Dimensional Variations of Left-Sided Double-Lumen Endobronchial Tubes

Abstract

Background. Tube size selection is critical in ventilating patients’ lungs using double-lumen endobronchial tubes (DLTs). Little information about relevant parameters is readily available from manufacturers. The aim of this study is to provide reference data for relevant dimensions of conventionally available DLTs. Methods. In this study in a benchmark in vitro setup, several dimensional parameters of four sizes of left-sided double-lumen endobronchial tubes from six different manufacturers were assessed, such as distances and diameters of tube shaft, cuff lengths, and diameters as well the angle at the tip. Results. Endobronchial tubes of ostensibly the same size revealed wide variation in measured parameters between brands from different manufacturers. In some parameters, there was an overlap between different sizes from the same manufacturer, i.e., diameters and distances did not increase with increasing nominal endobronchial tube size. The information about dimensions of endobronchial tubes provided by manufacturers’ leaflets is insufficient. Conclusions. Endobronchial tube size selection carries unnecessary uncertainty because clinically relevant parameters are unknown and vary considerably between different manufacturers.

A randomized comparison between the VivaSight double-lumen tube and standard double-lumen tube intubation in thoracic surgery patients

“…In a study by Hegland et al ( 20 ), DLT and VDLT dimensions were compared. Considerable differences were found in similarly sized tubes of different brands.…”

Comparisons of the segments of left-sided double-lumen tracheobronchial tubes as industrial products

“…Although Slinger [ 11 ] recommended radiological measurement of the left mainstem bronchial diameter as an objective guide to choosing a left DLT size, measurement of left bronchial diameter on chest computed tomographic scans can objectively guide the choice of left DLT size for an individual patient [ 9 ]. Hegland et al [ 3 ] also measured outer cuff diameters in their recent publication, but they did not obtain transverse and longitudinal measurements, despite the fact that cuffs may not be truly round in configuration. This was our justification for including these dimensions in our study.…”

“…Hegland et al [ 3 ] recently measured the cross-sectional area of the DLTs utilizing the measured width and height of the tube according to the formula “cross-sectional area = π × width/2 (= lateral) × height/2 (= anterior–posterior), whereas we measured various cross-sectional areas of tracheal and bronchial “lumens” and “tubules” for cuff inflation with area measurement software.…”

“…Although at least seven manufacturers are producing left-sided double-lumen tracheobronchial tubes (DLTs) [ 1 – 3 ], which are used for lung separation and one-lung ventilation [ 4 ], few reports have compared the segments of these DLTs. Benumof et al [ 5 ] defined the “margin of safety” in positioning a DLT as the length of the tracheobronchial tree over which the DLT may be moved or positioned without obstructing a conducting airway and measured the margin of safety in positioning three manufacturers’ DLTs available in 1987.…”

“…However, there have been few measurements and/or investigations of air volume in the cuffs, angles of bevels, the transverse and longitudinal external diameters of the tracheal and bronchial cuffs after cuff inflation, various lengths of different tubes, external diameters of both lumens and the tubules (air channels, inflation lumen [ 6 ]) for tracheal and bronchial cuff inflation, and various cross-sectional areas of tracheal and bronchial lumens and tubules for cuff inflation with area measurement software [ 3 ]. We thought it beneficial to measure these factors in various DLTs which are industrial products in greater detail.…”