Modification of the "Tochen Formula" to Measure the Accuracy of Endotracheal Tube Depth in Orotracheal Intubation of Neonates with Birth Weight Below 1500 Grams or Gestational Age Below 32 Weeks

Authors

  • Akira Prayudijanto
  • Adhi Teguh Perma Iskandar
  • Rinawati Rohsiswatmo
  • Haryanti Fauzia Wulandari
  • Irene Yuniar
  • Bambang Supriyatno

Keywords:

Birth weight, Endotracheal tube, Gestational age, Tochen’s formula

Abstract

Introduction: Accurate endotracheal tube (ETT) depth is crucial to prevent serious complications. The Tochen formula, commonly used in Indonesia, shows limitations in premature or low birth weight neonates due to a high rate of malposition. This study aimed to evaluate the accuracy of the Tochen formula and compare it with a modified formula for determining appropriate ETT depth in neonates weighing less than 1500 grams or with a gestational age below 32 weeks.

Methods: This retrospective cross-sectional study was conducted in the Neonatology Unit of RSCM between 1 January 2023 and 31 December 2024. Inclusion criteria were neonates with a birth weight under 1500 grams or a gestational age below 32 weeks who underwent orotracheal intubation and chest X-ray to assess ETT tip position.

Results: Only 22.2% of ETT placements using Tochen’s formula were accurate, versus 77.8% using the modified formula (p < 0.001). Spearman analysis showed gestational age (r = 0.996, p < 0.001) and birth weight (r = 0.792, p < 0.001) significantly influenced ideal ETT depth. Linear regression found both factors to be significant predictors (β = 0.081 and 0.108, p < 0.001 and 0.008, respectively). The modified formula yielded improved accuracy, though ICC analysis = 0.941 indicated extremely good agreement with Tochen’s.

Conclusion: Gestational age and birth weight significantly influence ideal ETT depth in group. The Tochen’s formula is less accurate for this group. The proposed modification provides improved precision for ETT placement in next longitudinal study for improve validity. Nevertheless, the potential for type 1 error was noted in the significant statistical results.

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References

Schaefer-Randolph JL, Shumway SG, Fuller CW, Ramjee VG, Vasan NR. Neonatal Tracheal Intubation in the NICU: A Literature Review. Healthcare. 2025 May 24;13(11):1242.

Kresnawati W, Pandie PJ, Rohsiswatmo R. Very low birth weight infant outcomes in a resource-limited setting: a five-year follow-up study. Front Pediatr. 2025;13:1581033.

Jańczewska I, Wierzba J, Jańczewska A, Szczurek-Gierczak M, Domżalska-Popadiuk I. Prematurity and Low Birth Weight and Their Impact on Childhood Growth Patterns and the Risk of Long-Term Cardiovascular Sequelae. Children (Basel). 2023 Sep 25;10(10):1599.

Volsko TA, McNinch NL, Page-Goertz C. Development and internal validation of an equation using anthropometric measures to predict correct endotracheal tube insertion depth. Can J Respir Ther. 2022;58:9–14.

Naseh N, Wallström L, Sindelar R, Ågren J. Standardized endotracheal tube and intravascular access placement in infants born at 22-23 weeks gestation. Pediatr Res [Internet]. 2025 Jun 18 [cited 2025 Jun 25]; Available from: https://www.nature.com/articles/s41390-025-04186-8

Miller KA, Kimia A, Monuteaux MC, Nagler J. Factors Associated with Misplaced Endotracheal Tubes During Intubation in Pediatric Patients. The Journal of Emergency Medicine. 2016 Jul;51(1):9–18.

Amarilyo G, Mimouni FB, Oren A, Tsyrkin S, Mandel D. Orotracheal tube insertion in extremely low birth weight infants. J Pediatr. 2009 May;154(5):764–5.

Chung HW, Lee WT, Chen HL. Reexamining the ideal depth of endotracheal tube in neonates. Pediatr Neonatol. 2018 Jun;59(3):258–62.

Avva U, Lata JM, Hendrix JM, Kiel J. Airway Management. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 [cited 2025 Jun 25]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK470403/

Cook TM, MacDougall-Davis SR. Complications and failure of airway management. British Journal of Anaesthesia. 2012 Dec;109:i68–85.

Takeuchi S, Arai J, Nagafuji M, Hinata A, Kamakura T, Hoshino Y, et al. Ideal endotracheal tube insertion depth in neonates with a birthweight less than 750 g. Pediatr Int. 2020 Aug;62(8):932–6.

Kempley ST, Moreiras JW, Petrone FL. Endotracheal tube length for neonatal intubation. Resuscitation. 2008 Jun;77(3):369–73.

Sakhuja P, Finelli M, Hawes J, Whyte H. Is It Time to Review Guidelines for ETT Positioning in the NICU? SCEPTIC-Survey of Challenges Encountered in Placement of Endotracheal Tubes in Canadian NICUs. Int J Pediatr. 2016;2016:7283179.

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Published

2025-07-23

How to Cite

1.
Prayudijanto A, Perma Iskandar AT, Rohsiswatmo R, Fauzia Wulandari H, Yuniar I, Supriyatno B. Modification of the "Tochen Formula" to Measure the Accuracy of Endotracheal Tube Depth in Orotracheal Intubation of Neonates with Birth Weight Below 1500 Grams or Gestational Age Below 32 Weeks. J Neonatal Surg [Internet]. 2025 Jul. 23 [cited 2026 May 30];14(13S):1354-61. Available from: https://jneonatalsurg.com/index.php/jns/article/view/8475

Issue

Vol. 14 No. 13S (2025): Journal of Neonatal Surgery

Section

Original Article

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