To Evaluate the Appropriate Depth of Endotracheal Tube Placement Guided by Topographical Landmarks

The trachea is a dynamic organ and its length varies by various static and dynamic factors leading to changing the tracheal length and variable endotracheal tube tip to carina (Ti-Ca) distance. Hence, upholding optimal Ti-Ca distance during changing tracheal length is of utmost importance to prevent complications associated with endotracheal tube (ETT) mal-positioning. When the length of ETT, which is to be inserted inside the trachea, is calculated as per an individual's tracheal morphometric dimensions, the appropriate depth of placement could be achieved and tube malpositioning can be prevented. In the topographical landmark technique, an individual tracheal length is estimated by measuring the various distance from mid-thyroid level (corresponds to vocal cords) to manubriosternal joint (corresponds to carina) in the sagittal plane. After estimating the tracheal length, tip to carina distance of 3cm was deducted from the estimated length of the trachea to provide the distance of the endotracheal tube to be kept beyond the vocal cords. Hence, the investigators planned this study to find the "utility and reliability" of the topographical landmark technique compared to the conventional intubation guide mark technique in providing the appropriate depth of endotracheal tube placement.