Determination of endotracheal tube size using ultrasonographic measurements in dogs under general anesthesia

In veterinary medicine, body weight, palpation of the trachea, width of the nasal septum, and thoracic radiographs are used to determine the size of the endotracheal tube. Since the breed, conformation, age, and body weight affect the tracheal diameter in dogs, a standard for correct tube selection has not been established. With this study, it was aimed to perform the transtracheal examination of rima glottis, which is the narrowest point of the laryngeal passage in dogs and to investigate the effectiveness in determining the endotracheal tube size with measurements using ultrasonography. Included in the study were dogs from 65 breeds, including seven brachiocephalic breeds and 58 mixed breeds, ranging from 4.75-42 kg (22.79±9.47) to Burdur Mehmet Akif Ersoy University Veterinary Faculty Animal Hospital Surgery Clinic for various reasons. It was. Thoracic radiographic images were taken to determine endotracheal tube size before induction of anesthesia in all dogs. Then, transtraceal measurements were made in the rima glottis region of the laryngeal transition in all patients. All patients included in the study were intubated with endotracheal tubes determined according to the clinical routine and appropriately sized endotracheal tube determined by air leak tests. In air leak tests, the size of the tube was considered appropriate when the sound of leakage was heard between 10-20 cmH2O pressure. When the inner and outer diameter correlations of the endotracheal tubes were compared, it was determined that there was a weakly positive relationship between the endotracheal tubes used in intubation and the endotracheal tubes to be used according to the X-ray and a positive positive relationship between the endotracheal tubes to be used according to the ultrasonography measurements. It was determined that the endotracheal tubes determined according to ultrasonography measurements could explain the inner and outer diameters of the tubes to be used in intubation by 98%. Thoracic radiographic measurements were not effective in determining the endotracheal tube sizes, but ultrasonographic measurements in the narrowest part of the laryngeal passage were thought to be effective. It is recommended that a separate study should be done in brachiocephalic races by increasing the sample size, especially since it is highly effective in brachiocephalic races that are difficult to intubate.