Bedside prediction of airway length by measuring upper incisor manubrio-sternal joint length

Abstract

Background:Malpositioning of endotracheal tube may lead to serious complications like endobronchial intubation or accidental extubation. Using anatomical measurements for prediction of airway length would be more practical in resource constrained settings.Materials and Methods:One hundred adult patients of American Society of Anesthesiologists (ASA) grade 1 or 2, without any evidence of difficult airway, were randomly allocated to two cohorts — a model cohort of 70 (50 males) and test cohort of 30 (20 males) subjects. Height, the straight length from the upper incisor to manubrio-sternal joint in fully extended head position (IncManustL), the length from upper incisor to the carina in neutral head position (IncCarinaL), and degree of neck extension were measured in all subjects. Relationship between the two lengths in the model cohort was explored by Pearson's coefficient (r). Predictions were made for subjects in the test cohort and actual and predicted values assessed for agreement using intra-class correlation coefficient (ICC).Results:Good agreement was found between IncManustL and IncCarinaL for both male (r = 0.69) and female (r = 0.54) subjects. Multiple regression analysis suggested height to be another significant predictor, unlike age, weight, and neck extension. The gender-specific regression equations were used to predict IncCarinaL for the test cohort. ICC for absolute agreement between the actual and predicted values was 0.723 (95% CI 0.495-0.858).Conclusions:It is possible to predict airway length in adult Indian subjects by making two simple anatomical measurements, namely stature and incisor manubrio-sternal joint length.

Chula Formula is recommended in Estimating the Length of Tracheal Tube Insertion in Patients Receiving Mechanical Ventilation in Intensive Care Units in the Absence of Chest X-Ray

“…The Chula formula technique is more significant than the Colombian formula technique because the subject's height has a relationship with the trachea's length. This study also supports the research of Mukherjee et al 6 explained that gender and weight did not affect determining the length of TT insertion. In this study, the combination of height and weight (Colombian formula) was no better than the height formula (Chula formula).…”

“…Too shallow TT insertion possibly hit the vocal cords so that the inflammation can trigger sympathetic stimulation, trauma, repetitive compression of the laryngeal nerve, and an increased risk of involuntary extubation. 6,7 The traditionally length TT insertion was 21 cm in women and 23 cm in men. Several scientific publications show that more than 33.4% of TT are incorrectly placed.…”

Determining Carina and Clavicular Distance-Dependent Positioning of Endotracheal Tube in Critically Ill Patients: An Artificial Intelligence-Based Approach

“…To date, a few studies have investigated various parameters for determining ETT insertion and final positioning. Some of them are based on vocal cord-carina distance and tracheal length [12], stature, and incisor manubrio-sternal joint length [13]. Further, an individual's height [14] and various anatomical landmarks have also been employed to predict airway length resulting in varying outcomes [13].…”

“…Some of them are based on vocal cord-carina distance and tracheal length [12], stature, and incisor manubrio-sternal joint length [13]. Further, an individual's height [14] and various anatomical landmarks have also been employed to predict airway length resulting in varying outcomes [13]. A seminal study reported that the tracheal midpoint corresponds internally to a line drawn between the medial heads of the clavicles and hence clavicles have also been employed as a reference point [15].…”

A morphometric study of adult human trachea in West Bengal population

“…Techanivate et al found moderate correlation between height of a person and canine to carinal length [8]. Evron et al used some topographic methods for detection of airway length [9].Mukherjee et al conducted a study for bedside prediction of airway length by measuring upper incisormanubriosternal joint length[10].…”