Normal Tracheal Measurements in the Saudi Population Using Computed Tomography

Objective The aim of this study is to set up the normal tracheal measurements in the Saudi population and to correlate such measures with those published internationally in order either to reinforce confidence in following the traditional tube sizes or further studies needed to determine which sizes would be more suitable. Methods Saudi patients aged 14-80 who underwent CT neck at our hospital during the period (January 2012-June 2014) were included. Patients with conditions that might affect the normal tracheal diameters were excluded so as the studies that didn?t include the carina in the field of view. Studies were viewed using both soft tissue and lung windows. The tracheal and laryngeal lengths were obtained. The maximum anteroposterior (AP), transverse (TRANS) and cross-sectional areas (CS) were taken at three levels, at the cricoid cartilage, junction of the proximal and middle trachea and the junction of the middle and distal trachea. The analysis was done using SPSS version 16.0. The mean AP, TRANS and CS were generated at each level then a uniform mean AP, TRANS and CS were calculated. Result The study included 68 patients 33 male (48.5%) and 35 female (51.5%). The mean anteroposterior diameter, mean transverse diameter and mean cross-sectional area of an adult male is as follows 21.70 mm, 16.97mm and 298.76 mm2. The mean Anteroposterior diameter, mean transverse diameter and mean cross-sectional area of an adult female is as follows 16.85mm, 14.22mm and 191.89mm2. The mean laryngeal length was 47.26mm in males and 36.29 mm in females while the mean tracheal length was 120.29 mm and 107.23 mm. Marked sexual dimorphism was noted No significant correlation between tracheal anteroposterior and transverse diameter and the subject's height or weight. However positive correlation between the subject's height and the laryngeal length was found, where 1 unit height (1 meter) predicts almost 0.7 cm extra length in the larynx. Conclusion We conclude that the tracheal dimensions in the Saudi population appear to be smaller than the New Zealanders and possibly the Americans and closer in parameters to the Iranian or Japanese population. Prospective studies using a larger sample size would be beneficial in an attempt to strengthen our conclusion