Airway dimensions from fetal life to adolescence—A literature overview

Schmid, Kathrin; Weiß, Markus

doi:10.1002/ppul.24046

Cited by 9 publications

(9 citation statements)

References 91 publications

(290 reference statements)

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“…Despite these limitations, Kemper et al used this data to mathematically assess the appropriateness of seven pediatric ETT brands, and found that none allowed safe ETT placement using five intubation depth strategies 24 . A subsequent systematic literature review concluded that the large heterogeneity of studies made it impossible to assemble them to nomograms for clinical use 25,26 . The purpose of our study was to 1) define the length of the subglottis and trachea in a large number of boys and girls, with normal and abnormal airways, from birth to adolescence broken into small age ranges, measured during spontaneous ventilation without airway obstruction, and analyzed in relation to age, body weight, height, and chest height; 2) use these measurements to predict a safe intubation depth to prevent subglottic cuff placement and endobronchial intubation.…”

Section: Introductionmentioning

confidence: 99%

Length of the Cricoid and Trachea in Children: Predicting Intubation Depth to Prevent Subglottic Stenosis

2021

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Objective Define the length of the subglottis and trachea in children to predict a safe intubation depth. Methods Patients <18 years undergoing rigid bronchoscopy from 2013 to 2020 were included. The carina and inferior borders of the cricoid and true vocal folds were marked on a bronchoscope and distances were measured. Patient age, weight, height, and chest height were recorded. Four styles of cuffed pediatric endotracheal tubes (ETT) were measured and potential positions of each cuff and tip were calculated within each trachea using five depth of intubation scenarios. Multivariate linear regression was performed to identify predictors of subglottic and tracheal length. Results Measurements were obtained from 210 children (141 male, 69 female), mean (SD) age 3.21 (3.66) years. Patient height was the best predictor of subglottic length (R2: 0.418): Lengthsg (mm) = 0.058 * height (cm) + 2.8, and tracheal length (R2: 0.733): Lengtht (mm) = 0.485 * height (cm) + 21.3. None of the depth of intubation scenarios maintained a cuff‐free subglottis for all ETT styles investigated. A formula for depth of intubation: Lengthdi (mm) = 0.06 * height (cm) + 8.8 found that no ETT cuffs would be in the subglottis and all tips would be above the carina. Conclusion Current strategies for determining appropriate depth of intubation pose a high risk of subglottic ETT cuff placement. Placing the inferior border of the vocal cords 0.06 * height (cm) + 8.8 from the superior border of the inflated ETT cuff may prevent subglottic cuff placement and endobronchial intubation. Level of Evidence 4 Laryngoscope, 132:S1–S10, 2022

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Section: Introductionmentioning

confidence: 99%

Length of the Cricoid and Trachea in Children: Predicting Intubation Depth to Prevent Subglottic Stenosis

2021

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“…Literature presenting dimensional data on tracheal diameters and lengths, cricoid diameters, subglottic and glottic dimensions, LMB and RMB data in pediatric patients was also found. Research studies measuring glottic and subglottic dimensions were excluded from graphs due to a major incongruence in definition, imprecise information about the site of measurement and their dependency on functional effects (spontaneous breathing vs muscle paralysis) . Diameters were measured as “ap” and transverse (lateral) and given for mid, proximal, distal trachea, and bronchi, respectively (Figures , and ; Table S2‐S6).…”

Section: Resultsmentioning

confidence: 99%

Pediatric airway dimensions—A summary and presentation of existing data

Kemper

Schmidt

Both

et al. 2019

Pediatric Anesthesia

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Background: Age-related pediatric airway dimension reference values for cricoid, tracheal, and bronchial diameters as well as tracheal and bronchial lengths are essential for distinguishing normal from pathological airway findings and for manufacturing and selecting appropriately sized airway equipment. Aim:The aim of this work was to summarize and present existing pediatric airway dimension data for the larynx, trachea, and main stem bronchi from fetus to adolescence. Methods:A systematic literature search was carried out using PubMed, Scopus, Embase, and Google Scholar. Publications containing original data on pediatric airway dimensions as mean or median in tabular form and spanning narrow age groups of 1 or 2 years were included in our study. Original data such as diameters, lengths, and cross-sectional areas of trachea, cricoid, left and right main bronchi in fetuses and children were collected and presented as figures.Results: Pediatric airway dimension data were gathered and compiled from 15 studies fulfilling the inclusion criteria. Data were obtained from different measurement methods such as autopsy, chest X-ray, computed tomography, magnetic resonance imaging, rigid and flexible bronchoscopy as well as ultrasound examinations. There was considerable variation among age-related data due to biologic heterogeneity, different presentation of data, different definitions, and various measurement techniques. Conclusion:This investigation revealed heterogeneous data on pediatric airway dimensions, making it impossible to compile them into standard reference values for airway dimensions. New studies with structured and standardized measurements and data presentation in large populations of children are required to provide more valid pediatric airway dimension data. K E Y W O R D S age, airway, child, techniques 1 | INTRODUC TI ON Reference values on age-related pediatric airway dimensions for cricoid, tracheal, and bronchial diameters as well as tracheal and bronchial lengths are helpful in distinguishing between normal and pathological airway findings and for designing and manufacturing age-related, appropriate pediatric airway equipment. In the past, several shortcomings in the design of cuffed pediatric tracheal tubes have been demonstrated. 1,2 Reliable data on the pediatric airway anatomy are required to optimize tracheal tube diameters, the S U PP O RTI N G I N FO R M ATI O N Additional supporting information may be found online in the Supporting Information section at the end of the article.

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“…We further did not assess the clinical consequences of the size variations (i.e., resistance) in a physical model with anatomic variations or in a clinical setting. Most importantly, it is not clear what degree of variation really presents a clinical problem, because, other than in children [21], there are no data on the anatomic parameters in adults that would predispose them for given DLT sizes. Being beyond the scope of this work, the ultimate clinical goal maybe would be to obtain data about the rate of necessary tube changes when following different guidelines for tube size selection.…”

Section: Discussionmentioning

confidence: 99%

Dimensional Variations of Left-Sided Double-Lumen Endobronchial Tubes

Hegland

Schnitzler

Ellensohn

et al. 2019

Anesthesiology Research and Practice

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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.

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Airway dimensions from fetal life to adolescence—A literature overview

Cited by 9 publications

References 91 publications

Length of the Cricoid and Trachea in Children: Predicting Intubation Depth to Prevent Subglottic Stenosis

Length of the Cricoid and Trachea in Children: Predicting Intubation Depth to Prevent Subglottic Stenosis

Pediatric airway dimensions—A summary and presentation of existing data

Dimensional Variations of Left-Sided Double-Lumen Endobronchial Tubes

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