Sizing double-lumen tubes by direct measurement of the mainstem bronchus

One popular technique of sizing left-sided double-lumen tube (DLT) is to use gender and height (male: 41F/39F for height > 170/ < 170 cm; female: 37F/35F for > 160/ < 160 cm).¹, ² The DLT bronchial stump should be 2–3 mm smaller than the bronchial internal diameter. However, based on 3 dimensional spiral computer tomography (CT), the gender-height approach underestimated the ideal size of left-DLT in 2/48 cases and overestimated in 9/48 cases.³

Tracheobronchial measurements can be estimated on a plain chest radiograph, but these measurements have a magnification factor of 1.05‒1.40. Additionally, bronchial borders are often obscure. Three-dimensional spiral CT reconstruction is seldom available. Conversely, CT scans are ubiquitous in thoracic surgery and can be utilized to estimate bronchial diameters for sizing DLT⁴; yet, the technique is not described in anesthesiology textbooks.

Tracheobronchial anatomy in thoracic patients is variable. In this CT of a 184 cm tall male (Fig. 1), the diameter of the left mainstem bronchus immediately distal to the carina is 11 mm. Based on height, this male would have been intubated with a 41F left-DLT, when, in fact, even a 35F left-DLT – which some authors have proposed as the universal size for all adults – might have been excessively large. An endobronchial block might have been more appropriate.

Figure 1
Axial computed tomography image of a 184 cm male immediately distal to the carina (red arrow) where the left main bronchial diameter is measured at 11 mm. Based on the gender-height approach (Table), this patient would likely have been intubated with a 41F double-lumen tube (DLT), when, in fact, even a 35F DLT might have been excessively large. Note that the table has been adapted from work by Hao et al.¹ (https://doi.org/10.1056/nejmvcm2026684) and Licker et al. (https://doi.org/10.1016/j.tacc.2014.04.003). OD, Outer Diameter; ID, Inner Diameter.

• Ethics and Consent
  Not applicable as neither the manuscript nor the image present patient identifiable data.
• Funding
  Support was provided solely from institutional and/or departmental sources. No external funding was acquired for the current work.

References

• ¹
  Hao D, Saddawi-Konefka D, Low S, et al. Placement of a doublelumen endotracheal tube. N Engl J Med. 2021;385:e52.
• ²
  Slinger P, Campos JH. Anesthesia for thoracic surgery. In: Miller’s Anesthesia, 9th ed. Ed. Gropper MA, Cohen NH, Eriksson LI, Fleisher LA, Leslie K, Wiener-Kronish JP. Elsevier, Philadelphia, 2020. PP. 1648–1776.
• ³
  Eberle B, Weiler N, Vogel N, et al. Computer tomography-based tracheobronchial image reconstruction allows selection of the individually appropriate double-lumen tube size. J Cardiothorac Vasc Anesth. 1999;13:632–7.
• ⁴
  Hannallah M, Benumof JL, Silverman PM, et al. Evaluation of an approach to choosing a left double-lumen tube size based on chest computed tomographic scan measurement of left main-stem bronchial diameter. J Cardiothorac Vasc Anesth. 1997;11:168–71.

Publication Dates

• Publication in this collection
  22 Apr 2024
• Date of issue
  2024

History

• Received
  01 June 2023
• Accepted
  19 Dec 2023
• Published
  04 Feb 2024