Title: Ultrasound (US) Imaging Use in the Management of the Difficult Tracheal Intubation

The ultrasound has been in clinical use since the early 1900s, but its use in the airway has not been published extensively so far. Combining the skills of USG with thorough knowledge of regional anatomy can prove to be a boon to improving the quality of care being delivered to patients. Preoperative use of USG at different levels of the neck combined with the risk assessment methods can help to organize predictors of difficult airway and difficult laryngoscopy. Basic comprehension of USG physics, transducer selection, and probe orientation and a better understanding of airway anatomy contribute to the accuracy of ultrasound interpretation. In day-to-day practice, there is a potential for failed tracheal intubations followed by failure of gaining adequate access to the airway, thus posing challenges to anesthesiologists. Besides predicting difficult airway, USG provides an incentive to properly place an endotracheal tube (ETT) to an adequate depth, estimation of the size of ETT particularly helpful in children and obese, laryngeal mask airway (LMA) confirmation, surgical airways, and post-extubation stridor assessment and thus prevents the risk of reintubation. With the promising and increasing number of evidence exists, there is potential for incorporation of upper airway USG into further standard of care assessment, monitoring, and imaging modalities.