The accuracy of ultrasound to predict endotracheal tube size for pediatric patients with congenital scoliosis

The accuracy of ultrasound to predict endotracheal tube size for pediatric patients with congenital scoliosis | 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 Help Center Sign In Submit a Preprint Cite Share Download PDF Research article The accuracy of ultrasound to predict endotracheal tube size for pediatric patients with congenital scoliosis Jianhong Hao, Jie Zhang, Buhuai Dong, Zhenguo Luo This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-24208/v3 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 31 Jul, 2020 Read the published version in BMC Anesthesiology → Version 3 posted 2 You are reading this latest preprint version Show more versions Abstract Background: Ultrasonography has been used to predict the necessary endotracheal tube (ETT) size by measuring the cricoid cartilage diameter. The aim of this study was to determine the accuracy of ultrasound to predict ETT size for pediatric patients with congenital scoliosis. Methods: Fifty pediatric patients who underwent scoliosis surgery were included in the study. According to the position of the scoliosis, patients were divided into three groups: Group C (cervical lateral bending), Group T (thoracic scoliosis), and Group L (lumbar scoliosis). For all participants, the transverse diameter of the cricoid cartilage was measured with ultrasonography. The initial ETT size was chosen according to the measurements, then the leak test was used to determine the best fit ETT size. The ETT size predicted by ultrasound and the best fit ETT size were compared using Bland-Altman analysis. Results: There was a strong correlation between the best fit ETT size and the ETT size predicted by ultrasound in Group T (r = 0.93, p < 0.001) and Group L (r = 0.94, p < 0.001) and a moderate correlation in Group C (r = 0.83, p < 0.001). Bland-Altman analysis showed that the ETT size was overestimated by ultrasound in pediatric patients with cervical lateral bending (bias = 0.73 mm, precision = 0.42 mm, limit of agreement = 0.08 to 1.38 mm). Conclusion: Ultrasound is a reliable tool to predict ETT size for pediatric patients with thoracic or lumbar scoliosis. However, pediatric patients with cervical lateral bending will need an ETT smaller than the size predicted by ultrasonography. Trial Registration: Chinese Clinical Trial Registry, TRN: ChiCTR1900023408, date of registration: 05.26.2019, 'retrospectively registered'. Anesthesiology & Pain Medicine Ultrasonography cricoid cartilage diameter endotracheal tube congenital scoliosis pediatric Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Background Selection of the optimal endotracheal tube (ETT) size is critical in pediatric anesthesia. A larger-than-optimal-sized ETT can damage the airway [1]. In contrast, a small-sized ETT increases the risk of aspiration and insufficient ventilation [2,3]. Various methods have been used to estimate the required ETT size, such as age formulas, height formulas, and finger size. However, because of the individual differences, these calculation methods have wide deviations, especially in children [4,5]. Recent studies have used ultrasonography to predict the optimal ETT size by measuring the cricoid cartilage diameter, and the success rate can reach above 90% [6-8]. Scoliosis is the most common 3-dimensional deformational abnormality of the spine. Rotation of the centrum can produce displacement or rotation of the mainstem bronchi, especially in cervical lateral bending and thoracic scoliosis [9,10]. Therefore, we conducted this study to assess the ability of ultrasound to accurately predict endotracheal tube size for pediatric patients with cervical lateral bending, thoracic scoliosis, and lumbar scoliosis. Methods The study protocol was approved by the institutional review board of HongHui Hospital. The trial was registered with the Chinese Clinical Trial Registry (ChiCTR: 1900023408). Informed written consent was obtained from the parents of all children. Fifty pediatric patients who underwent scoliosis surgery at Hong Hui Hospital, Xi'an Jiaotong University from February 2019 through December 2019 were consecutively enrolled in the study. The inclusion criteria were 1) age 5-12 years and 2) American Society of Anesthesiologists (ASA) physical status I-II. Patients with neck trauma, throat disorders, or an anticipated difficult airway were excluded. According to the location of scoliosis, patients were divided into three groups: Group C (cervical lateral bending), Group T (thoracic scoliosis), and Group L (lumbar scoliosis) (Figure 1). After transfer into the operating room, non-invasive blood pressure, electrocardiogram, pulse oximetry, end-tidal carbon dioxide concentration, and bispectral index were continuously monitored. The children were administered propofol 1.5 mg . kg - 1 IV for mild sedation and positioned in horizontal recumbency with slight extension of the head. Ultrasonography using a linear 7–15-MHz probe began with the identification of the true vocal folds. Then the probe was moved caudally to visualize the cricoid arch. The cricoid cartilage appears as a round hypoechoic structure with hyperechoic edges; the air column in the cricoid cartilage appears hyperechoic. The transverse air column diameter was considered to estimate the cricoid cartilage diameter (Figure 2). Based on the ultrasound measurements of the cricoid cartilage diameter, the corresponding ETT size was selected ( Supplemental Table). The measurements of the cricoid cartilage diameter were performed independently by two anesthesiologists, and the average was taken. Before this formal study began, the anesthesiologists had performed 30 measurements of cricoid cartilage diameter under ultrasound guidance. Anesthesia was induced with fentanyl 4 μg . kg -1 , propofol 2 mg . kg -1 , and atracurium 0.4 mg . kg -1 . After 3 minutes, tracheal intubation was performed. The leak test was used to determine the best‑fit ETT size. In the presence of resistance to passage of the tube into the trachea, or in the absence of an audible leak at airway pressure >25 cm H 2 O, the ETT was replaced with a tube of 0.5 mm less internal diameter. If a leak was audible at airway pressures 25 cm H 2 O, or if a peak airway pressure <25 cm H 2 O was observed during ventilation, the tube was exchanged for one a size larger. The ETT size predicted by ultrasonography and the best‑fit ETT size were recorded for each patient. The leak test and the tracheal intubation were performed by another investigator who was blinded to the cricoid cartilage diameter measurements. Anesthesia was maintained with remifentanil (0.16 μg . kg -1 . min -1 ) and sevoflurane (1.5%). At the end of all surgical procedures, sevoflurane and remifentanil infusion was stopped. The trachea was extubated when spontaneous ventilation returned. After extubation, the children were transferred to the PACU. The number of patients with laryngospasm was recorded. The data were analyzed using SPSS® v. 18 for Windows (IBM, Inc., Armonk, NY, USA). The demographic characteristics were compared using the chi-squared test or ANOVA. A scatter plot between the best‑fit ETT size and the ETT size predicted by ultrasound was constructed. A Bland-Altman plot was generated to analyze the agreement between the ETT size predicted by ultrasonography and the best‑fit ETT size. A P value < 0.05 was considered statistically significant. Results Fifty pediatric patients with congenital scoliosis were included in this study. No significant differences were found in age, sex, height, and weight between the three groups (Table 1). There were strong correlations between the best‑fit ETT size and the ETT size predicted by ultrasound in Group T (r = 0.93, p < 0.001; Figure 3b) and Group L (r = 0.94, p < 0.001; Figure 3c) and a moderate correlation with Group C (r = 0.83, p < 0.001, Figure 3a). Bland-Altman analysis showed no obvious bias between the ETT size predicted by ultrasonography and the best‑fit ETT size in Group T (bias = 0.02 mm, precision = 0.12 mm, limit of agreement = -0.42 to 0.46 mm; Figure 4b) and in Group L (bias = 0.09 mm, precision = 0.17 mm, limit of agreement = -0.31 to 0.49 mm; Figure 4c), but the ETT size was overestimated by ultrasound in Group C (bias = 0.73 mm, precision = 0.42 mm, limit of agreement = 0.08 to 1.38 mm; Figure 4a). Compared with Group T and Group L, the incidence of laryngospasm was higher in Group C (15.0% vs 3.8%, p < 0.05; and 15.0% vs 0.0%, p < 0.05, respectively). Discussion The cricoid cartilage, as the narrowest part of the larynx in children, plays an important role in the selection of optimal ETT size for intubation [11,12]. However, recently, Dalal et al. [13] found that the vocal cord and subvocal cord areas were the narrowest portion in pediatric airways. Compared with the vocal cords, the cricoid is a complete and relatively rigid cartilaginous ring and the most frequently damaged structure during endotracheal intubation [14]. Therefore, theoretically, the cricoid cartilage is the limiting factor during intubation and can be a predictive factor in the selection of optimal ETT size for intubation. Ultrasonography is safe, noninvasive, can be quickly performed, provides real-time images, and is relatively simple to learn. More importantly, the leading edge of the cricoid cartilage and the air column can be identified with ultrasound[15]. In our study, the cricoid cartilage diameters were estimated from the measurements of the transverse air column diameter, which is the most common approach to measure the transverse diameter of the cricoid cartilage in clinical research. To ensure the accuracy of the measurements, they were performed independently by two anesthesiologists and the average was taken, and the anesthesiologists who performed ultrasound examinations had performed 30 procedures before the formal experiment began. Lakhal et al.[16] found that 15 procedures were enough for an operator to obtain reliable measurements. Moreover, Julio et al. found that subglottic diameter ultrasound measurements had high intra-rater and inter-rater reproducibility[17]. Therefore, we believe that our measurements were accurate. The leak test is a classic experimental method and has been applied to determine the best‑fit ETT size for many years. Therefore, in our study, best‑fit ETT size was chosen according to the leak test. In prior studies, the allowed leak pressure often was 15-30 cm H 2 O for cuffed ETT [18]. Scoliosis can affect pulmonary function, and lung function abnormalities are mainly of the restrictive type [19]. During the procedure, the children are positioned in prone recumbency, and the operation can apply pressure to the chest. All these factors can cause elevation of the airway pressure. Therefore, we chose a higher leak pressure of 25 cm H 2 O to determine the best‑fit ETT size. Our study showed a strong correlation between the ETT size predicted by ultrasonography and the best‑fit ETT size in pediatric patients with thoracic or lumbar scoliosis. The Bland-Altman analysis showed no obvious bias between the ETT size predicted by ultrasonography and the best‑fit ETT size in pediatric patients with thoracic or lumbar scoliosis. Our findings were consistent with those reported by Pillai et al. [6]. In their study, the correlation was 0.98, and the bias was 0.041 mm. Therefore, it is feasible to predict ETT size by measuring the transverse diameter of the cricoid cartilage with ultrasonography in pediatric patients with thoracic or lumbar scoliosis. However, in pediatric patients with cervical lateral bending, there was a poor correlation between the ETT size predicted by ultrasonography and the best‑fit ETT size. Bland-Altman analysis showed that the average of the differences between the ETT sizes was 0.73 mm. Considering that the minimal increment for tube size change is 0.5 mm (according to the inner diameter of the ETT), the ETT size was overestimated by ultrasound in pediatric patients with cervical lateral bending. MRI is considered the reference standard for evaluating the larynx. High-quality images of the cricoid cartilage can be acquired by MRI, and the cricoid cartilage diameter can be accurately measured [20]. Therefore, in order to ascertain the cause of our result for Group C, we reviewed MRI images of four patients with cervical lateral bending. We found that the cricoid cartilage of the patients with cervical lateral bending was rotated (Figure 5). Previous research has shown that rotation of the centrum can produce displacement or rotation of the mainstem bronchi [9,10]. Therefore, we speculate that the rotation of the cricoid cartilage results from deviation or rotation of the cervical vertebrae. Under normal circumstances, the cricoid cartilage is elliptical, and the transverse diameter is smaller than the anteroposterior diameter [21]. When measuring the transverse diameter of the cricoid cartilage by ultrasound, the probe is positioned on the anterior neck, and the transverse air column diameter is measured to estimate the cricoid cartilage diameter. Because of this, rotation of the cricoid cartilage can broaden the air column as measured by ultrasound, resulting in a larger diameter measurement and overestimation of the necessary ETT size (Figure 6). In our study, we found that the ETT size predicted by ultrasonography was larger than the best‑fit ETT size in pediatric patients with cervical lateral bending. Therefore, compared to what is predicted by ultrasonography, these patients need a smaller ETT. The incidence of laryngospasm was higher in the patients with cervical lateral bending. There are two possible reasons for this result. First, in pediatric patients with cervical lateral bending, the initial ETT size predicted by ultrasound was larger, and a larger ETT can irritate the throat and increase the likelihood of laryngospasm. Second, operation on the neck can irritate the upper airway, also increasing the likelihood of laryngospasm. The present study has one limitation. Only four patients with cervical lateral bending underwent cervical MRI; therefore, it is not entirely clear whether the deviation of ultrasonographic measurements resulted only from the rotation of the cricoid cartilage in these patients. Further study is needed to analyze the influence of cricoid cartilage morphology on the accuracy of ultrasound to measure the cricoid cartilage diameter in pediatric patients with cervical lateral bending. Conclusion Ultrasound is a reliable tool to predict ETT size for pediatric patients with thoracic or lumbar scoliosis. However, compared to the ETT size predicted by ultrasonography, pediatric patients with cervical lateral bending need a smaller ETT. Abbreviations ETT, endotracheal tube; ASA: American Society of Anesthesiologists; PACU, post-anesthesia care unit; ANOVA, analysis of variance; MRI: magnetic resonance imaging Declarations Ethics approval and consent to participate The study protocol was approved by the institutional review board of HongHui Hospital. The trial was registered with the Chinese Clinical Trial Registry (ChiCTR: 1900023408). Informed written consent was obtained from the parents of all children. Consent for publication Not applicable. Availability of data and materials The datasets used and analyzed during the current study are available from the corresponding author on reasonable request. Competing interests The authors have no competing interests to declare. Funding This work was funded by the Key Research and Development Program of Shaanxi, Chian(NO.2019SF-205). The funding body was not involved in the design, preparation, or writing of this manuscript. Authors' contributions JH and ZL designed the project; JH, JZ and BD performed the experiments and data collection; JH prepared the figures and drafted the manuscript. All authors read and approved the final manuscript. Acknowledgments We would like to thank Editage (www.editage.cn) for English language editing. References Dillier CM, Trachsel D, Baulig W, Gysin C, Gerber AC, Weiss M: Laryngeal damage due to an unexpectedly large and inappropriately designed cuffed pediatric tracheal tube in a 13-month-old child. Can J Anaesth 2004; 51:72–75. Bae JY, Byon HJ, Han SS, Kim S, Kim JT. Usefulness of ultrasound for selecting a correctly sized uncuffed tracheal tube for pediatric patients. Anaesthesia. 2011; 66:994-998. Gupta K, Gupta PK, Rastogi B, Krishan A, Jain M, Garg G. Assessment of the subglottic region by ultrasonography for estimation of appropriate size endotracheal tube: A clinical prospective study. Anesth Essays Res. 2012; 6:157-160. Jagadish G Sutagatti, Ranjana Raja, Madhuri S Kurdi. Ultrasonographic Estimation of Endotracheal Tube Size in Paediatric Patients and its Comparison with Physical Indices Based Formulae: A Prospective Study . J Clin Diagn Res. 2017; 11(5): UC05–UC08. MAN Rajasekhar, Srilata Moningi, Sujatha Patnaik, Prasad Rao. Correlation between ultrasound-guided subglottic diameter and little finger breadth with the outer diameter of the endotracheal tube in paediatric patients-A prospective observational study . Indian J Anaesth. 2018; 62(12): 978– Rahul Pillai, Suresh Kumaran, L Jeyaseelan, Sajan P George, Raj Sahajanandan. Usefulness of Ultrasound-guided Measurement of Minimal Transverse Diameter of Subglottic Airway in Determining the Endotracheal Tube Size in Children with Congenital Heart Disease: A Prospective Observational Study . Ann Card Anaesth. 2018; 21(4): 382– Demet Altun, Mukadder Orhan Sungur, Achmet Ali. Ultrasonographic Measurement of Subglottic Diameter for Paediatric Cuffed Endotracheal Tube Size Selection: Feasibility Report . Turk J Anaesthesiol Reanim. 2016; 44(6): 301– Shibasaki M, Nakajima Y, Ishii S, Shimizu F, Shime N, Sessler DI, et al. Prediction of pediatric endotracheal tube size by ultrasonography. Anesthesiology 2010;113:819‑24. Borowitz D, Armstrong D, Cerny F: Relief of central airways obstruction following spinal release in a patient with idiopathic scoliosis. Pediatr Pulmonol 2001, 31(1):86-88. Bartlett W, Garrido E, Wallis C, Tucker SK, Noordeen H: Lordoscoliosis and large intrathoracic airway obstruction. Spine (Phila Pa 1976) 2009, 34(1): E59-E65. KluIka J, Štoura P, Štoudek R, Toukálková M, Harazim H, Kosinová M. Controversies in Pediatric Perioperative Airways. BioMed Research International. 2015; 2015: 368761. Shubhi Singh, Parul Jindal, Priya Ramakrishnan, Shailendra Raghuvanshi. Prediction of endotracheal tube size in children by predicting subglottic diameter using ultrasonographic measurement versus traditional formulas . Saudi J Anaesth. 2019 ; 13(2): 93– Dalal PG, Murray D, Messner AH, Feng A, McAllister J, Molter D, et al. Pediatric laryngeal dimensions: An age‑based analysis. Anesth Analg 2009;108:1475‑9. Frerk, V. S. Mitchell, A. F. McNarry, C. Mendonca, R. Bhagrath, A. Patel. Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults .Br J Anaesth. 2015; 115(6): 827–848. Adi Osman, Kok Meng Sum. Role of upper airway ultrasound in airway management. J Intensive Care. 2016; 4: 52. Lakhal K, Delplace X, Cottier JP, Tranquart F, Sauvagnac X, Mercier C, et al. The feasibility of ultrasound to assess subglottic diameter. Anesth Analg. 2007;104:611‑4. Julio, Jorge, Claudia, et al. Inter‑rater and intra‑rater reliability of the airway diameter measured by sonography.Journal of Ultrasound. 2018; 21:35– Schramm C, Knop J, Jensen K, Plaschke K. Role of ultrasound compared to age-related formulas for uncuffed endotracheal intubation in a pediatric population. Paediatr Anaesth 2012; 22: 781-6. Praud Jaen-Paul, Canet E: Chest Wall Function and Dysfunction. In Kendig’s Disorders of the Respiratory Tract in Children.. 7 edition. Edited by: Chernick V, Bertolani M, Calandra Buonaura P, Spina V, et al. Spin-echo anatomy of the larynx in MRI at 1.5 T. J Radiol 1993;74:1–12. Litman RS, Weissend EE, Shibata D, Westesson PL: Developmental changes of laryngeal dimensions in unparalyzed, sedated children. Anesthesiol Table Table 1 Demographic characteristics. Group C (n=13) T(n=26) L (n=11) Age(years) 7.5(1.6) 9.0(2.0) 8.5(1.8) Sex(male/female) 5/8 12/14 4/7 Hight(cm) 125.2(10.8) 130.4(15.7) 130.8(14.0) Weight(kg) 23.2(6.5) 27.8(10.4) 19.5(14.1) Data are mean (SD) or ratio. C: Cervical lateral bending; T: T horacic scoliosis; L: Lumbar scoliosis. Supplementary Table Supplemental Table Outer and inner diameters of cuffed endotracheal tubes of the used brand*. CCD (mm) >3.3 3.4-4.0 4.1-5.3 5.4-6.0 6.1-6.7 6.8-7.3 7.4-8.0 8.1-8.7 8.8-9.3 9.4-10.0 <10.1 OD (mm) 3.3 4.0 5.3 6.0 6.7 7.3 8.0 8.7 9.3 10.0 10.7 ID (mm) 2.0 2.5 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 *Xinxiang Tuoren Medical Equipment Co., Ltd, Henan, China. CCD: Cricoid cartilage diameter; OD: outer diameter; ID: inner diameter Cite Share Download PDF Status: Published Journal Publication published 31 Jul, 2020 Read the published version in BMC Anesthesiology → Version 3 posted Submission checks completed at journal 22 Jul, 2020 Editorial decision: Accept 22 Jul, 2020 You are reading this latest preprint version Show more versions 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies 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-24208","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research article","associatedPublications":[],"authors":[{"id":972774,"identity":"6f9c4c7a-3398-46d9-a6ca-ff48a2eb7da4","order_by":0,"name":"Jianhong Hao","email":"","orcid":"","institution":"Xi'an Jiaotong University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Jianhong","middleName":"","lastName":"Hao","suffix":""},{"id":972775,"identity":"2b6c949f-159e-4a9c-87aa-3ddab2ccb2df","order_by":1,"name":"Jie Zhang","email":"","orcid":"","institution":"Xi'an Jiaotong 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A larger-than-optimal-sized ETT can damage the airway [1]. In contrast, a small-sized ETT increases the risk of aspiration and insufficient ventilation [2,3]. Various methods have been used to estimate the required ETT size, such as age\u0026nbsp;formulas, height formulas, and finger size. However, because of the individual differences, these calculation methods have wide deviations, especially in children [4,5]. Recent studies have used ultrasonography to predict the optimal ETT size by measuring the cricoid cartilage diameter, and the success rate\u0026nbsp;can\u0026nbsp;reach\u0026nbsp;above\u0026nbsp;90% [6-8].\u003c/p\u003e\n\u003cp\u003eScoliosis is the most common 3-dimensional deformational abnormality of the spine.\u0026nbsp; Rotation of the centrum can produce displacement or rotation of the mainstem bronchi, especially in cervical lateral bending and thoracic scoliosis [9,10]. Therefore, we conducted this study to assess the ability of ultrasound to accurately predict endotracheal tube size for pediatric patients with cervical lateral bending, thoracic scoliosis, and lumbar scoliosis.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eThe study protocol was approved by the institutional review board of HongHui Hospital. The trial was registered with the Chinese Clinical Trial Registry (ChiCTR: 1900023408). Informed written consent was obtained from the parents of all children.\u003c/p\u003e\n\u003cp\u003eFifty pediatric patients who underwent\u0026nbsp;scoliosis\u0026nbsp;surgery at Hong Hui Hospital, Xi'an Jiaotong University from February 2019 through December 2019 were consecutively enrolled in the study. The inclusion criteria were 1) age 5-12 years and 2) American Society of Anesthesiologists (ASA) physical status I-II. Patients with neck\u0026nbsp;trauma, throat disorders, or an anticipated difficult airway were excluded. According to the location of scoliosis, patients were divided into three groups: Group C (cervical lateral bending), Group T (thoracic scoliosis), and Group L (lumbar scoliosis) (Figure 1).\u003c/p\u003e\n\u003cp\u003eAfter transfer into the operating room, non-invasive blood pressure, electrocardiogram, pulse oximetry,\u0026nbsp;end-tidal carbon dioxide concentration, and bispectral index were continuously monitored. The children\u0026nbsp;were\u0026nbsp;administered propofol 1.5 mg\u003csup\u003e.\u003c/sup\u003ekg\u003csup\u003e-\u003c/sup\u003e\u003csup\u003e1\u003c/sup\u003e IV for mild sedation\u0026nbsp;and positioned in horizontal recumbency with slight extension of the head. Ultrasonography using a linear 7\u0026ndash;15-MHz probe began with the identification of the true vocal folds. Then the probe was moved caudally to visualize the cricoid arch. The cricoid cartilage appears as a round hypoechoic structure with hyperechoic edges; the air column in the cricoid cartilage appears hyperechoic. The transverse air column diameter was considered to estimate the cricoid cartilage diameter (Figure 2). Based on the ultrasound measurements of the cricoid cartilage diameter, the corresponding ETT size was selected ( Supplemental Table). The measurements of the cricoid cartilage diameter were performed independently by two anesthesiologists, and the average was taken.\u0026nbsp;Before this formal study began, the anesthesiologists had performed 30 measurements of cricoid cartilage diameter under ultrasound guidance.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Anesthesia was induced with fentanyl 4 \u0026mu;g\u003csup\u003e.\u003c/sup\u003ekg\u003csup\u003e-1\u003c/sup\u003e, propofol 2 mg\u003csup\u003e.\u003c/sup\u003ekg\u003csup\u003e-1\u003c/sup\u003e, and atracurium 0.4 mg\u003csup\u003e.\u003c/sup\u003ekg\u003csup\u003e-1\u003c/sup\u003e. After 3 minutes, tracheal intubation was performed. The leak test was used to determine the best‑fit ETT size. In the presence of resistance to passage of the tube into the trachea, or in the absence of an audible leak at airway pressure \u0026gt;25 cm H\u003csub\u003e2\u003c/sub\u003eO, the ETT was replaced with a tube of 0.5 mm less internal diameter. If a leak was audible at airway pressures \u0026lt;10 cm H\u003csub\u003e2\u003c/sub\u003eO, if a seal could not be achieved with a cuff pressure \u0026gt;25 cm H\u003csub\u003e2\u003c/sub\u003eO, or if a peak airway pressure \u0026lt;25 cm H\u003csub\u003e2\u003c/sub\u003eO was observed during ventilation, the tube was exchanged for one a size larger. The ETT size predicted by ultrasonography and the best‑fit ETT size were recorded for each patient. The leak test and the tracheal intubation were performed by another investigator who was blinded to the cricoid cartilage diameter measurements.\u003c/p\u003e\n\u003cp\u003eAnesthesia was maintained with remifentanil (0.16 \u0026mu;g\u003csup\u003e.\u003c/sup\u003ekg\u003csup\u003e-1\u003c/sup\u003e\u003csup\u003e.\u003c/sup\u003emin\u003csup\u003e-1\u003c/sup\u003e) and sevoflurane (1.5%). At the end of all surgical procedures, sevoflurane and remifentanil infusion was stopped. The trachea was extubated when spontaneous ventilation returned. After extubation, the children were transferred to the PACU. The number of patients with laryngospasm was recorded.\u003c/p\u003e\n\u003cp\u003eThe data were analyzed using SPSS\u0026reg; v. 18 for Windows (IBM, Inc., Armonk, NY, USA). The demographic characteristics were compared using the chi-squared test or ANOVA. A scatter plot between the best‑fit ETT size and the ETT size predicted by ultrasound was constructed. A Bland-Altman plot was generated to analyze the agreement between the ETT size predicted by ultrasonography and the best‑fit ETT size. A P value \u0026lt; 0.05 was considered statistically significant.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eFifty pediatric patients with congenital scoliosis were included in this study. No significant differences were found in age, sex, height, and weight between the three groups (Table 1).\u003c/p\u003e\n\u003cp\u003eThere were strong correlations between the best‑fit ETT size and the ETT size predicted by ultrasound in Group T (r = 0.93, p \u0026lt; 0.001; Figure 3b) and Group L (r = 0.94, p \u0026lt; 0.001; Figure 3c) and a moderate correlation with Group C (r = 0.83, p \u0026lt; 0.001, Figure 3a).\u003c/p\u003e\n\u003cp\u003eBland-Altman analysis showed no\u0026nbsp;obvious bias between the ETT size predicted by ultrasonography and the best‑fit ETT size in Group T (bias = 0.02 mm, precision = 0.12 mm, limit of agreement = -0.42 to 0.46 mm; Figure 4b) and in Group L (bias = 0.09 mm, precision = 0.17 mm, limit of agreement = -0.31 to 0.49 mm; Figure 4c), but the ETT size was overestimated by ultrasound in Group C (bias = 0.73 mm, precision = 0.42 mm, limit of agreement = 0.08 to 1.38 mm; Figure 4a).\u003c/p\u003e\n\u003cp\u003eCompared with Group T and Group L, the incidence of laryngospasm was higher in Group C (15.0% vs 3.8%, p \u0026lt; 0.05; and 15.0% vs 0.0%, p \u0026lt; 0.05, respectively).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe cricoid cartilage, as the narrowest part of the larynx in children, plays an important role in the selection of optimal ETT size for intubation [11,12]. However, recently, Dalal et al. [13] found that the vocal cord and subvocal cord areas\u0026nbsp;were the narrowest portion in pediatric airways. Compared with the vocal cords, the cricoid is a complete and relatively rigid cartilaginous ring and the most frequently damaged structure during endotracheal intubation [14]. Therefore, theoretically, the cricoid cartilage is the limiting factor during intubation and can be a predictive factor in the selection of optimal ETT size for intubation.\u003c/p\u003e\n\u003cp\u003eUltrasonography is safe, noninvasive, can be quickly performed, provides real-time images, and is relatively simple to learn. More importantly, the leading edge of the cricoid cartilage and the air column can be identified with ultrasound[15]. In our study, the cricoid cartilage diameters\u0026nbsp;were estimated from\u0026nbsp;the measurements of the transverse air column diameter, which\u0026nbsp;is\u0026nbsp;the most\u0026nbsp;common approach\u0026nbsp;to\u0026nbsp;measure\u0026nbsp;the transverse diameter of the cricoid cartilage\u0026nbsp;in\u0026nbsp;clinical\u0026nbsp;research. To ensure the accuracy of the measurements, they were performed independently by two anesthesiologists and the average was taken, and the anesthesiologists who performed ultrasound examinations had performed 30 procedures before the formal experiment began. Lakhal et al.[16] found that 15 procedures were enough for an operator to obtain reliable measurements. Moreover, Julio et al. found that subglottic diameter ultrasound measurements had high intra-rater and inter-rater reproducibility[17]. Therefore, we believe that our measurements were accurate.\u003c/p\u003e\n\u003cp\u003eThe leak test is a classic experimental method and has been applied to determine the best‑fit ETT size for many years. Therefore, in our study, best‑fit ETT size was chosen according to the leak test. In prior studies, the allowed leak pressure often was 15-30 cm H\u003csub\u003e2\u003c/sub\u003eO for cuffed ETT [18]. Scoliosis can affect pulmonary function, and lung function abnormalities are mainly of the restrictive type [19]. During the procedure, the children\u0026nbsp;are\u0026nbsp;positioned in prone recumbency, and the operation can apply pressure to the chest. All these factors can cause elevation of the airway pressure. Therefore, we chose a higher leak pressure of 25 cm H\u003csub\u003e2\u003c/sub\u003eO to determine the best‑fit ETT size.\u003c/p\u003e\n\u003cp\u003eOur study showed a strong correlation between the ETT size predicted by ultrasonography and the best‑fit ETT size in pediatric patients with thoracic or lumbar scoliosis. The Bland-Altman analysis showed no\u0026nbsp;obvious bias between the ETT size predicted by ultrasonography and the best‑fit ETT size in pediatric patients with thoracic or lumbar scoliosis. Our findings were consistent with those reported by Pillai et al. [6]. In their study, the correlation was 0.98, and the bias was 0.041 mm. Therefore, it is feasible to predict ETT size by measuring the transverse diameter of the cricoid cartilage with ultrasonography in pediatric patients with thoracic or lumbar scoliosis.\u003c/p\u003e\n\u003cp\u003eHowever, in pediatric patients with cervical lateral bending, there was a poor correlation between the ETT size predicted by ultrasonography and the best‑fit ETT size. Bland-Altman analysis showed that the average of the differences between the ETT sizes was 0.73 mm. Considering that the minimal increment for tube size change is 0.5 mm (according\u0026nbsp;to\u0026nbsp;the inner diameter of the ETT), the ETT size was overestimated by ultrasound in pediatric patients with cervical lateral bending.\u003c/p\u003e\n\u003cp\u003eMRI is considered the reference standard for evaluating the larynx. High-quality images of the cricoid cartilage can be acquired by MRI, and the cricoid cartilage diameter can be accurately measured [20]. Therefore, in order to ascertain the cause of our result for Group C, we reviewed MRI images of four patients with cervical lateral bending. We found that the cricoid cartilage of the patients with cervical lateral bending was rotated (Figure 5). Previous\u0026nbsp;research\u0026nbsp;has shown that rotation of the centrum can produce displacement or rotation of the mainstem bronchi [9,10].\u0026nbsp;Therefore, we\u0026nbsp;speculate that the rotation of the cricoid cartilage results from deviation or rotation of the cervical vertebrae.\u003c/p\u003e\n\u003cp\u003eUnder\u0026nbsp;normal\u0026nbsp;circumstances, the cricoid cartilage is\u0026nbsp;elliptical, and the transverse diameter is smaller than the anteroposterior diameter [21]. When measuring the transverse diameter\u0026nbsp;of\u0026nbsp;the cricoid cartilage\u0026nbsp;by\u0026nbsp;ultrasound, the probe is positioned on the anterior neck, and the transverse air column diameter is measured to estimate the cricoid cartilage diameter. Because of this, rotation of the cricoid cartilage can broaden the air column\u0026nbsp;as measured by ultrasound, resulting\u0026nbsp;in a larger diameter measurement and overestimation of the necessary ETT size (Figure 6). In our study, we found that the ETT size predicted by ultrasonography was larger than the best‑fit ETT size in pediatric patients with cervical lateral bending. Therefore, compared to what is predicted by ultrasonography, these patients need a smaller ETT.\u003c/p\u003e\n\u003cp\u003eThe incidence of laryngospasm was higher in the patients with cervical lateral bending. There are\u0026nbsp;two\u0026nbsp;possible\u0026nbsp;reasons for this result. First, in pediatric patients with cervical lateral bending, the initial ETT size predicted by ultrasound was larger, and a larger ETT can irritate the throat and increase the likelihood of laryngospasm. Second, operation on the neck can irritate the upper airway, also increasing the likelihood of laryngospasm.\u003c/p\u003e\n\u003cp\u003eThe present study has one limitation. Only four patients with cervical lateral bending underwent cervical MRI; therefore, it is not\u0026nbsp;entirely\u0026nbsp;clear whether the deviation of ultrasonographic measurements resulted\u0026nbsp;only from the rotation of the cricoid cartilage in these patients. Further study is needed to analyze the\u0026nbsp;influence of cricoid cartilage morphology on the accuracy of ultrasound to measure the cricoid cartilage diameter in pediatric patients with cervical lateral bending.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eUltrasound is a reliable tool to predict ETT size for pediatric patients with thoracic or lumbar scoliosis. However, compared to the ETT size predicted by ultrasonography, pediatric patients with cervical lateral bending need a smaller ETT.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eETT, endotracheal tube; ASA: American Society of Anesthesiologists; PACU, post-anesthesia care unit; ANOVA, analysis of variance; MRI: magnetic resonance imaging\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study protocol was approved by the institutional review board of HongHui Hospital. The trial was registered with the Chinese Clinical Trial Registry (ChiCTR: 1900023408). Informed written consent was obtained from the parents of all children.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors have no competing interests to declare.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was funded by the Key Research and Development Program of Shaanxi, Chian(NO.2019SF-205). The funding body was not involved in the design, preparation, or writing of this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors' contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eJH and ZL designed the project; JH, JZ and BD performed the experiments and data collection; JH prepared the figures and drafted the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe would like to thank Editage (www.editage.cn) for English language editing.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eDillier CM, Trachsel D, Baulig W, Gysin C, Gerber AC, Weiss M: Laryngeal damage due to an unexpectedly large and inappropriately designed cuffed pediatric tracheal tube in a 13-month-old child. Can J Anaesth 2004; 51:72\u0026ndash;75.\u003c/li\u003e\n\u003cli\u003eBae JY, Byon HJ, Han SS, Kim S, Kim JT. Usefulness of ultrasound for selecting a correctly sized uncuffed tracheal tube for pediatric patients. Anaesthesia. 2011; 66:994-998.\u003c/li\u003e\n\u003cli\u003eGupta K, Gupta PK, Rastogi B, Krishan A, Jain M, Garg G. Assessment of the subglottic region by ultrasonography for estimation of appropriate size endotracheal tube: A clinical prospective study. Anesth Essays Res. 2012; 6:157-160.\u003c/li\u003e\n\u003cli\u003eJagadish G Sutagatti, Ranjana Raja, Madhuri S Kurdi. \u003ca href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5483782/\"\u003eUltrasonographic Estimation of Endotracheal Tube Size in Paediatric Patients and its Comparison with Physical Indices Based Formulae: A Prospective Study\u003c/a\u003e. J Clin Diagn Res.\u0026nbsp;2017;\u0026nbsp;11(5): UC05\u0026ndash;UC08.\u003c/li\u003e\n\u003cli\u003eMAN Rajasekhar, Srilata Moningi, Sujatha Patnaik, Prasad Rao. \u003ca href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6299778/\"\u003eCorrelation between ultrasound-guided subglottic diameter and little finger breadth with the outer diameter of the endotracheal tube in paediatric patients-A prospective observational study\u003c/a\u003e. Indian J Anaesth.\u0026nbsp;2018;\u0026nbsp;62(12): 978\u0026ndash;\u003c/li\u003e\n\u003cli\u003eRahul Pillai, Suresh Kumaran, L Jeyaseelan, Sajan P George, Raj Sahajanandan. \u003ca href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6206798/\"\u003eUsefulness of Ultrasound-guided Measurement of Minimal Transverse Diameter of Subglottic Airway in Determining the Endotracheal Tube Size in Children with Congenital Heart Disease: A Prospective Observational Study\u003c/a\u003e. Ann Card Anaesth.\u0026nbsp;2018;\u0026nbsp;21(4): 382\u0026ndash;\u003c/li\u003e\n\u003cli\u003eDemet Altun, Mukadder Orhan Sungur, Achmet Ali. \u003ca href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5207418/\"\u003eUltrasonographic Measurement of Subglottic Diameter for Paediatric Cuffed Endotracheal Tube Size Selection: Feasibility Report\u003c/a\u003e. Turk J Anaesthesiol Reanim.\u0026nbsp;2016;\u0026nbsp;44(6): 301\u0026ndash;\u003c/li\u003e\n\u003cli\u003eShibasaki M, Nakajima Y, Ishii S, Shimizu F, Shime N, Sessler DI, et al. Prediction of pediatric endotracheal tube size by ultrasonography. Anesthesiology 2010;113:819‑24.\u003c/li\u003e\n\u003cli\u003eBorowitz D, Armstrong D, Cerny F: Relief of central airways obstruction following spinal release in a patient with idiopathic scoliosis. Pediatr Pulmonol 2001, 31(1):86-88.\u003c/li\u003e\n\u003cli\u003eBartlett W, Garrido E, Wallis C, Tucker SK, Noordeen H: Lordoscoliosis and large intrathoracic airway obstruction. Spine (Phila Pa 1976) 2009, 34(1): E59-E65.\u003c/li\u003e\n\u003cli\u003eKluIka J, \u0026Scaron;toura P, \u0026Scaron;toudek R, Touk\u0026aacute;lkov\u0026aacute; M, Harazim H, Kosinov\u0026aacute; M. Controversies in Pediatric Perioperative Airways.\u0026nbsp;BioMed Research International.\u0026nbsp;2015; 2015: 368761.\u003c/li\u003e\n\u003cli\u003eShubhi Singh, Parul Jindal, Priya Ramakrishnan, Shailendra Raghuvanshi. \u003ca href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6448414/\"\u003ePrediction of endotracheal tube size in children by predicting subglottic diameter using ultrasonographic measurement versus traditional formulas\u003c/a\u003e. Saudi J Anaesth.\u0026nbsp;2019 ;\u0026nbsp;13(2): 93\u0026ndash;\u003c/li\u003e\n\u003cli\u003eDalal PG, Murray D, Messner AH, Feng A, McAllister J, Molter D, et al. Pediatric laryngeal dimensions: An age‑based analysis. Anesth Analg 2009;108:1475‑9.\u003c/li\u003e\n\u003cli\u003eFrerk, V. S. Mitchell, A. F. McNarry, C. Mendonca, R. Bhagrath, A. Patel.\u003ca href=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4650961/\"\u003eDifficult Airway Society 2015 guidelines for management of unanticipated difficult\u0026ensp;intubation\u0026ensp;in adults\u003c/a\u003e.Br J Anaesth.\u0026nbsp;2015;\u0026nbsp;115(6): 827\u0026ndash;848.\u003c/li\u003e\n\u003cli\u003eAdi Osman, Kok Meng Sum. Role of upper airway ultrasound in airway management. J Intensive Care.\u0026nbsp;2016;\u0026nbsp;4: 52.\u0026nbsp;\u003c/li\u003e\n\u003cli\u003eLakhal K, Delplace X, Cottier JP, Tranquart F, Sauvagnac X, Mercier C, et al. The feasibility of ultrasound to assess subglottic diameter. Anesth Analg. 2007;104:611‑4.\u003c/li\u003e\n\u003cli\u003eJulio, Jorge, Claudia, et al. Inter‑rater and intra‑rater reliability of the airway diameter measured by sonography.Journal of Ultrasound. 2018; 21:35\u0026ndash;\u003c/li\u003e\n\u003cli\u003eSchramm C, Knop J, Jensen K, Plaschke K. Role of ultrasound compared to age-related formulas for uncuffed endotracheal intubation in a pediatric population. Paediatr Anaesth 2012; 22: 781-6.\u003c/li\u003e\n\u003cli\u003ePraud Jaen-Paul, Canet E: Chest Wall Function and Dysfunction. In Kendig\u0026rsquo;s Disorders of the Respiratory Tract in Children.. 7 edition. Edited by: Chernick V,\u003c/li\u003e\n\u003cli\u003eBertolani M, Calandra Buonaura P, Spina V, et al. Spin-echo anatomy of the larynx in MRI at 1.5 T. J Radiol 1993;74:1\u0026ndash;12.\u003c/li\u003e\n\u003cli\u003eLitman RS, Weissend EE, Shibata D, Westesson PL: Developmental changes of laryngeal dimensions in unparalyzed, sedated children. Anesthesiol\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Table","content":"\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-style: initial; text-decoration-color: initial; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cstrong style=\"box-sizing: inherit; color: #363636; font-weight: bold;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px; line-height: 19.5px; font-family: Helvetica; color: #000000;\"\u003eTable 1 \u0026nbsp; Demographic characteristics.\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003ctable style=\"box-sizing: inherit; border-collapse: collapse; border-spacing: 0px; color: #4a4a4a; font-family: Roboto, BlinkMacSystemFont, -apple-system, 'Segoe UI', Oxygen, Ubuntu, Cantarell, 'Fira Sans', 'Droid Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-style: initial; text-decoration-color: initial; float: left; width: 420pt; border: none; margin-left: 6.75pt; margin-right: 6.75pt;\"\u003e\n\u003ctbody style=\"box-sizing: inherit;\"\u003e\n\u003ctr style=\"box-sizing: inherit;\"\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 137pt; border-top: 1pt solid windowtext; border-left: none; border-bottom: 1pt solid windowtext; border-right: none; height: 20.15pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003eGroup\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 124.95pt; border-top: 1pt solid windowtext; border-left: none; border-bottom: 1pt solid windowtext; border-right: none; height: 20.15pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003eC (n=13)\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 81pt; border-top: 1pt solid windowtext; border-left: none; border-bottom: 1pt solid windowtext; border-right: none; height: 20.15pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003eT(n=26)\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 81pt; border-top: 1pt solid windowtext; border-left: none; border-bottom: 1pt solid windowtext; border-right: none; height: 20.15pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003eL (n=11)\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr style=\"box-sizing: inherit;\"\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 137pt; border: none; height: 20.15pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003eAge(years)\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 124.95pt; border: none; height: 20.15pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003e7.5(1.6)\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 81pt; border: none; height: 20.15pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003e9.0(2.0)\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 81pt; border: none; height: 20.15pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003e8.5(1.8)\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr style=\"box-sizing: inherit;\"\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 137pt; border: none; height: 19.7pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003eSex(male/female)\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 124.95pt; border: none; height: 19.7pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003e5/8\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 81pt; border: none; height: 19.7pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003e12/14\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 81pt; border: none; height: 19.7pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003e4/7\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr style=\"box-sizing: inherit;\"\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 137pt; border: none; height: 19.7pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003eHight(cm)\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 124.95pt; border: none; height: 19.7pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003e125.2(10.8)\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 81pt; border: none; height: 19.7pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003e130.4(15.7)\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 81pt; border: none; height: 19.7pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003e130.8(14.0)\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr style=\"box-sizing: inherit;\"\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 137pt; border-top: none; border-right: none; border-left: none; border-image: initial; border-bottom: 1pt solid windowtext; height: 19.7pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003eWeight(kg)\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 124.95pt; border-top: none; border-right: none; border-left: none; border-image: initial; border-bottom: 1pt solid windowtext; height: 19.7pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003e23.2(6.5)\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 81pt; border-top: none; border-right: none; border-left: none; border-image: initial; border-bottom: 1pt solid windowtext; height: 19.7pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003e27.8(10.4)\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd style=\"box-sizing: inherit; padding: 0in 5.4pt; vertical-align: top; text-align: left; width: 81pt; border-top: none; border-right: none; border-left: none; border-image: initial; border-bottom: 1pt solid windowtext; height: 19.7pt;\"\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0in 0in 0.0001pt; padding: 0px 0px 10px; font-weight: 400; font-size: 14px; letter-spacing: 0.35px; line-height: 21px; color: #242c35; text-align: justify; font-family: Calibri, sans-serif;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-family: Helvetica; font-size: 13px; color: #000000;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; line-height: 19.5px;\"\u003e19.5(14.1)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr style=\"box-sizing: inherit; color: #4a4a4a; font-family: Roboto, BlinkMacSystemFont, -apple-system, 'Segoe UI', Oxygen, Ubuntu, Cantarell, 'Fira Sans', 'Droid Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-style: initial; text-decoration-color: initial;\" /\u003e\u003cbr style=\"box-sizing: inherit; color: #4a4a4a; font-family: Roboto, BlinkMacSystemFont, -apple-system, 'Segoe UI', Oxygen, Ubuntu, Cantarell, 'Fira Sans', 'Droid Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-style: initial; text-decoration-color: initial;\" /\u003e\u003cbr style=\"box-sizing: inherit; color: #4a4a4a; font-family: Roboto, BlinkMacSystemFont, -apple-system, 'Segoe UI', Oxygen, Ubuntu, Cantarell, 'Fira Sans', 'Droid Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-style: initial; text-decoration-color: initial;\" /\u003e\u003cbr style=\"box-sizing: inherit; color: #4a4a4a; font-family: Roboto, BlinkMacSystemFont, -apple-system, 'Segoe UI', Oxygen, Ubuntu, Cantarell, 'Fira Sans', 'Droid Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-style: initial; text-decoration-color: initial;\" /\u003e\u003cbr style=\"box-sizing: inherit; color: #4a4a4a; font-family: Roboto, BlinkMacSystemFont, -apple-system, 'Segoe UI', Oxygen, Ubuntu, Cantarell, 'Fira Sans', 'Droid Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-style: initial; text-decoration-color: initial;\" /\u003e\u003cbr style=\"box-sizing: inherit; color: #4a4a4a; font-family: Roboto, BlinkMacSystemFont, -apple-system, 'Segoe UI', Oxygen, Ubuntu, Cantarell, 'Fira Sans', 'Droid Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-style: initial; text-decoration-color: initial;\" /\u003e\u003cbr style=\"box-sizing: inherit; color: #4a4a4a; font-family: Roboto, BlinkMacSystemFont, -apple-system, 'Segoe UI', Oxygen, Ubuntu, Cantarell, 'Fira Sans', 'Droid Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-style: initial; text-decoration-color: initial;\" /\u003e\u003c/p\u003e\n\u003cp style=\"box-sizing: inherit; margin: 0px; padding: 0px 0px 10px; font-weight: 400; font-size: 0.925rem; letter-spacing: 0.35px; line-height: 1.65rem; color: #242c35; font-family: Roboto, BlinkMacSystemFont, -apple-system, 'Segoe UI', Oxygen, Ubuntu, Cantarell, 'Fira Sans', 'Droid Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-style: initial; text-decoration-color: initial;\"\u003e\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; font-size: 13px; line-height: 13.91px; font-family: Helvetica; color: #000000;\"\u003eData are mean (SD) or ratio. C: Cervical lateral bending; T: T\u003cspan style=\"box-sizing: inherit; font-style: inherit; font-weight: inherit; background: white;\"\u003ehoracic scoliosis;\u0026nbsp;\u003c/span\u003eL: Lumbar scoliosis.\u003c/span\u003e\u003c/p\u003e"},{"header":"Supplementary Table","content":"\u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:left;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cstrong\u003e\u003cspan style=\"font-size: 13px; line-height: 107%; font-family: Helvetica; color: rgb(0, 0, 0);\"\u003eSupplemental Table \u0026nbsp; Outer and inner diameters of cuffed endotracheal tubes of the used brand*.\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cdiv align=\"center\" style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\n \u003ctable style=\"float: left;width: 5.1e+2pt;border-collapse:collapse;border:none;margin-left:6.75pt;margin-right:6.75pt;\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width:50.45pt;border-top:solid windowtext 1.0pt;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:none;padding:0in 5.4pt 0in 5.4pt;height:79.1pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003eCCD\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e(mm)\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width:34.65pt;border-top:solid windowtext 1.0pt;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:none;padding:0in 5.4pt 0in 5.4pt;height:79.1pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e\u0026gt;3.3\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width:42.6pt;border-top:solid windowtext 1.0pt;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:none;padding:0in 5.4pt 0in 5.4pt;height:79.1pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e3.4-4.0\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width:42.6pt;border-top:solid windowtext 1.0pt;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:none;padding:0in 5.4pt 0in 5.4pt;height:79.1pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e4.1-5.3\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width:42.6pt;border-top:solid windowtext 1.0pt;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:none;padding:0in 5.4pt 0in 5.4pt;height:79.1pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e5.4-6.0\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width:42.6pt;border-top:solid windowtext 1.0pt;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:none;padding:0in 5.4pt 0in 5.4pt;height:79.1pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e6.1-6.7\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width:42.6pt;border-top:solid windowtext 1.0pt;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:none;padding:0in 5.4pt 0in 5.4pt;height:79.1pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e6.8-7.3\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width:42.6pt;border-top:solid windowtext 1.0pt;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:none;padding:0in 5.4pt 0in 5.4pt;height:79.1pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e7.4-8.0\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width:42.6pt;border-top:solid windowtext 1.0pt;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:none;padding:0in 5.4pt 0in 5.4pt;height:79.1pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e8.1-8.7\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width:42.6pt;border-top:solid windowtext 1.0pt;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:none;padding:0in 5.4pt 0in 5.4pt;height:79.1pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e8.8-9.3\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width:.65in;border-top:solid windowtext 1.0pt;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:none;padding: 0in 5.4pt 0in 5.4pt;height:79.1pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e9.4-10.0\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width:38.4pt;border-top:solid windowtext 1.0pt;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:none;padding:0in 5.4pt 0in 5.4pt;height:79.1pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e\u0026lt;10.1\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width:50.45pt;border:none;border-bottom:solid windowtext 1.0pt;padding:0in 5.4pt 0in 5.4pt;height:48.3pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003eOD\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e(mm)\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width:34.65pt;border:none;border-bottom:solid windowtext 1.0pt;padding:0in 5.4pt 0in 5.4pt;height:48.3pt;\"\u003e\n \u003cp 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107%;\"\u003e4.0\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width:42.6pt;border:none;border-bottom:solid windowtext 1.0pt;padding:0in 5.4pt 0in 5.4pt;height:48.3pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e5.3\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width:42.6pt;border:none;border-bottom:solid windowtext 1.0pt;padding:0in 5.4pt 0in 5.4pt;height:48.3pt;\"\u003e\n \u003cp 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style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e6.0\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width:42.6pt;border:none;border-bottom:solid windowtext 1.0pt;padding:0in 5.4pt 0in 5.4pt;height:48.75pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e6.5\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width:.65in;border:none;border-bottom:solid windowtext 1.0pt;padding:0in 5.4pt 0in 5.4pt;height:48.75pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e7.0\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width:38.4pt;border:none;border-bottom:solid windowtext 1.0pt;padding:0in 5.4pt 0in 5.4pt;height:48.75pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e7.5\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"12\" style=\"width:511.1pt;border:none;padding:0in 5.4pt 0in 5.4pt;height:48.75pt;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e*Xinxiang Tuoren Medical Equipment Co., Ltd, Henan, China.\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-size: 13px;\"\u003e\u003cspan style=\"font-family: Helvetica;\"\u003e\u003cspan style=\"line-height: 107%;\"\u003eCCD: Cricoid cartilage diameter; OD: outer diameter; ID: inner diameter\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;text-align:justify;line-height:107%;font-size:14px;font-family:\"Calibri\",sans-serif;'\u003e\u003cspan style=\"font-family: Helvetica; font-size: 13px; color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"line-height: 107%;\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-anesthesiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bane","sideBox":"Learn more about [BMC Anesthesiology](http://bmcanesthesiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bane","title":"BMC Anesthesiology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Ultrasonography, cricoid cartilage diameter, endotracheal tube, congenital scoliosis, pediatric","lastPublishedDoi":"10.21203/rs.3.rs-24208/v3","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-24208/v3","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBackground: Ultrasonography has been used to predict the necessary endotracheal tube (ETT) size by measuring the cricoid cartilage diameter. The aim of this study was to determine the accuracy of ultrasound to predict ETT size for pediatric patients with congenital scoliosis. \u003c/p\u003e\u003cp\u003eMethods: Fifty pediatric patients who underwent scoliosis surgery were included in the study. According to the position of the scoliosis, patients were divided into three groups: Group C (cervical lateral bending), Group T (thoracic scoliosis), and Group L (lumbar scoliosis). For all participants, the transverse diameter of the cricoid cartilage was measured with ultrasonography. The initial ETT size was chosen according to the measurements, then the leak test was used to determine the best\u001efit ETT size. The ETT size predicted by ultrasound and the best\u001efit ETT size were compared using Bland-Altman analysis. \u003c/p\u003e\u003cp\u003eResults: There was a strong correlation between the best\u001efit ETT size and the ETT size predicted by ultrasound in Group T (r = 0.93, p \u0026lt; 0.001) and Group L (r = 0.94, p \u0026lt; 0.001) and a moderate correlation in Group C (r = 0.83, p \u0026lt; 0.001). Bland-Altman analysis showed that the ETT size was overestimated by ultrasound in pediatric patients with cervical lateral bending (bias = 0.73 mm, precision = 0.42 mm, limit of agreement = 0.08 to 1.38 mm). \u003c/p\u003e\u003cp\u003eConclusion: Ultrasound is a reliable tool to predict ETT size for pediatric patients with thoracic or lumbar scoliosis. However, pediatric patients with cervical lateral bending will need an ETT smaller than the size predicted by ultrasonography. \u003c/p\u003e\u003cp\u003eTrial Registration: Chinese Clinical Trial Registry, TRN: ChiCTR1900023408, date of registration: 05.26.2019, 'retrospectively registered'.\u003c/p\u003e","manuscriptTitle":"The accuracy of ultrasound to predict endotracheal tube size for pediatric patients with congenital scoliosis","msid":"","msnumber":"","nonDraftVersions":[{"code":3,"date":"2020-07-29 14:52:38","doi":"10.21203/rs.3.rs-24208/v3","editorialEvents":[{"type":"communityComments","content":0},{"type":"checksComplete","content":"","date":"2020-07-22T12:00:00+00:00","index":"","fulltext":""},{"type":"decision","content":"Accept","date":"2020-07-22T12:00:00+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-anesthesiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bane","sideBox":"Learn more about [BMC Anesthesiology](http://bmcanesthesiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bane","title":"BMC Anesthesiology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}},{"code":2,"date":"2020-06-22 17:06:43","doi":"10.21203/rs.3.rs-24208/v2","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Minor revision","date":"2020-07-20T12:00:00+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2020-06-18T12:00:00+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2020-06-17T12:00:00+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2020-06-17T12:00:00+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-anesthesiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bane","sideBox":"Learn more about [BMC Anesthesiology](http://bmcanesthesiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bane","title":"BMC Anesthesiology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}},{"code":1,"date":"2020-05-07 17:36:51","doi":"10.21203/rs.3.rs-24208/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revision","date":"2020-05-31T12:00:00+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2020-05-27T12:00:00+00:00","index":2,"fulltext":"Recommendation: Accept after minor essential revisions\nForm responses:\n---\n\nComments to Author:\n---\nTo the Authors.\nI read with interest your paper: any new insight that might help the choice of the ETT in such a variate population is an interesting one.\nEven if the study population in quite small, you managed to work a good statistical analysis and draw interesting results.\n\nBesides some typos and language slips that can be easily addressed, I would like you to further clarify some details on the Methods section:\n- Did you take one only measure per patient? Or was the final one a mean value over more measurements?\n- If not, how did you take into account any possible errors in measurement?\n- Were the two practitioners both involved on each patient?\n\nI find worthy of attention your remarks on the tracheal deformity in cervical scoliosis. As a further development of your study, I would suggest to run MRI in every patient of this group, in order to try and develop a measure of deformity/rotation that might correlate with the errors in the US measurements.\n\nFinally, I do agree that the Leak test you used is solid and validated, thought we do all know the clinical consequences of a wrong choice in ETT size: wouldn't it be possible to retrieve from post-op charts the data on laryngospasms/stridor for this same paper, in order to power it with a clinical correlation of no adverse effects?\n* Are the methods appropriate and well described?: **No**\n* Does the work include the necessary controls?: **Yes**\n* Are the conclusions drawn adequately supported by the data shown?: **Yes**\n* Are you able to assess any statistics in the manuscript or would you recommend an additional statistical review?: **I am able to assess the statistics**\n* Quality of written English: **Needs some language corrections before being published**\n* Declaration of competing interests: **I declare that I have no competing interests**\n* Reviewer Publication Consent. I agree for my report to be made available under an Open Access Creative Commons CC-BY License (http://creativecommons.org/licenses/by/4.0) if this manuscript is accepted for publication. Any comments that I do not wish to be included in the published report have been included as confidential comments to the editor, which will not be published.: **I agree to the terms of the CC-BY 4.0 license; please do not publish my name with my report. (default)**\n"},{"type":"editorInvitedReview","content":"","date":"2020-05-24T12:00:00+00:00","index":1,"fulltext":"Recommendation: Major revisions required\nForm responses:\n---\n\nComments to Author:\n---\nI would like to thank the Authors for their work.\nThis is a prospective cohort that investigated the possible use of ultrasonography in predicting endotracheal tube for children who underwent orthopaedic surgery for congenital scoliosis.\nThe aim of the study is interesting not only in the paediatric population.\nHowever, some issues are presents.\n\nThe Authors enrolled 50 patients in a period of 11 months and divided them according to the type of orthopaedic interventions. In the manuscript there isn't sample size or power calculation, how the decided Authors the number of patients to enrol?\nAnother not mentioned issue is if the Authors consecutively enrolled the patients. This information seem to affect the external validity of the study. Can the Authors comment this point?\nMoreover, it wasn't mentioned the training of the two anesthesiologists who performed the ultrasonography. At the time of the study, which was their training in ultrasound? This point should be clarified and added in the Methods section. In addition, based on this explanation, a comment on how this might affect the external validity as well has to be added. \n\nThe Authors reported the Blad-Altam plot for analysing the agreement between the ultrasonography and the linear regression. Only a single measurement of the cricoid cartilage diameter was performed and by a single operator. Is it possible to have additional measurements and an estimate of inter-operator agreement? It would be critical in order to evaluate the reliability of the sonographic measurement of the cricoid cartilage.\nIt is also not clear why and how the Authors use the linear regression in the analysis of agreement. Figure 3 seems to be a correlation analysis between the best-fit endotracheal tube size and the size predicted using ultrasound. This point has to be clarified.\n\nThe description of the sonographic measurement of the cricoid cartilage is reported in the Discussion but it seems to be part of Methods and it should be moved in this section.\nMoreover, is it possible to increase the quality of figure 2 and to add more labeled details?\n\nTable 1 reports the details of the endotracheal tubes used in the study. I suggest to use table 1 for patients' baseline characteristics and to add these information in a supplemental table.\nThe explanation of the leak test can be added in the manuscript by eliminating table 2. \n\nA part of the Discussion is about the Authors' explanation of poor correlation results among patients with cervical lateral bending. It is interesting but no clues about this part are reported in the Methods section. I suggest to add details about it.\n\nThe paragraph on the study limitation is very concise, I strongly suggest to add details on the burden for the study of each limitation.\n\nFinally, the manuscript seems to need an English language revision.* Are the methods appropriate and well described?: **No**\n* Does the work include the necessary controls?: **Unable to assess**\n* Are the conclusions drawn adequately supported by the data shown?: **No**\n* Are you able to assess any statistics in the manuscript or would you recommend an additional statistical review?: **I am able to assess the statistics**\n* Quality of written English: **Needs some language corrections before being published**\n* Declaration of competing interests: **I declare that I have no competing interests**\n* Reviewer Publication Consent. I agree for my report to be made available under an Open Access Creative Commons CC-BY License (http://creativecommons.org/licenses/by/4.0) if this manuscript is accepted for publication. Any comments that I do not wish to be included in the published report have been included as confidential comments to the editor, which will not be published.: **I agree to the terms of the CC-BY 4.0 license; please do not publish my name with my report. (default)**\n"},{"type":"reviewerAgreed","content":"","date":"2020-05-07T12:00:00+00:00","index":2,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2020-05-05T12:00:00+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2020-05-05T12:00:00+00:00","index":1,"fulltext":""},{"type":"submitted","content":"","date":"2020-04-28T12:00:00+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2020-04-28T12:00:00+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2020-04-27T12:00:00+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2020-04-27T12:00:00+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-anesthesiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bane","sideBox":"Learn more about [BMC Anesthesiology](http://bmcanesthesiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bane","title":"BMC Anesthesiology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ef9bf694-2b03-4cfa-8c4b-e2fb22975a13","owner":[],"postedDate":"July 29th, 2020","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":216842,"name":"Anesthesiology \u0026 Pain Medicine"}],"tags":[],"updatedAt":"2020-08-04T22:37:32+00:00","versionOfRecord":{"articleIdentity":"rs-24208","link":"https://doi.org/10.1186/s12871-020-01106-7","journal":{"identity":"bmc-anesthesiology","isVorOnly":false,"title":"BMC Anesthesiology"},"publishedOn":"2020-07-31 12:00:00","publishedOnDateReadable":"July 31st, 2020"},"versionCreatedAt":"2020-07-29 14:52:38","video":"","vorDoi":"10.1186/s12871-020-01106-7","vorDoiUrl":"https://doi.org/10.1186/s12871-020-01106-7","workflowStages":[]},"version":"v3","identity":"rs-24208","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-24208","identity":"rs-24208","version":["v3"]},"buildId":"oE6Zbj460LM0Up2FdVbMZ","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}