OSAHS patients. This study aims to identify high-risk pediatric patients with OSAHS more likely to experience postoperative hypoxemia so that enhanced monitoring and preventive measures can be implemented following extubation and transfer to the PACU, ultimately reducing respiratory complications and facilitating smoother perioperative recovery.\u003c/p\u003e"},{"header":"2. Materials and Method","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e\u003cb\u003e2.1\u003c/b\u003e Object\u003c/h2\u003e \u003cp\u003eThis retrospective study analyzed pediatric patients with OSAHS who underwent tonsillectomy and adenoidectomy under general anesthesia between February and June 2023 at a specialized children's hospital in Shanghai. Following extubation, these patients were transferred to the PACU without supplemental oxygen. The study obtained informed consent from the guardians and was approved by the Clinical Trial Ethics Committee of Shanghai Children's Hospital (Approval No. 2024R032-E01). Inclusion criteria: (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e) Pediatric patients diagnosed with OSAHS were evaluated and confirmed by otolaryngologists based on nasal endoscopy findings in the outpatient clinic and scheduled for surgery under general anesthesia. (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e) American Society of Anesthesiologists (ASA) physical status classification I or II. (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e) Patients extubated at the end of surgery and transferred to the PACU without receiving oxygen via face mask. (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e) Patients under 18 years of age. (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e) Availability of complete and detailed medical records. Exclusion criteria: (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e) Preoperative SpO₂ \u0026lt; 95% without supplemental oxygen. (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e) History of chronic or severe anemia. (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e) Presence of comorbidities such as congenital heart disease, liver dysfunction, or renal dysfunction. (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e) Cases in which surgery was canceled due to other factors or patients who required resuscitation during the procedure.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Date collection and management\u003c/h2\u003e \u003cp\u003eThis study collected basic patient information from the hospital\u0026rsquo;s inpatient system, including sex, age, height, weight, and presence of cough within one week prior to surgery, as well as laboratory and imaging results such as white blood cell count, COVID-19 IgG antibody levels, and chest X-ray findings. Surgical and anesthetic data\u0026mdash;including intraoperative administration of sufentanil, remifentanil, midazolam, dexmedetomidine, and duration of surgery\u0026mdash;were obtained from the anesthesia information system. The study also recorded any episodes of oxygen desaturation in the PACU and evaluated whether normal SpO₂ levels could be restored using interventions such as face mask oxygen supplementation, jaw support, or the use of an oropharyngeal airway or bag-mask ventilation.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3 Anesthetic Management\u003c/h2\u003e \u003cp\u003eAll children fasted for 8 hours for solids and 2 hours for clear liquids before surgery. Upon arrival in the anesthesia preparation room, oral midazolam (0.5 mg/kg, up to a maximum of 15 mg) was administered for preoperative sedation. After entering the operating room, standard monitoring was initiated, including pulse oximetry, noninvasive blood pressure, and electrocardiography. Once all medications and equipment were fully prepared, anesthesia induction began. Sufentanil (0\u0026ndash;0.2 \u0026micro;g/kg) and/or remifentanil (0\u0026ndash;2 \u0026micro;g/kg) were administered, along with rocuronium (0.6 mg/kg) or cisatracurium besylate (0.1 mg/kg), and propofol (3 mg/kg). Atropine (0.01 mg/kg) was routinely given to reduce oral and airway secretions. Mask-assisted ventilation was performed, followed by endotracheal intubation under video laryngoscope guidance. Mechanical ventilation was initiated using pressure control mode with a tidal volume of 6\u0026ndash;8 mL/kg and a respiratory rate of 15\u0026ndash;22 breaths/min, maintaining pressure of end-expiratory carbon dioxide (Et CO₂) between 35\u0026thinsp;~\u0026thinsp;45 mmHg. Anesthesia was maintained with sevoflurane inhalation, targeting a minimum alveolar concentration (MAC) of approximately 1.2.\u003c/p\u003e \u003cp\u003eAt the end of the surgey, sevoflurane was discontinued, and the airway and oral secretions were cleared. Once the child regained spontaneous respiration, neostigmine (0.04\u0026ndash;0.07 mg/kg) was administered to reverse muscle relaxation. The endotracheal tube was removed when a tidal volume of at least 5 mL/kg was achieved, and face mask oxygen was provided as needed. After confirming oxygen saturation had reached 100%, the child was transferred to the PACU under the supervision of an anesthesiologist. In the PACU, vital signs were continuously monitored, and supplemental oxygen was administered as needed.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.4 Study groups\u003c/h2\u003e \u003cp\u003ePatients were divided into two groups based on the occurrence of hypoxemia in the PACU: the hypoxemia group and the non-hypoxemia group. In the hypoxemia group, patients required interventions such as face mask oxygen supplementation and jaw thrust to restore normal oxygen saturation. If these measures failed to correct hypoxemia, positive pressure ventilation via face mask or endotracheal intubation was performed to re-establish airway control and normalize oxygen saturation levels.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e2.5 Diagnostic Criteria for Hypoxemia and recent cough\u003c/h2\u003e \u003cp\u003eIn the PACU, if a patient who is not receiving supplemental oxygen has a continuously monitored SpO2\u0026thinsp;\u0026lt;\u0026thinsp;91% for more than 30 seconds, it can be determined that the patient is experiencing hypoxemia(\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eA recent cough was defined as a distinct and persistent coughing episode lasting more than 5 seconds, occurring within one week prior to hospital admission(\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e2.6 Statistical Analysis\u003c/h2\u003e \u003cp\u003eStatistical analysis was performed using SPSS version 26.0. For normally distributed continuous data, results were expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation, and comparisons between groups were conducted using the independent samples t-test. Non-normally distributed continuous data were presented as median, and comparisons were made using the non-parametric Mann\u0026ndash;Whitney U test. Categorical variables were expressed as number (percentage) [n(%)] and compared using the chi-square test. Baseline clinical characteristics and preoperative laboratory results were compared between the two groups. Variables with statistically significant differences in univariate analysis were further analyzed using univariate logistic regression. Variables with P\u0026thinsp;\u0026lt;\u0026thinsp;0.05 in the univariate logistic regression were included in a multivariate logistic regression model to identify independent risk factors for postoperative hypoxemia in children with OSAHS. A P-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Result","content":"\u003cp\u003e\u003cstrong\u003e3.1 Comparison of general information between the two groups\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study included 660 pediatric cases of OSAHS. Thirteen cases were excluded due to incomplete medical records, and 16 due to additional concurrent surgeries, resulting in 631 eligible cases. Among these, 146 children developed hypoxemia, while 485 did not, as shown in the flowchart (Fig. 1). No significant differences were found between the two groups in terms of gender, age, height, weight, BMI, or white blood cell count. General clinical data for both groups are presented in Table 1.\u003c/p\u003e\n\u003cp\u003eIn the hypoxemia group, 41.1% of the children tested negative for COVID-19 Anti-IgG before surgery, 85.6% had normal chest X-rays with no blurred lung markings, and 58.9% had no preoperative cough. Anesthetic use, including remifentanil, midazolam, and dexmedetomidine hydrochloride, as well as the duration of surgery, did not differ significantly between the groups. However, intraoperative sufentanil dosage was notably higher in the hypoxemia group compared to the non-hypoxemia group (2.9±1.4 µg vs. 2.5±1.2µg), (Table 1). No special interventions were needed in the non-hypoxemia group. Additionally, neither group had any cases requiring re-intubation or tracheostomy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2 Incidence of Hypoxemia During PACU\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study included 631 children with OSAHS who underwent tonsillectomy and adenoidectomy under general anesthesia and were admitted to the PACU without supplemental oxygen. Among these patients, 146 experienced hypoxemia, with an incidence rate of 23.1%.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.3 Logistic Regression Analysis of Risk Factors for Hypoxemia During PACU\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe risk of hypoxemia in OSAHS children upon admission to the PACU was assessed as follows: hypoxemia present = 1, hypoxemia absent = 0. Significant factors identified in Table 1 were assigned the following values: COVID-19 Anti-IgG positive = 1, abnormal preoperative chest X-ray = 1, and presence of cough in the week before surgery = 1. A binary logistic regression analysis of risk factors for postoperative hypoxemia in OSAHS patients in the PACU indicated that recent cough, abnormal chest X-ray findings, COVID-19 Anti-IgG status, and sufentanil dosage were independent risk factors. Children with abnormal preoperative chest X-rays were found to have a 13.4 times higher risk of hypoxemia, and those with a recent cough had a 4.6 times higher risk compared to children with normal X-rays and no recent cough (Fig. 2).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.4 Management of hypoxemia in children with preoperative cough\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAmong the 631 children in the study, 99 had a history of preoperative cough. Of these, 61 children (61.6%) required supplemental oxygen via a face mask to address oxygen desaturation. Additionally, 28 children (28.3%) needed jaw support, 7 children (7.1%) required an oropharyngeal airway, and 5 children (5.1%) needed positive pressure oxygen via bag-mask ventilation to restore normal SpO\u003csub\u003e2\u003c/sub\u003e levels (Table 2).\u003c/p\u003e"},{"header":"4. Discussion","content":"\u003cp\u003eOur previous research indicated that children with OSAS undergoing adenoidectomy or tonsillectomy are at a higher risk of experiencing postoperative hypoxemia (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). This study further examined hypoxemia rates among children with OSAHS in the PACU without supplemental oxygen, finding an incidence of 23.1%. Independent risk factors included the presence of a cough within one week prior to surgery, increased and blurred lung markings on preoperative chest X-rays, and the intraoperative dosage of sufentanil. Respiratory complications during hospitalization are closely associated with hypoventilation in the PACU. Identified risk factors include OSAHS, preoperative use of extended-release opioids, higher intraoperative opioid administration, isoflurane-based anesthesia, and prolonged surgical duration (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). In our study, however, the total dose of sufentanil was relatively low in both the hypoxemia and non-hypoxemia groups (2.9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4 \u0026micro;g vs. 2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.2 \u0026micro;g), yet respiratory adverse events still occurred postoperatively. This may suggest that pediatric patients with OSAHS are inherently more sensitive to opioids, such that even small doses can contribute to respiratory depression. Further research is warranted to clarify this association. Laporta et al. noted that a considerable amount of opioid-induced apnea occurs within the first few hours post-PACU discharge, often signaling early deterioration(\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e).\u003c/p\u003e \u003cp\u003ePatients with OSAHS often experience chronic hypoxia due to obstructed airway ventilation, which may increase their sensitivity to opioids. As a result, even low doses of opioids can pose a risk of respiratory depression or apnea in these patients. Excessive use of opioids is known to increase the risk of respiratory depression and apnea. Studies have recommended reducing opioid dosages during pediatric adenotonsillectomy and advocating for individualized analgesic regimens based on patient-specific needs(\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e). However, in our study, even a relatively low dose of sufentanil (approximately 0.1\u0026ndash;0.13 \u0026micro;g/kg) was associated with an increased risk of perioperative respiratory adverse events. This may be partially attributed to a synergistic effect with midazolam, which was used as premedication in some patients. Previous research comparing midazolam and dexmedetomidine in pediatric tonsillectomy found no significant differences in extubation time or length of stay in the PACU between the two groups(\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). However, dexmedetomidine demonstrated superior efficacy in postoperative pain control, suggesting that it may offer analgesic benefits without increasing the risk of respiratory compromise.\u003c/p\u003e \u003cp\u003eCurrent PACU discharge criteria do not include systematic assessment of respiratory drive, particularly in patients receiving mask oxygen, which can delay the detection of early respiratory decline(\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). Gail et al. reported that patients experiencing apnea or oxygen desaturation in the PACU face a 33% risk of respiratory complications during their hospital stay, while those without such episodes have a risk of \u0026le;\u0026thinsp;2%(\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). In our study, we did not quantify hypoxemia rates in children who received mask oxygen; however, most patients in the PACU were placed on oxygen supplementation immediately upon arrival. This suggests that even patients with normal SpO\u003csub\u003e2\u003c/sub\u003e levels might still be at risk for hypoxemia.\u003c/p\u003e \u003cp\u003ePreoperative symptoms such as coughing and abnormal chest X-ray findings\u0026mdash;such as increased or blurred pulmonary markings\u0026mdash;may indicate airway hypersensitivity or underlying pathological changes. These conditions can predispose children to postoperative hypoxemia, particularly when supplemental oxygen is not administered in the PACU. Sanz et al. investigated the association between mild pneumonia and hypoxemia, identifying chronic pulmonary disease, bilateral chest X-ray involvement, and hypoalbuminemia as contributing factors(\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). Given the retrospective nature of this study and the limited number of patients with preoperative cough, we did not perform a stratified analysis based on the severity of cough or chest X-ray abnormalities. For children requiring surgery who have had a recent upper respiratory tract infection, it is generally recommended to delay surgery for at least two weeks after symptom resolution. A normal preoperative chest X-ray may help reduce the risk of perioperative respiratory complications(\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). A prospective study on children undergoing inguinal hernia repair revealed that the presence of respiratory symptoms and exposure to passive smoking are significant risk factors for perioperative respiratory adverse events. For children with respiratory symptoms, postponing surgery by 15 days may be insufficient, as these patients tend to experience a higher incidence of complications compared to those without such symptoms(\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). The results of this study showed that children with preoperative chest X-rays indicating increased or blurred pulmonary markings had a 13.4-fold higher risk of developing postoperative hypoxemia compared to those with normal chest X-ray findings. Similarly, children with a preoperative cough had a 4.6-fold higher risk of hypoxemia than those without cough symptoms.\u003c/p\u003e \u003cp\u003eA recent study on the use of high-flow nasal oxygen after extubation in gynecological surgeries indicated that compared to traditional oxygen therapy strategies, providing 2 hours of high-flow nasal oxygen after extubation can improve oxygen exchange and reduce atelectasis(\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). However, not all research findings are consistent. One study comparing the use of nasal cannula oxygen (2\u0026ndash;4 L/min) to air during the transfer from the operating room to the PACU found that the incidence of mild hypoxemia (SpO\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;\u0026le;\u0026thinsp;92%) was 6% in the oxygen group and 20% in the air group, while the incidence of moderate hypoxemia (SpO\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;\u0026le;\u0026thinsp;90%) was 2% and 10% respectively (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). Mild hypoxemia is relatively common during the transfer from the operating room to the PACU, however, its incidence and severity could be decreased by administration of supplemental oxygen. It remains unclear whether short-term exposure to mild to moderate hypoxemia is harmful to patients, eventually each event of mild to moderate hypoxemia should be avoided. On the other hand, routine supplemental oxygen may risk exposing patients to hyperoxia(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). Therefore, in clinical anesthesia practice, real-time monitoring of patient SpO\u003csub\u003e2\u003c/sub\u003e and adjusting the oxygen concentration based on actual conditions may be a more effective approach.\u003c/p\u003e \u003cp\u003eIn this study, several essential preoperative tests were required for pediatric patients due to various factors. These tests included complete blood count, coagulation profile, liver and renal function tests, and electrolyte levels to assess the patients' internal environment prior to surgery. Additionally, preoperative chest X-rays and electrocardiograms were performed to evaluate cardiopulmonary function, ensuring the safe administration of surgical procedures and anesthetic agents. Given the high prevalence of OSAHS in the local population and cultural factors influencing families' decisions, some guardians still requested surgery for patients exhibiting recent cough or mild pulmonary infections. Consequently, a number of patients with abnormal chest X-ray findings underwent surgery in this study. The current research aims to evaluate the risk of postoperative hypoxemia in children with preoperative abnormal chest X-rays, thereby providing valuable insights for subsequent treatment considerations.\u003c/p\u003e \u003cp\u003eThis study is a retrospective analysis, and its limited sample size may constrain the ability to include additional relevant factors in the statistical analysis. These factors include the use of antibiotics in the 1\u0026ndash;2 weeks prior to surgery, the experience level of the surgeon, the anesthesiologist overseeing the case, neuromuscular blockade recovery, the timing and frequency of hypoxemia episodes in the PACU, and the length of stay in the recovery room. Each of these factors could potentially impact the outcomes observed. Furthermore, SpO\u003csub\u003e2\u003c/sub\u003e was not monitored during the transfer from the operating room to the PACU, which may have resulted in undetected hypoxemia in some patients. Finally, there was no follow-up on the OSAHS children to assess the incidence of respiratory-related events, such as respiratory depression and hypoxemia, after PACU discharge, which could provide additional insights into final outcomes. This identifies an important direction for future research aimed at enhancing post-PACU monitoring strategies for high-risk patients predisposed to hypoxemia.\u003c/p\u003e"},{"header":"5. Conclusion","content":"\u003cp\u003eDuring the early stages of anesthesia recovery, it is crucial to monitor all patients for signs of respiratory depression. For children with OSAS undergoing adenotonsillectomy, those who had a cough within the week before surgery, abnormal chest X-ray findings such as increased or blurred lung markings, or a recent COVID-19 infection, close postoperative monitoring is especially important. Additionally, the intraoperative dose of sufentanil is an independent risk factor for hypoxemia in children with OSAHS, underscoring the need for careful observation in these high-risk cases.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eASA American Society of Anesthesiologists, BMI body mass index, OSAHS obstructive sleep apnea hypopnea syndrome, PACU post-anesthesia care unit, SpO₂ peripheral capillary oxygen saturation, WBC white blood cell count.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was supported by department of Anesthesiology, Shanghai Children’s Hospital. The authors would like to thank the patients who participated in this trial.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eYSH and WR designed the study, conducted the study, acquired the data and revised the manuscript. CJJ acquired the data, analyzed the data, prepared figures and tables, wrote the manuscript and modified the language. YXT and LY acquired the data and analyzed the data. JY analyzed the data and wrote the manuscript. LY and ZTX revised the manuscript and modified the language. All authors read and approved the final version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analyzed during the current study is available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding and Conflict of Interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was funded by the Clinical Research Training Program of Shanghai Children's Hospital (2023YLY08). No competing interests or funding declared.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study protocol was in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines and approved by Ethics Committee of Shanghai Children’s Hospital\u0026nbsp;(2024R032-E01).\u003c/p\u003e\n\u003cp\u003ePermission to reproduce material from other sources\u003c/p\u003e\n\u003cp\u003eThis manuscript does not include any material reproduced or adapted from other sources.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical trial registration\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eD. M. Wudineh, Y. W. Berhe, W. B. Chekol, H. Adane and M. M. Workie. 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Effect of Intranasal Dexmedetomidine or Midazolam for Premedication on the Occurrence of Respiratory Adverse Events in Children Undergoing Tonsillectomy and Adenoidectomy: A Randomized Clinical Trial. \u003cem\u003eJAMA Netw Open\u003c/em\u003e (2022), 5(8): e2225473. doi:10.1001/jamanetworkopen.2022.25473\u003c/li\u003e\n\u003cli\u003eJ. Zalan, J. P. Vaccani and K. T. Murto. Paediatric adenotonsillectomy, part 2: considerations for anaesthesia. \u003cem\u003eBJA Educ\u003c/em\u003e (2020), 20(6): 193-200. doi:10.1016/j.bjae.2020.03.001\u003c/li\u003e\n\u003cli\u003eS. L. Katz, A. Monsour, N. Barrowman, L. Hoey, M. Bromwich, F. Momoli, T. Chan, R. Goldberg, A. Patel, L. Yin and K. Murto. Predictors of postoperative respiratory complications in children undergoing adenotonsillectomy. \u003cem\u003eJ Clin Sleep Med\u003c/em\u003e (2020), 16(1): 41-8. doi:10.5664/jcsm.8118\u003c/li\u003e\n\u003cli\u003eD. Karalapillai, L. Weinberg, P. J. Peyton, L. Ellard, R. Hu, B. Pearce, C. Tan, D. Story, M. O\u0026apos;Donnell, P. Hamilton, C. Oughton, J. Galtieri, A. Wilson, G. Eastwood, R. Bellomo and D. Jones. Frequency of hyperoxaemia during and after major surgery. \u003cem\u003eAnaesth Intensive Care\u003c/em\u003e (2020), 48(3): 213-20. doi:10.1177/0310057x20905320\u003c/li\u003e\n\u003cli\u003eA. F. Arriaga. The PATH to patient safety. \u003cem\u003eBr J Anaesth\u003c/em\u003e (2021), 127(6): 830-3. doi:10.1016/j.bja.2021.09.006\u003c/li\u003e\n\u003cli\u003eH. Li, Y. Zhang, J. Cai, H. Wang and R. Wei. Risk Factors of Hypoxemia in the Postanesthesia Care Unit After General Anesthesia in Children. \u003cem\u003eJ Perianesth Nurs\u003c/em\u003e (2023), 38(5): 799-803. doi:10.1016/j.jopan.2023.02.003\u003c/li\u003e\n\u003cli\u003eM. L. Laporta, J. Sprung and T. N. Weingarten. Respiratory depression in the post-anesthesia care unit: Mayo Clinic experience. \u003cem\u003eBosnian Journal of Basic Medical Sciences\u003c/em\u003e (2020). doi:10.17305/bjbms.2020.4816\u003c/li\u003e\n\u003cli\u003eM. I. Hardman, S. C. Kruthiventi, M. R. Schmugge, A. N. Cavalcante, J. B. Jensen, D. R. Schroeder, J. Sprung and T. N. Weingarten. Risk factors and outcomes of postoperative emergency response team activation: a matched case-control study. \u003cem\u003eCrit Care Resusc\u003c/em\u003e (2020), 22(1): 6-14. doi:10.51893/2020.1.oa1\u003c/li\u003e\n\u003cli\u003eN. M. Kistler, O. Ayo-Ajibola, A. C. Park, D. Kwon and M. R. Timbang. Effect of otolaryngology analgesia guidelines on opioid prescribing in pediatric tonsillectomy. \u003cem\u003eInt J Pediatr Otorhinolaryngol\u003c/em\u003e (2025), 195: 112440. doi:10.1016/j.ijporl.2025.112440\u003c/li\u003e\n\u003cli\u003eP. Jeizan, K. Baharimehr, R. Kamvar, A. Abolghasemi Fard, S. Zojaji, A. Karimi and R. Zojaji. Dexmedetomidine Leads to Less Emergence Delirium Compared to Midazolam in Pediatric Tonsillectomy and/or Adenoidectomy: A Systematic Review and Meta-Analysis. \u003cem\u003eCureus\u003c/em\u003e (2025), 17(4): e81686. doi:10.7759/cureus.81686\u003c/li\u003e\n\u003cli\u003eT. N. Weingarten, T. S. Bergan, B. J. Narr, D. R. Schroeder and J. Sprung. Effects of changes in intraoperative management on recovery from anesthesia: a review of practice improvement initiative. \u003cem\u003eBMC Anesthesiol\u003c/em\u003e (2015), 15: 54. doi:10.1186/s12871-015-0040-x\u003c/li\u003e\n\u003cli\u003eB. Gali, F. X. Whalen, D. R. Schroeder, P. C. Gay and D. J. Plevak. Identification of patients at risk for postoperative respiratory complications using a preoperative obstructive sleep apnea screening tool and postanesthesia care assessment. \u003cem\u003eAnesthesiology\u003c/em\u003e (2009), 110(4): 869-77. doi:10.1097/ALN.0b013e31819b5d70\u003c/li\u003e\n\u003cli\u003eF. Sanz, M. I. Restrepo, E. Fern\u0026aacute;ndez, M. L. Briones, R. Blanquer, E. M. Mortensen, E. Chiner and J. Blanquer. Is it possible to predict which patients with mild pneumonias will develop hypoxemia? \u003cem\u003eRespir Med\u003c/em\u003e (2009), 103(12): 1871-7. doi:10.1016/j.rmed.2009.06.013\u003c/li\u003e\n\u003cli\u003eL. Frassanito, D. L. Grieco, B. A. Zanfini, S. Catarci, T. Ros\u0026agrave;, D. Settanni, C. Fedele, G. Scambia, G. Draisci and M. Antonelli. Effect of a pre-emptive 2-hour session of high-flow nasal oxygen on postoperative oxygenation after major gynaecologic surgery: a randomised clinical trial. \u003cem\u003eBr J Anaesth\u003c/em\u003e (2023), 131(4): 775-85. doi:10.1016/j.bja.2023.07.002\u003c/li\u003e\n\u003cli\u003eD. D. Mathes, M. R. Conaway and W. T. Ross. Ambulatory surgery: room air versus nasal cannula oxygen during transport after general anesthesia. \u003cem\u003eAnesth Analg\u003c/em\u003e (2001), 93(4): 917-21. doi:10.1097/00000539-200110000-00024\u003c/li\u003e\n\u003cli\u003eD. R. Frei. Clinically important hypoxaemia during transfer from the operating theatre to the postanaesthesia care unit. Comment on Br J Anaesth 2023; 131: 775-85. \u003cem\u003eBr J Anaesth\u003c/em\u003e (2023), 131(6): e186-e7. doi:10.1016/j.bja.2023.09.009\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 Comparison of Demographic information Between the Two Groups\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eVariables\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003eHypoxemia Group（n=146）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003eNon-Hypoxemia Group（n=485）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003eP\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eAge, (years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e5.3\u0026plusmn;2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e5.5\u0026plusmn;2.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.252\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eSex，n\u003c/p\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e93 (63.7%)\u003c/p\u003e\n \u003cp\u003e53 (36.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e296 (61.0%)\u003c/p\u003e\n \u003cp\u003e189 (39.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.628\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eHeight (cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e116.1\u0026plusmn;14.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e118.7\u0026plusmn;15.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.069\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eWeight (kg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e23.2\u0026plusmn;9.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e24.5\u0026plusmn;9.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.157\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eBMI, kg/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e16.7\u0026plusmn;2.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e16.8\u0026plusmn;2.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.791\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eDuration of surgery (min)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e20.9\u0026plusmn;7.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e21.1\u0026plusmn;6.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.729\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eWBC count (x 10\u003csup\u003e9\u003c/sup\u003e/L)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e7.3\u0026plusmn;1.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e7.2\u0026plusmn;1.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.634\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eCOVID-19 Anti-ig G, (Positive/ %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e86（58.9%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e161（33.2%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eChest X-ray, (Abnormal/%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e21（14.4%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e3（0.6%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eCough, (Y/%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e61（41.8%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e49（10.1%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eSufentanil（mg）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e2.9\u0026plusmn;1.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e2.5\u0026plusmn;1.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eRemifentanil（mg）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e22.3\u0026plusmn;11.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e20.9\u0026plusmn;11.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.201\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eMidazolam（Y/%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e132（90.4%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e449（92.6%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.471\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eDexmedetomidine（Y/%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e78（53.4%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e242（49.9%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.606\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eNote: BMI,\u0026nbsp;Body Mass Index. WBC count, White Blood Cell count. Y, Yes.\u003c/p\u003e\n\u003cp\u003eTable 2 Management of hypoxemia in children with cough between the two groups\u003c/p\u003e\n\u003cp\u003eTable 2 Management of hypoxemia in children with cough between the two groups\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eMeasures\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003ecough（n=99）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003eNon-cough（n=532）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003eP\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eOxygen via face mask\u003c/p\u003e\n \u003cp\u003eYES\u003c/p\u003e\n \u003cp\u003eNO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e61\u003c/p\u003e\n \u003cp\u003e38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e86\u003c/p\u003e\n \u003cp\u003e446\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eJaw support\u003c/p\u003e\n \u003cp\u003eYES\u003c/p\u003e\n \u003cp\u003eNO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e28\u003c/p\u003e\n \u003cp\u003e71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e41\u003c/p\u003e\n \u003cp\u003e491\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eOropharyngeal airway\u003c/p\u003e\n \u003cp\u003eYES\u003c/p\u003e\n \u003cp\u003eNO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003cp\u003e92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003cp\u003e526\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 180px;\"\u003e\n \u003cp\u003eBag-mask ventilation\u003c/p\u003e\n \u003cp\u003eYES\u003c/p\u003e\n \u003cp\u003eNO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 160px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003cp\u003e94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 174px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e531\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 119px;\"\u003e\n \u003cp\u003e0.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bped","sideBox":"Learn more about [BMC Pediatrics](http://bmcpediatr.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bped/default.aspx","title":"BMC Pediatrics","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Obstructive sleep apnea hypopnea syndrome, post anesthesia care unit, hypoxemia, perioperative complications, risk factors, pediatrics","lastPublishedDoi":"10.21203/rs.3.rs-7906867/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7906867/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBaclground\u003c/h2\u003e \u003cp\u003e: This study aimed to identify risk factors for perioperative respiratory adverse events in children with obstructive sleep apnea hypopnea syndrome (OSAHS) undergoing tonsillectomy under general anesthesia without supplemental oxygen in the post-anesthesia care unit (PACU), in order to provide clinical practice and improve management strategies.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eA retrospective analysis was conducted on OSAHS pediatric patients admitted to the PACU without oxygen supplementation after surgery at our hospital between February and June 2023. Patients were categorized into hypoxemia and non-hypoxemia groups based on their PACU oxygen saturation levels. Binary logistic regression analysis was employed to identify independent risk factors for hypoxemia.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eA total of 660 pediatric patients were reviewed, of which 631 met the inclusion criteria. Among these, 146 children (23.1%) developed hypoxemia in the PACU. Preoperative abnormalities on chest X-ray findings (such as increased and blurred lung markings) and the COVID-19 Anit-IgG in blood tests showed statistically significant differences between the hypoxemia and non-hypoxemia groups. The sufentanil dose used intraoperatively was significantly higher in the hypoxemia group compared to the non-hypoxemia group (2.9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4 \u0026micro;g vs. 2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.2 \u0026micro;g, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Notably, children who had a cough within one week prior to surgery were higher risk of developing hypoxemia in the PACU (61.6% vs. 16.0%). Among these patients, 28.3% required a chin lift, 7.1% required an oropharyngeal airway, and 5.1% needed bag-mask ventilation. Binary logistic regression analysis identified abnormal chest X-ray findings, recent preoperative cough, COVID-19 Anti-IgG positive, and higher intraoperative sufentanil dosage as independent risk factors for hypoxemia in the PACU.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003ePostoperative hypoxemia in pediatric OSAHS patients is significantly associated with preoperative cough, abnormal chest X-ray, and sufentanil dosage. Enhanced perioperative monitoring and tailored management strategies are recommended for high-risk patients.\u003c/p\u003e","manuscriptTitle":"Risk Factors for Postoperative Hypoxemia in Pediatric OSAHS Patients Undergoing Adenotonsillectomy: A Retrospective Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-22 08:58:17","doi":"10.21203/rs.3.rs-7906867/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2025-12-20T18:10:08+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"230789301840112104461072990760624475086","date":"2025-12-20T17:56:18+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-12-12T05:48:42+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-11-14T06:22:25+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-10-28T05:52:04+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-28T01:48:24+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pediatrics","date":"2025-10-28T01:45:23+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bped","sideBox":"Learn more about [BMC Pediatrics](http://bmcpediatr.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bped/default.aspx","title":"BMC Pediatrics","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"925e1a64-1857-4a94-bbff-f071acff408c","owner":[],"postedDate":"December 22nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-12-22T08:58:17+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-22 08:58:17","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7906867","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7906867","identity":"rs-7906867","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}