Development of a clinical tool to aid endotracheal tube size selection in dogs

Abstract

ObjectiveTo identify phenotypic parameters correlating with the inner tracheal diameter (ITD) and endotracheal tube size (ETS) in adult dogs and to develop a chart for ETS estimation.MethodsFive-hundred and forty-four adult dogs; 100 dogs were enrolled prospectively and 444 dogs retrospectively. Different phenotypic parameters, the ITD on latero-lateral radiography and ETS were prospectively measured in dogs that underwent general anaesthesia. The parameter correlated best with the ITD was used to develop a graphic chart for ETS estimation. The accuracy of this chart was then retrospectively tested.ResultsIn prospective cohort, the correlation between body size and body mass and ITD (r=0.85 and r=0.84) was good, and the highest correlation observed between ETS and body mass (rs=0.92, P<0.001). In the retrospective assessment, the mean difference between the predicted and used ETS was 0.0 (sd±0.84) for mesocephalic/dolicocephalic (MDC) dogs, showing high accuracy, but for brachycephalic dogs, it was 1.3 (sd±0.98).ConclusionA graphic chart for ETS selection in dogs, using body mass, was designed in this study and was demonstrated to be accurate for ETS prediction in MDC dogs but not in brachycephalic dogs.

Endotracheal tube complication during extubation following surgical repair of a traumatic tracheal laceration

“…Use of thoracic radiographs for measuring internal tracheal diameter has been shown to aid reliably in selection of appropriately sized ETTs but increases radiation exposure to animals and staff, as well as costs to the client 20. The recent development of a clinical tool to allow for estimation of appropriate ETT size based on body mass following analysis of multiple phenotypic parameters may be beneficial but would require prospective clinical validation 21. Currently, there is no guaranteed method of correctly selecting ETT size, although tracheal pathology should be considered.…”

Difficult extubation with silicone endotracheal tubes in three dogs

“…9 A chart can be used as a clinical tool to aid appropriate endotracheal tube size selection in mesocephalic and dolichocephalic dogs. However, this tool is not accurate in brachycephalic breeds 10 and a recent study showed that some of the previously published anatomical measurements and calculations may fail to accurately predict the endotracheal tube size. 11 One reasonable approach to select the appropriate endotracheal tube size is to ensure a leak is present when the cuff is not inflated and the breathing system is pressurised at 25 cmH 2 O.…”

Predicting dog tracheal diameter and length: A tool for improved intubation

“…Veterinarians often face challenges in selecting the appropriate ETT size for intubation in dogs because of the anatomical diversity and size differences among breeds [ 3 , 10 ]. Despite various suggested methods, no standard technique exists for accurate ETT size selection [ 7 , 10 ]. Common methods include predicting ETT size based on lean body weight [ 4 ] or externally palpating the trachea [ 7 , 11 ].…”

“…Common methods include predicting ETT size based on lean body weight [ 4 ] or externally palpating the trachea [ 7 , 11 ]. However, both methods present limitations: significant differences in weight among various body condition scores [ 3 , 10 ], the external and internal diameters of tracheal tubes differ significantly, and the diameter of the tracheal lumen narrows upon entering the thoracic cavity [ 12 ].…”

“…The formula is a method used to estimate endotracheal size and depth. However, there are only a few specific formulas developed specifically for dog applications, and only a few studies are available [ 10 , 14 ]. In contrast, in human medicine, especially in pediatrics, multiple formulas have been proposed to predict optimal ETT size and insertion depth [ 15 , 16 ].…”