Optimal depth of endotracheal intubation in pediatric patients

With the growing number of pediatric endotracheal intubations performed during general anesthesia, ensuring the correct placement of pediatric endotracheal tubes has become increasingly critical. Improving the accuracy of tracheal intubation and reducing complications of tracheal intubation are essential challenges faced by anesthesiologists. This review examines recent research on the optimal positioning of pediatric endotracheal tubes, focusing on the types and models of endotracheal tubes, the placement standards and positioning methods. Additionally, it explores the mechanism and impact of factors such as height, age and head and neck movement (flexion and extension) on tube positioning. This analysis aims to enhance the understanding of pediatric endotracheal intubation to improve clinical outcomes and patient safety.

Tracheal tract; Tracheal length; Bronchial intubation; Head and neck flexion; Head and neck extension

[1] Canadian Agency for Drugs and Technologies in Health. Airway management in out-of-hospital emergencies: health technologies. 2024. Available at: http://www.ncbi.nlm.nih.gov/books/NBK609610/ (Accessed: 02 March 2025).

[2] Salazar JH, Goldstein SD, Yang J, Gause C, Swarup A, Hsiung GE, et al. Regionalization of pediatric surgery: trends already underway. Annals of Surgery. 2016; 263: 1062–1066.

[3] Disma N, Asai T, Cools E, Cronin A, Engelhardt T, Fiadjoe J, et al. Airway management in neonates and infants: European Society of Anaesthesiology and Intensive Care and British Journal of Anaesthesia joint guidelines. European Journal of Anaesthesiology. 2024; 41: 3–23.

[4] Ebenebe CU, Schriever K, Apostolidou S, Wolf M, Herrmann J, Singer D, et al. Recommendations for endotracheal tube insertion depths in children. Emergency Medicine Journal. 2023; 40: 583–587.

[5] Ebenebe CU, Schriever K, Wolf M, Herrmann J, Singer D, Deindl P. Recommendations for nasotracheal tube insertion depths in neonates. Frontiers in Pediatrics. 2022; 10: 990423.

[6] Via LL, Messina S, Merola F, Tornitore F, Sanfilippo G, Santonocito C, et al. Combined laryngo-bronchoscopy intubation approach in the normal airway scenario: a simulation study on anesthesiology residents. Signa Vitae. 2023; 19: 91–98.

[7] Kim M, Im KS, Cho DH, Lee DS, Cho H. Endotracheal intubation with video laryngoscope at semilateral decubitus position: a case report of a pediatric patient with a back stab wound. Signa Vitae. 2021; 17: 213–215.

[8] Kim S. Comparison of the cuff pressures of a TaperGuard endotracheal tube during ipsilateral and contralateral rotation of the head: a randomized prospective study. Medicine. 2018; 97: e12702.

[9] Chen DY, Devsam B, Sett A, Perkins EJ, Johnson MD, Tingay DG. Factors that determine first intubation attempt success in high-risk neonates. Pediatric Research. 2024; 95: 729–735.

[10] Zimmermann L, Maiellare F, Veyckemans F, Fuchs A, Scquizzato T, Riva T, et al. Airway management in pediatrics: improving safety. Journal of Anesthesia. 2025; 39: 123–133.

[11] de Wit M, Peelen LM, van Wolfswinkel L, de Graaff JC. The incidence of postoperative respiratory complications: a retrospective analysis of cuffed vs. uncuffed tracheal tubes in children 0–7 years of age. Pediatric Anesthesia. 2018; 28: 210–217.

[12] De Orange FA, Andrade RG, Lemos A, Borges PS, Figueiroa JN, Kovatsis PG. Cuffed versus uncuffed endotracheal tubes for general anaesthesia in children aged eight years and under. Cochrane Database of Systematic Reviews. 2017; 11: CD011954.

[13] Taylor C, Subaiya L, Corsino D. Pediatric cuffed endotracheal tubes: an evolution of care. Ochsner Journal. 2011; 11: 52–56.

[14] Wani TM, Bissonnette B, Engelhardt T, Buchh B, Arnous H, AlGhamdi F, et al. The pediatric airway: historical concepts, new findings, and what matters. International Journal of Pediatric Otorhinolaryngology. 2019; 121: 29–33.

[15] Isa M, Holzki J, Hagemeier A, Rothschild MA, Coté CJ. Anatomical in vitro investigations of the pediatric larynx: a call for manufacturer redesign of tracheal tube cuff location and perhaps a call to reconsider the use of uncuffed tracheal tubes. Anesthesia & Analgesia. 2021; 133: 894–902.

[16] Kemper M, Fischer M, Grass B, Dave MH, Weiss M. Insertion of cuff inflation line into pediatric tracheal tubes related to oral and nasal tracheal intubation depth. Pediatric Anesthesia. 2021; 31: 695–701.

[17] Park RS, Peyton JM, Kovatsis PG. Neonatal airway management. Clinics in Perinatology. 2019; 46: 745–763.

[18] Dariya V, Moresco L, Bruschettini M, Brion LP. Cuffed versus uncuffed endotracheal tubes for neonates. Cochrane Database of Systematic Reviews. 2022; 1: CD013736.

[19] Thomas RE, Erickson S, Hullett B, Minutillo C, Lethbridge M, Vijayasekaran S, et al. Comparison of the efficacy and safety of cuffed versus uncuffed endotracheal tubes for infants in the intensive care setting: a pilot, unblinded RCT. Archives of Disease in Childhood. 2021; 106: 614–620.

[20] Williams ZC, Kim SS, Naguib A, Shafy SZ, Tobias JD. Use of cuffed endotracheal tubes in infants less than 5 kilograms: a retrospective cohort study. Journal of Pediatric Surgery. 2022; 57: 375–381.

[21] Zander D, Grass B, Weiss M, Buehler PK, Schmitz A. Cuffed endotracheal tubes in neonates and infants of less than 3 kg body weight—a retrospective audit. Paediatric Anaesthesia. 2021; 31: 604–610.

[22] Sarhan K, Walaa R, Hasanin A, Elgohary M, Alkonaiesy R, Nawwar K, et al. Cuffed versus uncuffed endotracheal tubes in neonates undergoing noncardiac surgeries: a randomized controlled trial. Paediatric Anaesthesia. 2024; 34: 1045–1052.

[23] Kim JH, Ahn JH, Chae YJ. Pediatric application of cuffed endotracheal tube. The Western Journal of Emergency Medicine. 2023; 24: 579–587.

[24] Klabusayová E, Klučka J, Kratochvíl M, Musilová T, Vafek V, Skříšovská T, et al. Airway management in pediatric patients: cuff-solved problem? Children. 2022; 9: 1490.

[25] Topjian AA, Raymond TT, Atkins D, Chan M, Duff JP, Joyner BL III, et al. Part 4: pediatric basic and advanced life support: 2020 american heart association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2020; 142: S469–S523.

[26] Saravia A, Saravia RW, Mudd P, Jones JW. Examining the pediatric subglottic airway by ultrasound: a systematic review. International Journal of Pediatric Otorhinolaryngology. 2023; 166: 111482.

[27] Pillai R, Kumaran S, Jeyaseelan L, George SP, Sahajanandan R. 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. Annals of Cardiac Anaesthesia. 2018; 21: 382–387.

[28] Gupta B, Ahluwalia P. Prediction of endotracheal tube size in the pediatric age group by ultrasound: a systematic review and meta-analysis. Journal of Anaesthesiology Clinical Pharmacology. 2022; 38: 371–383.

[29] Yang JL, Zheng F, Zhu KL, Wang W, Ding LM, Wang CG. Utilizing ultrasonography to determine the minimal transverse diameter of the subglottic airway for informed selection of reinforced cuffed endotracheal tube models in children. European Archives of Oto-Rhino-Laryngology. 2024; 281: 6533–6538.

[30] Shibasaki M, Nakajima Y, Ishii S, Shimizu F, Shime N, Sessler DI. Prediction of pediatric endotracheal tube size by ultrasonography. Anesthesiology. 2010; 113: 819–824.

[31] Abdel-Ghaffar HS, Thabet OH, Abbas YH, El-Hagagy NYM, Abedalmohsen AM. The accuracy of the ultrasound measured transverse cricoid diameter and the epiphyseal transverse diameter of the distal radius in predicting the pediatric endotracheal tube size. Pediatric Anesthesia. 2024; 34: 68–78.

[32] Pei B, Jin C, Cao S, Eckle T, Park HJ, Ji N, et al. The development of prediction model for cuffed tracheal tube size from the middle finger in pediatrics: a concise and feasible approach. Translational Pediatrics. 2023; 12: 2222–2231.

[33] Christiansen P, Pedersen CH, Selter H, Odder L, Riisager JP, Damgaard K, et al. How does tube size affect patients’ experiences of postoperative sore throat and hoarseness? A randomised controlled blinded study. Journal of Clinical Medicine. 2021; 10: 5846.

[34] Cook TM, MacDougall-Davis SR. Complications and failure of airway management. British Journal of Anaesthesia. 2012; 109: i68–i85.

[35] Kemper M, Imach S, Buehler PK, Thomas J, Dave M, Weiss M. Tube tip and cuff position using different strategies for placement of currently available paediatric tracheal tubes. British Journal of Anaesthesia. 2018; 121: 490–495.

[36] Puttawong D, Manopunya S, Visrutaratna P, Kosarat S, Khuwuthyakorn V, Tantiprabha W. Accuracy of various recent recommendations to estimate the optimal depth of orotracheal tube in Thai neonates. The Journal of Maternal-Fetal & Neonatal Medicine. 2022; 35: 3343–3347.

[37] Lee SU, Jung JY, Kim DK, Kwak YH, Kwon H, Cho JH, et al. New decision formulas for predicting endotracheal tube depth in children: analysis of neck CT images. Emergency Medicine Journal. 2018; 35: 303–308.

[38] Propst EJ, Gorodensky JH, Wolter NE. Length of the cricoid and trachea in children: predicting intubation depth to prevent subglottic stenosis. The Laryngoscope. 2022; 132: S1–S10.

[39] Zhuang PE, Lu JH, Wang WK, Cheng MH. A new formula based on height for determining endotracheal intubation depth in pediatrics: a prospective study. Journal of Clinical Anesthesia. 2023; 86: 111079.

[40] Logia P, Theagrajan A, M S R, Prabhu M. New formula for depth of insertion of endotracheal tube in children: a prospective observational study. Indian Journal of Pediatrics. 2024; 91: 125–130.

[41] Zhou QH, Xiao WP, Zhou HM. Middle finger length-based tracheal intubation depth improves the rate of appropriate tube placement in children. Paediatric Anaesthesia. 2015; 25: 1132–1138.

[42] Techanivate A, Kumwilaisak K, Samranrean S. Estimation of the proper length of orotracheal intubation by Chula formula. Journal of the Medical Association of Thailand. 2005; 88: 1838–1846.

[43] Techanivate A, Kumwilaisak K, Worasawate W, Tanyong A. Estimation of the proper length of nasotracheal intubation by Chula formula. Journal of the Medical Association of Thailand. 2008; 91: 173–180.

[44] Liu HK, Yang YN, Tey SL, Wu PL, Yang SN, Wu CY. Weight is more accurate than gestational age when estimating the optimal endotracheal tube depth in neonates. Children. 2021; 8: 324.

[45] Khanna P, Garg H, Ray BR, Singh A, Kundu R, Sinha R. Accuracy of predictive equations in guiding tracheal intubation depth in children: a prospective study. Paediatric Anaesthesia. 2021; 31: 1304–1309.

[46] Tailleur R, Bathory I, Dolci M, Frascarolo P, Kern C, Schoettker P. Endotracheal tube displacement during head and neck movements. Observational clinical trial. Journal of Clinical Anesthesia. 2016; 32: 54–58.

[47] Wani TM, John J, Bahun V, AlGhamdi F, Tumin D, Tobias JD. Endotracheal tube cuff position in relation to the cricoid in children: a retrospective computed tomography-based analysis. Saudi Journal of Anaesthesia. 2021; 15: 403–408.

[48] Wani TM, Siddique AY, Khan WN, Rehman S, Tram NK, Tobias JD. Endotracheal tube cuff position in relationship to the walls of the trachea: a retrospective computed tomography-based analysis. Saudi Journal of Anaesthesia. 2024; 18: 346–351.

[49] Wani TM, John J, Rehman S, Bhaskar P, Sahabudheen AF, Mahfoud ZR, et al. Point-of-care ultrasound to confirm endotracheal tube cuff position in relationship to the cricoid in the pediatric population. Paediatric Anaesthesia. 2021; 31: 1310–1315.

[50] Majeedi A, Peebles PJ, Li Y, McAdams RM. Glottic opening detection using deep learning for neonatal intubation with video laryngoscopy. Journal of Perinatology. 2025; 45: 242–248.

[51] Deasy A, O’Sullivan EP. Capnography: a fundamental in safe airway management. International Anesthesiology Clinics. 2024; 62: 29–36.

[52] Chau JPC, Liu X, Choi KC, Lo SHS, Lam SKY, Chan KM, et al. Diagnostic accuracy of end-tidal carbon dioxide detection in determining correct placement of nasogastric tube: an updated systematic review with meta-analysis. International Journal of Nursing Studies. 2021; 123: 104071.

[53] Damam S, Meshram RJ, Taksande A, Lohiya S, Khurana A, Patel A, et al. Navigating pediatric capnography: a comprehensive review of scope and limitations. Cureus. 2024; 16: e53289.

[54] Kerrey BT, Geis GL, Quinn AM, Hornung RW, Ruddy RM. A prospective comparison of diaphragmatic ultrasound and chest radiography to determine endotracheal tube position in a pediatric emergency department. Pediatrics. 2009; 123: e1039–e1044.

[55] Galicinao J, Bush AJ, Godambe SA. Use of bedside ultrasonography for endotracheal tube placement in pediatric patients: a feasibility study. Pediatrics. 2007; 120: 1297–1303.

[56] Kozyak BW, Yuerek M, Conlon TW. Contemporary use of ultrasonography in acute care pediatrics. Indian Journal of Pediatrics. 2023; 90: 459–469.

[57] Sahin O, Tasar S, Colak D, Yavanoglu Atay F, Guran O, Mungan Akin I. Point-of-care ultrasound for the tip of the endotracheal tube: a neonatologist perspective. American Journal of Perinatology. 2024; 41: e2886–e2892.

[58] Guerder M, Maurin O, Merckx A, Foissac F, Oualha M, Renolleau S, et al. Diagnostic value of pleural ultrasound to refine endotracheal tube placement in pediatric intensive care unit. Archives of Pediatrics. 2021; 28: 712–717.

[59] Levkovitz O, Schujovitzky D, Stackievicz R, Fayoux P, Morag I, Litmanovitz I, et al. Ultrasound assessment of endotracheal tube depth in neonates: a prospective feasibility study. Archives of Disease in Childhood. 2023; 109: 94–99.

[60] Congedi S, Savio F, Auciello M, Salvadori S, Nardo D, Bonadies L. Sonographic evaluation of the endotracheal tube position in the neonatal population: a comprehensive review and meta-analysis. Frontiers in Pediatrics. 2022; 10: 886450.

[61] Lin MJ, Gurley K, Hoffmann B. Bedside ultrasound for tracheal tube verification in pediatric emergency department and ICU patients: a systematic review. Pediatric Critical Care Medicine. 2016; 17: e469–e476.

[62] Das SK, Choupoo NS, Haldar R, Lahkar A. Transtracheal ultrasound for verification of endotracheal tube placement: a systematic review and meta-analysis. Canadian Journal of Anesthesia. 2015; 62: 413–423.

[63] Muslu B, Sert H, Kaya A, Demircioglu RI, Gözdemir M, Usta B, et al. Use of sonography for rapid identification of esophageal and tracheal intubations in adult patients. Journal of Ultrasound in Medicine. 2011; 30: 671–676.

[64] Salvadori S, Nardo D, Frigo AC, Oss M, Mercante I, Moschino L, et al. Ultrasound for endotracheal tube tip position in term and preterm infants. Neonatology. 2021; 118: 569–577.

[65] Alonso Quintela P, Oulego Erroz I, Mora Matilla M, Rodríguez Blanco S, Mata Zubillaga D, Regueras Santos L. Usefulness of bedside ultrasound compared to capnography and X-ray for tracheal intubation. Anales de Pediatría. 2014; 81: 283–288. (In Spanish)

[66] Datta S, Sankar J, Pathak M, Tungal S, Kandasamy D, Dhochak N, et al. Diagnostic accuracy of airway ultrasound in confirming the endotracheal tube depth in critically ill children. American Journal of Emergency Medicine. 2024; 85: 52–58.

[67] Song Y, Oh J, Chee Y, Lim T, Kang H, Cho Y. A novel method to position an endotracheal tube at the correct depth using an infrared sensor stylet. Canadian Journal of Anesthesia. 2013; 60: 444–449.

[68] Lu T, Khampang P, Beydoun A, Berezovsky A, Rohde R, Hong W, et al. Continuous monitoring of endotracheal tube position with near infrared light. Journal of Biomedical Optics. 2024; 29: 035001.

[69] Angelotti T, Weiss EL, Lemmens HJM, Brock-Utne J. Verification of endotracheal tube placement by prehospital providers: is a portable fiberoptic bronchoscope of value? Air Medical Journal. 2006; 25: 74–78; discussion 78–80.

[70] Reyes G, Ramilo J, Horowitz I, Freter AE, Husayni T, Sulayman R, et al. Use of an optical fiber scope to confirm endotracheal tube placement in pediatric patients. Critical Care Medicine. 2001; 29: 175–177.

[71] Yamamoto T, Schindler E. Ideal depth of endotracheal intubation at the vocal cord level in pediatric patients considering racial differences in tracheal length. Journal of Clinical Medicine. 2022; 11: 864.

[72] Jordi Ritz EM, Von Ungern-Sternberg BS, Keller K, Frei FJ, Erb TO. The impact of head position on the cuff and tube tip position of preformed oral tracheal tubes in young children. Anaesthesia. 2008; 63: 604–609.

[73] Ho AMH, Aun CST, Karmakar MK. The margin of safety associated with the use of cuffed paediatric tracheal tubes. Anaesthesia. 2002; 57: 173–175.

[74] Lee KS, Yang CC. Tracheal length of infants under three months old. Annals of Otology, Rhinology & Laryngology. 2001; 110: 268–270.

[75] Kim JT, Kim HJ, Ahn W, Kim HS, Bahk JH, Lee SC, et al. Head rotation, flexion, and extension alter endotracheal tube position in adults and children. Canadian Journal of Anesthesia. 2009; 56: 751–756.

[76] Yan S, Zhang H. Impact of changes in head position during head and neck surgery on the depth of tracheal tube intubation in anesthetized children. BMC Anesthesiology. 2020; 20: 124.

[77] Kang DH, Kim SH, You HE, Kim WM. Is endotracheal tube displacement during head and neck extension due to ascending movement or tracheal lengthening? An observational ultrasonographic study. Journal of Clinical Monitoring and Computing. 2023; 37: 139–145.

[78] Zhuang P, Wang W, Cheng M. Effect of head position changes on the depth of tracheal intubation in pediatric patients: a prospective, observational study. Frontiers in Pediatrics. 2022; 10: 998294.

[79] Weiss M, Knirsch W, Kretschmar O, Dullenkopf A, Tomaske M, Balmer C, et al. Tracheal tube-tip displacement in children during head-neck movement—a radiological assessment. British Journal of Anaesthesia. 2006; 96: 486–491.

[80] Jin-Hee K, Ro YJ, Seong-Won M, Chong-Soo K, Seong-Deok K, Lee JH, et al. Elongation of the trachea during neck extension in children: implications of the safety of endotracheal tubes. Anesthesia & Analgesia. 2005; 101: 974–977.

[81] Park JH, Lee HJ, Lee SH, Kim JS. Changes in tapered endotracheal tube cuff pressure after changing position to hyperextension of neck: a randomized clinical trial. Medicine. 2021; 100: e26633.

[82] Seol G, Jin J, Oh J, Byun SH, Jeon Y. Pressure changes in tapered and cylindrical shaped cuff after extension of head and neck: a randomized controlled trial. World Journal of Clinical Cases. 2022; 10: 11419–11426.

[83] Veder LL, Joosten KFM, Timmerman MK, Pullens B. Factors associated with laryngeal injury after intubation in children: a systematic review. European Archives of Oto-Rhino-Laryngology. 2024; 281: 2833–2847.

[84] Weiss M, Dave M, Bailey M, Gysin C, Hoeve H, Hammer J, et al. Endoscopic airway findings in children with or without prior endotracheal intubation. Pediatric Anesthesia. 2013; 23: 103–110.

[85] Veder LL, Joosten KFM, Schlink K, Timmerman MK, Hoeve LJ, van der Schroeff MP, et al. Post-extubation stridor after prolonged intubation in the pediatric intensive care unit (PICU): a prospective observational cohort study. European Archives of Oto-Rhino-Laryngology. 2020; 277: 1725–1731.

[86] Bharti B, Syed KA, Ebenezer K, Varghese AM, Kurien M. Post intubation laryngeal injuries in a pediatric intensive care unit of tertiary hospital in India: a fibreoptic endoscopic study. International Journal of Pediatric Otorhinolaryngology. 2016; 85: 84–90.

[87] Bibl K, Pracher L, Küng E, Wagner M, Roesner I, Berger A, et al. Incidence of post-extubation stridor in infants with cuffed vs. uncuffed endotracheal tube: a retrospective cohort analysis. Frontiers in Pediatrics. 2022; 10: 864766.

[88] Vahabzadeh-Hagh AM, Marsh-Armstrong BP, Patel SH, Lindenmuth L, Feng Z, Gong R, et al. Endotracheal tube forces exerted on the larynx and a novel support device to reduce it. Laryngoscope Investigative Otolaryngology. 2023; 8: 989–995.

[89] Burton L, Loberger J, Baker M, Prabhakaran P, Bhargava V. Pre-extubation ultrasound measurement of in situ cuffed endotracheal tube laryngeal air column width difference: single-center pilot study of relationship with post-extubation stridor in subjects younger than 5 years old. Pediatric Critical Care Medicine. 2024; 25: 222–230.

[90] Güneş K, Sever F, Özmert S. Determining optimal cuff volume for cuffed endotracheal tubes commonly used in pediatric patients: a prospective observational study. Saudi Medical Journal. 2024; 45: 147–153.