Report an error   

Submitted: 18 February 2019 Modified: 20 August 2019
HERDIN Record #: 108908-19021821244939

Tracheal diameter estimates using age-related formula versus radiographic findings: which approximates the actual tracheostomy tube in pediatric patients?.

Isaac Cesar  S. De Guzman

See More

Objective: To compare actual tracheostomy tube sizes with estimated endotracheal tube sizes using age-related formula and tracheal diameter from preoperative radiographs among pediatric Filipino patients aged 0-18 years old undergoing tracheostomy.


Study Design: Review of records

Setting:           Tertiary Private University Hospital in Dasmarinas, Cavite, Philippines

Patients:         Pediatric patients regardless of gender, aged 0 to 18 years old, with a preoperative radiograph of the trachea, and who subsequently underwent tracheostomy anytime from January 1, 2007 to December 31, 2016 were considered for inclusion. Radiographs were measured, endotracheal tube sizes were computed using age-related formula, and recorded tracheotomy tube sizes were retrieved.

Results: Twenty-two patients (12 males, 10 females) aged 10 months to 18-years-old (median age: 11 years) were included in the study. Mean tube sizes were 6.46mm (+/- 1.492 SD) for age-related formula, 5.67mm (+/- 1.1849 SD) for radiograph-based estimation, and 5.0 for actual tracheostomy tube inserted in each patient. The Bland-Altman plot showed the bias estimate at 0.7913 and the lower and upper limits of agreement at -1.3598 and 2.9423 (confidence level 95% or 2 standard deviations away from the mean).

Conclusions: The average value derived from radiograph-based estimation is less than the corresponding average value from age-related formula. There is a significant difference between age-related formula-based estimation and actual tracheostomy tube inserted. Since the range of differences between the two estimation methods is high, these results imply that the bias or the difference between measures from the two methods is not consistent, with the two methods exhibiting very poor agreement.

Keywords: Tracheostomy, Intubation, Intra Tracheal, Penlington Formula, Trachea Radiograph Measurement, age related formula for endotracheal tube estimation


Publication Type
Publication Sub Type
Journal Article, Original
Philippine Journal of Otolaryngology Head and Neck Surgery
Publication Date
January-December 2018
LocationLocation CodeAvailable FormatAvailability
Philippine Society of Otolaryngology-Head and Neck Surgery Fulltext pdf (Download)
Philippine Society of Otolaryngology-Head and Neck Surgery Fulltext External Link (View)
Philippine Council for Health Research and Development Fulltext Print Format (Request Document)
1. Behl, S , Watt, J W. "Prediction oftracheostomy tube size for paediatric long term ventilation: an audit ofchildren with spinal cord injury." Br JAnesth 94(1): 88-91, January 2005
2. Barash, P G. Clinical Anesthesia. Philadelphia: Lippincott Williams & Wilkins, A Wolters Kluwer Business, 2013. 1237. (7th ed.)
3. Park, H P. "Appropriate tube size selection based on radiological images." Korean J Anesthesiol 66(3): 181-182, March 2014
4. Park, H P, Hwang, J W, Lee, J H, Nahm, F S, Park, S H, Oh, A Y. "Predicting the appropriate uncuffedendotracheal tube size for children: a radiograph-based formula versus twoage-based formulas" J Clin Anesth. 25(5): 384–387, August 2013
5. Chen, S J, Shih, T T, Liu, K L, Wu, M H, Chen, H Y. "Measurement of tracheal size in childrenwith congenital heart disease by computed tomography" Ann Thorac Surg 77(4): 1216–1221, April 2004
6. Lakhal, K , Delplace, X , Cottier, J P, Tranquart, F , Sauvagnac, X , Mercier, C . "The feasibility ofultrasound to assess subglottic diameter" AnesthAnalg. 104(3): 611–614, March 2007
7. Carp, H , Bundy, A . "Apreliminary study of the ultrasound examination of the vocal cords and larynx." Anesth Analg 75(4): 639–640, October 1992
8. Seymour, A H, Prakash, N . "A cadaver study to measure the adult glottis and subglottis: defining a problem associated with the use of double-lumen tubes" J Cardiothorac Vasc Anesth 16(2): 198-196, October 1992
9. Randestad, A , Lindholm, C E, Fabian, F . "Dimensions of the cricoid cartilage and the trachea." Laryngoscope 110(11): 1957-1961, November 2000
10. Mostafa, S M. "Variation in subglottic size in children" Proc R Soc Med 69(11): 793-795, November 1976
11. Turkistani, A , Abdullah, K M, Delvi, B , Al-Mazroua, K A. "The ‘best fit’ endotracheal tube in children – comparison of four formulae" Middle East J Anaesthesiol 69(11): 793-95, October 2009
12. Lee, K W, Templeton, J J. "Tracheal tube sizeand postintubation croup in children" Anesthes 53, 325, 1980
13. Magill, I W. "Techniquein endotracheal anaesthesia" Br Med J 2(3645): 817–9, November 1930
14. Mir, F , Sandhu, G , Poncia, J . "Size matters: choosing the right tracheal tube" Anaesthesia 67(12): 1402-1403, December 2012
15. Brown, E S. "Resistance factors in pediatric endotracheal tubes and connectors" Anesth Analg 50(3): 355-60, May 1971-June 1971
16. Divatia, J V, Bhowmick, K . "Complications of endotracheal intubation and otherairway management procedures." Indian J Anaesth 49(4): 308 -318, 2005
17. Shih, M H, Chung, C Y, Su, B C, Hung, C T, Wong, S Y, Wong, T K. "Accuracy of a new body length-based formula forpredicting tracheal tube size in Chinese children" Chang GungMed J 31(3): 276-80, May 2008-June 2008
18. Karsli, C H, Isaac, L A, Roy, W L. Induction of anesthesia. In: Bissonnette B, Dalens BJ (editors).Pediatric Anaesthesia Principles and Practice (edition 1) New York, NY,: McGraw-Hill., 2002. 483-527.
19. Litman, R S, Keon, T P. "Postintubation croup inchildren" Anesthesiology 75(6): 1122-3, December 1991
20. Finholt, D A, Henry, D B, Raphaely, R C. "Factors affecting leak around tracheal tubes in children" Can Anaesth Soc J 32(4): 326–329, July 1985
21. Schwartz, R E, Stayer, S A, Pasquariello, C A. "Tracheal tube leak test—is there inter-observer agreement?" Can J Anaesth 40(11): 1049–1052., November 1993
22. Takita, K , Morimoto, Y , Okamura, A , Kemmotsu, O . "Do age-based formulae predict the appropriate endotracheal tube sizes in Japanese children?" J Anaesth 15(3): 145-48, 2001
23. Finholt, D A, Henry, D B, Raphaely, R C. "A “leak” test: a standard method for assessing tracheal tube fit in pediatric patients" Anesthesiology 61, 450, 1984
24. Covidien, . (2017, February 27). Tracheostomy Products Quick Reference Guide. . Retrieved from: http://